/* MT Copilot — Nebula Light Design System
 * Tokens aligned with frontend/src/styles/tokens.css & DESIGN.md
 */

/* ── Design Tokens ─────────────────────── */
:root {
  /* Surface hierarchy */
  --color-background: #f9f9f9;
  --color-surface: #ffffff;
  --color-surface-dim: #dadada;
  --color-surface-container-low: #f3f3f3;
  --color-surface-container: #eeeeee;
  --color-surface-container-high: #e8e8e8;
  --color-surface-container-highest: #e2e2e2;

  /* Text */
  --color-on-surface: #1a1c1c;
  --color-on-surface-variant: #444748;

  /* Borders */
  --color-outline: #747878;
  --color-outline-variant: #c4c7c7;
  --color-border-subtle: rgba(0, 0, 0, 0.06);

  /* Brand */
  --color-primary: #000000;
  --color-secondary: #0058bc;
  --color-secondary-container: #0070eb;
  --color-on-secondary: #ffffff;

  /* Accents */
  --color-accent-purple: #ab7ff6;
  --color-accent-purple-light: #ecdcff;
  --color-accent-blue: #007aff;

  /* Semantic */
  --color-error: #ba1a1a;
  --color-success: #16a34a;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.08), 0 4px 8px rgba(0, 0, 0, 0.04);

  /* Typography */
  --font: 'MiSans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', Consolas, monospace;

  /* Radius */
  --radius: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Layout */
  --max-w: 1200px;
  --nav-h: 64px;
}

/* ── Reset ─────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; -webkit-text-size-adjust: 100%; }
body { font-family: var(--font); background: var(--color-background); color: var(--color-on-surface); line-height: 1.6; overflow-x:hidden; -webkit-font-smoothing: antialiased; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

::selection { background-color: var(--color-accent-purple-light); color: var(--color-on-surface); }
:focus-visible { outline: 2px solid var(--color-accent-blue); outline-offset: 2px; border-radius: 0.375rem; }

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background-color: var(--color-outline-variant); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background-color: var(--color-outline); }

/* ── Skip link ─────────────────────────── */
.skip-link {
  position: absolute; top: -100%; left: 1rem;
  padding: 0.5rem 1rem; background: var(--color-primary); color: #fff;
  border-radius: var(--radius); z-index: 1000; font-size: 0.875rem;
}
.skip-link:focus { top: 1rem; }

/* ── Header ────────────────────────────── */
.site-header {
  position: sticky; top: 0; z-index: 100; height: var(--nav-h);
  background: rgba(249, 249, 249, 0.88); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-subtle);
  display: flex; align-items: center;
  transition: box-shadow 0.2s ease;
}
.site-header.scrolled { box-shadow: var(--shadow-sm); }
.site-header .wrap {
  max-width: var(--max-w); width: 100%; margin: 0 auto;
  padding: 0 2rem; display: flex; align-items: center; justify-content: space-between;
}

.logo {
  display: flex; align-items: center; gap: 0.625rem;
  font-weight: 600; font-size: 1rem; letter-spacing: -0.02em; color: var(--color-on-surface);
}
.logo-mark {
  width: 32px; height: 32px; border-radius: var(--radius-md);
}

nav { display: flex; align-items: center; gap: 1.75rem; }
nav a {
  font-size: 0.8125rem; font-weight: 500; color: var(--color-on-surface-variant);
  transition: color 0.15s; letter-spacing: 0.01em;
}
nav a:hover { color: var(--color-on-surface); }
nav a.active {
  color: var(--color-on-surface);
  font-weight: 600;
}
nav a.active:hover { color: var(--color-on-surface); }

.mobile-toggle {
  display: none; background: none; border: none; cursor: pointer; padding: 0.5rem;
  border-radius: var(--radius); color: var(--color-on-surface);
  transition: background-color 0.15s;
}
.mobile-toggle:hover { background: var(--color-surface-container); }
.mobile-toggle svg { width: 20px; height: 20px; }

