/* OKX Download Portal — single stylesheet, responsive */
:root {
    --primary: #0d9488;
    --primary-dark: #0f766e;
    --primary-light: #14b8a6;
    --secondary: #1e1b4b;
    --accent: #f59e0b;
    --accent-soft: #fef3c7;
    --surface: #ffffff;
    --surface-2: #f0fdfa;
    --surface-3: #ecfdf5;
    --text: #134e4a;
    --text-muted: #5b7c78;
    --border: #b2e8df;
    --border-strong: #7dd3c7;
    --shadow: 0 2px 12px rgba(13, 148, 136, 0.08);
    --shadow-lg: 0 8px 28px rgba(30, 27, 75, 0.1);
    --radius: 10px;
    --radius-lg: 14px;
    --container: 1120px;
    --nav-h: 64px;
    --card-pad: 1.25rem;
    --section-y: 3.5rem;
    --grid-gap: 1.25rem;
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
    --transition: 0.25s var(--ease);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    scroll-padding-top: calc(var(--nav-h) + 12px);
}

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
    color: var(--text);
    line-height: 1.65;
    background: var(--surface);
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }

ul { list-style: none; }

.container {
    width: 100%;
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 1rem;
}

.section {
    padding: var(--section-y) 0;
    overflow: hidden;
}
.section--alt { background: var(--surface-2); }
.section--dark {
    background: linear-gradient(135deg, var(--secondary) 0%, #312e81 50%, var(--primary-dark) 100%);
    color: #fff;
}

.section-head {
    text-align: center;
    max-width: 640px;
    margin: 0 auto 2rem;
    padding: 0 0.25rem;
}

.section-head h2 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: 0.75rem;
}

.section-head p {
    color: var(--text-muted);
    font-size: 1.05rem;
}

.section--dark .section-head h2,
.section--dark .section-head p { color: rgba(255,255,255,0.95); }
.section--dark .section-head p { opacity: 0.85; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.65rem 1.25rem;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: 999px;
    border: 1px solid transparent;
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
    white-space: nowrap;
    max-width: 100%;
}

.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.btn:active { transform: translateY(0); }

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    border-color: transparent;
}

.btn-primary:hover { color: #fff; }

.btn-light {
    background: #fff;
    color: var(--primary-dark);
    border-color: #fff;
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: #fff;
}

.btn-lg { padding: 0.9rem 1.75rem; font-size: 1rem; }

/* Navigation */
.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.96);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    min-height: var(--nav-h);
    padding-top: max(0.5rem, env(safe-area-inset-top));
    padding-bottom: 0.5rem;
}

.brand {
    flex-shrink: 0;
    min-width: 0;
}

.brand img {
    height: 38px;
    width: auto;
    max-width: min(160px, 42vw);
    object-fit: contain;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    background: none;
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    padding: 0;
}

.nav-toggle span {
    display: block;
    width: 20px;
    height: 2px;
    margin: 0 auto;
    background: var(--secondary);
    border-radius: 2px;
    transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.is-active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.is-active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

.site-nav {
    min-width: 0;
}

.site-nav > .container {
    padding-top: 0;
    padding-bottom: 0;
}

.site-nav ul {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 0.1rem;
}

.site-nav a {
    display: block;
    padding: 0.4rem 0.6rem;
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text);
    border-radius: 6px;
    line-height: 1.3;
}

.site-nav a:hover,
.site-nav .current > a {
    color: var(--primary);
    background: var(--surface-3);
}

body.nav-open {
    overflow: hidden;
}

/* Hero */
.hero {
    position: relative;
    padding: 3rem 0 3.5rem;
    background: linear-gradient(160deg, var(--surface-3) 0%, #fff 45%, var(--surface-2) 100%);
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    top: -40%;
    right: -15%;
    width: 55%;
    height: 120%;
    background: radial-gradient(circle, rgba(13,148,136,0.15) 0%, transparent 70%);
    pointer-events: none;
}

.hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 2rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-copy {
    min-width: 0;
}

.hero-badge {
    display: inline-block;
    padding: 0.35rem 0.9rem;
    background: var(--accent-soft);
    color: #b45309;
    font-size: 0.8rem;
    font-weight: 600;
    border-radius: 999px;
    margin-bottom: 1rem;
}

.hero h1 {
    font-size: clamp(1.85rem, 4.5vw, 2.75rem);
    font-weight: 800;
    line-height: 1.2;
    color: var(--secondary);
    margin-bottom: 1rem;
}

.hero-lead {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    max-width: 100%;
    word-break: break-word;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1.25rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.hero-meta strong { color: var(--primary-dark); }

.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    min-width: 0;
    padding: 0 0.5rem;
}

.hero-visual img {
    width: 100%;
    max-width: 280px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    margin: 0 auto;
}

.hero-card-float {
    position: absolute;
    bottom: 8%;
    right: 5%;
    left: auto;
    max-width: calc(100% - 1rem);
    background: #fff;
    padding: 0.5rem 0.85rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary-dark);
    white-space: nowrap;
}

/* Shared card shell */
.card-shell {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--card-pad);
    min-width: 0;
    height: 100%;
}

/* Feature grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--grid-gap);
    align-items: stretch;
}

.feature-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--card-pad);
    min-width: 0;
    height: 100%;
    display: flex;
    flex-direction: column;
    transition: box-shadow var(--transition), border-color var(--transition);
}

.feature-card:hover {
    border-color: var(--border-strong);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.35rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--secondary);
}

.feature-card p {
    font-size: 0.88rem;
    color: var(--text-muted);
    flex: 1;
    word-break: break-word;
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--grid-gap);
}

.stats-grid > div {
    text-align: center;
    padding: 1.25rem 0.75rem;
    border-radius: var(--radius);
    border: 1px solid rgba(255, 255, 255, 0.15);
    background: rgba(255, 255, 255, 0.06);
    min-width: 0;
}

.stat-num {
    font-size: clamp(1.5rem, 3.5vw, 2.1rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 0.35rem;
    word-break: break-word;
}

.stat-label {
    font-size: 0.88rem;
    opacity: 0.9;
    line-height: 1.35;
}

/* Download */
.download-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--grid-gap);
    align-items: stretch;
}

.download-card {
    background: #fff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    padding: var(--card-pad);
    display: flex;
    flex-direction: column;
    min-width: 0;
    height: 100%;
    transition: box-shadow var(--transition), border-color var(--transition);
}

.download-card:hover { box-shadow: var(--shadow-lg); }

.download-card-head {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 1rem;
    min-width: 0;
}

.download-card-head > div:last-child {
    min-width: 0;
    flex: 1;
}

.download-card-head h3 {
    word-break: break-word;
    line-height: 1.35;
}

.platform-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: #fff;
    flex-shrink: 0;
}

.platform-icon--ios { background: linear-gradient(135deg, #6366f1, #4f46e5); }
.platform-icon--android { background: linear-gradient(135deg, #22c55e, #16a34a); }
.platform-icon--win { background: linear-gradient(135deg, #3b82f6, #2563eb); }

.download-card h3 {
    font-size: 1.05rem;
    color: var(--secondary);
}

.download-card .sub { font-size: 0.85rem; color: var(--text-muted); }

.download-list {
    flex: 1;
    margin-bottom: 1.25rem;
}

.download-list li {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    padding: 0.35rem 0;
}

.download-list li::before {
    content: "✓";
    color: var(--primary);
    font-weight: 700;
    flex-shrink: 0;
}

.download-card .btn {
    width: 100%;
    margin-top: auto;
    white-space: normal;
    text-align: center;
    line-height: 1.35;
    padding: 0.65rem 1rem;
}

/* Guide / intro block */
.guide-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: 2rem;
    align-items: start;
}

