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

:root {
    --primary: #1976d2;
    --primary-dark: #1565c0;
    --primary-light: #e3f2fd;
    --accent: #ff6b35;
    --bg: #ffffff;
    --bg-alt: #f5f8fc;
    --text: #1a237e;
    --text-body: #37474f;
    --text-muted: #607d8b;
    --border: #e3eaf2;
    --shadow: 0 8px 32px rgba(25, 118, 210, 0.12);
    --radius: 12px;
    --max: 1140px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Microsoft YaHei UI", "PingFang SC", "Segoe UI", sans-serif;
    color: var(--text-body);
    line-height: 1.65;
    background: var(--bg);
}

.container {
    max-width: var(--max);
    margin: 0 auto;
    padding: 0 24px;
}

/* Top bar */
.top-bar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(8px);
}

.top-bar-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text);
    font-weight: 700;
    font-size: 1.125rem;
}

.brand-icon {
    width: 36px;
    height: 36px;
    border-radius: 8px;
}

.top-nav {
    display: flex;
    gap: 12px;
    align-items: center;
}

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
    padding: 6px 4px;
    transition: color 0.15s;
}

.nav-link:hover {
    color: var(--primary);
}

/* Download section */
.download-box {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 32px;
    align-items: center;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
}

.download-table {
    width: 100%;
    border-collapse: collapse;
}

.download-table th,
.download-table td {
    padding: 10px 0;
    text-align: left;
    vertical-align: top;
    border-bottom: 1px solid var(--border);
}

.download-table tr:last-child th,
.download-table tr:last-child td {
    border-bottom: none;
}

.download-table th {
    width: 120px;
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.875rem;
}

.download-table code {
    background: #e8eef5;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.875rem;
}

.download-action {
    text-align: center;
    min-width: 200px;
}

.download-note {
    margin-top: 12px;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.download-options {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 24px;
    margin-bottom: 24px;
}

.download-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
}

.download-card h3 {
    color: var(--text);
    margin-bottom: 8px;
    font-size: 1.125rem;
}

.download-card p {
    color: var(--text-muted);
    font-size: 0.9375rem;
    margin-bottom: 12px;
}

.download-meta {
    list-style: none;
    margin: 0 0 16px;
    padding: 0;
    font-size: 0.875rem;
    color: var(--text-body);
}

.download-meta li {
    padding: 4px 0;
}

.download-meta code {
    background: #e8eef5;
    padding: 2px 8px;
    border-radius: 4px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    border-radius: 999px;
    font-size: 0.9375rem;
    font-weight: 600;
    text-decoration: none;
    border: 2px solid transparent;
    transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
    cursor: pointer;
    white-space: nowrap;
}

.btn:hover {
    transform: translateY(-1px);
}

.btn-primary {
    background: linear-gradient(135deg, #1976d2, #1565c0);
    color: #fff;
    box-shadow: 0 4px 16px rgba(25, 118, 210, 0.35);
}

.btn-primary:hover {
    box-shadow: 0 6px 24px rgba(25, 118, 210, 0.45);
    color: #fff;
}

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

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

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

.btn-lg {
    padding: 14px 32px;
    font-size: 1.0625rem;
}

/* Hero */
.hero {
    padding: 56px 0 72px;
    background: linear-gradient(180deg, #e3f2fd 0%, #ffffff 55%);
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
}

.hero-kicker {
    display: inline-block;
    padding: 4px 14px;
    background: var(--primary-light);
    color: var(--primary-dark);
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.hero-title {
    font-size: clamp(2rem, 4vw, 2.75rem);
    font-weight: 800;
    color: var(--text);
    line-height: 1.2;
    margin-bottom: 12px;
}

.hero-lead {
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 24px;
}

.hero-bullets {
    list-style: none;
    margin-bottom: 32px;
}

.hero-bullets li {
    position: relative;
    padding-left: 1.5em;
    margin-bottom: 12px;
    font-size: 0.975rem;
}

.hero-bullets li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.hero-actions.center {
    justify-content: center;
}

.hero-visual img {
    width: 100%;
    max-width: 480px;
    margin: 0 auto;
    display: block;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

/* Sections */
.section {
    padding: 72px 0;
}

.section-alt {
    background: var(--bg-alt);
}

.section-title {
    text-align: center;
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 800;
    color: var(--text);
    margin-bottom: 48px;
    line-height: 1.35;
}

.subtitle-sm {
    display: block;
    font-size: 0.85em;
    font-weight: 600;
    color: var(--text-muted);
    margin-top: 8px;
}

.section-hint {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 24px;
}

/* Steps */
.steps-row {
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.step-card {
    flex: 1 1 240px;
    max-width: 300px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 20px;
    text-align: center;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}

.step-num {
    width: 36px;
    height: 36px;
    line-height: 36px;
    margin: 0 auto 16px;
    background: var(--primary);
    color: #fff;
    border-radius: 50%;
    font-weight: 700;
}

