/* ── Reset & Base ──────────────────────────────────── */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #ffffff;
  --bg-card: #f8fafc;
  --bg-code: #f1f5f9;
  --bg-pre: #f8fafc;
  --border: #e2e8f0;
  --fg: #0f172a;
  --fg-muted: #64748b;
  --fg-code: #1e293b;
  --accent: #3b82f6;
  --accent-fg: #ffffff;
  --ring: rgba(59, 130, 246, 0.35);
  --radius: 0.5rem;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.08);
  --font: "Inter", ui-sans-serif, system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", ui-monospace, monospace;
  --container: 960px;
}

[data-theme="dark"] {
  --bg: #09090b;
  --bg-card: #111113;
  --bg-code: #1c1c1f;
  --bg-pre: #0c0c0e;
  --border: #27272a;
  --fg: #fafafa;
  --fg-muted: #a1a1aa;
  --fg-code: #e4e4e7;
  --ring: rgba(59, 130, 246, 0.4);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.4);
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition:
    background 0.2s,
    color 0.2s;
}

/* ── Typography ─────────────────────────────────────── */
h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
}
h1 {
  font-size: 2.25rem;
}
h2 {
  font-size: 1.5rem;
  margin-top: 3rem;
  margin-bottom: 1rem;
}
h3 {
  font-size: 1.125rem;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}
p {
  margin-bottom: 1rem;
  color: var(--fg-muted);
}
a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
strong {
  color: var(--fg);
}

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-code);
  color: var(--fg);
  padding: 0.15em 0.35em;
  border-radius: 0.25rem;
}
pre {
  position: relative;
  background: var(--bg-pre) !important;
  color: var(--fg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 2.5rem 1.25rem 1.25rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}
pre code {
  background: none;
  padding: 0;
  font-size: inherit;
  color: inherit;
}

/* ── Layout ────────────────────────────────────────── */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── Header ────────────────────────────────────────── */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.5rem;
}
.header-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--fg);
}
.header-badge {
  font-size: 0.65rem;
  font-weight: 600;
  background: var(--bg-code);
  color: var(--fg-muted);
  padding: 0.1rem 0.45rem;
  border-radius: 9999px;
}
.header-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.header-nav a {
  font-size: 0.85rem;
  color: var(--fg-muted);
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius);
  transition:
    background 0.15s,
    color 0.15s;
}
.header-nav a:hover {
  background: var(--bg-code);
  color: var(--fg);
  text-decoration: none;
}

/* ── Theme Toggle ──────────────────────────────────── */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--fg-muted);
  transition:
    background 0.15s,
    color 0.15s,
    border-color 0.15s;
}
.theme-toggle:hover {
  background: var(--bg-code);
  color: var(--fg);
  border-color: var(--fg-muted);
}
.theme-toggle svg {
  width: 16px;
  height: 16px;
}

/* ── Hero ──────────────────────────────────────────── */
.hero {
  padding: 4rem 0 3rem;
  text-align: center;
}
.hero h1 {
  margin-bottom: 0.75rem;
}
.hero p {
  font-size: 1.1rem;
  max-width: 560px;
  margin: 0 auto 2rem;
}
.hero-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Buttons ───────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.15rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
  font-family: var(--font);
}
.btn-primary {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
}
.btn-primary:hover {
  opacity: 0.9;
  text-decoration: none;
}
.btn-outline {
  background: var(--bg);
  color: var(--fg);
}
.btn-outline:hover {
  background: var(--bg-code);
  text-decoration: none;
}

/* ── Card ────────────────────────────────────────────── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

/* ── Install block ────────────────────────────────── */
.install-block {
  display: flex;
  align-items: center;
  background: var(--bg-pre);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.6rem 1rem;
  gap: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--fg-code);
  max-width: 400px;
  margin: 0 auto 1.5rem;
}
.install-block .prefix {
  color: var(--fg-muted);
  user-select: none;
}
.install-block .cmd {
  flex: 1;
}
.copy-btn {
  background: transparent;
  border: none;
  color: var(--fg-muted);
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 0.25rem;
  display: flex;
  align-items: center;
}
.copy-btn:hover {
  color: var(--fg-code);
}
.copy-btn svg {
  width: 14px;
  height: 14px;
}
.copy-btn.copied {
  color: #22c55e;
}

/* ── Code Copy Button ──────────────────────────────── */
.code-copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.75rem;
  height: 1.75rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 0.3rem;
  cursor: pointer;
  color: var(--fg-code);
  opacity: 0.4;
  transition: all 0.15s;
}
.code-copy-btn:hover {
  opacity: 1;
  background: var(--bg-pre);
}
.code-copy-btn.copied {
  opacity: 1;
  color: #22c55e;
  background: rgba(34, 197, 94, 0.12);
  border-color: rgba(34, 197, 94, 0.3);
}

/* ── hljs overrides ────────────────────────────────── */
pre code.hljs {
  background: transparent !important;
  padding: 0;
}

