:root {
    --bg: #0f1117;
    --bg-secondary: #161822;
    --bg-card: #1c1e2e;
    --border: #2a2d3e;
    --text: #e4e6f0;
    --text-secondary: #8b8fa3;
    --accent: #6c5ce7;
    --accent-light: #a29bfe;
    --accent-glow: rgba(108, 92, 231, 0.12);
    --success: #00cec9;
    --warning: #fdcb6e;
    --provider-openai: #10a37f;
    --provider-anthropic: #d4a574;
    --provider-google: #4285f4;
    --provider-deepseek: #4d6bfe;
    --provider-kimi: #6366f1;
    --provider-qwen: #ff6a00;
    --provider-zhipu: #2563eb;
    --provider-doubao: #ff4757;
    --provider-minimax: #00d2ff;
    --info-bg: rgba(108, 92, 231, 0.1);
    --info-border: rgba(108, 92, 231, 0.25);
    --radius: 12px;
    --shadow: 0 4px 24px rgba(0,0,0,0.3);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "Noto Sans TC", "Noto Sans JP", "Noto Sans KR", "Noto Sans Bengali", "Noto Sans Devanagari", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.8;
    min-height: 100vh;
}

/* Header */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: 0 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(20px);
}

.header-inner {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text);
    font-weight: 700;
    font-size: 1.2rem;
}

.logo-icon {
    font-size: 1.6rem;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.lang-switcher {
    position: relative;
}

.lang-btn {
    padding: 7px 14px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    cursor: pointer;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.lang-btn:hover { border-color: var(--accent); }

.lang-dropdown {
    display: none;
    position: absolute;
    right: 0;
    top: 42px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    min-width: 200px;
    box-shadow: var(--shadow);
    z-index: 200;
    max-height: 400px;
    overflow-y: auto;
}

.lang-dropdown.show { display: block; }

.lang-dropdown a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.88rem;
    transition: all 0.15s;
}

.lang-dropdown a:hover {
    background: var(--accent-glow);
    color: var(--text);
}

.lang-dropdown a.active {
    color: var(--accent-light);
    font-weight: 600;
}

.search-box {
    position: relative;
    width: 300px;
}

.search-box input {
    width: 100%;
    padding: 9px 14px 9px 38px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 0.88rem;
    outline: none;
    transition: all 0.3s;
}

.search-box input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.search-box input::placeholder { color: var(--text-secondary); }

.search-box::before {
    content: "\1F50D";
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 0.85rem;
}

/* Layout */
.layout {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 250px 1fr 220px;
    gap: 0;
    min-height: calc(100vh - 64px);
}

/* Sidebar */
.sidebar {
    border-right: 1px solid var(--border);
    padding: 20px 0;
    position: sticky;
    top: 64px;
    height: calc(100vh - 64px);
    overflow-y: auto;
}

.sidebar-title {
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-secondary);
    padding: 0 20px;
    margin: 16px 0 6px;
}

.sidebar-title:first-child { margin-top: 0; }

.nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 20px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.88rem;
    cursor: pointer;
    transition: all 0.15s;
    border-left: 3px solid transparent;
}

.nav-item:hover {
    background: var(--accent-glow);
    color: var(--text);
}

.nav-item.active {
    color: var(--accent-light);
    background: var(--accent-glow);
    border-left-color: var(--accent);
    font-weight: 500;
}

.nav-icon { font-size: 1rem; width: 22px; text-align: center; }

/* Main Content */
.main {
    padding: 28px 44px;
    min-width: 0;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.83rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.breadcrumb a { color: var(--text-secondary); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent-light); }

.page-title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--text), var(--accent-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.page-subtitle {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 28px;
    line-height: 1.7;
}

.content-section { display: none; }
.content-section.active { display: block; }

/* Article blocks */
.article {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    margin-bottom: 20px;
    animation: fadeIn 0.35s ease;
}