/* ── Hero ──────────────────────────────── */
.hero { padding: 5rem 2rem 4rem; position: relative; }
.hero .wrap {
  max-width: var(--max-w); margin: 0 auto;
  display: grid; grid-template-columns: 1fr 1.15fr;
  gap: 3rem; align-items: center;
}
.hero-text { max-width: 560px; }
.hero-text .badge {
  display: inline-flex; align-items: center; gap: 0.375rem;
  padding: 0.3125rem 0.875rem; border-radius: var(--radius-full);
  font-size: 0.75rem; font-weight: 500;
  background: rgba(0, 122, 255, 0.08); color: var(--color-secondary);
  margin-bottom: 1.25rem;
}
.hero-text .badge .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--color-success); animation: pulse 2s infinite;
}
.hero h1 {
  font-size: 2.75rem; font-weight: 600; line-height: 1.1; letter-spacing: -0.02em;
  margin-bottom: 1.25rem; color: var(--color-on-surface);
}
.hero h1 .gradient {
  background: linear-gradient(135deg, var(--color-secondary-container), var(--color-accent-purple));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: 1rem; line-height: 1.65; color: var(--color-on-surface-variant);
  max-width: 520px; margin-bottom: 2rem;
}
.hero-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.hero-visual img {
  width: 100%; height: auto;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
}

/* ── Buttons ───────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.625rem 1.25rem; border-radius: var(--radius);
  font-size: 0.875rem; font-weight: 500; cursor: pointer; border: none;
  transition: all 0.15s cubic-bezier(0.16, 1, 0.3, 1);
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--color-secondary-container); color: #fff; }
.btn-primary:hover { filter: brightness(1.08); box-shadow: var(--shadow-md); }
.btn-secondary {
  background: var(--color-surface); color: var(--color-on-surface);
  border: 1px solid var(--color-outline-variant);
}
.btn-secondary:hover { background: var(--color-surface-container-low); border-color: var(--color-outline); }
.btn-ghost {
  background: rgba(255, 255, 255, 0.15); color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.3);
}
.btn-ghost:hover { background: rgba(255, 255, 255, 0.25); }

/* ── Hero visual ───────────────────────── */
/* ── Sections ──────────────────────────── */
section { padding: 4.5rem 2rem; }
section .wrap { max-width: var(--max-w); margin: 0 auto; }
.section-title {
  font-size: 1.75rem; font-weight: 600; letter-spacing: -0.01em;
  margin-bottom: 0.5rem; color: var(--color-on-surface);
}
.section-sub {
  font-size: 0.9375rem; color: var(--color-on-surface-variant);
  max-width: 560px; margin-bottom: 2.5rem;
}

/* ── Features grid ─────────────────────── */
.features {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
}
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.feature-card {
  padding: 1.5rem; border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-subtle);
  background: var(--color-surface);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}
.feature-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.feature-icon {
  width: 40px; height: 40px; border-radius: var(--radius-md);
  display: grid; place-items: center; margin-bottom: 0.875rem;
}
.feature-icon.blue { background: rgba(0, 122, 255, 0.08); color: var(--color-secondary); }
.feature-icon.purple { background: rgba(171, 127, 246, 0.1); color: var(--color-accent-purple); }
.feature-icon.green { background: rgba(22, 163, 74, 0.08); color: var(--color-success); }
.feature-card h3 { font-size: 0.9375rem; font-weight: 600; margin-bottom: 0.375rem; letter-spacing: -0.01em; }
.feature-card p { font-size: 0.8125rem; line-height: 1.55; color: var(--color-on-surface-variant); }

