/* 快连官网 - 全局样式（主题：智能科技 / 青色） */
:root {
    --brand: #06b6d4;
    --brand-dark: #0891b2;
    --brand-light: #22d3ee;
    --brand-soft: #ecfeff;
    --ink: #0f172a;
    --muted: #64748b;
    --bg: #ffffff;
    --bg-alt: #f0f9ff;
    --border: #e2e8f0;
    --radius: 14px;
    --shadow: 0 10px 30px rgba(6, 182, 212, 0.14);
    --shadow-sm: 0 4px 14px rgba(6, 182, 212, 0.1);
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    color: var(--ink);
    background: var(--bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--brand-dark);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--brand);
}

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

.container {
    width: min(1120px, 92%);
    margin: 0 auto;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== Header ===== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    min-height: 64px;
}

.logo {
    display: inline-flex;
    align-items: center;
}

.logo img {
    height: 40px;
    width: auto;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 6px;
}

.header-nav a {
    padding: 8px 14px;
    border-radius: 8px;
    color: var(--ink);
    font-size: 15px;
    font-weight: 500;
}

.header-nav a:hover {
    color: var(--brand-dark);
    background: var(--brand-soft);
}

.header-nav a[aria-current="page"] {
    color: var(--brand-dark);
    background: var(--brand-soft);
    font-weight: 600;
}

.btn-download-header {
    padding: 9px 20px;
    border-radius: 999px;
    background: var(--brand);
    color: #fff;
    font-size: 14px;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
}

.btn-download-header:hover {
    background: var(--brand-dark);
    color: #fff;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--ink);
    border-radius: 2px;
    transition: transform 0.2s ease, opacity 0.2s ease;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.2s ease;
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-primary {
    background: var(--brand);
    color: #fff;
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    background: var(--brand-dark);
    color: #fff;
    transform: translateY(-1px);
}

.btn-ghost {
    background: transparent;
    color: var(--brand-dark);
    border-color: var(--brand-light);
}

.btn-ghost:hover {
    background: var(--brand-soft);
    color: var(--brand-dark);
}

.btn-block {
    width: 100%;
}

/* ===== Hero ===== */
.hero {
    background: linear-gradient(135deg, #ecfeff 0%, #f0f9ff 45%, #e0f2fe 100%);
    padding: 84px 0 72px;
    overflow: hidden;
}

.hero-inner {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 48px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    border-radius: 999px;
    background: #fff;
    border: 1px solid var(--brand-light);
    color: var(--brand-dark);
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: clamp(30px, 4vw, 44px);
    line-height: 1.25;
    margin-bottom: 18px;
    color: var(--ink);
}

.hero-lead {
    font-size: 17px;
    color: var(--muted);
    max-width: 560px;
    margin-bottom: 28px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-bottom: 26px;
}

.hero-points {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
}

.hero-points li {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    font-size: 14px;
    color: var(--muted);
}

.hero-points i {
    color: var(--brand);
}

.hero-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-visual svg {
    width: 100%;
    max-width: 460px;
    height: auto;
}

/* ===== Sections ===== */
.section {
    padding: 68px 0;
}

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

.section-title {
    font-size: clamp(24px, 3vw, 30px);
    text-align: center;
    margin-bottom: 10px;
    color: var(--ink);
}

.section-sub {
    text-align: center;
    color: var(--muted);
    margin-bottom: 38px;
    font-size: 15px;
}

/* ===== Cards ===== */
.grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 26px 22px;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.card-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--brand-soft);
    color: var(--brand-dark);
    font-size: 22px;
    margin-bottom: 16px;
}

.card h3 {
    font-size: 17px;
    margin-bottom: 8px;
    color: var(--ink);
}

.card p {
    font-size: 14px;
    color: var(--muted);
}

.card-download {
    text-align: center;
}

.card-download .card-icon {
    margin: 0 auto 16px;
}

.card-download .btn {
    margin-top: 16px;
}

/* ===== Steps ===== */
.steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 22px;
}

.step {
    position: relative;
    text-align: center;
    padding: 28px 18px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.step-num {
    position: absolute;
    top: 12px;
    right: 16px;
    font-size: 40px;
    font-weight: 800;
    color: var(--brand-soft);
    line-height: 1;
}

.step-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 14px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--brand), var(--brand-light));
    color: #fff;
    font-size: 22px;
}

.step h3 {
    font-size: 16px;
    margin-bottom: 6px;
}

.step p {
    font-size: 13px;
    color: var(--muted);
}

/* ===== Feature rows ===== */
.feature-rows {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.feature-row {
    display: grid;
    grid-template-columns: 1fr 120px;
    align-items: center;
    gap: 28px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 26px 28px;
    box-shadow: var(--shadow-sm);
}

.feature-text h3 {
    font-size: 19px;
    margin-bottom: 8px;
    color: var(--ink);
}

.feature-text p {
    font-size: 15px;
    color: var(--muted);
}

.feature-visual {
    width: 108px;
    height: 108px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
}

.feature-visual-cyan {
    background: linear-gradient(135deg, var(--brand-soft), #cffafe);
    color: var(--brand-dark);
}

/* ===== Table ===== */
.table-wrap {
    overflow-x: auto;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: #fff;
}

