:root {
  --bg: #0a0a0f;
  --bg2: #12121a;
  --bg3: #1a1a2e;
  --surface: #16162a;
  --border: #2a2a4a;
  --text: #e0e0f0;
  --text2: #8888aa;
  --accent: #10b981;
  --accent2: #06d6a0;
  --gradient: linear-gradient(135deg, #10b981, #06d6a0);
  --gradient2: linear-gradient(135deg, #10b98122, #06d6a022);
  --success: #10b981;
  --danger: #ef4444;
  --radius: 12px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; }
a { color: var(--accent2); text-decoration: none; }
a:hover { text-decoration: underline; }
button, .btn { cursor: pointer; border: none; font-family: inherit; font-size: 0.95rem; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 10px 24px; border-radius: 8px; font-weight: 600; transition: all 0.2s; }
.btn-primary { background: var(--gradient); color: #fff; }
.btn-primary:hover { opacity: 0.9; transform: translateY(-1px); }
.btn-secondary { background: var(--surface); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { border-color: var(--accent); }
.btn-sm { padding: 6px 16px; font-size: 0.85rem; }
.btn-ghost { background: transparent; color: var(--text2); }
.btn-ghost:hover { color: var(--text); }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* Nav */
nav { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: rgba(10,10,15,0.85); backdrop-filter: blur(20px); border-bottom: 1px solid var(--border); }
nav .nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; max-width: 1200px; margin: 0 auto; padding: 0 24px; }
nav .logo { font-size: 1.3rem; font-weight: 700; background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
nav .nav-links { display: flex; gap: 8px; align-items: center; }
nav .nav-links a, nav .nav-links button { padding: 8px 16px; border-radius: 8px; color: var(--text2); font-size: 0.9rem; transition: color 0.2s; background: none; border: none; font-family: inherit; }
nav .nav-links a:hover, nav .nav-links button:hover { color: var(--text); text-decoration: none; }
nav .nav-links a.active { color: var(--text); background: var(--surface); }
.hamburger { display: none; background: none; border: none; color: var(--text); font-size: 1.5rem; }

/* Hero */
.hero { padding: 140px 0 80px; text-align: center; position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%; background: radial-gradient(circle at 50% 50%, #10b98111 0%, transparent 50%); }
.hero h1 { font-size: 3.5rem; font-weight: 800; line-height: 1.2; margin-bottom: 20px; position: relative; }
.hero h1 span { background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.hero p { font-size: 1.25rem; color: var(--text2); max-width: 600px; margin: 0 auto 40px; position: relative; }
.hero-buttons { display: flex; gap: 16px; justify-content: center; position: relative; }

/* Features */
.features { padding: 80px 0; }
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 24px; }
.feature-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; transition: border-color 0.2s; }
.feature-card:hover { border-color: var(--accent); }
.feature-card .icon { font-size: 2rem; margin-bottom: 16px; }
.feature-card h3 { margin-bottom: 8px; font-size: 1.1rem; }
.feature-card p { color: var(--text2); font-size: 0.9rem; }

/* Pricing */
.pricing { padding: 80px 0; }
.section-title { text-align: center; font-size: 2rem; font-weight: 700; margin-bottom: 12px; }
.section-subtitle { text-align: center; color: var(--text2); margin-bottom: 48px; }
.pricing-table { width: 100%; border-collapse: collapse; background: var(--surface); border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border); }
.pricing-table th, .pricing-table td { padding: 16px 24px; text-align: left; border-bottom: 1px solid var(--border); }
.pricing-table th { background: var(--bg3); color: var(--text2); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; }
.pricing-table tr:last-child td { border-bottom: none; }
.pricing-table .model-name { font-weight: 600; color: var(--text); }
.badge { display: inline-block; padding: 2px 10px; border-radius: 99px; font-size: 0.75rem; font-weight: 600; }
.badge-purple { background: #10b98122; color: #34d399; }
.badge-green { background: #10b98122; color: #34d399; }
.badge-blue { background: #3b82f622; color: #60a5fa; }
.badge-green { background: #10b98122; color: #34d399; }