/* ── Modes ─────────────────────────────── */
.modes { background: var(--color-surface); border-top: 1px solid var(--color-border-subtle); }
.modes-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.mode-card {
  padding: 1.5rem; border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-subtle);
  background: var(--color-surface);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}
.mode-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.mode-header { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; }
.mode-header h3 { font-size: 1rem; font-weight: 600; flex: 1; }
.mode-icon {
  width: 40px; height: 40px; border-radius: var(--radius-md);
  display: grid; place-items: center;
}
.mode-icon.byok { background: rgba(171, 127, 246, 0.1); color: var(--color-accent-purple); }
.mode-icon.member { background: rgba(0, 122, 255, 0.08); color: var(--color-secondary); }
.mode-icon.local { background: rgba(22, 163, 74, 0.08); color: var(--color-success); }
.mode-badge {
  font-size: 0.6875rem; font-weight: 600;
  padding: 0.1875rem 0.5rem; border-radius: var(--radius-full);
  background: rgba(0, 122, 255, 0.08); color: var(--color-secondary);
}
.mode-badge.secondary { background: rgba(171, 127, 246, 0.1); color: var(--color-accent-purple); }
.mode-badge.tertiary { background: rgba(22, 163, 74, 0.08); color: var(--color-success); }
.mode-desc { font-size: 0.8125rem; color: var(--color-on-surface-variant); margin-bottom: 1rem; line-height: 1.55; }
.mode-features li {
  font-size: 0.8125rem; color: var(--color-on-surface-variant);
  padding: 0.375rem 0; border-bottom: 1px solid var(--color-border-subtle);
  display: flex; align-items: center; gap: 0.5rem;
}
.mode-features li:last-child { border-bottom: none; }
.mode-features li::before {
  content: ''; width: 4px; height: 4px; border-radius: 50%;
  background: var(--color-secondary-container); flex-shrink: 0;
}

/* ── API docs ──────────────────────────── */
.api-docs { background: var(--color-surface); border-top: 1px solid var(--color-border-subtle); }
.api-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
.api-card {
  padding: 1.5rem; border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-subtle);
  background: var(--color-surface);
}
.api-card h3 {
  font-size: 0.9375rem; font-weight: 600; margin-bottom: 0.625rem;
  display: flex; align-items: center; gap: 0.5rem;
}
.api-card .method {
  font-family: var(--mono); font-size: 0.6875rem; font-weight: 600;
  padding: 0.125rem 0.5rem; border-radius: var(--radius);
}
.api-card .method.post { background: rgba(0, 122, 255, 0.08); color: var(--color-secondary); }
.api-card .method.get { background: rgba(22, 163, 74, 0.08); color: var(--color-success); }
.api-card .path { font-family: var(--mono); font-size: 0.8125rem; color: var(--color-on-surface-variant); }
.api-card p { font-size: 0.8125rem; color: var(--color-on-surface-variant); margin-bottom: 1rem; line-height: 1.55; }

.code-block {
  position: relative; background: #1e1e2e;
  border-radius: var(--radius-md); overflow: hidden;
}
.code-block pre {
  padding: 1rem; overflow-x: auto;
  font-family: var(--mono); font-size: 0.75rem; line-height: 1.65;
  color: #cdd6f4; margin: 0;
}
.code-block .copy-btn {
  position: absolute; top: 0.5rem; right: 0.5rem;
  background: rgba(255, 255, 255, 0.08); border: 1px solid rgba(255, 255, 255, 0.1);
  color: #cdd6f4; border-radius: var(--radius);
  padding: 0.25rem 0.5rem; font-size: 0.625rem;
  cursor: pointer; display: flex; align-items: center; gap: 0.25rem;
  transition: background 0.15s;
}
.code-block .copy-btn:hover { background: rgba(255, 255, 255, 0.15); }
.code-block .copy-btn.copied { color: var(--color-success); border-color: rgba(22, 163, 74, 0.3); }

.api-preview { margin-top: 2rem; }
.api-preview img {
  border-radius: var(--radius-xl); box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border-subtle); width: 100%;
}

