:root {
  color-scheme: light dark;
  --bg: #f5f6fa;
  --surface: #ffffff;
  --surface-2: #f0f1f6;
  --border: #dfe2ea;
  --text: #1a1d29;
  --text-dim: #6b7280;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --accent-soft: #eef0fe;
  --danger: #c0392b;
  --danger-soft: #fdecea;
  --ok: #1a7f4e;
  --ok-soft: #e8f7ef;
  --code-bg: #1e1e2e;
  --code-text: #e6e6f0;
  --radius: 10px;
  --sidebar-w: 240px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14151f;
    --surface: #1b1d29;
    --surface-2: #23253333;
    --border: #2c2f40;
    --text: #e7e8f0;
    --text-dim: #9497a8;
    --accent: #7c74f1;
    --accent-hover: #948dff;
    --accent-soft: #26254a;
    --danger: #ff8079;
    --danger-soft: #3a1f22;
    --ok: #55d693;
    --ok-soft: #12301f;
    --code-bg: #0f1017;
    --code-text: #dcdce8;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", -apple-system, system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

a { color: var(--accent); }

/* ---------- top header/nav (sticky) ---------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.topbar-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.7rem 1.5rem;
}

.brand {
  font-weight: 700;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--text);
  white-space: nowrap;
}

.brand .dot { color: var(--accent); }

.nav-search { flex: 1 1 auto; max-width: 280px; margin-left: auto; }
.nav-search input {
  width: 100%;
  padding: 0.45rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.84rem;
}
.nav-search-empty {
  display: none;
  padding: 0 1.5rem 0.5rem;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.topbar-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.2rem;
  padding: 0.35rem 1rem 0.6rem;
  border-top: 1px solid var(--border);
}

.topbar-link, .nav-dropdown-trigger {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.65rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-family: inherit;
  color: var(--text);
  text-decoration: none;
  background: transparent;
  border: none;
  cursor: pointer;
  white-space: nowrap;
}

.topbar-link:hover, .nav-dropdown-trigger:hover { background: var(--surface-2); }

.topbar-link.active, .nav-dropdown.has-active .nav-dropdown-trigger {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.nav-dropdown-trigger::after {
  content: '\25BE';
  font-size: 0.6rem;
  color: var(--text-dim);
}

.nav-dropdown { position: relative; }

.nav-dropdown-panel {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  margin-top: 0.35rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.16);
  padding: 0.5rem;
  min-width: 230px;
  max-height: 65vh;
  overflow-y: auto;
}

.nav-dropdown-panel.wide { min-width: 460px; column-count: 2; column-gap: 0.4rem; }

.nav-dropdown.open .nav-dropdown-panel { display: block; }

.nav-dropdown-panel .nav-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.42rem 0.6rem;
  border-radius: 8px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.85rem;
  break-inside: avoid;
}

.nav-dropdown-panel .nav-link:hover { background: var(--surface-2); }

.nav-dropdown-panel .nav-link.active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.nav-link .icon { font-size: 1rem; width: 1.2em; text-align: center; flex: 0 0 auto; }

/* ---------- main ---------- */

.main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 2.25rem 3rem;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 1rem;
}
.breadcrumb a { color: var(--text-dim); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb .sep { opacity: 0.5; }
.breadcrumb span:last-child { color: var(--text); font-weight: 600; }

.page-header { margin-bottom: 1.5rem; }
.page-header h1 {
  font-size: 1.65rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 0.4rem;
}
.page-header p { color: var(--text-dim); margin: 0; max-width: 72ch; font-size: 0.92rem; line-height: 1.55; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  margin-bottom: 1.25rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

/* dashboard: grouped by category so a large tool count stays scannable */

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.85rem;
  margin-bottom: 1.5rem;
}

.category-card {
  aspect-ratio: 1 / 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font: inherit;
  color: var(--text);
  text-align: center;
  padding: 1rem;
  transition: border-color 0.15s, transform 0.15s, background 0.15s;
}
.category-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.category-card.active { border-color: var(--accent); background: var(--accent-soft); }
.category-card .category-icon { font-size: 1.9rem; }
.category-card h3 { margin: 0; font-size: 0.88rem; }
.category-card .count { font-size: 0.72rem; color: var(--text-dim); }

.dash-section { display: none; margin-bottom: 1.75rem; }
.dash-section.open { display: block; }
.dash-section-title {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  font-weight: 700;
  margin: 0 0 0.6rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 0.85rem;
}

.tool-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.9rem 1.05rem;
  text-decoration: none;
  color: var(--text);
  display: block;
  transition: border-color 0.15s, transform 0.15s;
}