.guide-content h2 {
    font-size: 1.65rem;
    color: var(--secondary);
    margin-bottom: 1rem;
}

.guide-content p {
    color: var(--text-muted);
    margin-bottom: 1rem;
    font-size: 0.98rem;
}

.guide-steps {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.guide-step {
    display: flex;
    gap: 0.85rem;
    padding: 1rem;
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    min-width: 0;
}

.guide-step > div:last-child {
    min-width: 0;
    flex: 1;
}

.step-num {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 0.9rem;
}

.guide-step h4 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
    color: var(--secondary);
}

.guide-step p {
    font-size: 0.88rem;
    color: var(--text-muted);
    margin: 0;
}

/* Security */
.security-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--grid-gap);
    align-items: stretch;
}

.security-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: var(--card-pad);
    text-align: center;
    border: 1px solid var(--border);
    min-width: 0;
    height: 100%;
    display: flex;
    flex-direction: column;
    transition: box-shadow var(--transition), border-color var(--transition);
}

.security-card:hover {
    border-color: var(--border-strong);
    box-shadow: var(--shadow);
}

.security-card ul {
    flex: 1;
}

.security-card .icon {
    font-size: 2rem;
    margin-bottom: 0.75rem;
}

.security-card h3 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    color: var(--secondary);
}

.security-card ul { text-align: left; }

.security-card li {
    font-size: 0.85rem;
    color: var(--text-muted);
    padding: 0.3rem 0;
    padding-left: 1.1rem;
    position: relative;
}

.security-card li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--primary);
}

.cert-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--grid-gap);
    margin-top: 2rem;
}

.cert-card {
    background: var(--surface-3);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    padding: 1.15rem;
    text-align: center;
    min-width: 0;
    height: 100%;
}

.cert-card h4 {
    font-size: 0.95rem;
    color: var(--secondary);
    margin: 0.5rem 0 0.35rem;
}

.cert-card p {
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* FAQ */
.faq-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.85rem;
    max-width: 920px;
    margin: 0 auto;
}

.faq-item {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    min-width: 0;
}

.faq-item summary {
    padding: 0.9rem 1rem;
    font-weight: 600;
    font-size: 0.92rem;
    cursor: pointer;
    color: var(--secondary);
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 0.75rem;
    line-height: 1.45;
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
    content: "+";
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 400;
    flex-shrink: 0;
    line-height: 1.4;
    margin-top: 0.05rem;
}

.faq-item[open] summary::after { content: "−"; }

.faq-item p {
    padding: 0 1rem 0.9rem;
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.6;
    word-break: break-word;
}

/* Articles */
.article-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2rem;
}

.article-header h2 {
    font-size: 1.5rem;
    color: var(--secondary);
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--grid-gap);
    align-items: stretch;
}

.article-card {
    background: #fff;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    min-width: 0;
    height: 100%;
    display: flex;
    flex-direction: column;
    transition: box-shadow var(--transition), border-color var(--transition);
}

.article-card:hover { box-shadow: var(--shadow); }

.article-card img {
    width: 100%;
    height: 110px;
    object-fit: cover;
    flex-shrink: 0;
}

.article-card-body {
    padding: 0.75rem;
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.article-card .meta {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 0.4rem;
}

.article-card h3 {
    font-size: 0.88rem;
    font-weight: 600;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    word-break: break-word;
}

.article-card h3 a { color: var(--secondary); }
.article-card h3 a:hover { color: var(--primary); }

/* Footer */
.site-footer {
    background: var(--secondary);
    color: rgba(255,255,255,0.85);
    padding: 3.5rem 0 1.5rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.4fr) repeat(3, minmax(0, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.footer-grid--links {
    margin-bottom: 1.25rem;
    padding-top: 0.25rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-grid--links .footer-col {
    grid-column: 1 / -1;
}