/* ── Pricing Page ──────────────────────── */
.pricing-hero { padding: 5rem 2rem 3rem; text-align: center; position: relative; }
.pricing-hero .wrap { max-width: 720px; margin: 0 auto; }
.pricing-hero .badge {
  display: inline-flex; align-items: center; gap: 0.375rem;
  padding: 0.3125rem 0.875rem; border-radius: var(--radius-full);
  font-size: 0.75rem; font-weight: 500;
  background: rgba(0, 122, 255, 0.08); color: var(--color-secondary);
  margin-bottom: 1.25rem;
}
.pricing-hero .badge .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--color-success); animation: pulse 2s infinite;
}
.pricing-hero h1 {
  font-size: 2.5rem; font-weight: 600; line-height: 1.15; letter-spacing: -0.02em;
  margin-bottom: 1rem;
}
.pricing-hero p {
  font-size: 0.9375rem; line-height: 1.65; color: var(--color-on-surface-variant);
  max-width: 560px; margin: 0 auto 2rem;
}
.pricing-hero .hero-actions { justify-content: center; }

/* Model cards */
.pricing-models {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
}
.model-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem; margin-bottom: 2rem;
}
.model-card {
  padding: 1.75rem; border-radius: var(--radius-xl);
  border: 1px solid var(--color-border-subtle);
  background: var(--color-surface);
  transition: box-shadow 0.2s, transform 0.2s;
  position: relative;
}
.model-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.model-header {
  display: flex; align-items: center; gap: 0.75rem;
  margin-bottom: 1.5rem;
}
.model-logo {
  width: 40px; height: 40px; border-radius: var(--radius-md);
  display: grid; place-items: center; flex-shrink: 0;
}
.model-logo.qwen { background: rgba(0, 122, 255, 0.08); color: var(--color-secondary); }
.model-logo.google { background: rgba(171, 127, 246, 0.1); color: var(--color-accent-purple); }
.model-meta { flex: 1; min-width: 0; }
.model-meta h3 {
  font-size: 1rem; font-weight: 600; letter-spacing: -0.01em;
  font-family: var(--mono); margin-bottom: 0.125rem;
}
.model-provider { font-size: 0.75rem; color: var(--color-on-surface-variant); }
.model-tag {
  font-size: 0.6875rem; font-weight: 600;
  padding: 0.1875rem 0.5rem; border-radius: var(--radius-full);
  background: rgba(0, 122, 255, 0.08); color: var(--color-secondary);
  white-space: nowrap;
}
.model-tag.alt { background: rgba(171, 127, 246, 0.1); color: var(--color-accent-purple); }

.model-price {
  display: flex; align-items: baseline; gap: 0.5rem;
  padding-bottom: 1.25rem; margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--color-border-subtle);
}
.price-amount { display: flex; align-items: baseline; gap: 0.125rem; }
.price-currency { font-size: 1rem; font-weight: 500; color: var(--color-on-surface-variant); }
.price-num {
  font-size: 2.25rem; font-weight: 700; letter-spacing: -0.02em;
  font-family: var(--mono); color: var(--color-on-surface);
}
.price-unit { font-size: 0.8125rem; color: var(--color-on-surface-variant); }

.model-features {
  display: flex; flex-direction: column; gap: 0.5rem;
  margin-bottom: 1.25rem;
}
.model-features li {
  font-size: 0.8125rem; color: var(--color-on-surface-variant);
  display: flex; align-items: center; gap: 0.5rem;
}
.model-features li::before {
  content: ''; width: 4px; height: 4px; border-radius: 50%;
  background: var(--color-secondary-container); flex-shrink: 0;
}

.batch-note {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.75rem 1rem; border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(22, 163, 74, 0.06), rgba(22, 163, 74, 0.02));
  border: 1px solid rgba(22, 163, 74, 0.15);
}
.batch-pill {
  font-size: 0.75rem; font-weight: 600;
  padding: 0.1875rem 0.625rem; border-radius: var(--radius-full);
  background: var(--color-success); color: #fff;
}
.batch-price { font-size: 0.8125rem; font-weight: 600; color: var(--color-success); font-family: var(--mono); }

.pricing-foot {
  display: flex; flex-wrap: wrap; gap: 1.5rem 2.5rem;
  padding-top: 1rem; border-top: 1px solid var(--color-border-subtle);
}
.foot-item {
  display: flex; align-items: center; gap: 0.5rem;
  font-size: 0.8125rem; color: var(--color-on-surface-variant);
}
.foot-item svg { color: var(--color-success); flex-shrink: 0; }
.foot-item strong { color: var(--color-on-surface); font-weight: 600; }