.article h2 {
    font-size: 1.35rem;
    margin-bottom: 16px;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 10px;
}

.article h3 {
    font-size: 1.05rem;
    margin: 22px 0 10px;
    color: var(--accent-light);
}

.article p {
    color: var(--text-secondary);
    margin-bottom: 14px;
    line-height: 1.85;
}

.article ul, .article ol {
    margin: 10px 0;
    padding-left: 22px;
    color: var(--text-secondary);
}

.article li { margin-bottom: 8px; line-height: 1.7; }

.article strong { color: var(--text); }

.article code {
    background: var(--bg);
    padding: 2px 7px;
    border-radius: 4px;
    font-size: 0.86em;
    color: var(--accent-light);
    font-family: "JetBrains Mono", "Fira Code", "SF Mono", monospace;
}

.article pre {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 18px;
    overflow-x: auto;
    margin: 14px 0;
    position: relative;
}

.article pre code {
    background: none;
    padding: 0;
    color: #c9d1d9;
    font-size: 0.88em;
    line-height: 1.6;
}

/* Copy button */
.copy-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    padding: 4px 10px;
    background: var(--border);
    border: none;
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.75rem;
    opacity: 0;
    transition: all 0.2s;
}

.article pre:hover .copy-btn { opacity: 1; }
.copy-btn:hover { background: var(--accent); color: white; }

/* Callouts */
.callout {
    padding: 16px 18px;
    border-radius: 8px;
    margin: 18px 0;
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

.callout-tip {
    background: rgba(0, 206, 201, 0.08);
    border: 1px solid rgba(0, 206, 201, 0.2);
}

.callout-warn {
    background: rgba(253, 203, 110, 0.08);
    border: 1px solid rgba(253, 203, 110, 0.2);
}

.callout-info {
    background: var(--info-bg);
    border: 1px solid var(--info-border);
}

.callout-danger {
    background: rgba(231, 76, 60, 0.08);
    border: 1px solid rgba(231, 76, 60, 0.2);
}

.callout-icon { font-size: 1.15rem; flex-shrink: 0; margin-top: 2px; }
.callout-text { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.65; }

/* Step cards */
.step {
    display: flex;
    gap: 18px;
    margin: 20px 0;
    padding: 22px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    transition: all 0.2s;
}

.step:hover { border-color: var(--accent); }

.step-num {
    width: 42px;
    height: 42px;
    background: linear-gradient(135deg, var(--accent), var(--accent-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1.1rem;
    color: white;
    flex-shrink: 0;
}

.step-content { flex: 1; }
.step-content h4 { margin-bottom: 6px; font-size: 1rem; color: var(--text); }
.step-content p { margin-bottom: 8px; font-size: 0.9rem; color: var(--text-secondary); }

/* Home cards grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
    margin-top: 20px;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px;
    cursor: pointer;
    transition: all 0.25s;
}

.card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.card-icon { font-size: 1.8rem; margin-bottom: 10px; }
.card h3 { font-size: 1rem; margin-bottom: 6px; color: var(--text); }
.card p { font-size: 0.83rem; color: var(--text-secondary); line-height: 1.6; }

.card-tag {
    display: inline-block;
    padding: 2px 10px;
    background: var(--accent-glow);
    color: var(--accent-light);
    border-radius: 20px;
    font-size: 0.72rem;
    margin-top: 10px;
}

/* TOC */
.toc {
    border-left: 1px solid var(--border);
    padding: 20px;
    position: sticky;
    top: 64px;
    height: calc(100vh - 64px);
    overflow-y: auto;
}

.toc-title {
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-secondary);
    margin-bottom: 14px;
}

.toc-link {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 4px 0 4px 12px;
    border-left: 2px solid transparent;
    transition: all 0.15s;
}

.toc-link:hover { color: var(--text); }
.toc-link.active { color: var(--accent-light); border-left-color: var(--accent); }
.toc-link.sub { padding-left: 24px; font-size: 0.78rem; }