.tool-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.tool-card .tool-icon { font-size: 1.25rem; margin-bottom: 0.4rem; }
.tool-card h3 { margin: 0 0 0.25rem; font-size: 0.92rem; }
.tool-card p { margin: 0; font-size: 0.8rem; color: var(--text-dim); line-height: 1.35; }
.tool-card .badge {
  display: inline-block; margin-top: 0.6rem; font-size: 0.72rem;
  background: var(--accent-soft); color: var(--accent); padding: 0.15rem 0.5rem; border-radius: 999px;
}

/* ---------- forms ---------- */

label.field-label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
  color: var(--text-dim);
}

input[type="text"], input[type="file"], textarea, select {
  width: 100%;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-2, var(--surface));
  background-color: var(--bg);
  color: var(--text);
  font-family: inherit;
  font-size: 0.9rem;
  transition: border-color 0.15s, box-shadow 0.15s;
}

input[type="text"]:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

textarea { font-family: "Cascadia Code", Consolas, monospace; font-size: 0.85rem; resize: vertical; }

.field { margin-bottom: 1rem; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
  border: none;
  background: var(--accent);
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
  transition: background 0.15s, transform 0.1s;
}

.btn:hover { background: var(--accent-hover); }
.btn:active { transform: translateY(1px); }

.btn.secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn.secondary:hover { border-color: var(--accent); color: var(--accent); }

.mode-toggle { display: flex; gap: 1.25rem; margin-bottom: 0.6rem; font-size: 0.88rem; flex-wrap: wrap; }
.mode-toggle label { display: flex; align-items: center; gap: 0.35rem; cursor: pointer; }

.hint { font-size: 0.82rem; color: var(--text-dim); margin: 0.35rem 0 0; }

.workspace { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 900px) { .workspace { grid-template-columns: 1fr; } }

/* ---------- results ---------- */

.summary {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 0.9rem 1.1rem;
  margin: 1.1rem 0;
  font-size: 0.88rem;
}

.summary .ok { color: var(--ok); font-weight: 600; }
.summary .warn { color: var(--danger); }
.summary-row { margin: 0.25rem 0; }

.error {
  background: var(--danger-soft);
  color: var(--danger);
  border: 1px solid var(--danger);
  border-radius: var(--radius);
  padding: 0.8rem 1rem;
  font-weight: 600;
  margin: 1rem 0;
  font-size: 0.9rem;
}

.warning-list {
  background: var(--danger-soft);
  border: 1px solid var(--danger);
  border-radius: var(--radius);
  padding: 0.7rem 1rem;
  margin: 1rem 0;
  font-size: 0.85rem;
  color: var(--text);
}
.warning-list ul { margin: 0.3rem 0 0; padding-left: 1.2rem; }

.file-block { margin: 1.2rem 0; }
.file-block .file-head {
  display: flex; align-items: center; justify-content: space-between;
  font-family: monospace; font-size: 0.85rem; margin-bottom: 0.35rem;
}
.file-block .file-head .download { font-size: 0.78rem; }

pre.code {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 1rem;
  overflow-x: auto;
  border-radius: 8px;
  font-size: 0.83rem;
  margin: 0;
}

.example-note {
  background: var(--accent-soft);
  border-radius: 8px;
  padding: 0.7rem 0.9rem;
  font-size: 0.82rem;
  margin-bottom: 1rem;
}
.example-note pre { margin: 0.4rem 0 0; background: transparent; padding: 0; color: inherit; font-size: 0.8rem; }

.mermaid-frame {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  overflow-x: auto;
}

/* difflib.HtmlDiff output -- re-skinned to fit the site theme instead of
   its own hardcoded inline colors (see comparer/diff.py) */
.diff-frame {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  overflow-x: auto;
}
table.diff {
  width: 100%;
  border-collapse: collapse;
  font-family: "Cascadia Code", Consolas, monospace;
  font-size: 0.82rem;
}
table.diff td, table.diff th {
  padding: 0.15rem 0.5rem;
  vertical-align: top;
  white-space: pre-wrap;
  word-break: break-word;
}
table.diff .diff_header {
  color: var(--text-dim);
  text-align: right;
  user-select: none;
  background: var(--surface-2);
}
table.diff .diff_next {
  display: none;
}
table.diff thead .diff_header {
  text-align: left;
  font-weight: 600;
  color: var(--text);
  background: transparent;
}
table.diff .diff_add { background: var(--ok-soft); }
table.diff .diff_sub { background: var(--danger-soft); }
table.diff .diff_chg { background: var(--accent-soft); }

pre.regex-text {
  white-space: pre-wrap;
  word-break: break-word;
  font-family: "Cascadia Code", Consolas, monospace;
  font-size: 0.85rem;
  margin: 0;
}
mark.regex-hit {
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 3px;
  padding: 0 2px;
}