/* Why cards */
.why { background: var(--color-surface); border-top: 1px solid var(--color-border-subtle); }
.why-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem;
}
.why-card {
  position: relative;
  padding: 1.75rem 1.5rem 1.5rem;
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border-subtle);
  background: var(--color-surface);
  transition: box-shadow 0.2s, transform 0.2s;
  display: flex; flex-direction: column;
}
.why-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.why-card.highlight {
  border-color: rgba(22, 163, 74, 0.3);
  background: linear-gradient(180deg, rgba(22, 163, 74, 0.03), transparent 50%);
}
.why-num {
  position: absolute; top: 1.25rem; right: 1.5rem;
  font-size: 2.5rem; font-weight: 700; letter-spacing: -0.04em;
  font-family: var(--mono);
  color: var(--color-outline-variant);
  line-height: 1; opacity: 0.5;
  pointer-events: none;
}
.why-icon {
  width: 44px; height: 44px; border-radius: var(--radius-md);
  display: grid; place-items: center; margin-bottom: 0.875rem;
}
.why-icon.blue { background: rgba(0, 122, 255, 0.08); color: var(--color-secondary); }
.why-icon.purple { background: rgba(171, 127, 246, 0.1); color: var(--color-accent-purple); }
.why-icon.green { background: rgba(22, 163, 74, 0.08); color: var(--color-success); }
.why-card h3 { font-size: 1.0625rem; font-weight: 600; margin-bottom: 0.5rem; letter-spacing: -0.01em; }
.why-card > p { font-size: 0.8125rem; line-height: 1.6; color: var(--color-on-surface-variant); margin-bottom: 1rem; }
.why-card > p strong { color: var(--color-on-surface); font-weight: 600; }

.discount-bar {
  display: flex; align-items: center; gap: 0.625rem;
  padding: 0.625rem 0.75rem; margin-bottom: 1rem;
  border-radius: var(--radius);
  background: var(--color-surface-container-low);
  font-size: 0.75rem; font-weight: 600;
}
.discount-original, .discount-actual { color: var(--color-on-surface-variant); white-space: nowrap; }
.discount-actual { color: var(--color-success); }
.discount-track {
  flex: 1; height: 6px; border-radius: var(--radius-full);
  background: var(--color-surface-container-high); position: relative; overflow: hidden;
}
.discount-fill {
  position: absolute; left: 0; top: 0; height: 100%;
  width: 70%;
  background: linear-gradient(90deg, var(--color-success), #4ade80);
  border-radius: var(--radius-full);
}

.fusion-vis {
  display: flex; align-items: center; gap: 0.375rem;
  margin-bottom: 1rem; padding: 0.75rem;
  background: var(--color-surface-container-low);
  border-radius: var(--radius); font-size: 0.75rem;
  font-weight: 500;
}
.fusion-node {
  flex: 1; padding: 0.5rem 0.25rem;
  border-radius: var(--radius);
  text-align: center; white-space: nowrap;
}
.fusion-node.image { background: rgba(0, 122, 255, 0.1); color: var(--color-secondary); }
.fusion-node.text { background: rgba(171, 127, 246, 0.12); color: var(--color-accent-purple); }
.fusion-node.result {
  background: linear-gradient(135deg, var(--color-secondary-container), var(--color-accent-purple));
  color: #fff;
}
.fusion-plus, .fusion-equals {
  color: var(--color-outline); font-weight: 600; font-size: 0.875rem;
  flex-shrink: 0;
}

.why-points { display: flex; flex-direction: column; gap: 0.375rem; margin-top: auto; }
.why-points li {
  font-size: 0.8125rem; color: var(--color-on-surface-variant);
  display: flex; align-items: center; gap: 0.5rem;
}
.why-points li::before {
  content: ''; width: 4px; height: 4px; border-radius: 50%;
  background: var(--color-secondary-container); flex-shrink: 0;
}

