From 87b463990c3fa57a0c5011e1ecc9364564c0a9ea Mon Sep 17 00:00:00 2001
From: l0ng-ai <24760907+l0ng-ai@users.noreply.github.com>
Date: Sat, 24 Oct 2026 22:58:23 +0800
Subject: [PATCH] feat(nav): Follow links, file paths and CSS references with
 Go to Declaration

Go to Declaration and Cmd-click said "Cannot find declaration" on HTML href/src, CSS url() and @import, Markdown links and CSS selectors: language servers expose paths as document links, not definitions, and none resolves class/id to selectors.

- ide-lsp: textDocument/documentLink (lsp_document_links), resolving links that lack a target.
- Editor: when the server has no definition, follow its document links, then URLs and quoted / Markdown / url() paths in any language. Server file links are checked to exist; root-relative paths also resolve against resource roots. Cmd-hover underlines the whole link.
- ide-language: tree-sitter web references (class / id attributes, href="#id", var(--x)) and .class / #id / --var definitions from stylesheets and <style> elements, indexed as symbols. web_goto looks them up by exact name (ProjectIndex::symbols_named), using the open document's unsaved text.
- Detect public/ of package.json modules as a resource root (Vite, Next, CRA serve it at /).
---
 crates/ide-index/src/lib.rs              |   5 +
 crates/ide-index/src/matching.rs         |  28 +++
 crates/ide-index/src/tests.rs            |  18 ++
 crates/ide-language/src/lib.rs           |   4 +-
 crates/ide-language/src/syntax/mod.rs    |  64 +++++-
 crates/ide-language/src/syntax/tests.rs  |  69 +++++++
 crates/ide-language/src/syntax/web.rs    | 252 +++++++++++++++++++++++
 crates/ide-lsp/src/caps.rs               |   2 +
 crates/ide-lsp/src/convert.rs            |  42 ++++
 crates/ide-lsp/src/lib.rs                |  46 +++++
 crates/ide-lsp/src/types.rs              |  15 ++
 crates/ide-workspace/src/roots/detect.rs |   4 +
 src-tauri/src/commands/lsp.rs            |  11 +
 src-tauri/src/commands/mod.rs            |   2 +
 src-tauri/src/commands/nav.rs            |  57 ++++-
 src/bindings.ts                          |  49 +++++
 src/editor/lsp/links.test.ts             |  73 +++++++
 src/editor/lsp/links.ts                  | 238 +++++++++++++++++++++
 src/editor/lsp/navigation.ts             |  83 +++++++-
 src/platform/openUrl.ts                  |  11 +
 20 files changed, 1060 insertions(+), 13 deletions(-)
 create mode 100644 crates/ide-language/src/syntax/web.rs
 create mode 100644 src/editor/lsp/links.test.ts
 create mode 100644 src/editor/lsp/links.ts
 create mode 100644 src/platform/openUrl.ts

diff --git a/crates/ide-index/src/lib.rs b/crates/ide-index/src/lib.rs
index 874407e99..eef25d350 100644
--- a/crates/ide-index/src/lib.rs
+++ b/crates/ide-index/src/lib.rs
@@ -121,6 +121,11 @@ impl ProjectIndex {
         matching::find_symbols(&d, &matching::Recents { paths: &recent }, query, filter, limit)
     }
 
+    /// Symbols named exactly `name` (of `kind`, if given): `.card` selectors for `class="card"`.
+    pub fn symbols_named(&self, name: &str, kind: Option<SymbolKind>, limit: usize) -> Vec<SymbolMatch> {
+        matching::symbols_named(&self.shared.data.read(), name, kind, limit)
+    }
+
     /// Incrementally re-indexes changed paths (called from the vfs watcher).
     /// Cheap: the work is queued for the indexing thread.
     pub fn update(&self, changed: &[PathBuf], removed: &[PathBuf]) {
diff --git a/crates/ide-index/src/matching.rs b/crates/ide-index/src/matching.rs
index 8d066717d..bea3f3c5e 100644
--- a/crates/ide-index/src/matching.rs
+++ b/crates/ide-index/src/matching.rs
@@ -7,6 +7,7 @@
 
 use crate::data::{FileEntry, IndexData, char_mask};
 use crate::{FileMatch, SymbolFilter, SymbolMatch};
+use ide_core::SymbolKind;
 use nucleo_matcher::{Config, Matcher, Utf32Str, Utf32String};
 use rayon::prelude::*;
 use std::cell::RefCell;
@@ -419,6 +420,33 @@ pub(crate) fn find_symbols(
         .collect()
 }
 
+/// Symbols named exactly `name` (and of `kind`, when given), by path then position.
+pub(crate) fn symbols_named(data: &IndexData, name: &str, kind: Option<SymbolKind>, limit: usize) -> Vec<SymbolMatch> {
+    let mask = char_mask(name);
+    let mut out: Vec<SymbolMatch> = data
+        .files
+        .iter()
+        .flatten()
+        .flat_map(|e| {
+            e.symbols.iter().filter(|s| s.mask == mask && &*s.name == name && kind.is_none_or(|k| s.kind == k)).map(
+                move |s| SymbolMatch {
+                    name: s.name.to_string(),
+                    kind: s.kind,
+                    container: s.container.as_deref().map(str::to_owned),
+                    path: e.path.clone().into(),
+                    rel_path: e.rel.to_string(),
+                    range: s.range,
+                    score: 0,
+                    indices: Vec::new(),
+                },
+            )
+        })
+        .collect();
+    out.sort_by(|a, b| a.rel_path.cmp(&b.rel_path).then_with(|| a.range.cmp(&b.range)));
+    out.truncate(limit);
+    out
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/crates/ide-index/src/tests.rs b/crates/ide-index/src/tests.rs
index c815fcbbc..36468d7b6 100644
--- a/crates/ide-index/src/tests.rs
+++ b/crates/ide-index/src/tests.rs
@@ -381,3 +381,21 @@ fn synthetic_index_answers_queries() {
     assert!(!s.find_symbols("PaySe", SymbolFilter::All, 20).is_empty());
     assert!(s.find_symbols("PaySe", SymbolFilter::Types, 20).iter().all(|m| m.kind == SymbolKind::Class));
 }
+
+#[test]
+fn css_selectors_are_found_by_exact_name() {
+    let f = Fixture::new(&[
+        ("web/a.css", ".card { --gap: 1px }\n.cardigan {}\n"),
+        ("web/b.scss", ".list { .card { } }\n"),
+        ("web/index.html", "<style>.card{}</style>\n<div class=\"card\"></div>\n"),
+    ]);
+    let idx = f.open();
+    let found: Vec<(String, u32)> = idx
+        .symbols_named(".card", Some(SymbolKind::Class), 10)
+        .into_iter()
+        .map(|m| (m.rel_path, m.range.start.line))
+        .collect();
+    assert_eq!(found, vec![("web/a.css".into(), 0), ("web/b.scss".into(), 0), ("web/index.html".into(), 0)]);
+    assert_eq!(idx.symbols_named("--gap", None, 10).len(), 1);
+    assert!(idx.symbols_named(".card", Some(SymbolKind::Field), 10).is_empty());
+}
diff --git a/crates/ide-language/src/lib.rs b/crates/ide-language/src/lib.rs
index 97b1b3520..67388a227 100644
--- a/crates/ide-language/src/lib.rs
+++ b/crates/ide-language/src/lib.rs
@@ -13,8 +13,8 @@ mod registry;
 mod syntax;
 pub use registry::LanguageRegistry;
 pub use syntax::{
-    MAX_CACHED_TREES, MAX_PARSE_BYTES, ParsedTree, Syntax, SyntaxCache, SyntaxCacheStats, SyntaxHighlightKind,
-    SyntaxHighlights, TreeError,
+    CSS_CLASS, CSS_ID, CSS_VARIABLE, MAX_CACHED_TREES, MAX_PARSE_BYTES, ParsedTree, Syntax, SyntaxCache,
+    SyntaxCacheStats, SyntaxHighlightKind, SyntaxHighlights, TreeError, WebReference, WebReferenceKind,
 };
 
