:root {
  --accent: #f95a36;
  --accent-soft: #f95a3614;
  --accent-strong: #e04722;
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --text: #1b1e24;
  --text-soft: #667085;
  --border: #e6e8ec;
  --code-bg: #14161b;
  --shadow: 0 8px 30px rgba(16, 24, 40, 0.07);
  --radius: 14px;
}

[data-theme="dark"] {
  --bg: #0f1115;
  --bg-soft: #171a21;
  --text: #e8eaee;
  --text-soft: #98a1b0;
  --border: #262b35;
  --accent-soft: #f95a361f;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  display: grid;
  grid-template-columns: 290px minmax(0, 1fr) 220px;
  min-height: 100vh;
  transition: background 0.4s, color 0.4s;
}

/* ---------- progress bar ---------- */
#progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--accent), #ffb199);
  z-index: 50;
  transition: width 0.15s ease-out;
}

/* ---------- sidebar ---------- */
#sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 26px 20px;
  border-right: 1px solid var(--border);
  background: var(--bg-soft);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.logo { display: flex; align-items: center; gap: 12px; }

.logo-mark {
  width: 46px; height: 46px;
  animation: spin-in 1s cubic-bezier(0.2, 0.8, 0.2, 1);
  transition: transform 0.5s cubic-bezier(0.2, 0.8, 0.2, 1.4);
}
.logo:hover .logo-mark { transform: rotate(120deg); }

@keyframes spin-in { from { transform: rotate(-180deg) scale(0); opacity: 0; } }

.logo h1 { margin: 0; font-size: 1.25rem; letter-spacing: -0.02em; }
.logo h1 span { color: var(--accent); }
#build-tag { margin: 2px 0 0; font-size: 0.68rem; color: var(--text-soft); }

#search {
  width: 100%;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1.5px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.25s, box-shadow 0.25s;
}
#search:focus { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }

#doc-list { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 4px; }

.doc-link {
  display: block;
  padding: 10px 14px;
  border-radius: 10px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.92rem;
  border-left: 3px solid transparent;
  animation: slide-in 0.45s cubic-bezier(0.2, 0.8, 0.2, 1) backwards;
  transition: background 0.2s, border-color 0.2s, transform 0.2s;
  cursor: pointer;
}
.doc-link:hover { background: var(--accent-soft); transform: translateX(4px); }
.doc-link.active { background: var(--accent-soft); border-left-color: var(--accent); font-weight: 600; }
.doc-link .badge {
  font-size: 0.62rem;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 20px;
  padding: 1px 7px;
  margin-left: 6px;
  vertical-align: middle;
}

@keyframes slide-in { from { opacity: 0; transform: translateX(-18px); } }

.sidebar-footer { display: flex; gap: 8px; }

/* ---------- buttons ---------- */
.ghost-btn, .accent-btn {
  border-radius: 10px;
  padding: 9px 14px;
  font-size: 0.88rem;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.2s;
  font-family: inherit;
}
.ghost-btn {
  background: transparent;
  border: 1.5px solid var(--border);
  color: var(--text);
}
.ghost-btn:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
.ghost-btn.danger:hover { border-color: #d33; color: #d33; }
.accent-btn {
  background: var(--accent);
  border: 1.5px solid var(--accent);
  color: #fff;
  font-weight: 600;
}
.accent-btn:hover {
  background: var(--accent-strong);
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(249, 90, 54, 0.35);
}
.accent-btn:active, .ghost-btn:active { transform: translateY(1px); }

/* ---------- main ---------- */
#main { padding: 34px 52px 90px; max-width: 900px; width: 100%; justify-self: center; }

#doc-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 16px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 18px;
  margin-bottom: 26px;
}
#doc-title { margin: 0; font-size: 2rem; letter-spacing: -0.03em; }
#doc-meta { margin: 6px 0 0; color: var(--text-soft); font-size: 0.8rem; }
.header-actions { display: flex; gap: 8px; flex-shrink: 0; }