/* Cost calculator */
.calc { background: var(--color-surface); border-top: 1px solid var(--color-border-subtle); }
.calc-card {
  display: grid; grid-template-columns: 1.2fr 1fr; gap: 0;
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}
.calc-controls { padding: 1.75rem; display: flex; flex-direction: column; gap: 1.25rem; }
.calc-field label {
  display: block; font-size: 0.75rem; font-weight: 600;
  color: var(--color-on-surface-variant);
  text-transform: uppercase; letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}
.calc-input-wrap {
  position: relative; display: flex; align-items: center;
  background: var(--color-surface-container-low);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius);
  padding: 0 0.875rem;
  transition: border-color 0.15s;
}
.calc-input-wrap:focus-within { border-color: var(--color-secondary); }
.calc-input-wrap input {
  flex: 1; min-width: 0;
  background: none; border: none; outline: none;
  font-family: var(--font); font-size: 1rem; font-weight: 600;
  color: var(--color-on-surface);
  padding: 0.625rem 0;
  font-family: var(--mono);
}
.calc-input-wrap input::-webkit-inner-spin-button,
.calc-input-wrap input::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
.calc-input-wrap input[type=number] { -moz-appearance: textfield; }
.calc-unit { font-size: 0.8125rem; color: var(--color-on-surface-variant); }

.calc-range {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 4px; margin-top: 0.75rem;
  background: var(--color-surface-container-high);
  border-radius: var(--radius-full); outline: none;
  cursor: pointer;
}
.calc-range::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--color-secondary-container);
  cursor: pointer; border: 2px solid #fff;
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s;
}
.calc-range::-webkit-slider-thumb:hover { transform: scale(1.15); }
.calc-range::-moz-range-thumb {
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--color-secondary-container);
  cursor: pointer; border: 2px solid #fff;
  box-shadow: var(--shadow-sm);
}

.calc-tabs { display: flex; gap: 0.375rem; }
.calc-tab {
  flex: 1; padding: 0.5rem 0.75rem;
  background: var(--color-surface-container-low);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius);
  font-family: var(--font); font-size: 0.75rem; font-weight: 500;
  color: var(--color-on-surface-variant);
  cursor: pointer; transition: all 0.15s;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.calc-tab:hover {
  background: var(--color-surface-container);
  color: var(--color-on-surface);
}
.calc-tab.active {
  background: var(--color-secondary-container);
  border-color: var(--color-secondary-container);
  color: #fff;
}

.calc-result {
  padding: 2rem 1.75rem;
  background: linear-gradient(135deg, var(--color-primary), #1a1c1c);
  color: #fff;
  display: flex; flex-direction: column; justify-content: center;
}
.calc-result-label {
  font-size: 0.75rem; font-weight: 600;
  color: rgba(255, 255, 255, 0.6);
  text-transform: uppercase; letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}
.calc-result-value {
  display: flex; align-items: baseline; gap: 0.25rem;
  margin-bottom: 0.75rem;
}
.calc-currency { font-size: 1.25rem; font-weight: 500; color: rgba(255, 255, 255, 0.7); }
#calc-amount {
  font-size: 2.75rem; font-weight: 700; letter-spacing: -0.02em;
  font-family: var(--mono); line-height: 1;
}
.calc-result-meta {
  font-size: 0.75rem; color: rgba(255, 255, 255, 0.6);
  display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap;
  margin-bottom: 0.75rem;
}
.calc-result-meta strong { color: #fff; font-weight: 600; font-family: var(--mono); }
.calc-divider { color: rgba(255, 255, 255, 0.3); }
.calc-result-detail {
  font-size: 0.6875rem;
  color: rgba(255, 255, 255, 0.5);
  font-family: var(--mono);
  padding-top: 0.75rem; margin-top: 0.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.cta-actions { display: flex; gap: 0.75rem; justify-content: center; flex-wrap: wrap; }