 /// Parsed form of `languages/<id>.toml`. Backend-only; the UI gets [`LanguageInfo`].
diff --git a/crates/ide-language/src/syntax/mod.rs b/crates/ide-language/src/syntax/mod.rs
index fed5514fe..ac4cb7daf 100644
--- a/crates/ide-language/src/syntax/mod.rs
+++ b/crates/ide-language/src/syntax/mod.rs
@@ -7,16 +7,18 @@ mod highlight;
 pub(crate) mod lines;
 mod outline;
 mod selection;
+mod web;
 
 use crate::{FoldRange, LanguageConfig, LanguageRegistry, SymbolTag};
 pub use cache::{MAX_CACHED_TREES, SyntaxCache, SyntaxCacheStats};
 use grammars::{SPECS, Spec};
 pub use highlight::{SyntaxHighlightKind, SyntaxHighlights};
-use ide_core::{LanguageId, OutlineItem, Range};
+use ide_core::{LanguageId, OutlineItem, Pos, Range};
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::sync::OnceLock;
 use tree_sitter::{Language, Parser, Tree};
+pub use web::{CSS_CLASS, CSS_ID, CSS_VARIABLE, WebReference, WebReferenceKind};
 
 /// Texts larger than this are not parsed (minified bundles, generated dumps).
 pub const MAX_PARSE_BYTES: usize = 16 * 1024 * 1024;
@@ -117,6 +119,8 @@ impl Syntax {
         FP.get_or_init(|| {
             let mut h = blake3::Hasher::new();
             h.update(env!("CARGO_PKG_VERSION").as_bytes());
+            // Bump when web definitions (`.class`, `#id`, `--var` tags) change.
+            h.update(b"web-definitions-1");
             for s in SPECS {
                 h.update(s.name.as_bytes());
                 h.update(&Language::new(s.language).abi_version().to_le_bytes());
@@ -141,7 +145,8 @@ impl Syntax {
     /// Whether [`Syntax::tags`] can return anything for this language (data
     /// formats such as JSON only have an outline). Lets indexers skip parsing.
     pub fn has_symbols(&self, lang: &LanguageId) -> bool {
-        self.grammar(lang).and_then(Grammar::outline_query).is_some_and(|q| q.has_tags)
+        self.web_grammar(lang).is_some()
+            || self.grammar(lang).and_then(Grammar::outline_query).is_some_and(|q| q.has_tags)
     }
 
     pub fn outline(&self, lang: &LanguageId, text: &str) -> Vec<OutlineItem> {
@@ -158,11 +163,56 @@ impl Syntax {
     }
 
     pub fn tags(&self, lang: &LanguageId, text: &str) -> Vec<SymbolTag> {
-        self.analyze(lang, text, |g, tree, text| {
-            let query = g.outline_query()?;
-            Some(outline::tags(g, query, tree, text))
-        })
-        .unwrap_or_default()
+        let mut tags = self
+            .analyze(lang, text, |g, tree, text| {
+                let query = g.outline_query()?;
+                Some(outline::tags(g, query, tree, text))
+            })
+            .unwrap_or_default();
+        tags.extend(self.web_definitions(lang, text));
+        tags
+    }
+
+    /// The grammar web features parse `lang` with: its own for HTML and CSS, the
+    /// CSS grammar for SCSS / Less (selectors and custom properties parse alike),
+    /// HTML for Vue / Svelte single-file components.
+    fn web_grammar(&self, lang: &LanguageId) -> Option<&Grammar> {
+        let name = match lang.as_str() {
+            "scss" | "less" => "css",
+            "vue" | "svelte" => "html",
+            _ => self.grammar(lang).map(|g| g.spec.name)?,
+        };
+        web::is_web_grammar(name).then(|| self.grammar(&LanguageId::new(name))).flatten()
+    }
+
+    fn with_web_tree<R>(
+        &self,
+        lang: &LanguageId,
+        text: &str,
+        f: impl FnOnce(&Grammar, Option<&Grammar>, &Tree) -> R,
+    ) -> Option<R> {
+        let g = self.web_grammar(lang)?;
+        if text.len() > MAX_PARSE_BYTES {
+            return None;
+        }
+        let tree = parse(&g.language, text, None)?;
+        Some(f(g, self.grammar(&LanguageId::new("css")), &tree))
+    }
+
+    /// CSS class (`.card`), id (`#main`) and custom property (`--accent`)
+    /// definitions of a stylesheet or of the `<style>` elements of a document.
+    pub fn web_definitions(&self, lang: &LanguageId, text: &str) -> Vec<SymbolTag> {
+        self.with_web_tree(lang, text, |g, css, tree| web::definitions(g, css, tree, text)).unwrap_or_default()
+    }
+
+    /// The `class` / `id` / `href="#…"` / `var(--…)` reference at `pos`.
+    pub fn web_reference_at(&self, lang: &LanguageId, text: &str, pos: Pos) -> Option<WebReference> {
+        self.with_web_tree(lang, text, |g, css, tree| web::reference_at(g, css, tree, text, pos)).flatten()
+    }
+
+    /// Value ranges of the `id="name"` / `name="name"` attributes in an HTML document.
+    pub fn web_anchors(&self, lang: &LanguageId, text: &str, name: &str) -> Vec<Range> {
+        self.with_web_tree(lang, text, |_, _, tree| web::anchors(tree, text, name)).unwrap_or_default()
     }
 