.step-img {
    width: 80px;
    height: 80px;
    object-fit: contain;
    margin-bottom: 16px;
    opacity: 0.9;
}

.step-card h3 {
    font-size: 1.05rem;
    color: var(--text);
    margin-bottom: 8px;
}

.step-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.step-arrow {
    align-self: center;
    font-size: 1.5rem;
    color: var(--primary);
    font-weight: 300;
    opacity: 0.5;
}

/* Scenarios */
.scenario-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.scenario-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 20px;
    text-align: center;
    transition: box-shadow 0.2s;
}

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

.scenario-icon {
    font-size: 2.5rem;
    margin-bottom: 12px;
}

.scenario-card h3 {
    font-size: 1.05rem;
    color: var(--text);
    margin-bottom: 8px;
}

.scenario-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Dual feature */
.dual-feature {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.feature-label {
    font-size: 1.25rem;
    color: var(--primary);
    margin-bottom: 20px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--primary-light);
}

.feature-list {
    list-style: none;
}

.feature-list li {
    margin-bottom: 14px;
    font-size: 0.975rem;
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tag-cloud span {
    padding: 8px 16px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 0.875rem;
    color: var(--text-body);
}

.center-actions {
    text-align: center;
}

/* Formats */
.format-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.format-card {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
}

.format-card h4 {
    color: var(--primary-dark);
    font-size: 1.05rem;
    margin-bottom: 10px;
}

.format-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* Devices */
.device-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 32px;
}

.device-item {
    text-align: center;
    min-width: 100px;
}

.device-item span {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 8px;
}

.device-item p {
    font-size: 0.9375rem;
    color: var(--text-body);
    font-weight: 600;
}

/* Pricing */
.pricing-box {
    text-align: center;
    max-width: 720px;
}

.pricing-desc {
    color: var(--text-muted);
    margin-bottom: 32px;
    font-size: 1.05rem;
}

/* CTA banner */
.cta-banner {
    background: linear-gradient(135deg, #0d47a1, #1976d2);
    padding: 48px 0;
    color: #fff;
}

.cta-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    flex-wrap: wrap;
}

.cta-icon {
    width: 64px;
    height: 64px;
    border-radius: 14px;
}

.cta-inner h2 {
    font-size: 1.5rem;
    margin-bottom: 4px;
}

.cta-inner p {
    opacity: 0.9;
    font-size: 0.9375rem;
}

/* Footer */
.site-footer {
    background: #263238;
    color: #b0bec5;
    padding: 32px 0;
    text-align: center;
    font-size: 0.875rem;
}

.footer-icp {
    margin-top: 10px;
    font-size: 0.875rem;
}

.footer-icp a {
    color: #fff;
    font-weight: 600;
}

.footer-sub {
    margin-top: 8px;
    font-size: 0.8125rem;
    opacity: 0.75;
}

.site-footer a {
    color: #90caf9;
    text-decoration: none;
}

.site-footer a:hover {
    text-decoration: underline;
}

/* Admin-editable product showcases */
.showcase-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
    margin-bottom: 48px;
}

.showcase-row:last-child {
    margin-bottom: 0;
}

.showcase-row-reverse .showcase-media {
    order: 2;
}

.showcase-row-reverse .showcase-copy {
    order: 1;
}

.showcase-media img {
    width: 100%;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.showcase-copy h3 {
    font-size: 1.35rem;
    color: var(--text);
    margin-bottom: 12px;
}

.showcase-copy p {
    color: var(--text-muted);
    line-height: 1.7;
}

/* Legal pages */
.legal-page {
    max-width: 760px;
    margin: 0 auto;
}

.legal-page h1 {
    font-size: 2rem;
    color: var(--text);
    margin-bottom: 8px;
}

.legal-updated {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 28px;
}

.legal-page h2 {
    font-size: 1.1rem;
    color: var(--text);
    margin: 28px 0 12px;
}

.legal-page p,
.legal-page li {
    color: var(--text-body);
    margin-bottom: 10px;
}

.legal-page ul {
    padding-left: 1.4rem;
}

.legal-page a {
    color: var(--primary);
}

@media (max-width: 900px) {
    .showcase-row,
    .showcase-row-reverse {
        grid-template-columns: 1fr;
    }

    .showcase-row-reverse .showcase-media,
    .showcase-row-reverse .showcase-copy {
        order: unset;
    }

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

    .hero-bullets {
        text-align: left;
        max-width: 480px;
        margin-left: auto;
        margin-right: auto;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-visual {
        order: -1;
    }

    .hero-visual img {
        max-width: 280px;
    }

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

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

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

    .step-arrow {
        display: none;
    }

    .cta-inner {
        flex-direction: column;
        text-align: center;
    }

    .top-nav .nav-link {
        display: none;
    }

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

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

    .download-action {
        width: 100%;
    }

    .top-nav .btn-outline {
        display: none;
    }
}

@media (max-width: 480px) {
    .scenario-grid {
        grid-template-columns: 1fr;
    }

    .hero-actions .btn-lg {
        width: 100%;
    }
}