#content { animation: content-in 0.5s cubic-bezier(0.2, 0.8, 0.2, 1); }
#content.switching { opacity: 0; transform: translateY(14px); transition: 0.18s; }
@keyframes content-in { from { opacity: 0; transform: translateY(14px); } }

/* ---------- markdown ---------- */
.markdown-body { line-height: 1.75; font-size: 1.0rem; }
.markdown-body h1, .markdown-body h2, .markdown-body h3 { letter-spacing: -0.02em; scroll-margin-top: 20px; }
.markdown-body h2 { border-bottom: 1px solid var(--border); padding-bottom: 8px; margin-top: 2.2em; }
.markdown-body a { color: var(--accent); text-decoration: none; border-bottom: 1px dashed var(--accent); }
.markdown-body a:hover { border-bottom-style: solid; }
.markdown-body blockquote {
  margin: 1em 0;
  padding: 10px 20px;
  border-left: 3px solid var(--accent);
  background: var(--bg-soft);
  border-radius: 0 10px 10px 0;
  color: var(--text-soft);
}
.markdown-body table { border-collapse: collapse; width: 100%; margin: 1.2em 0; font-size: 0.92rem; display: block; overflow-x: auto; }
.markdown-body th, .markdown-body td { border: 1px solid var(--border); padding: 9px 13px; text-align: left; }
.markdown-body th { background: var(--bg-soft); border-bottom: 2px solid var(--accent); }
.markdown-body tr { transition: background 0.15s; }
.markdown-body tbody tr:hover { background: var(--bg-soft); }
.markdown-body code { background: var(--bg-soft); border: 1px solid var(--border); border-radius: 6px; padding: 1px 6px; font-size: 0.88em; }
.markdown-body pre code { background: none; padding: 0; }

.code-block {
  position: relative;
  background: var(--code-bg);
  border-radius: var(--radius);
  padding: 18px 20px;
  overflow-x: auto;
  box-shadow: var(--shadow);
  transition: transform 0.2s;
}
.code-block:hover { transform: scale(1.005); }
.copy-btn {
  position: absolute;
  top: 10px; right: 10px;
  background: #ffffff14;
  color: #ddd;
  border: 1px solid #ffffff2a;
  border-radius: 8px;
  padding: 4px 9px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.2s, background 0.2s;
}
.code-block:hover .copy-btn { opacity: 1; }
.copy-btn:hover { background: var(--accent); border-color: var(--accent); color: #fff; }

/* ---------- editor ---------- */
#editor { animation: content-in 0.35s; }
.editor-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  color: var(--text-soft);
  font-size: 0.85rem;
}
.editor-bar div { display: flex; gap: 8px; }
#editor-text {
  width: 100%;
  min-height: 62vh;
  border-radius: var(--radius);
  border: 1.5px solid var(--border);
  background: var(--bg-soft);
  color: var(--text);
  padding: 20px;
  font-family: Consolas, "Fira Code", monospace;
  font-size: 0.9rem;
  line-height: 1.6;
  resize: vertical;
  outline: none;
  transition: border-color 0.25s, box-shadow 0.25s;
}
#editor-text:focus { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }

/* ---------- toc ---------- */
#toc-panel { position: sticky; top: 0; height: 100vh; padding: 40px 18px; font-size: 0.82rem; overflow-y: auto; }
#toc-panel h3 { color: var(--text-soft); text-transform: uppercase; font-size: 0.68rem; letter-spacing: 0.1em; }
#toc a {
  display: block;
  color: var(--text-soft);
  text-decoration: none;
  padding: 4px 0 4px 10px;
  border-left: 2px solid var(--border);
  transition: color 0.2s, border-color 0.2s, padding-left 0.2s;
}
#toc a.lvl-3 { padding-left: 24px; }
#toc a:hover, #toc a.current { color: var(--accent); border-left-color: var(--accent); padding-left: 14px; }