.site-footer .brand img { filter: brightness(0) invert(1); opacity: 0.95; }

.site-footer p {
    font-size: 0.9rem;
    margin-top: 1rem;
    line-height: 1.6;
    opacity: 0.8;
}

.footer-col h5 {
    font-size: 0.95rem;
    margin-bottom: 1rem;
    color: #fff;
}

.footer-col a {
    display: block;
    color: rgba(255,255,255,0.7);
    font-size: 0.88rem;
    padding: 0.25rem 0;
}

.footer-col a:hover { color: var(--primary-light); }

.friend-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
    padding: 0;
}

.friend-links li a {
    color: rgba(255,255,255,0.65);
    font-size: 0.85rem;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.12);
    padding-top: 1.5rem;
    text-align: center;
    font-size: 0.85rem;
    opacity: 0.75;
}

.footer-bottom p { margin-bottom: 0.35rem; }
.footer-bottom a { color: rgba(255,255,255,0.8); }

/* Inner pages */
.page-main {
    padding: 2.5rem 0 4rem;
    background: var(--surface-2);
    min-height: calc(100vh - var(--nav-h) - 120px);
}

.page-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(260px, 300px);
    gap: 1.5rem;
    align-items: start;
}

.page-card {
    background: #fff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    padding: var(--card-pad);
    box-shadow: var(--shadow);
    min-width: 0;
    overflow: hidden;
}

.page-title {
    font-size: 1.5rem;
    color: var(--secondary);
    margin-bottom: 0.5rem;
}

.page-desc {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
}

.list-item {
    display: grid;
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 1rem;
    padding-bottom: 1.25rem;
    margin-bottom: 1.25rem;
    border-bottom: 1px solid var(--border);
    min-width: 0;
}

.list-item > div {
    min-width: 0;
}

.list-item:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.list-item img {
    width: 100%;
    height: 84px;
    object-fit: cover;
    border-radius: var(--radius);
}

.list-item .meta {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.35rem;
}

.list-item h2 {
    font-size: 1.05rem;
    margin-bottom: 0.35rem;
}

.list-item h2 a { color: var(--secondary); font-weight: 600; }
.list-item p { font-size: 0.9rem; color: var(--text-muted); }

.sidebar-card {
    background: #fff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    padding: 1.25rem;
    margin-bottom: 1.25rem;
    min-width: 0;
    overflow: hidden;
}

.sidebar-card h3 {
    font-size: 1rem;
    margin-bottom: 1rem;
    color: var(--secondary);
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary);
}

.sidebar-card li { margin-bottom: 0.5rem; }
.sidebar-card li a { font-size: 0.9rem; color: var(--text); }
.sidebar-card li.current a { color: var(--primary); font-weight: 600; }

.hot-item {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 0.85rem;
    align-items: flex-start;
}

.hot-item img {
    width: 72px;
    height: 54px;
    object-fit: cover;
    border-radius: 8px;
    flex-shrink: 0;
}

.hot-item a {
    font-size: 0.88rem;
    color: var(--text);
    line-height: 1.4;
    min-width: 0;
    word-break: break-word;
}

.hot-item:last-child {
    margin-bottom: 0;
}

.article-header .btn {
    white-space: normal;
    text-align: center;
}

.article-detail h1 {
    font-size: 1.45rem;
    color: var(--secondary);
    margin-bottom: 0.75rem;
}

.article-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border);
}

.article-cover {
    max-width: 100%;
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    max-height: 320px;
    object-fit: cover;
}

.article-content {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text);
}

.article-content img { margin: 1rem auto; border-radius: var(--radius); }

.meta-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.meta-tags a {
    padding: 0.25rem 0.75rem;
    background: var(--surface-3);
    border-radius: 999px;
    font-size: 0.82rem;
}

.prenext {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.related-list .list-item { grid-template-columns: 100px minmax(0, 1fr); }