/* Auth */
.auth-page { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 80px 24px; }
.auth-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 48px; width: 100%; max-width: 420px; }
.auth-card h2 { margin-bottom: 8px; }
.auth-card .subtitle { color: var(--text2); margin-bottom: 32px; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 0.9rem; color: var(--text2); }
.form-group input { width: 100%; padding: 12px 16px; background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; color: var(--text); font-size: 1rem; outline: none; transition: border-color 0.2s; }
.form-group input:focus { border-color: var(--accent); }
.auth-card .btn { width: 100%; justify-content: center; padding: 14px; font-size: 1rem; }
.auth-card .switch { text-align: center; margin-top: 20px; color: var(--text2); font-size: 0.9rem; }
.error-msg { color: var(--danger); font-size: 0.85rem; margin-bottom: 16px; display: none; padding: 10px; background: #ef444422; border-radius: 8px; }
.error-msg.show { display: block; }

/* Dashboard */
.dashboard { padding: 80px 0 40px; }
.dash-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 32px; flex-wrap: wrap; gap: 16px; }
.stat-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin-bottom: 32px; }
.stat-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.stat-card .label { color: var(--text2); font-size: 0.85rem; margin-bottom: 4px; }
.stat-card .value { font-size: 1.8rem; font-weight: 700; }
.stat-card .value.gradient { background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.api-key-box { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; margin-bottom: 32px; }
.api-key-box h3 { margin-bottom: 12px; }
.api-key-row { display: flex; gap: 8px; align-items: center; }
.api-key-row input { flex: 1; padding: 12px; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; color: var(--text); font-family: 'SF Mono', monospace; font-size: 0.9rem; }
.chart-box { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; margin-bottom: 24px; }
.chart-box h3 { margin-bottom: 16px; }
.chart-container { height: 200px; display: flex; align-items: flex-end; gap: 4px; padding-top: 20px; }
.chart-bar { flex: 1; background: var(--gradient); border-radius: 4px 4px 0 0; min-height: 2px; position: relative; transition: all 0.3s; }
.chart-bar:hover { opacity: 0.8; }
.chart-bar .tooltip { position: absolute; bottom: 100%; left: 50%; transform: translateX(-50%); background: var(--bg3); padding: 4px 8px; border-radius: 4px; font-size: 0.7rem; white-space: nowrap; opacity: 0; transition: opacity 0.2s; pointer-events: none; }
.chart-bar:hover .tooltip { opacity: 1; }
.recent-table { width: 100%; border-collapse: collapse; }
.recent-table th, .recent-table td { padding: 10px 16px; text-align: left; border-bottom: 1px solid var(--border); font-size: 0.85rem; }
.recent-table th { color: var(--text2); }

/* Docs */
.docs { padding: 100px 0 60px; }
.docs-layout { display: grid; grid-template-columns: 220px 1fr; gap: 40px; }
.docs-nav { position: sticky; top: 80px; height: fit-content; }
.docs-nav a { display: block; padding: 8px 16px; color: var(--text2); border-left: 2px solid var(--border); margin-bottom: 4px; font-size: 0.9rem; transition: all 0.2s; }
.docs-nav a:hover, .docs-nav a.active { color: var(--text); border-color: var(--accent); text-decoration: none; }
.docs-content h2 { font-size: 1.5rem; margin: 48px 0 16px; padding-top: 16px; }
.docs-content h2:first-child { margin-top: 0; }
.docs-content p { color: var(--text2); margin-bottom: 16px; }
.code-block { background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 20px; margin-bottom: 24px; overflow-x: auto; position: relative; }
.code-block pre { color: #e0e0f0; font-family: 'SF Mono', 'Fira Code', monospace; font-size: 0.85rem; line-height: 1.7; white-space: pre; }
.code-block .lang { position: absolute; top: 8px; right: 12px; font-size: 0.7rem; color: var(--text2); text-transform: uppercase; }
.code-block .copy-btn { position: absolute; top: 8px; right: 60px; background: var(--bg3); border: 1px solid var(--border); color: var(--text2); padding: 4px 10px; border-radius: 4px; font-size: 0.75rem; cursor: pointer; }
.code-block .copy-btn:hover { color: var(--text); }
.endpoint { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; margin-bottom: 24px; }
.endpoint .method { display: inline-block; background: var(--accent); color: #fff; padding: 2px 10px; border-radius: 4px; font-size: 0.8rem; font-weight: 700; margin-right: 8px; }
.endpoint .path { font-family: monospace; font-size: 0.95rem; }