     /// Highlighting from the grammar's own query; `None` without one.
diff --git a/crates/ide-language/src/syntax/tests.rs b/crates/ide-language/src/syntax/tests.rs
index 9c6fb6f0d..68691e5c5 100644
--- a/crates/ide-language/src/syntax/tests.rs
+++ b/crates/ide-language/src/syntax/tests.rs
@@ -1085,3 +1085,72 @@ fn large_input_is_not_parsed() {
     let big = "a".repeat(MAX_PARSE_BYTES + 1);
     assert!(syntax().outline(&lang("rust"), &big).is_empty());
 }
+
+// --- web references -------------------------------------------------------------
+
+fn web_defs(id: &str, src: &str) -> Vec<(String, SymbolKind, u32, u32)> {
+    syntax()
+        .web_definitions(&lang(id), src)
+        .into_iter()
+        .map(|t| (t.name, t.kind, t.range.start.line, t.range.start.col))
+        .collect()
+}
+
+fn web_ref(id: &str, src: &str) -> Option<(WebReferenceKind, String, u32, u32)> {
+    let at = src.find('|').expect("caret marker");
+    let text = src.replace('|', "");
+    let line = text[..at].matches('\n').count() as u32;
+    let col = (at - text[..at].rfind('\n').map_or(0, |i| i + 1)) as u32;
+    syntax()
+        .web_reference_at(&lang(id), &text, Pos::new(line, col))
+        .map(|r| (r.kind, r.name, r.range.start.col, r.range.end.col))
+}
+
+#[test]
+fn web_definitions_of_stylesheets_and_style_elements() {
+    let css = ".a.b, div#main > .c:hover { color: var(--x); --y: 1px; }\n@media (x) { .d {} }\n";
+    assert_eq!(
+        web_defs("css", css),
+        vec![
+            (".a".into(), CSS_CLASS, 0, 1),
+            (".b".into(), CSS_CLASS, 0, 3),
+            ("#main".into(), CSS_ID, 0, 10),
+            (".c".into(), CSS_CLASS, 0, 18),
+            ("--y".into(), CSS_VARIABLE, 0, 45),
+            (".d".into(), CSS_CLASS, 1, 14),
+        ]
+    );
+    // Pseudo-classes (`:hover`) are not classes; nested SCSS rules parse with the CSS grammar.
+    assert!(!web_defs("css", css).iter().any(|d| d.0 == ".hover"));
+    assert!(web_defs("scss", ".card { &:hover { } .title { } }").iter().any(|d| d.0 == ".title"));
+    let html = "<p class=\"x\">\n<style>\n  .card { --gap: 2px }\n</style>";
+    assert_eq!(web_defs("html", html), vec![(".card".into(), CSS_CLASS, 2, 3), ("--gap".into(), CSS_VARIABLE, 2, 10)]);
+    assert!(syntax().tags(&lang("css"), css).iter().any(|t| t.name == ".a"));
+    assert!(syntax().has_symbols(&lang("css")) && syntax().has_symbols(&lang("vue")));
+}
+
+#[test]
+fn web_references_in_attributes_and_stylesheets() {
+    use WebReferenceKind::*;
+    assert_eq!(web_ref("html", r##"<div class="card bi|g">"##), Some((Class, "big".into(), 17, 20)));
+    assert_eq!(web_ref("html", r##"<div class="|card big">"##), Some((Class, "card".into(), 12, 16)));
+    assert_eq!(web_ref("html", r##"<div id="ma|in">"##), Some((Id, "main".into(), 9, 13)));
+    assert_eq!(web_ref("html", r##"<a href="#to|p">"##), Some((Anchor, "top".into(), 9, 13)));
+    assert_eq!(web_ref("html", r##"<a href="page.ht|ml">"##), None);
+    assert_eq!(
+        web_ref("html", r##"<p style="color: var(--ac|cent)">"##),
+        Some((CssVariable, "--accent".into(), 21, 29))
+    );
+    assert_eq!(web_ref("html", "<style>\n.a { color: var(--x|) }\n</style>").map(|r| r.1), Some("--x".into()));
+    assert_eq!(web_ref("css", ".a { color: var(--a|ccent, red) }"), Some((CssVariable, "--accent".into(), 16, 24)));
+    assert_eq!(web_ref("css", ".a { color: re|d }"), None);
+    assert_eq!(web_ref("vue", r##"<template><div class="ti|tle"/></template>"##).map(|r| r.0), Some(Class));
+}
+
+#[test]
+fn web_anchors_find_ids_and_names() {
+    let html = "<h2 id=\"top\">x</h2>\n<a name=\"top\"></a>\n<p class=\"top\">";
+    let found: Vec<(u32, u32)> =
+        syntax().web_anchors(&lang("html"), html, "top").into_iter().map(|r| (r.start.line, r.start.col)).collect();
+    assert_eq!(found, vec![(0, 8), (1, 9)]);
+}
diff --git a/crates/ide-language/src/syntax/web.rs b/crates/ide-language/src/syntax/web.rs
new file mode 100644
index 000000000..b221ae721
--- /dev/null
+++ b/crates/ide-language/src/syntax/web.rs
@@ -0,0 +1,252 @@
+//! Web references that no language server resolves: HTML `class` / `id`
+//! attributes to the CSS selectors that style them, `href="#id"` to the element
+//! with that id, and `var(--x)` to the custom property's declarations.
+//!
+//! Definitions (`.card`, `#main`, `--accent`) come from stylesheets and the
+//! `<style>` elements of HTML documents and feed the symbol index (see
+//! [`super::Syntax::tags`]), so a lookup is an exact index query.
+
+use super::lines::{LineIndex, utf16_to_byte};
+use super::{Grammar, parse};
+use crate::SymbolTag;
+use ide_core::{Pos, Range, SymbolKind};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use tree_sitter::{Node, Tree};
+
+/// Index symbol kinds of web definitions; names carry the CSS sigil.
+pub const CSS_CLASS: SymbolKind = SymbolKind::Class;
+pub const CSS_ID: SymbolKind = SymbolKind::Field;
+pub const CSS_VARIABLE: SymbolKind = SymbolKind::Variable;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum WebReferenceKind {
+    /// A class in a `class` / `className` attribute: `.name` selectors.
+    Class,
+    /// An `id` attribute value: `#name` selectors.
+    Id,
+    /// `href="#name"`: the element with that id in the same document.
+    Anchor,
+    /// `var(--name)`: the custom property's declarations.
+    CssVariable,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct WebReference {
+    pub kind: WebReferenceKind,
+    /// Without sigil: `card`, `main`, `--accent`.
+    pub name: String,
+    pub range: Range,
+}
+
+impl WebReference {
+    /// The index symbol a reference resolves to: `.card`, `#main`, `--accent`.
+    pub fn symbol(&self) -> Option<(String, SymbolKind)> {
+        match self.kind {
+            WebReferenceKind::Class => Some((format!(".{}", self.name), CSS_CLASS)),
+            WebReferenceKind::Id => Some((format!("#{}", self.name), CSS_ID)),
+            WebReferenceKind::CssVariable => Some((self.name.clone(), CSS_VARIABLE)),
+            WebReferenceKind::Anchor => None,
+        }
+    }
+}
+
+/// Grammars whose documents carry web definitions and references.
+pub(crate) fn is_web_grammar(name: &str) -> bool {
+    matches!(name, "css" | "html")
+}
+
+/// Stylesheet text embedded in a document: `(byte offset, text)`.
+fn css_regions<'t>(grammar: &str, tree: &Tree, text: &'t str) -> Vec<(usize, &'t str)> {
+    match grammar {
+        "css" => vec![(0, text)],
+        "html" => {
+            let mut out = Vec::new();
+            walk(tree.root_node(), &mut |n| {
+                if n.kind() == "style_element" {
+                    let mut c = n.walk();
+                    for raw in n.children(&mut c).filter(|c| c.kind() == "raw_text") {
+                        out.push((raw.start_byte(), &text[raw.start_byte()..raw.end_byte()]));
+                    }
+                    return false;
+                }
+                true
+            });
+            out
+        }
+        _ => Vec::new(),
+    }
+}
+
+/// Pre-order walk; `f` returns whether to descend.
+fn walk<'t>(n: Node<'t>, f: &mut dyn FnMut(Node<'t>) -> bool) {
+    if !f(n) {
+        return;
+    }
+    let mut c = n.walk();
+    for child in n.children(&mut c) {
+        walk(child, f);
+    }
+}
+
+fn text_of<'t>(n: Node, text: &'t str) -> &'t str {
+    text.get(n.start_byte()..n.end_byte()).unwrap_or_default()
+}
+
+/// `.name`, `#name` and `--name` definitions in `text` (a stylesheet, or a document with `<style>`).
+pub(crate) fn definitions(g: &Grammar, css: Option<&Grammar>, tree: &Tree, text: &str) -> Vec<SymbolTag> {
+    let idx = LineIndex::new(text);
+    let mut out = Vec::new();
+    for (base, css_text) in css_regions(g.spec.name, tree, text) {
+        let parsed;
+        let css_tree = if base == 0 && g.spec.name == "css" {
+            tree
+        } else {
+            let Some(css) = css else { continue };
+            let Some(t) = parse(&css.language, css_text, None) else { continue };
+            parsed = t;
+            &parsed
+        };
+        walk(css_tree.root_node(), &mut |n| {
+            let def = match n.kind() {
+                "class_name" if n.parent().is_some_and(|p| p.kind() == "class_selector") => {
+                    Some((format!(".{}", text_of(n, css_text)), CSS_CLASS))
+                }
+                "id_name" => Some((format!("#{}", text_of(n, css_text)), CSS_ID)),
+                "property_name" if text_of(n, css_text).starts_with("--") => {
+                    Some((text_of(n, css_text).to_owned(), CSS_VARIABLE))
+                }
+                _ => None,
+            };
+            if let Some((name, kind)) = def {
+                let range = idx.range(base + n.start_byte(), base + n.end_byte());
+                out.push(SymbolTag { name, kind, container: None, range });
+            }
+            true
+        });
+    }
+    out
+}
+
+fn byte_at(text: &str, pos: Pos) -> Option<usize> {
+    let mut start = 0;
+    for _ in 0..pos.line {
+        start += text[start..].find('\n')? + 1;
+    }
+    let line_end = text[start..].find('\n').map_or(text.len(), |i| start + i);
+    Some(start + utf16_to_byte(&text[start..line_end], pos.col as usize))
+}
+
+/// The whitespace-separated token of `value` (starting at byte `base`) around byte `at`.
+fn token_at(value: &str, base: usize, at: usize) -> Option<(usize, &str)> {
+    let rel = at.checked_sub(base)?;
+    let start = value[..rel.min(value.len())].rfind(char::is_whitespace).map_or(0, |i| i + 1);
+    let end = value[rel.min(value.len())..].find(char::is_whitespace).map_or(value.len(), |i| rel + i);
+    (start < end).then(|| (base + start, &value[start..end]))
+}
+
+/// `var(--name)` around byte `at` of a stylesheet tree.
+fn css_variable_at(tree: &Tree, css_text: &str, at: usize) -> Option<(usize, usize, String)> {
+    let mut n = tree.root_node().descendant_for_byte_range(at, at)?;
+    if n.kind() != "plain_value" {
+        // The caret right after `--x` in `var(--x)`.
+        n = tree.root_node().descendant_for_byte_range(at.saturating_sub(1), at.saturating_sub(1))?;
+    }
+    let name = text_of(n, css_text);
+    let call = n.parent()?.parent()?;
+    let is_var = call.kind() == "call_expression"
+        && call
+            .child_by_field_name("function_name")
+            .or_else(|| call.child(0))
+            .is_some_and(|f| text_of(f, css_text) == "var");
+    (n.kind() == "plain_value" && name.starts_with("--") && is_var)
+        .then(|| (n.start_byte(), n.end_byte(), name.to_owned()))
+}
+
+/// The web reference at `pos` of a document parsed as `tree`.
+pub(crate) fn reference_at(
+    g: &Grammar,
+    css: Option<&Grammar>,
+    tree: &Tree,
+    text: &str,
+    pos: Pos,
+) -> Option<WebReference> {
+    let at = byte_at(text, pos)?;
+    let idx = LineIndex::new(text);
+    let make = |kind, from: usize, to: usize, name: String| WebReference { kind, name, range: idx.range(from, to) };
+
+    // Stylesheet regions: `var(--x)`.
+    for (base, css_text) in css_regions(g.spec.name, tree, text) {
+        if at < base || at > base + css_text.len() {
+            continue;
+        }
+        let parsed;
+        let css_tree = if g.spec.name == "css" {
+            tree
+        } else {
+            parsed = parse(&css?.language, css_text, None)?;
+            &parsed
+        };
+        let (from, to, name) = css_variable_at(css_tree, css_text, at - base)?;
+        return Some(make(WebReferenceKind::CssVariable, base + from, base + to, name));
+    }
+    if g.spec.name != "html" {
+        return None;
+    }
+
+    // HTML attribute values.
+    let node = tree.root_node().descendant_for_byte_range(at, at)?;
+    let value = std::iter::successors(Some(node), |n| n.parent()).find(|n| n.kind() == "attribute_value")?;
+    let attribute = std::iter::successors(value.parent(), |n| n.parent()).find(|n| n.kind() == "attribute")?;
+    let attr_name = attribute.child(0).map(|n| text_of(n, text).to_ascii_lowercase())?;
+    let (vs, vtext) = (value.start_byte(), text_of(value, text));
+    match attr_name.as_str() {
+        "class" | "classname" | "class:list" => {
+            let (from, token) = token_at(vtext, vs, at)?;
+            Some(make(WebReferenceKind::Class, from, from + token.len(), token.to_owned()))
+        }
+        "id" => {
+            let (from, token) = token_at(vtext, vs, at)?;
+            Some(make(WebReferenceKind::Id, from, from + token.len(), token.to_owned()))
+        }
+        "href" | "xlink:href" if vtext.len() > 1 && vtext.starts_with('#') => {
+            Some(make(WebReferenceKind::Anchor, vs, vs + vtext.len(), vtext[1..].to_owned()))
+        }
+        "style" => {
+            // An inline declaration list: parse it as the block of a rule.
+            let wrapped = format!("x{{{vtext}}}");
+            let t = parse(&css?.language, &wrapped, None)?;
+            let (from, to, name) = css_variable_at(&t, &wrapped, at - vs + 2)?;
+            Some(make(WebReferenceKind::CssVariable, vs + from - 2, vs + to - 2, name))
+        }
+        _ => None,
+    }
+}
+
+/// Elements whose `id` (or `<a name>`) is `name`: the targets of `href="#name"`.
+pub(crate) fn anchors(tree: &Tree, text: &str, name: &str) -> Vec<Range> {
+    let idx = LineIndex::new(text);
+    let mut out = Vec::new();
+    walk(tree.root_node(), &mut |n| {
+        if n.kind() == "attribute" {
+            let attr = n.child(0).map(|a| text_of(a, text).to_ascii_lowercase());
+            if matches!(attr.as_deref(), Some("id" | "name")) {
+                let mut found = None;
+                walk(n, &mut |v| {
+                    if v.kind() == "attribute_value" && text_of(v, text) == name {
+                        found = Some(v);
+                    }
+                    found.is_none()
+                });
+                if let Some(v) = found {
+                    out.push(idx.range(v.start_byte(), v.end_byte()));
+                }
+            }
+            return false;
+        }
+        true
+    });
+    out
+}
diff --git a/crates/ide-lsp/src/caps.rs b/crates/ide-lsp/src/caps.rs
index a66d4b155..39b51ff0e 100644
--- a/crates/ide-lsp/src/caps.rs
+++ b/crates/ide-lsp/src/caps.rs
@@ -121,6 +121,7 @@ pub fn client_capabilities() -> Value {
                 "honorsChangeAnnotations": false
             },
             "codeLens": { "dynamicRegistration": false },
+            "documentLink": { "dynamicRegistration": false, "tooltipSupport": true },
             "formatting": { "dynamicRegistration": false },
             "rangeFormatting": { "dynamicRegistration": false },
             "rename": {
@@ -205,6 +206,7 @@ pub fn capability_key(method: &str) -> Option<&'static str> {
         "textDocument/inlayHint" => "inlayHintProvider",
         "textDocument/semanticTokens" | "textDocument/semanticTokens/full" => "semanticTokensProvider",
         "textDocument/codeLens" => "codeLensProvider",
+        "textDocument/documentLink" => "documentLinkProvider",
         "textDocument/prepareCallHierarchy" => "callHierarchyProvider",
         "textDocument/prepareTypeHierarchy" => "typeHierarchyProvider",
         _ => return None,
diff --git a/crates/ide-lsp/src/convert.rs b/crates/ide-lsp/src/convert.rs
index 508f5e482..8f1fc8419 100644
--- a/crates/ide-lsp/src/convert.rs
+++ b/crates/ide-lsp/src/convert.rs
@@ -783,6 +783,27 @@ pub fn code_lens(conv: &Conv, path: &Path, l: lsp::CodeLens) -> CodeLens {
     CodeLens { range: conv.range(path, l.range), command: l.command.map(command) }
 }
 
