:root {
    --bg: #0c1220;
    --bg-2: #101b2d;
    --panel: rgba(255, 255, 255, 0.06);
    --panel-strong: rgba(255, 255, 255, 0.12);
    --border: rgba(255, 255, 255, 0.08);
    --accent: #3bd1c3;
    --accent-2: #7ad3ff;
    --text: #e9f1ff;
    --muted: #a8b6cc;
    --danger: #ff6b6b;
    --warn: #f6b73c;
    --success: #6ee7b7;
    --shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
    --radius: 18px;
    --radius-sm: 12px;
    --max-w: 1200px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: 'Noto Sans SC', 'Space Grotesk', system-ui, -apple-system, sans-serif;
    color: var(--text);
    background: radial-gradient(120% 120% at 10% 10%, rgba(59, 209, 195, 0.08), transparent),
        radial-gradient(120% 120% at 90% 0%, rgba(122, 211, 255, 0.1), transparent),
        linear-gradient(145deg, var(--bg), var(--bg-2));
    padding: 0 18px 64px;
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
}

h2 {
    font-weight: 700;
    color: #f6b73c
}

h3 {
    font-weight: 600;
    color: #21bb0c
}

h4 {
    font-family: 'Space Grotesk', 'Noto Sans SC', sans-serif;
    margin: 0;
}

.container {
    max-width: var(--max-w);
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero {
    padding: 52px 0 28px;
    display: grid;
    gap: 18px;
}

.eyebrow {
    color: var(--accent);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    font-weight: 600;
    font-size: 13px;
}

.title {
    font-size: clamp(28px, 4vw, 44px);
    line-height: 1.2;
}

.lede {
    color: var(--muted);
    max-width: 760px;
    font-size: 16px;
    line-height: 1.65;
}

.hero-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    align-items: center;
}

.btn {
    padding: 11px 18px;
    border-radius: 999px;
    font-weight: 600;
    border: 1px solid var(--border);
    background: var(--panel);
    color: var(--text);
    box-shadow: var(--shadow);
    transition: transform 0.12s ease, box-shadow 0.12s ease, border-color 0.12s ease;
}

.btn:hover {
    transform: translateY(-1px);
    border-color: var(--accent);
    box-shadow: 0 14px 36px rgba(59, 209, 195, 0.25);
}

.btn.primary {
    background: linear-gradient(120deg, var(--accent), var(--accent-2));
    color: #031521;
    border: none;
}

.meta-badges {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-top: 4px;
}

.badge {
    padding: 6px 10px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--panel);
    color: var(--muted);
    font-size: 13px;
}

.toc {
    position: sticky;
    top: 0;
    width: 100vw;
    margin-left: calc(50% - 50vw);
    background: var(--panel);
    border-bottom: 1px solid var(--border);
    border-radius: 0;
    padding: 10px 16px;
    backdrop-filter: blur(10px);
    margin-bottom: 18px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
    z-index: 5;
    position: sticky;
}

.nav-btn {
    font: inherit;
    cursor: pointer;
}

.nav-left {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
}

.nav-logo {
    height: 36px;
    width: 36px;
    object-fit: contain;
}

.nav-brand-label {
    font-family: 'Ma Shan Zheng', 'Pacifico', cursive;
    font-weight: 400;
    letter-spacing: 0.12em;
    color: #07efbd;
    font-size: 30px;
    padding: 2px 0;
    text-transform: none;
    background: none;
    border: none;
    box-shadow: none;
    flex-shrink: 0;
}

.nav-group {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
    margin: 0 auto;
}

.toc .nav-btn {
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    background: var(--panel-strong);
    color: var(--text);
    border: 1px solid var(--accent);
    transition: background 0.16s ease, color 0.16s ease, border-color 0.16s ease, box-shadow 0.16s ease;
}

.toc .nav-btn:hover,
.toc .nav-btn.active {
    background: linear-gradient(120deg, var(--accent), var(--accent-2));
    color: #031521;
    border-color: transparent;
    box-shadow: 0 10px 30px rgba(59, 209, 195, 0.35);
    font-weight: 700;
}

section {
    margin-bottom: 28px;
}

.card {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 18px 20px;
    box-shadow: var(--shadow);
    backdrop-filter: blur(10px);
}