/* Stats */
.stats-bar { display: flex; gap: 16px; margin-bottom: 28px; flex-wrap: wrap; }
.stat-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 18px 24px;
    flex: 1;
    min-width: 120px;
    text-align: center;
}
.stat-number { font-size: 1.6rem; font-weight: 800; color: var(--accent-light); }
.stat-label { font-size: 0.78rem; color: var(--text-secondary); margin-top: 2px; }

/* Platform tabs */
.platform-tabs {
    display: flex;
    gap: 0;
    margin-bottom: 0;
    border-bottom: 1px solid var(--border);
}

.platform-tab {
    padding: 10px 20px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.88rem;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

.platform-tab:hover { color: var(--text); }
.platform-tab.active { color: var(--accent-light); border-bottom-color: var(--accent); }

.platform-content { display: none; padding-top: 16px; }
.platform-content.active { display: block; }

/* FAQ accordion */
.faq-item {
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 10px;
    overflow: hidden;
}

.faq-q {
    padding: 16px 20px;
    background: var(--bg-card);
    cursor: pointer;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.2s;
}

.faq-q:hover { background: var(--accent-glow); }
.faq-q::after { content: "+"; font-size: 1.2rem; color: var(--text-secondary); transition: transform 0.2s; }
.faq-item.open .faq-q::after { content: "-"; }

.faq-a {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s;
    color: var(--text-secondary);
    line-height: 1.8;
}

.faq-item.open .faq-a {
    padding: 16px 20px;
    max-height: 800px;
}

/* Footer */
.footer {
    text-align: center;
    padding: 28px;
    color: var(--text-secondary);
    font-size: 0.78rem;
    border-top: 1px solid var(--border);
    margin-top: 40px;
}

.footer a { color: var(--accent-light); text-decoration: none; }
.footer a:hover { text-decoration: underline; }

/* Mobile */
@media (max-width: 1024px) {
    .layout { grid-template-columns: 1fr; }
    .sidebar, .toc { display: none; }
    .main { padding: 20px 16px; }
    .search-box { width: 160px; }
    .header-inner { gap: 8px; }
    .stats-bar { flex-direction: column; }
    .cards-grid { grid-template-columns: 1fr; }
}

/* Mobile menu toggle */
.mobile-menu-btn {
    display: none;
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 6px 10px;
    color: var(--text);
    cursor: pointer;
    font-size: 1.2rem;
}

@media (max-width: 1024px) {
    .mobile-menu-btn { display: block; }
    .sidebar.mobile-open {
        display: block;
        position: fixed;
        top: 64px;
        left: 0;
        width: 280px;
        height: calc(100vh - 64px);
        background: var(--bg-secondary);
        z-index: 150;
        box-shadow: var(--shadow);
    }
}

/* Scrollbar */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* Provider badge */
.provider-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 14px;
    border-radius: 20px;
    font-size: 0.82rem;
    font-weight: 600;
    color: white;
}
.provider-badge.openai { background: var(--provider-openai); }
.provider-badge.anthropic { background: var(--provider-anthropic); }
.provider-badge.google { background: var(--provider-google); }
.provider-badge.deepseek { background: var(--provider-deepseek); }
.provider-badge.kimi { background: var(--provider-kimi); }
.provider-badge.qwen { background: var(--provider-qwen); }
.provider-badge.zhipu { background: var(--provider-zhipu); }
.provider-badge.doubao { background: var(--provider-doubao); }
.provider-badge.minimax { background: var(--provider-minimax); }