+pub fn document_link(conv: &Conv, path: &Path, l: lsp::DocumentLink) -> Option<DocumentLink> {
+    let target = l.target?;
+    let target = target.as_str();
+    let (file, url) = match uri_to_path(target) {
+        Some(p) => (Some(p), None),
+        None => (None, Some(target.to_owned())),
+    };
+    let fragment = file
+        .as_ref()
+        .and_then(|_| target.split_once('#'))
+        .map(|(_, f)| percent_encoding::percent_decode_str(f).decode_utf8_lossy().into_owned())
+        .filter(|f| !f.is_empty());
+    Some(DocumentLink {
+        range: conv.range(path, l.range),
+        path: file.map(Into::into),
+        fragment,
+        url,
+        tooltip: l.tooltip,
+    })
+}
+
 pub fn call_item(conv: &Conv, item: &lsp::CallHierarchyItem, from_ranges: Vec<Range>) -> Option<HierarchyItem> {
     let (path, uri) = uri_target(item.uri.as_str());
     Some(HierarchyItem {
@@ -1112,4 +1133,25 @@ mod tests {
         assert_eq!(h.kind, InlayKind::Type);
         assert!(h.padding_left && !h.padding_right);
     }
+
+    #[cfg(unix)]
+    #[test]
+    fn document_links_split_file_targets_and_urls() {
+        let conv = Conv::utf16();
+        let link = |target: Option<&str>| {
+            serde_json::from_value::<lsp::DocumentLink>(json!({
+                "range": { "start": { "line": 0, "character": 6 }, "end": { "line": 0, "character": 15 } },
+                "target": target,
+            }))
+            .unwrap()
+        };
+        let here = Path::new("/p/index.html");
+        let file = document_link(&conv, here, link(Some("file:///p/a%20b.md#L12"))).unwrap();
+        assert_eq!(file.path.as_deref(), Some(Path::new("/p/a b.md")));
+        assert_eq!(file.fragment.as_deref(), Some("L12"));
+        assert_eq!(file.range, Range::new(p(0, 6), p(0, 15)));
+        let web = document_link(&conv, here, link(Some("https://example.com/#top"))).unwrap();
+        assert_eq!((web.path, web.url.as_deref(), web.fragment), (None, Some("https://example.com/#top"), None));
+        assert!(document_link(&conv, here, link(None)).is_none());
+    }
 }
diff --git a/crates/ide-lsp/src/lib.rs b/crates/ide-lsp/src/lib.rs
index 90033735b..14f0ed799 100644
--- a/crates/ide-lsp/src/lib.rs
+++ b/crates/ide-lsp/src/lib.rs
@@ -1422,6 +1422,52 @@ impl LspManager {
         out.finish(Vec::new())
     }
 
+    /// The document's links; ones without a target are resolved when the server can.
+    pub async fn document_links(&self, doc: DocId) -> IdeResult<Vec<DocumentLink>> {
+        let (snap, targets) = self.doc_targets(doc, "document links", |c| c.has("documentLinkProvider")).await?;
+        let requests = targets.iter().map(|t| {
+            let params = json!({ "textDocument": snap.ident() });
+            async move {
+                let links = self
+                    .call::<_, Option<Vec<lsp::DocumentLink>>>(
+                        t,
+                        "textDocument/documentLink",
+                        params,
+                        None,
+                        DEFAULT_TIMEOUT,
+                    )
+                    .await?
+                    .unwrap_or_default();
+                if !t.caps().has_sub("documentLinkProvider", "resolveProvider") {
+                    return Ok::<_, IdeError>((t, links));
+                }
+                let resolved = join_all(links.into_iter().map(|l| async move {
+                    if l.target.is_some() {
+                        return l;
+                    }
+                    let original = l.clone();
+                    self.call::<_, lsp::DocumentLink>(t, "documentLink/resolve", l, None, DEFAULT_TIMEOUT)
+                        .await
+                        .unwrap_or(original)
+                }))
+                .await;
+                Ok((t, resolved))
+            }
+        });
+        let mut out = Outcome::new();
+        for r in join_all(requests).await {
+            match r {
+                Ok((t, links)) => {
+                    let conv = self.conv(t.enc());
+                    let acc = out.value.get_or_insert_with(Vec::new);
+                    acc.extend(links.into_iter().filter_map(|l| convert::document_link(&conv, &snap.path, l)));
+                }
+                Err(e) => out.fail(e),
+            }
+        }
+        out.finish(Vec::new())
+    }
+
     pub async fn call_hierarchy(
         &self,
         doc: DocId,
diff --git a/crates/ide-lsp/src/types.rs b/crates/ide-lsp/src/types.rs
index 56fc16ea0..5fe534d4f 100644
--- a/crates/ide-lsp/src/types.rs
+++ b/crates/ide-lsp/src/types.rs
@@ -214,6 +214,21 @@ pub struct CodeLens {
     pub command: Option<Command>,
 }
 