.pagebar { margin-top: 1.5rem; }

.pagelist {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    list-style: none;
    padding: 0;
}

.pagelist li { display: inline-flex; }

.pagelist a,
.pagelist span {
    display: inline-block;
    padding: 0.4rem 0.85rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    font-size: 0.9rem;
    color: var(--text);
}

.pagelist a:hover,
.pagelist .thisclass span {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* Desktop header: logo + nav one row */
@media (min-width: 769px) {
    .site-header {
        display: flex;
        align-items: center;
        flex-wrap: nowrap;
    }

    .header-bar {
        flex: 0 0 auto;
        min-height: var(--nav-h);
        padding-top: 0.5rem;
        padding-bottom: 0.5rem;
    }

    .nav-toggle {
        display: none !important;
    }

    .site-nav {
        flex: 1;
        min-width: 0;
        position: static;
        max-height: none !important;
        overflow: visible !important;
        border: none;
        box-shadow: none;
    }

    .site-nav > .container {
        display: flex;
        justify-content: flex-end;
        max-width: none;
        width: 100%;
        padding-right: 1rem;
        padding-left: 0.5rem;
    }
}

/* Responsive */
@media (max-width: 1100px) {
    .site-nav a {
        padding: 0.35rem 0.5rem;
        font-size: 0.78rem;
    }
}

@media (max-width: 1024px) {
    :root {
        --section-y: 3rem;
        --grid-gap: 1rem;
    }

    .feature-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .download-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .download-grid .download-card:last-child {
        grid-column: 1 / -1;
        max-width: 480px;
        margin: 0 auto;
        width: 100%;
    }
    .security-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .article-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .guide-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    :root {
        --section-y: 2.5rem;
        --card-pad: 1rem;
        --nav-h: 52px;
    }

    html {
        scroll-padding-top: calc(var(--nav-h) + 8px);
    }

    .site-header {
        position: sticky;
    }

    .nav-toggle {
        display: flex;
    }

    .site-nav {
        position: absolute;
        z-index: 999;
        top: 100%;
        left: 0;
        right: 0;
        width: 100%;
        background: #fff;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-lg);
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s var(--ease);
        -webkit-overflow-scrolling: touch;
    }

    .site-nav.is-open {
        max-height: min(75vh, 520px);
        overflow-y: auto;
    }

    .site-nav > .container {
        padding: 0;
    }

    .site-nav ul {
        flex-direction: column;
        align-items: stretch;
        justify-content: flex-start;
        gap: 0;
        padding: 0.5rem 0 0.75rem;
    }

    .site-nav li {
        border-bottom: 1px solid var(--surface-2);
    }

    .site-nav li:last-child {
        border-bottom: none;
    }

    .site-nav a {
        padding: 0.85rem 1rem;
        font-size: 0.95rem;
        min-height: 44px;
        display: flex;
        align-items: center;
    }

    .section-head {
        margin-bottom: 1.5rem;
    }

    .section-head h2 {
        font-size: 1.35rem;
    }

    .section-head p {
        font-size: 0.92rem;
        line-height: 1.55;
    }

    .hero {
        padding: 1.5rem 0 2rem;
    }

    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 1.25rem;
    }

    .hero h1 {
        font-size: clamp(1.5rem, 6vw, 1.85rem);
        word-break: break-word;
    }

    .hero-lead {
        font-size: 0.92rem;
        line-height: 1.6;
        margin-bottom: 1.25rem;
    }

    .hero-badge {
        font-size: 0.75rem;
        max-width: 100%;
    }

    .hero-actions {
        flex-direction: column;
        align-items: stretch;
        width: 100%;
        gap: 0.65rem;
    }

    .hero-actions .btn {
        width: 100%;
        white-space: normal;
        line-height: 1.35;
        padding: 0.75rem 1rem;
    }

    .hero-meta {
        flex-direction: column;
        align-items: center;
        gap: 0.5rem;
        font-size: 0.82rem;
    }