/* ── FAQ ────────────────────────────────── */
.faq { background: var(--color-surface); border-top: 1px solid var(--color-border-subtle); }
.faq-list { max-width: 760px; display: flex; flex-direction: column; }
.faq-item { border-bottom: 1px solid var(--color-border-subtle); }
.faq-q {
  width: 100%; display: flex; justify-content: space-between; align-items: center;
  padding: 1.125rem 0; background: none; border: none; cursor: pointer;
  font-family: var(--font); font-size: 0.875rem; font-weight: 600;
  color: var(--color-on-surface); text-align: left;
}
.faq-q .chevron { width: 18px; height: 18px; color: var(--color-outline); transition: transform 0.25s; flex-shrink: 0; }
.faq-item.open .chevron { transform: rotate(180deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-a p { padding: 0 0 1.125rem; font-size: 0.8125rem; line-height: 1.6; color: var(--color-on-surface-variant); }
.faq-item.open .faq-a { max-height: 300px; }

/* ── CTA ────────────────────────────────── */
.cta {
  background: var(--color-primary); color: #fff; text-align: center;
  padding: 4rem 2rem;
}
.cta h2 { font-size: 1.75rem; font-weight: 600; letter-spacing: -0.01em; margin-bottom: 0.625rem; }
.cta p { font-size: 0.9375rem; color: rgba(255, 255, 255, 0.7); margin-bottom: 2rem; max-width: 480px; margin-left: auto; margin-right: auto; }
.cta .btn-primary { padding: 0.75rem 1.75rem; font-size: 0.9375rem; }

/* ── Footer ─────────────────────────────── */
footer {
  background: var(--color-surface-container-low);
  border-top: 1px solid var(--color-border-subtle);
  padding: 2rem;
}
footer .wrap {
  max-width: var(--max-w); margin: 0 auto;
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem;
}
footer .copy { font-size: 0.8125rem; color: var(--color-on-surface-variant); }
footer .links { display: flex; gap: 1.25rem; }
footer .links a {
  font-size: 0.8125rem; color: var(--color-on-surface-variant);
  transition: color 0.15s;
}
footer .links a:hover { color: var(--color-on-surface); }

/* ── Animations ─────────────────────────── */
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }

.fade-in {
  opacity: 0; transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ── Responsive ─────────────────────────── */
@media (max-width: 1024px) {
  .hero .wrap { grid-template-columns: 1fr; gap: 2rem; }
  .hero-text { max-width: none; text-align: center; margin: 0 auto; }
  .hero p { margin-left: auto; margin-right: auto; }
  .hero-actions { justify-content: center; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .api-grid { grid-template-columns: 1fr; }
  .modes-grid { grid-template-columns: 1fr; }
  .model-grid { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: 1fr; }
  .calc-card { grid-template-columns: 1fr; }
  .calc-result { padding: 1.5rem 1.25rem; }
}

@media (max-width: 640px) {
  :root { --nav-h: 56px; }
  .hero { padding: 3rem 1rem 2.5rem; }
  .hero h1 { font-size: 2rem; }
  .hero p { font-size: 0.9375rem; }
  section { padding: 3rem 1rem; }
  .section-title { font-size: 1.375rem; }
  .features-grid { grid-template-columns: 1fr; }
  .pricing-hero h1 { font-size: 1.875rem; }
  .pricing-foot { gap: 0.75rem 1.25rem; }
  .pricing-hero .hero-actions { flex-direction: column; align-items: stretch; }
  .pricing-hero .hero-actions .btn { justify-content: center; }
  .calc-tabs { flex-wrap: wrap; }
  .calc-tab { flex: 1 1 calc(50% - 0.25rem); min-width: 0; }

  nav {
    position: fixed; top: var(--nav-h); left: 0; right: 0;
    background: var(--color-surface); flex-direction: column;
    padding: 1.25rem; gap: 0.5rem;
    border-bottom: 1px solid var(--color-border-subtle);
    transform: translateY(-100%); opacity: 0;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    pointer-events: none; box-shadow: var(--shadow-md);
  }
  nav.open { transform: translateY(0); opacity: 1; pointer-events: all; }
  nav a { padding: 0.625rem 0; }
  .mobile-toggle { display: block; }

  footer .wrap { flex-direction: column; text-align: center; }
}