+/// A link in a document (`textDocument/documentLink`): an HTML `href`, a
+/// Markdown link, an `#include`, a JSON `$schema`…
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct DocumentLink {
+    pub range: Range,
+    /// A `file:` target.
+    pub path: Option<ide_core::IpcPath>,
+    /// The `#fragment` of a `file:` target (`L12`, `L12,5`, a heading or element id).
+    pub fragment: Option<String>,
+    /// Any other target (`https:`, …).
+    pub url: Option<String>,
+    pub tooltip: Option<String>,
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub enum HierarchyDirection {
diff --git a/crates/ide-workspace/src/roots/detect.rs b/crates/ide-workspace/src/roots/detect.rs
index 19facc053..3212bcffb 100644
--- a/crates/ide-workspace/src/roots/detect.rs
+++ b/crates/ide-workspace/src/roots/detect.rs
@@ -192,6 +192,8 @@ fn module_roots(root: &Path, rel: &str, files: &[String], out: &mut Vec<SourceFo
         // A JVM build's `src` holds source sets, not JavaScript.
         if !has("pom.xml") && !GRADLE_FILES.iter().any(|f| has(f)) {
             add("src", RootKind::Source, "package.json");
+            // Served at `/` by Vite, Next and Create React App: `href="/logo.svg"` resolves here.
+            add("public", RootKind::Resources, "package.json");
             for t in ["test", "tests", "__tests__"] {
                 add(t, RootKind::Test, "package.json");
             }
@@ -330,6 +332,7 @@ mod tests {
             "flat/tests/",
             "web/package.json",
             "web/src/",
+            "web/public/",
             "web/__tests__/",
             "web/node_modules/x/package.json",
             "web/dist/",
@@ -351,6 +354,7 @@ mod tests {
                 "web/__tests__=Test@web/package.json",
                 "web/dist=Excluded@web/package.json",
                 "web/node_modules=Excluded@web/package.json",
+                "web/public=Resources@web/package.json",
                 "web/src=Source@web/package.json",
             ]
         );
diff --git a/src-tauri/src/commands/lsp.rs b/src-tauri/src/commands/lsp.rs
index 3bd91e73c..1a22b9f3a 100644
--- a/src-tauri/src/commands/lsp.rs
+++ b/src-tauri/src/commands/lsp.rs
@@ -243,6 +243,17 @@ pub async fn lsp_code_lens(window: Window, state: State<'_, AppState>, doc: DocI
     project!(window, state).lsp.code_lens(doc).await
 }
 
+/// Links in a document (`href`s, Markdown links, `#include`s…) from its language servers.
+#[tauri::command]
+#[specta::specta]
+pub async fn lsp_document_links(
+    window: Window,
+    state: State<'_, AppState>,
+    doc: DocId,
+) -> IdeResult<Vec<DocumentLink>> {
+    project!(window, state).lsp.document_links(doc).await
+}
+
 #[tauri::command]
 #[specta::specta]
 pub async fn lsp_call_hierarchy(
diff --git a/src-tauri/src/commands/mod.rs b/src-tauri/src/commands/mod.rs
index 214bf3247..e3f462486 100644
--- a/src-tauri/src/commands/mod.rs
+++ b/src-tauri/src/commands/mod.rs
@@ -103,6 +103,7 @@ pub fn builder() -> tauri_specta::Builder<tauri::Wry> {
         nav::find_symbols,
         nav::mark_recent,
         nav::recent_files,
+        nav::web_goto,
         search::search_start,
         search::replace_in_files,
         search::replace_preview,
@@ -125,6 +126,7 @@ pub fn builder() -> tauri_specta::Builder<tauri::Wry> {
         lsp::lsp_inlay_hints,
         lsp::lsp_semantic_tokens,
         lsp::lsp_code_lens,
+        lsp::lsp_document_links,
         lsp::lsp_call_hierarchy,
         lsp::lsp_type_hierarchy,
         lsp::lsp_servers,
diff --git a/src-tauri/src/commands/nav.rs b/src-tauri/src/commands/nav.rs
index 6b34f2d87..eb20d9e1a 100644
--- a/src-tauri/src/commands/nav.rs
+++ b/src-tauri/src/commands/nav.rs
@@ -1,6 +1,10 @@
+use super::doc::blocking;
 use crate::state::AppState;
-use ide_core::IdeResult;
+use ide_core::{DocId, IdeResult, Location, Pos};
 use ide_index::{FileMatch, IndexStatus, SymbolFilter, SymbolMatch};
+use ide_language::WebReference;
+use serde::{Deserialize, Serialize};
+use specta::Type;
 use std::path::PathBuf;
 use tauri::{State, Window};
 
@@ -41,3 +45,54 @@ pub fn mark_recent(window: Window, state: State<'_, AppState>, path: PathBuf) ->
 pub fn recent_files(window: Window, state: State<'_, AppState>) -> IdeResult<Vec<ide_core::IpcPath>> {
     Ok(state.project(window.label())?.index.recent_files().into_iter().map(Into::into).collect())
 }
+
+/// A web reference no language server resolves and where it points: `class="card"` →
+/// `.card` selectors, `id` → `#id` selectors, `href="#top"` → the element, `var(--x)` →
+/// `--x:` declarations.
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct WebGoto {
+    pub reference: WebReference,
+    pub targets: Vec<Location>,
+}
+
+const MAX_WEB_TARGETS: usize = 200;
+
+/// The web reference at `pos` of `doc` and its targets; `None` when there is no reference.
+#[tauri::command]
+#[specta::specta]
+pub async fn web_goto(window: Window, state: State<'_, AppState>, doc: DocId, pos: Pos) -> IdeResult<Option<WebGoto>> {
+    let project = state.project(window.label())?;
+    let syntax = state.syntax();
+    blocking(move || {
+        let snap = project.documents.snapshot(doc)?;
+        if snap.large {
+            return Ok(None);
+        }
+        let Some(reference) = syntax.web_reference_at(&snap.language, &snap.text, pos) else { return Ok(None) };
+        let here = |range| Location { path: snap.path.clone(), range, uri: None };
+        let targets = match reference.symbol() {
+            None => syntax.web_anchors(&snap.language, &snap.text, &reference.name).into_iter().map(here).collect(),
+            Some((name, kind)) => {
+                // The open document from its (possibly unsaved) text, other files from the index.
+                let mut targets: Vec<Location> = syntax
+                    .web_definitions(&snap.language, &snap.text)
+                    .into_iter()
+                    .filter(|t| t.name == name && t.kind == kind)
+                    .map(|t| here(t.range))
+                    .collect();
+                targets.extend(
+                    project
+                        .index
+                        .symbols_named(&name, Some(kind), MAX_WEB_TARGETS)
+                        .into_iter()
+                        .filter(|m| *m.path != *snap.path)
+                        .map(|m| Location { path: m.path, range: m.range, uri: None }),
+                );
+                targets
+            }
+        };
+        Ok(Some(WebGoto { reference, targets }))
+    })
+    .await
+}
diff --git a/src/bindings.ts b/src/bindings.ts
index 61a44c4aa..7ccc71a16 100644
--- a/src/bindings.ts
+++ b/src/bindings.ts
@@ -186,6 +186,11 @@ export const commands = {
 	markRecent: (path: string) => typedError<null, IdeError>(__TAURI_INVOKE("mark_recent", { path })),
 	/**  Recently opened files, most recent first (⌘E). */
 	recentFiles: () => typedError<IpcPath[], IdeError>(__TAURI_INVOKE("recent_files")),
+	/**  The web reference at `pos` of `doc` and its targets; `None` when there is no reference. */
+	webGoto: (doc: DocId, pos: Pos) => typedError<{
+	reference: WebReference,
+	targets: Location[],
+} | null, IdeError>(__TAURI_INVOKE("web_goto", { doc, pos })),
 	/**
 	 *  Find in Files. Results stream through `on_event`; ends with `Done`.
 	 *  Cancel with `cancel_request(request)`.
@@ -248,6 +253,8 @@ export const commands = {
 	tokenModifiers: string[],
 } | null, IdeError>(__TAURI_INVOKE("lsp_semantic_tokens", { doc })),
 	lspCodeLens: (doc: DocId) => typedError<CodeLens[], IdeError>(__TAURI_INVOKE("lsp_code_lens", { doc })),
+	/**  Links in a document (`href`s, Markdown links, `#include`s…) from its language servers. */
+	lspDocumentLinks: (doc: DocId) => typedError<DocumentLink[], IdeError>(__TAURI_INVOKE("lsp_document_links", { doc })),
 	lspCallHierarchy: (doc: DocId, pos: Pos, direction: HierarchyDirection) => typedError<HierarchyItem[], IdeError>(__TAURI_INVOKE("lsp_call_hierarchy", { doc, pos, direction })),
 	lspTypeHierarchy: (doc: DocId, pos: Pos, direction: HierarchyDirection) => typedError<HierarchyItem[], IdeError>(__TAURI_INVOKE("lsp_type_hierarchy", { doc, pos, direction })),
 	lspServers: () => typedError<ServerInfo[], IdeError>(__TAURI_INVOKE("lsp_servers")),
@@ -1575,6 +1582,21 @@ export type DocumentInfo = {
 	uri?: string | null,
 };
 