    .hero-visual {
        order: -1;
        padding: 0;
    }

    .hero-visual img {
        max-width: min(240px, 72vw);
    }

    .hero-card-float {
        display: none;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 0.75rem;
    }

    .stats-grid > div {
        padding: 0.85rem 0.5rem;
    }

    .stat-num {
        font-size: 1.5rem;
    }

    .stat-label {
        font-size: 0.8rem;
    }

    .download-grid {
        grid-template-columns: 1fr;
    }

    .download-grid .download-card:last-child {
        grid-column: auto;
        max-width: none;
        margin: 0;
    }

    .guide-grid {
        gap: 1.5rem;
    }

    .guide-content h2 {
        font-size: 1.35rem;
        text-align: center;
    }

    .guide-content p {
        font-size: 0.9rem;
    }

    .security-grid,
    .cert-grid {
        grid-template-columns: 1fr;
    }

    .faq-grid {
        grid-template-columns: 1fr;
        max-width: none;
        gap: 0.65rem;
    }

    .article-header {
        flex-direction: column;
        align-items: stretch;
        gap: 0.75rem;
        margin-bottom: 1.25rem;
    }

    .article-header h2 {
        font-size: 1.25rem;
    }

    .article-header .btn {
        width: 100%;
    }

    .article-grid {
        grid-template-columns: 1fr;
        gap: 0.85rem;
    }

    .article-card img {
        height: 140px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }

    .site-footer {
        padding: 2.5rem 0 1.25rem;
        padding-bottom: max(1.25rem, env(safe-area-inset-bottom));
    }

    .page-main {
        padding: 1.5rem 0 2.5rem;
    }

    .page-title {
        font-size: 1.25rem;
        word-break: break-word;
    }

    .page-desc {
        font-size: 0.88rem;
        margin-bottom: 1rem;
    }

    .page-layout {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }

    .page-card {
        padding: 1rem;
    }

    .list-item {
        grid-template-columns: 96px minmax(0, 1fr);
        gap: 0.75rem;
        padding-bottom: 1rem;
        margin-bottom: 1rem;
    }

    .list-item img {
        height: 72px;
    }

    .list-item h2 {
        font-size: 0.95rem;
    }

    .list-item p {
        font-size: 0.85rem;
        display: -webkit-box;
        -webkit-line-clamp: 3;
        -webkit-box-orient: vertical;
        overflow: hidden;
    }

    .article-detail h1 {
        font-size: 1.2rem;
        word-break: break-word;
    }

    .article-meta {
        flex-direction: column;
        gap: 0.35rem;
        font-size: 0.8rem;
    }

    .article-cover {
        max-height: 200px;
        width: 100%;
    }

    .article-content {
        font-size: 0.95rem;
        overflow-wrap: anywhere;
    }

    .article-content img {
        max-width: 100% !important;
        height: auto !important;
    }

    .pagelist a,
    .pagelist span {
        padding: 0.35rem 0.65rem;
        font-size: 0.85rem;
    }

    .hot-item img {
        width: 64px;
        height: 48px;
    }

    .hot-item a {
        font-size: 0.85rem;
    }
}

@media (max-width: 480px) {
    :root {
        --section-y: 2rem;
        --nav-h: 50px;
    }

    .container {
        padding-left: max(0.85rem, env(safe-area-inset-left));
        padding-right: max(0.85rem, env(safe-area-inset-right));
    }

    .brand img {
        height: 34px;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .list-item {
        grid-template-columns: 1fr;
    }

    .list-item img {
        height: 160px;
    }

    .related-list .list-item {
        grid-template-columns: 88px minmax(0, 1fr);
    }

    .related-list .list-item img {
        height: 68px;
    }

    .btn-lg {
        padding: 0.7rem 1rem;
        font-size: 0.88rem;
    }
}

@media (max-width: 768px) and (min-width: 481px) {
    .feature-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .article-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}