/* Env block — for showing config JSON / env variables */
.env-block {
    background: #0d1117;
    border: 1px solid #30363d;
    border-radius: 8px;
    padding: 18px;
    margin: 14px 0;
    font-family: "JetBrains Mono", "Fira Code", "SF Mono", monospace;
    font-size: 0.85em;
    color: #c9d1d9;
    line-height: 1.6;
    overflow-x: auto;
    position: relative;
}
.env-block .key { color: #79c0ff; }
.env-block .val { color: #a5d6ff; }
.env-block .str { color: #a5d6ff; }
.env-block .comment { color: #8b949e; font-style: italic; }
.env-block .highlight { background: rgba(108, 92, 231, 0.2); padding: 1px 4px; border-radius: 3px; }

/* Pricing / comparison table */
.compare-table {
    width: 100%;
    border-collapse: collapse;
    margin: 18px 0;
    font-size: 0.88rem;
}
.compare-table th {
    background: var(--bg);
    padding: 12px 16px;
    text-align: left;
    font-weight: 700;
    color: var(--text);
    border-bottom: 2px solid var(--accent);
    white-space: nowrap;
}
.compare-table td {
    padding: 10px 16px;
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
}
.compare-table tr:hover td { background: var(--accent-glow); }
.compare-table .check { color: var(--success); font-weight: 700; }
.compare-table .cross { color: #ef4444; }
.compare-table .price { color: var(--accent-light); font-weight: 600; }

/* Quick-select cards (for quickstart page) */
.quick-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 14px;
    margin: 18px 0;
}
.quick-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 18px;
    text-decoration: none;
    transition: all 0.25s;
    display: block;
}
.quick-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}
.quick-card .qc-icon { font-size: 1.5rem; margin-bottom: 8px; }
.quick-card .qc-name { font-weight: 700; color: var(--text); font-size: 0.95rem; margin-bottom: 4px; }
.quick-card .qc-desc { font-size: 0.8rem; color: var(--text-secondary); line-height: 1.5; }
.quick-card .qc-tag {
    display: inline-block;
    margin-top: 8px;
    padding: 2px 10px;
    border-radius: 20px;
    font-size: 0.7rem;
    font-weight: 600;
}
.qc-tag.free { background: rgba(0,206,201,0.15); color: var(--success); }
.qc-tag.paid { background: rgba(108,92,231,0.15); color: var(--accent-light); }
.qc-tag.china { background: rgba(255,107,107,0.15); color: #ff6b6b; }

/* Inline key display */
.key-display {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 6px 14px;
    font-family: "JetBrains Mono", monospace;
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin: 4px 0;
}
.key-display .mask { letter-spacing: 2px; }

/* Tip box */
.tip-box {
    background: linear-gradient(135deg, rgba(108, 92, 231, 0.08), rgba(162, 155, 254, 0.05));
    border: 1px solid rgba(108, 92, 231, 0.25);
    border-radius: 10px;
    padding: 18px 22px;
    margin: 18px 0;
}
.tip-box h4 { color: var(--accent-light); margin-bottom: 8px; font-size: 0.95rem; }
.tip-box p { color: var(--text-secondary); font-size: 0.88rem; line-height: 1.7; margin: 0; }

/* Provider header card */
.provider-header {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 24px;
}
.provider-header .ph-icon { font-size: 2.8rem; }
.provider-header .ph-info { flex: 1; }
.provider-header .ph-name { font-size: 1.5rem; font-weight: 800; color: var(--text); }
.provider-header .ph-meta { display: flex; gap: 16px; margin-top: 6px; flex-wrap: wrap; }
.provider-header .ph-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 12px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.78rem;
    color: var(--text-secondary);
}

/* Cross-link box */
.cross-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    text-decoration: none;
    margin: 12px 0;
    transition: all 0.2s;
}
.cross-link:hover { border-color: var(--accent); background: var(--accent-glow); }
.cross-link .cl-icon { font-size: 1.3rem; }
.cross-link .cl-text { font-size: 0.88rem; color: var(--text-secondary); }
.cross-link .cl-text strong { color: var(--text); }
.cross-link .cl-arrow { margin-left: auto; color: var(--text-secondary); }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}