+/**
+ *  A link in a document (`textDocument/documentLink`): an HTML `href`, a
+ *  Markdown link, an `#include`, a JSON `$schema`…
+ */
+export type DocumentLink = {
+	range: Range,
+	/**  A `file:` target. */
+	path: IpcPath | null,
+	/**  The `#fragment` of a `file:` target (`L12`, `L12,5`, a heading or element id). */
+	fragment: string | null,
+	/**  Any other target (`https:`, …). */
+	url: string | null,
+	tooltip: string | null,
+};
+
 export type DuplicateGroup = {
 	tokens: number,
 	/**  Lines of the first fragment. */
@@ -4028,6 +4050,33 @@ export type VirtualDocument = {
 	decompiled: boolean,
 };
 
+/**
+ *  A web reference no language server resolves and where it points: `class="card"` →
+ *  `.card` selectors, `id` → `#id` selectors, `href="#top"` → the element, `var(--x)` →
+ *  `--x:` declarations.
+ */
+export type WebGoto = {
+	reference: WebReference,
+	targets: Location[],
+};
+
+export type WebReference = {
+	kind: WebReferenceKind,
+	/**  Without sigil: `card`, `main`, `--accent`. */
+	name: string,
+	range: Range,
+};
+
+export type WebReferenceKind = 
+/**  A class in a `class` / `className` attribute: `.name` selectors. */
+"class" | 
+/**  An `id` attribute value: `#name` selectors. */
+"id" | 
+/**  `href="#name"`: the element with that id in the same document. */
+"anchor" | 
+/**  `var(--name)`: the custom property's declarations. */
+"cssVariable";
+
 /**  Edits to many files, applied atomically from the user's point of view. */
 export type WorkspaceEdit = {
 	files: FileEdit[],
diff --git a/src/editor/lsp/links.test.ts b/src/editor/lsp/links.test.ts
new file mode 100644
index 000000000..7d402c358
--- /dev/null
+++ b/src/editor/lsp/links.test.ts
@@ -0,0 +1,73 @@
+import { describe, expect, it } from "vitest";
+import { Text } from "@codemirror/state";
+import { fragmentOffset, linkReference, looksLikePath, normalizePath, pathCandidates, textReference } from "./links";
+
+const at = (src: string, marker = "|") => {
+  const offset = src.indexOf(marker);
+  return { text: Text.of(src.replace(marker, "").split("\n")), offset };
+};
+
+describe("text references", () => {
+  it("finds URLs, trimming trailing punctuation", () => {
+    const { text, offset } = at("// see https://exa|mple.com/a?b=1.");
+    expect(textReference(text, offset)).toMatchObject({ kind: "url", url: "https://example.com/a?b=1" });
+  });
+
+  it("finds quoted paths in any language", () => {
+    const { text, offset } = at('df = open("data/x|.csv")');
+    expect(textReference(text, offset)).toMatchObject({ kind: "path", value: "data/x.csv" });
+    expect(textReference(...(Object.values(at("<link href='sty|le.css'>")) as [Text, number]))).toMatchObject({
+      value: "style.css",
+    });
+  });
+
+  it("finds Markdown link targets and unquoted CSS urls", () => {
+    let { text, offset } = at("See [theme](css/the|me.css#L1) now");
+    expect(textReference(text, offset)).toMatchObject({ kind: "path", value: "css/theme.css#L1" });
+    ({ text, offset } = at(".a { background: url(img/lo|go.svg); }"));
+    expect(textReference(text, offset)).toMatchObject({ kind: "path", value: "img/logo.svg" });
+  });
+
+  it("ignores prose and identifiers", () => {
+    expect(looksLikePath("hello world.txt")).toBe(false);
+    expect(looksLikePath("utf-8")).toBe(false);
+    expect(looksLikePath("main")).toBe(false);
+    expect(looksLikePath("http://x")).toBe(false);
+    expect(looksLikePath("../a/b")).toBe(true);
+    expect(looksLikePath("logo.svg#icon")).toBe(true);
+    const { text, offset } = at('log("do|ne")');
+    expect(textReference(text, offset)).toBeNull();
+  });
+});
+
+describe("path resolution", () => {
+  it("resolves against the file's directory, then the project root", () => {
+    expect(pathCandidates("../img/a%20b.png?v=2", "/p/web/x/index.html", "/p")).toEqual(["/p/web/img/a b.png"]);
+    expect(pathCandidates("img/a.png", "/p/web/index.html", "/p")).toEqual(["/p/web/img/a.png", "/p/img/a.png"]);
+    expect(pathCandidates("/splash.css", "/p/index.html", "/p", ["/p/public"])).toEqual([
+      "/p/splash.css",
+      "/p/public/splash.css",
+      "/splash.css",
+    ]);
+    expect(normalizePath("/a/./b/../c")).toBe("/a/c");
+  });
+});
+
+describe("links and fragments", () => {
+  it("picks the server link around the offset", () => {
+    const text = Text.of(['<a href="b.html#top">']);
+    const range = { start: { line: 0, col: 9 }, end: { line: 0, col: 19 } };
+    const link = { range, path: "/p/b.html", fragment: "top", url: null, tooltip: null };
+    expect(linkReference(text, [link], 12)).toMatchObject({ kind: "file", path: "/p/b.html", fragment: "top" });
+    expect(linkReference(text, [link], 2)).toBeNull();
+  });
+
+  it("locates line, element id and Markdown heading fragments", () => {
+    expect(fragmentOffset("a\nbc\nd", "/x.ts", "L2")).toBe(2);
+    expect(fragmentOffset("a\nbc\nd", "/x.ts", "L2,2")).toBe(3);
+    const html = '<p>\n<div class="x" id="main">';
+    expect(fragmentOffset(html, "/i.html", "main")).toBe(html.indexOf("id="));
+    expect(fragmentOffset("# Intro\n\n## Getting Started!\n", "/r.md", "getting-started")).toBe(9);
+    expect(fragmentOffset("x", "/i.html", "nope")).toBeNull();
+  });
+});
diff --git a/src/editor/lsp/links.ts b/src/editor/lsp/links.ts
new file mode 100644
index 000000000..8208435d3
--- /dev/null
+++ b/src/editor/lsp/links.ts
@@ -0,0 +1,238 @@
+/**
+ * References that Go to Declaration and ⌘-click follow when the language
+ * server has no definition there, in every language:
+ *  - document links from the server (`textDocument/documentLink`: HTML `href`,
+ *    CSS `url()`, Markdown links, `#include`, JSON `$schema`…);
+ *  - without one, URLs in the text and quoted strings naming an existing file
+ *    (IDEA's file references: `open("data/x.csv")`, `include_str!("a.txt")`).
+ */
+import type { Text } from "@codemirror/state";
+import type { EditorView } from "@codemirror/view";
+import { whenSynced, type EditorDocContext } from "@/editor/api";
+import { call, commands, isTauri, type DocumentLink } from "@/platform/ipc";
+import { openExternalUrl } from "@/platform/openUrl";
+import { useProject } from "@/platform/project";
+import { currentRoots } from "@/platform/projectRoots";
+import { editorService } from "@/workbench/contributions";
+import { lspRequest } from "./lsp";
+import { rangeToOffsets } from "./positions";
+
+export type Reference =
+  | { kind: "file"; from: number; to: number; path: string; fragment?: string | null }
+  | { kind: "url"; from: number; to: number; url: string }
+  /** A quoted path that still has to be resolved against the file system. */
+  | { kind: "path"; from: number; to: number; value: string }
+  /** A link whose file does not exist (reported, never opened). */
+  | { kind: "missing"; from: number; to: number; value: string };
+
+// --- document links ----------------------------------------------------------
+
+const linkCache = new WeakMap<Text, Promise<DocumentLink[]>>();
+const fetchedLinks = new WeakMap<Text, DocumentLink[]>();
+
+/** The server's links of the document as it is now (cached per document version). */
+export function documentLinks(view: EditorView, doc: EditorDocContext): Promise<DocumentLink[]> {
+  const text = view.state.doc;
+  let links = linkCache.get(text);
+  if (!links) {
+    links = whenSynced(view)
+      .then(() => lspRequest(() => commands.lspDocumentLinks(doc.doc)))
+      .catch(() => [])
+      .then((list) => {
+        fetchedLinks.set(text, list);
+        return list;
+      });
+    linkCache.set(text, links);
+  }
+  return links;
+}
+
+/** Links already fetched for the current text, if any (the ⌘-hover underline is synchronous). */
+export function knownLinks(view: EditorView): DocumentLink[] | undefined {
+  return fetchedLinks.get(view.state.doc);
+}
+
+export function linkReference(text: Text, links: readonly DocumentLink[], offset: number): Reference | null {
+  for (const l of links) {
+    const { from, to } = rangeToOffsets(text, l.range);
+    if (offset < from || offset > to) continue;
+    if (l.path) return { kind: "file", from, to, path: l.path, fragment: l.fragment };
+    if (l.url) return { kind: "url", from, to, url: l.url };
+  }
+  return null;
+}
+
+// --- references found in the text -------------------------------------------
+
+const URL_RE = /\b(?:https?:\/\/|mailto:)[^\s"'`<>()[\]{}]+[^\s"'`<>()[\]{},.;:!?]/g;
+const QUOTED_RE = /"([^"\\\n]*)"|'([^'\\\n]*)'|`([^`\\\n]*)`/g;
+/** Unquoted targets: Markdown `[x](path)` / `![x](path "title")`, CSS `url(path)`. */
+const BARE_RE = /\]\(([^()\s]+)(?:\s+"[^"]*")?\)|\burl\(\s*([^()'"\s]+)\s*\)/g;
+const MAX_PATH = 260;
+
+/** Whether a string literal looks like a file path rather than prose or an identifier. */
+export function looksLikePath(value: string): boolean {
+  if (!value || value.length > MAX_PATH || /^[a-z][\w+.-]*:/i.test(value) || /[\s<>|*?]/.test(value)) return false;
+  const bare = value.replace(/[?#].*$/, "");
+  return /\//.test(bare) || /^\.{0,2}[\w@~-][\w.@~-]*\.[A-Za-z0-9]{1,8}$/.test(bare);
+}
+
+/** A URL or path-like quoted string at `offset`, found on its line. */