/* Playground */
.playground { padding: 80px 0 20px; height: 100vh; display: flex; flex-direction: column; }
.playground-container { flex: 1; display: flex; flex-direction: column; max-width: 900px; margin: 0 auto; width: 100%; padding: 0 24px; }
.pg-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; flex-wrap: wrap; gap: 8px; }
.pg-model-select { padding: 8px 16px; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; color: var(--text); font-size: 0.9rem; }
.chat-messages { flex: 1; overflow-y: auto; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; margin-bottom: 16px; min-height: 300px; }
.msg { margin-bottom: 16px; }
.msg.user { text-align: right; }
.msg .bubble { display: inline-block; max-width: 80%; padding: 12px 18px; border-radius: 16px; font-size: 0.95rem; line-height: 1.6; text-align: left; white-space: pre-wrap; word-break: break-word; }
.msg.user .bubble { background: var(--gradient); color: #fff; border-bottom-right-radius: 4px; }
.msg.assistant .bubble { background: var(--bg3); color: var(--text); border-bottom-left-radius: 4px; }
.msg .sender { font-size: 0.75rem; color: var(--text2); margin-bottom: 4px; }
.chat-input { display: flex; gap: 8px; }
.chat-input textarea { flex: 1; padding: 14px; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; color: var(--text); font-size: 1rem; resize: none; height: 52px; outline: none; font-family: inherit; }
.chat-input textarea:focus { border-color: var(--accent); }
.chat-input button { padding: 14px 28px; }

/* Footer */
footer { padding: 40px 0; border-top: 1px solid var(--border); text-align: center; color: var(--text2); font-size: 0.85rem; margin-top: 80px; }

/* Page visibility */
.page { display: none; }
.page.active { display: block; }
.page-flex.active { display: flex; }

/* Responsive */
@media (max-width: 768px) {
  .hero h1 { font-size: 2.2rem; }
  .hero p { font-size: 1rem; }
  .hero-buttons { flex-direction: column; align-items: center; }
  .docs-layout { grid-template-columns: 1fr; }
  .docs-nav { display: none; }
  .hamburger { display: block; }
  nav .nav-links { display: none; position: absolute; top: 64px; left: 0; right: 0; background: var(--bg); flex-direction: column; padding: 16px; border-bottom: 1px solid var(--border); }
  nav .nav-links.open { display: flex; }
  .pricing-table { font-size: 0.85rem; }
  .pricing-table th, .pricing-table td { padding: 10px 12px; }
  .dash-header { flex-direction: column; align-items: flex-start; }
  .api-key-row { flex-direction: column; }
}

/* Payment modal */
.amount-btn.active, .token-btn.active {
  background: var(--accent) !important;
  color: #fff !important;
  border-color: var(--accent) !important;
}
.amount-btn:not(.active):hover, .token-btn:not(.active):hover {
  border-color: var(--accent);
}


/* Light / Eye-care Theme */
[data-theme="light"] {
  --bg: #f5f5f0;
  --bg2: #eeeee8;
  --bg3: #e8e8e0;
  --surface: #ffffff;
  --border: #d0d0c8;
  --text: #2a2a2a;
  --text2: #6a6a6a;
  --accent: #0d9668;
  --accent2: #059669;
}
[data-theme="light"] nav {
  background: rgba(245,245,240,0.9);
}
[data-theme="light"] .msg.assistant .bubble {
  background: var(--surface) !important;
}
[data-theme="light"] .msg.user .bubble {
  background: var(--accent) !important;
  color: #fff !important;
}
[data-theme="light"] .stat-card {
  background: var(--surface);
  border-color: var(--border);
}
[data-theme="light"] .chart-box {
  background: var(--surface);
}
[data-theme="light"] .api-key-box {
  background: var(--surface);
}