/* ---------- brain break ---------- */
#brain-btn {
  position: fixed;
  bottom: 26px; right: 26px;
  width: 58px; height: 58px;
  border-radius: 50%;
  border: none;
  background: var(--accent);
  font-size: 1.5rem;
  cursor: pointer;
  box-shadow: 0 10px 26px rgba(249, 90, 54, 0.45);
  transition: transform 0.25s cubic-bezier(0.2, 0.8, 0.2, 1.6);
  z-index: 40;
}
#brain-btn:hover { transform: scale(1.15) rotate(-8deg); }
#brain-btn.wiggle { animation: wiggle 0.8s ease-in-out 3; }
@keyframes wiggle {
  0%, 100% { transform: rotate(0); }
  25% { transform: rotate(-14deg) scale(1.1); }
  75% { transform: rotate(14deg) scale(1.1); }
}

/* ---------- dialogs ---------- */
dialog {
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--bg);
  color: var(--text);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.3);
  padding: 26px;
  width: min(500px, 92vw);
}
dialog::backdrop { background: rgba(20, 12, 8, 0.55); backdrop-filter: blur(3px); }
dialog[open] { animation: pop 0.35s cubic-bezier(0.2, 0.8, 0.2, 1.4); }
@keyframes pop { from { transform: scale(0.85) translateY(20px); opacity: 0; } }

#login-form { display: flex; flex-direction: column; gap: 12px; }
#login-form h3 { margin: 0 0 4px; }
#login-form input {
  padding: 11px 14px;
  border-radius: 10px;
  border: 1.5px solid var(--border);
  background: var(--bg-soft);
  color: var(--text);
  font-size: 0.95rem;
  outline: none;
}
#login-form input:focus { border-color: var(--accent); }
.form-error { color: #d33; font-size: 0.8rem; min-height: 1em; margin: 0; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 8px; }

/* ---------- game ---------- */
#game-dialog { width: min(520px, 94vw); }
.game-head { display: flex; justify-content: space-between; align-items: center; }
.game-head h3 { margin: 0; }
.game-sub { color: var(--text-soft); font-size: 0.85rem; margin-top: 4px; }
#game-canvas {
  width: 100%;
  border-radius: var(--radius);
  background: var(--bg-soft);
  border: 1.5px solid var(--border);
  cursor: crosshair;
  touch-action: manipulation;
}
.game-foot { display: flex; justify-content: space-between; align-items: center; margin-top: 12px; }
#game-score { font-weight: 700; color: var(--accent); font-variant-numeric: tabular-nums; }
#leaderboard { margin-top: 14px; }
#leaderboard h4 { margin: 0 0 6px; color: var(--text-soft); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; }
#scores { margin: 0; padding-left: 22px; font-size: 0.88rem; }
#scores li { padding: 2px 0; }
#scores li:first-child { color: var(--accent); font-weight: 700; }

/* ---------- toast ---------- */
#toast {
  position: fixed;
  bottom: 30px; left: 50%;
  transform: translate(-50%, 80px);
  background: var(--text);
  color: var(--bg);
  padding: 12px 22px;
  border-radius: 30px;
  font-size: 0.9rem;
  opacity: 0;
  transition: transform 0.4s cubic-bezier(0.2, 0.8, 0.2, 1.3), opacity 0.4s;
  z-index: 60;
  pointer-events: none;
}
#toast.show { transform: translate(-50%, 0); opacity: 1; }

/* ---------- responsive ---------- */
@media (max-width: 1180px) {
  body { grid-template-columns: 270px minmax(0, 1fr); }
  #toc-panel { display: none; }
}
@media (max-width: 780px) {
  body { grid-template-columns: 1fr; }
  #sidebar { position: relative; height: auto; }
  #main { padding: 24px 20px 90px; }
}