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

.platform-table th,
.platform-table td {
    padding: 14px 18px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.platform-table thead th {
    background: var(--brand-soft);
    color: var(--brand-dark);
    font-weight: 600;
    white-space: nowrap;
}

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

.platform-table tbody tr:hover {
    background: var(--bg-alt);
}

/* ===== FAQ ===== */
.faq-list {
    max-width: 820px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.faq-item {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-item summary {
    list-style: none;
    cursor: pointer;
    padding: 16px 20px;
    font-weight: 600;
    font-size: 15px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

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

.faq-item summary::after {
    content: "\f078";
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    font-size: 13px;
    color: var(--brand);
    transition: transform 0.2s ease;
    flex-shrink: 0;
}

.faq-item[open] summary::after {
    transform: rotate(180deg);
}

.faq-item p {
    padding: 0 20px 18px;
    font-size: 14px;
    color: var(--muted);
}

/* ===== Page hero ===== */
.page-hero {
    background: linear-gradient(135deg, #ecfeff 0%, #f0f9ff 100%);
    padding: 60px 0 44px;
    text-align: center;
}

.page-hero h1 {
    font-size: clamp(26px, 3.4vw, 38px);
    margin-bottom: 12px;
}

.page-hero p {
    color: var(--muted);
    font-size: 16px;
    max-width: 640px;
    margin: 0 auto;
}

.tutorial-jump {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-top: 22px;
}

.tutorial-jump a {
    padding: 8px 18px;
    border-radius: 999px;
    background: #fff;
    border: 1px solid var(--brand-light);
    color: var(--brand-dark);
    font-size: 14px;
    font-weight: 500;
}

.tutorial-jump a:hover {
    background: var(--brand-soft);
}

/* ===== Guide block ===== */
.guide-block {
    max-width: 780px;
    margin: 0 auto;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 30px;
    box-shadow: var(--shadow-sm);
}

.guide-block h3 {
    font-size: 17px;
    color: var(--brand-dark);
    margin-bottom: 6px;
}

.guide-block h3:not(:first-child) {
    margin-top: 22px;
}

.guide-block p {
    font-size: 15px;
    color: var(--muted);
}

/* ===== Feature list ===== */
.feature-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 22px;
}

.feature-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow-sm);
}

.feature-card-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--brand-soft);
    color: var(--brand-dark);
    font-size: 22px;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--ink);
}

.feature-card p {
    font-size: 14px;
    color: var(--muted);
}

/* ===== FAQ search ===== */
.faq-search {
    position: relative;
    max-width: 520px;
    margin: 22px auto 0;
}

.faq-search input {
    width: 100%;
    padding: 12px 44px 12px 18px;
    border-radius: 999px;
    border: 1px solid var(--brand-light);
    background: #fff;
    font-size: 15px;
    color: var(--ink);
    outline: none;
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.faq-search input:focus {
    border-color: var(--brand);
    box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.15);
}

.faq-search i {
    position: absolute;
    right: 18px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--muted);
    pointer-events: none;
}

/* ===== About ===== */
.about-block {
    max-width: 780px;
    margin: 0 auto;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 30px;
    box-shadow: var(--shadow-sm);
}

.about-block p {
    font-size: 15px;
    color: var(--muted);
    margin-bottom: 14px;
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

/* ===== Legal ===== */
.legal-body {
    max-width: 820px;
    margin: 0 auto;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 34px 36px;
    box-shadow: var(--shadow-sm);
}

.legal-body h2 {
    font-size: 20px;
    color: var(--brand-dark);
    margin-bottom: 10px;
}

.legal-body h2:not(:first-child) {
    margin-top: 28px;
}

.legal-body p {
    font-size: 15px;
    color: var(--muted);
    margin-bottom: 12px;
}

/* ===== Notice ===== */
.notice-list {
    max-width: 780px;
    margin: 0 auto;
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.notice-list li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 14px 18px;
    font-size: 14px;
    color: var(--muted);
}

.notice-list i {
    color: var(--brand);
    margin-top: 4px;
}

/* ===== Footer ===== */
.site-footer {
    background: #0f172a;
    color: #cbd5e1;
    padding: 40px 0 26px;
    margin-top: 40px;
}

.footer-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px 22px;
    margin-bottom: 24px;
}

.footer-nav a {
    color: #cbd5e1;
    font-size: 14px;
}

.footer-nav a:hover {
    color: var(--brand-light);
}

.footer-bottom {
    text-align: center;
    font-size: 13px;
    color: #94a3b8;
}

/* ===== Responsive ===== */
@media (max-width: 960px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

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

    .feature-visual {
        display: none;
    }

    .hero-inner {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .hero-visual {
        order: -1;
    }

    .hero-visual svg {
        max-width: 340px;
    }
}

@media (max-width: 720px) {
    .section {
        padding: 48px 0;
    }

    .header-nav {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        align-items: stretch;
        padding: 16px 20px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
    }

    .header-nav.open {
        display: flex;
    }

    .header-nav a {
        padding: 12px 10px;
    }

    .nav-toggle {
        display: flex;
    }

    .grid-4,
    .steps,
    .about-grid,
    .feature-list {
        grid-template-columns: 1fr;
    }

    .legal-body {
        padding: 24px 20px;
    }
}

/* ===== Accessibility ===== */
:focus-visible {
    outline: 3px solid rgba(6, 182, 212, 0.45);
    outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        scroll-behavior: auto !important;
    }
}