+export function textReference(text: Text, offset: number): Reference | null {
+  const line = text.lineAt(offset);
+  const col = offset - line.from;
+  for (const m of line.text.matchAll(URL_RE)) {
+    if (col >= m.index && col <= m.index + m[0].length)
+      return { kind: "url", from: line.from + m.index, to: line.from + m.index + m[0].length, url: m[0] };
+  }
+  const strings = [
+    ...[...line.text.matchAll(QUOTED_RE)].map((m) => ({ value: m[1] ?? m[2] ?? m[3] ?? "", from: m.index + 1 })),
+    ...[...line.text.matchAll(BARE_RE)].map((m) => {
+      const value = m[1] ?? m[2] ?? "";
+      return { value, from: m.index + m[0].indexOf(value) };
+    }),
+  ];
+  for (const { value, from } of strings) {
+    if (col < from || col > from + value.length || !looksLikePath(value)) continue;
+    return { kind: "path", from: line.from + from, to: line.from + from + value.length, value };
+  }
+  return null;
+}
+
+function dirname(path: string): string {
+  const i = path.lastIndexOf("/");
+  return i > 0 ? path.slice(0, i) : "/";
+}
+
+/** `a/./b/../c` → `a/c`. */
+export function normalizePath(path: string): string {
+  const out: string[] = [];
+  for (const seg of path.split("/")) {
+    if (seg === "." || (seg === "" && out.length)) continue;
+    if (seg === ".." && out.length > 1) out.pop();
+    else out.push(seg);
+  }
+  return out.join("/") || "/";
+}
+
+/**
+ * Where a path-like string may point, most likely first. `/x` resolves against
+ * the project root and its resource roots (`resourceRoots`, absolute), like IDEA.
+ */
+export function pathCandidates(value: string, from: string, root: string | null, resourceRoots: readonly string[] = []): string[] {
+  const bare = decodeURIComponentSafe(value.replace(/[?#].*$/, ""));
+  const list: string[] = [];
+  if (bare.startsWith("/")) {
+    if (root) list.push(`${root}${bare}`);
+    list.push(...resourceRoots.map((d) => `${d}${bare}`));
+    list.push(bare);
+  } else if (!bare.startsWith("~")) {
+    list.push(`${dirname(from)}/${bare}`);
+    if (root && !bare.startsWith("..")) list.push(`${root}/${bare}`);
+  }
+  return [...new Set(list.map(normalizePath))];
+}
+
+function decodeURIComponentSafe(s: string): string {
+  try {
+    return decodeURIComponent(s);
+  } catch {
+    return s;
+  }
+}
+
+async function isFile(path: string): Promise<boolean> {
+  if (!isTauri()) return false;
+  try {
+    await call(commands.fsProbe(path));
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+/** Resolves a `path` reference to an existing file; null when none exists. */
+export async function resolvePath(ref: Reference, from: string): Promise<Reference | null> {
+  if (ref.kind !== "path") return ref;
+  const root = useProject.getState().project?.root ?? null;
+  const resources = root
+    ? currentRoots()
+        .filter((r) => r.kind === "resources")
+        .map((r) => (r.path ? `${root}/${r.path}` : root))
+    : [];
+  for (const path of pathCandidates(ref.value, from, root, resources))
+    if (await isFile(path)) return { kind: "file", from: ref.from, to: ref.to, path, fragment: ref.value.split("#")[1] ?? null };
+  return null;
+}
+
+// --- following ----------------------------------------------------------------
+
+/** The offset a `#fragment` names in `text` of `path`: `L12[,5]`, an element id or a Markdown heading. */
+export function fragmentOffset(text: string, path: string, fragment: string): number | null {
+  const line = /^L(\d+)(?:[,:C](\d+))?$/i.exec(fragment);
+  const lines = text.split("\n");
+  if (line) {
+    const n = Math.min(Number(line[1]) - 1, lines.length - 1);
+    if (n < 0) return null;
+    const col = Math.min(Math.max(Number(line[2] ?? 1) - 1, 0), lines[n]!.length);
+    return lines.slice(0, n).reduce((a, l) => a + l.length + 1, 0) + col;
+  }
+  const esc = fragment.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+  if (/\.(md|markdown|mdx)$/i.test(path)) {
+    let offset = 0;
+    for (const l of lines) {
+      const h = /^#{1,6}\s+(.*?)\s*#*$/.exec(l);
+      if (h && slug(h[1]!) === fragment.toLowerCase()) return offset;
+      offset += l.length + 1;
+    }
+    return null;
+  }
+  const m = new RegExp(`\\b(?:id|name)\\s*=\\s*["']?${esc}(?=["'\\s>])`).exec(text);
+  return m ? m.index : null;
+}
+
+const slug = (s: string) =>
+  s
+    .toLowerCase()
+    .replace(/[^\p{L}\p{N}\s-]/gu, "")
+    .trim()
+    .replace(/\s+/g, "-");
+
+export async function followReference(ref: Reference): Promise<void> {
+  if (ref.kind === "missing") throw new Error(`Cannot find file '${ref.value}'`);
+  if (ref.kind === "url") {
+    await openExternalUrl(ref.url);
+    return;
+  }
+  if (ref.kind !== "file") return;
+  let selection: { line: number; col: number } | undefined;
+  if (ref.fragment) {
+    const text = await call(commands.fsReadText(ref.path)).catch(() => null);
+    const offset = text === null ? null : fragmentOffset(text, ref.path, ref.fragment);
+    if (text !== null && offset !== null) {
+      const before = text.slice(0, offset);
+      const line = before.split("\n").length - 1;
+      selection = { line, col: offset - (before.lastIndexOf("\n") + 1) };
+    }
+  }
+  await editorService().openFile(ref.path, { focus: true, ...(selection ? { selection } : {}) });
+}
+
+/**
+ * The reference at `offset`: a server link, else a URL or an existing file
+ * named by a quoted path. Null when there is none.
+ */
+export async function referenceAt(view: EditorView, doc: EditorDocContext, offset: number): Promise<Reference | null> {
+  const link = linkReference(view.state.doc, await documentLinks(view, doc), offset);
+  const ref = textReference(view.state.doc, offset);
+  if (link?.kind !== "file") {
+    if (link) return link;
+    if (!ref || doc.virtual) return ref?.kind === "url" ? ref : null;
+    return resolvePath(ref, doc.path);
+  }
+  if (await isFile(link.path)) return link;
+  // Servers resolve `/x` against the file system or workspace root; web roots (`public/`) are ours.
+  const own = ref && !doc.virtual ? await resolvePath(ref, doc.path) : null;
+  if (own) return own;
+  return { kind: "missing", from: link.from, to: link.to, value: view.state.sliceDoc(link.from, link.to) };
+}
diff --git a/src/editor/lsp/navigation.ts b/src/editor/lsp/navigation.ts
index c92105ff7..c5515a69c 100644
--- a/src/editor/lsp/navigation.ts
+++ b/src/editor/lsp/navigation.ts
@@ -6,7 +6,15 @@
  */
 import { EditorSelection, Prec, StateEffect, StateField, type Extension } from "@codemirror/state";
 import { Decoration, EditorView, ViewPlugin, keymap, type DecorationSet, type ViewUpdate } from "@codemirror/view";
-import { commands, isCancelled, type GotoKind, type Highlight, type Location, type Pos } from "@/platform/ipc";
+import {
+  commands,
+  isCancelled,
+  type GotoKind,
+  type Highlight,
+  type Location,
+  type Pos,
+  type WebReferenceKind,
+} from "@/platform/ipc";
 import {
   CONTRIBUTED_DEFINITION,
   activeEditor,
@@ -26,6 +34,7 @@ import { SYNTAX_NOTE, declarationFallback, isSelfTarget, localHighlights, type D
 import { showHint } from "./hint";
 import { caretAnchor, openPopup, type ListPopupItem } from "./popupStore";
 import { readManyFileLines } from "./files";
+import { documentLinks, followReference, knownLinks, linkReference, referenceAt, textReference } from "./links";
 import { serverBackoff } from "./availability";
 import { editorPrefs } from "@/platform/editorSettings";
 import { isVirtualUri, virtualContainer } from "@/platform/virtualDocs";
@@ -101,13 +110,18 @@ export async function gotoTargets(view: EditorView, kind: GotoKind, at?: number)
   const pos = offsetToPos(view.state.doc, offset);
   let locs: DeclarationTarget[];
   let fromSyntax = false;
+  const declaration = kind === "definition" || kind === "declaration";
+  let serverDown = false;
   try {
     locs = dedupeLocations(await lspRequest(() => commands.lspGoto(doc.doc, pos, kind)));
   } catch (e) {
-    if (isCancelled(e) || (kind !== "definition" && kind !== "declaration")) {
+    if (isCancelled(e) || !declaration) {
       reportLspError(view, e, true);
       return;
     }
+    // Web references and links need no server.
+    if ((await gotoWebReference(view, doc, pos, offset)) || (await followReferenceAt(view, doc, offset))) return;
+    serverDown = isUnavailable(e);
     // Dumb mode: the server is not ready / failing — answer from the syntax tree.
     const fb = await gotoFallback(view, doc, pos);
     if (!fb) {
@@ -118,7 +132,14 @@ export async function gotoTargets(view: EditorView, kind: GotoKind, at?: number)
     fromSyntax = true;
   }
   if (!locs.length) {
-    showHint(view, NOT_FOUND[kind]);
+    // The server has no definition here: a link (`href`, `#include`, Markdown) or a file path.
+    if (
+      declaration &&
+      !fromSyntax &&
+      ((await gotoWebReference(view, doc, pos, offset)) || (await followReferenceAt(view, doc, offset)))
+    )
+      return;
+    showHint(view, serverDown ? `${NOT_FOUND[kind]}: no language server is running for this file` : NOT_FOUND[kind]);
     return;
   }
   // IDEA: ⌘B on a declaration shows its usages.
@@ -144,6 +165,52 @@ export async function gotoTargets(view: EditorView, kind: GotoKind, at?: number)
   });
 }
 