.section-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
}

.section-title {
    font-size: 20px;
}

.section-desc {
    color: var(--muted);
    font-size: 14px;
    margin-top: 4px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 14px;
}

.pill {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 10px;
    background: var(--panel-strong);
    border-radius: 999px;
    font-size: 13px;
    color: var(--text);
    border: 1px solid var(--border);
}

.pill.warn {
    color: var(--warn);
    border-color: rgba(246, 183, 60, 0.4);
}

.pill.danger {
    color: var(--danger);
    border-color: rgba(255, 107, 107, 0.45);
}

.pill.success {
    color: var(--success);
    border-color: rgba(110, 231, 183, 0.4);
}

.step-list {
    counter-reset: step;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 12px;
}

.step {
    position: relative;
    padding-left: 52px;
    min-height: 80px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 14px 14px 52px;
}

.step::before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 16px;
    top: 14px;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    color: #031521;
    font-weight: 700;
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
}

.step h4 {
    margin: 0 0 6px;
    font-size: 16px;
}

.step p {
    margin: 0;
    color: var(--muted);
    line-height: 1.55;
}

.logic-flow {
    display: grid;
    gap: 12px;
}

.logic-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 10px;
    align-items: stretch;
}

.logic-node {
    position: relative;
    padding: 14px;
    border-radius: var(--radius);
    background: var(--panel);
    border: 1px solid var(--border);
}

.logic-node h4 {
    margin: 0 0 6px;
}

.logic-node p {
    margin: 0;
    color: var(--muted);
    line-height: 1.5;
}

.logic-node .tag {
    font-size: 12px;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.logic-connector {
    text-align: center;
    color: var(--muted);
    font-size: 14px;
}

.two-col {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 14px;
}

.list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 10px;
}

.list li {
    padding: 12px 12px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--muted);
    line-height: 1.55;
}

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

.table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

.table th,
.table td {
    padding: 10px 12px;
    border-bottom: 1px solid var(--border);
    text-align: left;
}

.table th {
    color: var(--muted);
    font-weight: 600;
}

.table tr:hover td {
    background: var(--panel-strong);
}

.alert {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--panel-strong);
    color: var(--muted);
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 12px;
}

.footer {
    margin-top: 28px;
    padding: 16px;
    text-align: center;
    color: var(--muted);
    font-size: 13px;
    border: 1px solid var(--border);
    background: var(--panel);
    border-radius: var(--radius-sm);
}

.backtop {
    position: fixed;
    right: 18px;
    bottom: 18px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--panel);
    color: var(--text);
    display: grid;
    place-items: center;
    box-shadow: var(--shadow);
    cursor: pointer;
    opacity: 0.9;
}

.backtop:hover {
    background: var(--panel-strong);
}

.mt-12 {
    margin-top: 12px;
}

.scroll-x {
    overflow-x: auto;
}

.list-ordered {
    counter-reset: item;
    list-style: none;
}

.view-section {
    display: none;
    opacity: 0;
    transform: translateY(8px);
}

.view-section.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

.view-section.fade-in {
    animation: fadeInUp 0.32s ease;
}

.step-flow {
    position: relative;
    display: grid;
    gap: 24px;
    padding: 10px 0;
}

.flow-item {
    display: grid;
    grid-template-columns: 180px 1fr;
    align-items: center;
    gap: 16px;
    padding: 16px 18px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
    position: relative;
    transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.flow-title {
    font-weight: 700;
    color: var(--accent);
}

.flow-desc {
    color: var(--muted);
    line-height: 1.55;
    font-size: 14px;
    text-align: center;
}

.flow-item:hover,
.flow-item:focus-within {
    transform: translateY(-4px) scale(1.1);
    border-color: var(--accent);
    box-shadow: 0 22px 44px rgba(59, 209, 195, 0.28);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 640px) {
    .hero {
        padding-top: 34px;
    }

    .toc {
        position: relative;
        top: 0;
        padding-left: 60px;
    }

    .nav-left {
        left: 10px;
        padding: 4px 8px;
    }

    .step {
        padding-left: 46px;
    }

    .step::before {
        left: 12px;
    }
}