/* ── Install Tabs ──────────────────────────────────── */
.install-tabs {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.install-tab-buttons {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg-code);
  overflow-x: auto;
}
.install-tab-btn {
  padding: 0.55rem 1rem;
  font-size: 0.8rem;
  font-weight: 500;
  font-family: var(--font);
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--fg-muted);
  cursor: pointer;
  white-space: nowrap;
  transition:
    color 0.15s,
    border-color 0.15s;
}
.install-tab-btn:hover {
  color: var(--fg);
}
.install-tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}
.install-tab-panel {
  display: none;
  padding: 0.25rem 0;
}
.install-tab-panel.active {
  display: block;
}
.install-tab-panel pre {
  border: none;
  border-radius: 0;
  margin: 0;
}
.tab-note {
  font-size: 0.78rem;
  color: var(--fg-muted);
  padding: 0 1.25rem 0.75rem;
}
.tab-note a {
  color: var(--accent);
  text-decoration: none;
}
.tab-note a:hover {
  text-decoration: underline;
}

/* ── Demo Section ──────────────────────────────────── */
.demo-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 1.5rem;
  align-items: start;
}
@media (max-width: 768px) {
  .demo-grid {
    grid-template-columns: 1fr;
  }
}

.demo-chart-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 400px;
}
.demo-chart-wrap .body-chart-container {
  padding: 0 !important;
}

.demo-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.view-toggle {
  display: flex;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.view-toggle button {
  flex: 1;
  padding: 0.45rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  background: var(--bg);
  color: var(--fg-muted);
  border: none;
  cursor: pointer;
  transition: all 0.15s;
  font-family: var(--font);
}
.view-toggle button.active {
  background: var(--accent);
  color: var(--accent-fg);
}
.view-toggle button:not(:last-child) {
  border-right: 1px solid var(--border);
}

.info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.35rem 0;
  font-size: 0.85rem;
}
.info-label {
  color: var(--fg-muted);
}
.info-value {
  font-weight: 600;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.badge {
  display: inline-block;
  padding: 0.1rem 0.5rem;
  font-size: 0.7rem;
  font-weight: 600;
  border-radius: 9999px;
}
.badge-blue {
  background: rgba(59, 130, 246, 0.12);
  color: var(--accent);
}
.badge-gray {
  background: var(--bg-code);
  color: var(--fg-muted);
}

.intensity-bar {
  display: flex;
  gap: 3px;
  margin-top: 0.5rem;
}
.intensity-swatch {
  flex: 1;
  height: 24px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.6rem;
  font-weight: 700;
  font-family: var(--font-mono);
  cursor: default;
}

.group-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.group-chip {
  padding: 0.25rem 0.6rem;
  font-size: 0.7rem;
  font-weight: 500;
  border: 1px solid var(--border);
  border-radius: 9999px;
  background: var(--bg);
  color: var(--fg-muted);
  cursor: pointer;
  transition: all 0.15s;
  font-family: var(--font);
}
.group-chip:hover,
.group-chip.active {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
}

.demo-actions {
  display: flex;
  gap: 0.5rem;
}
.demo-actions .btn {
  flex: 1;
  justify-content: center;
  font-size: 0.8rem;
  padding: 0.4rem 0.75rem;
}

/* ── Muscle List ───────────────────────────────────── */
.muscle-list {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  max-height: 320px;
  overflow-y: auto;
}
.muscle-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.45rem 0.6rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg);
  transition: border-color 0.15s;
}
.muscle-item:hover {
  border-color: var(--fg-muted);
}
.muscle-item-name {
  flex: 1;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--fg);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}
.muscle-item-slider {
  width: 80px;
  accent-color: var(--accent);
  cursor: pointer;
}
.muscle-item-value {
  font-size: 0.7rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--fg-muted);
  min-width: 1.4rem;
  text-align: right;
}
.muscle-item-toggle {
  width: 16px;
  height: 16px;
  border-radius: 4px;
  border: 1.5px solid var(--border);
  background: var(--bg);
  cursor: pointer;
  transition: all 0.15s;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.muscle-item-toggle.active {
  background: var(--accent);
  border-color: var(--accent);
}
.muscle-item-toggle.active::after {
  content: "";
  display: block;
  width: 6px;
  height: 6px;
  border-radius: 2px;
  background: #fff;
}

/* ── Features Grid ─────────────────────────────────── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}
@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
  }
}
.feature-card {
  padding: 1.25rem;
}
.feature-icon {
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent);
  border-radius: var(--radius);
  margin-bottom: 0.75rem;
  font-size: 1rem;
}
.feature-card h3 {
  margin-top: 0;
  font-size: 0.95rem;
  margin-bottom: 0.35rem;
}
.feature-card p {
  font-size: 0.85rem;
  margin-bottom: 0;
}

/* ── API Table ─────────────────────────────────────── */
.api-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  margin-bottom: 1.5rem;
}
.api-table th {
  text-align: left;
  padding: 0.6rem 0.75rem;
  border-bottom: 2px solid var(--border);
  font-weight: 600;
  color: var(--fg);
}
.api-table td {
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid var(--border);
  color: var(--fg-muted);
}
.api-table code {
  font-size: 0.78rem;
}

/* ── Section spacer ────────────────────────────────── */
section {
  padding: 2rem 0;
}
section:last-child {
  padding-bottom: 4rem;
}

/* ── Footer ────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  text-align: center;
  font-size: 0.8rem;
  color: var(--fg-muted);
}

/* ── Scroll anchor offset ──────────────────────────── */
[id] {
  scroll-margin-top: 4rem;
}