+const WEB_LANGUAGES = new Set(["html", "css", "scss", "less", "vue", "svelte"]);
+
+const WEB_SIGIL: Record<WebReferenceKind, string> = { class: ".", id: "#", anchor: "#", cssVariable: "" };
+
+/**
+ * `class` / `id` attributes to their CSS selectors, `href="#x"` to the element,
+ * `var(--x)` to its declarations (no language server resolves these); false
+ * when there is no such reference at `pos`.
+ */
+async function gotoWebReference(view: EditorView, doc: EditorDocContext, pos: Pos, offset: number): Promise<boolean> {
+  if (!WEB_LANGUAGES.has(doc.language) || doc.virtual) return false;
+  let found;
+  try {
+    await whenSynced(view);
+    found = await lspRequest(() => commands.webGoto(doc.doc, pos));
+  } catch (e) {
+    console.debug("[web] goto", e);
+    return false;
+  }
+  if (!found) return false;
+  const { reference, targets } = found;
+  const label = `${WEB_SIGIL[reference.kind]}${reference.name}`;
+  if (!targets.length) showHint(view, `Cannot find declaration of '${label}'`);
+  else if (targets.length === 1) await navigateTo(targets[0]!);
+  else
+    openPopup({
+      kind: "list",
+      anchor: caretAnchor(view, offset),
+      title: `Choose Declaration of '${label}' (${targets.length} found)`,
+      items: await locationItems(targets),
+    });
+  return true;
+}
+
+/** Follows the link, URL or file path at `offset`; false when there is none. */
+async function followReferenceAt(view: EditorView, doc: EditorDocContext, offset: number): Promise<boolean> {
+  const ref = await referenceAt(view, doc, offset);
+  if (!ref) return false;
+  try {
+    await followReference(ref);
+  } catch (e) {
+    showHint(view, e instanceof Error ? e.message : String(e), { tone: "error" });
+  }
+  return true;
+}
+
 /** Declaration targets from the structure service; null when it cannot answer for this file. */
 async function gotoFallback(view: EditorView, doc: EditorDocContext, pos: Pos): Promise<DeclarationTarget[] | null> {
   try {
@@ -173,9 +240,13 @@ const linkField = StateField.define<DecorationSet>({
   provide: (f) => EditorView.decorations.from(f),
 });
 
+/** What ⌘-hover underlines: a whole link, URL or path, else the word. */
 function linkAt(view: EditorView, x: number, y: number) {
   const pos = view.posAtCoords({ x, y }, false);
   if (pos == null) return null;
+  const links = knownLinks(view);
+  const ref = (links && linkReference(view.state.doc, links, pos)) ?? textReference(view.state.doc, pos);
+  if (ref) return ref;
   const word = view.state.wordAt(pos);
   return word && word.from < word.to ? word : null;
 }
@@ -185,6 +256,12 @@ const linkPlugin = ViewPlugin.fromClass(
     last: { x: number; y: number } | null = null;
     constructor(readonly view: EditorView) {}
     show(meta: boolean) {
+      const doc = meta ? docOf(this.view) : null;
+      // Underline whole links once the server's links are in.
+      if (doc && !doc.virtual && !knownLinks(this.view))
+        void documentLinks(this.view, doc).then(() => {
+          if (this.view.state.field(linkField).size) this.show(true);
+        });
       const current = this.view.state.field(linkField);
       const target = meta && this.last ? linkAt(this.view, this.last.x, this.last.y) : null;
       let same = false;
diff --git a/src/platform/openUrl.ts b/src/platform/openUrl.ts
new file mode 100644
index 000000000..bb0f40db5
--- /dev/null
+++ b/src/platform/openUrl.ts
@@ -0,0 +1,11 @@
+import { isTauri } from "./ipc";
+
+/** Opens a web or `mailto:` URL with the system handler (the default browser). */
+export async function openExternalUrl(url: string): Promise<void> {
+  if (!isTauri()) {
+    window.open(url, "_blank", "noopener");
+    return;
+  }
+  const { openUrl } = await import("@tauri-apps/plugin-opener");
+  await openUrl(url);
+}