/* ============================================
   H2testw.cn - 官方推广网站样式表
   配色：基于Logo（USB + 绿色对勾）
   主色：#16A34A（活力绿）  辅色：#1F2937（深灰）  点缀：#DC2626（红）
   风格：扁平 / 现代 / 专业
   ============================================ */

/* ---------- 1. 全局变量 ---------- */
:root {
    /* 主色调 */
    --color-primary: #16A34A;          /* 主绿 - 对勾色 */
    --color-primary-dark: #15803D;
    --color-primary-light: #22C55E;
    --color-primary-bg: #F0FDF4;
    --color-primary-bg-2: #DCFCE7;

    /* 中性色 */
    --color-dark: #1F2937;             /* 深灰 - USB边框 */
    --color-dark-2: #374151;
    --color-gray: #6B7280;
    --color-gray-light: #9CA3AF;
    --color-bg: #FFFFFF;
    --color-bg-soft: #F9FAFB;
    --color-bg-alt: #F3F4F6;
    --color-border: #E5E7EB;

    /* 点缀色 */
    --color-accent: #DC2626;           /* 红 - 指示灯色 */
    --color-warn: #F59E0B;
    --color-info: #2563EB;

    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
    --shadow-green: 0 10px 30px -10px rgba(22, 163, 74, 0.4);

    /* 圆角 */
    --radius-sm: 6px;
    --radius: 10px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-full: 9999px;

    /* 间距 */
    --container: 1200px;
    --header-h: 72px;

    /* 字体 */
    --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB",
                 "Helvetica Neue", -apple-system, BlinkMacSystemFont, "Segoe UI",
                 Roboto, Arial, sans-serif;
    --font-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, monospace;

    /* 过渡 */
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- 2. Reset & 基础 ---------- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    scroll-padding-top: calc(var(--header-h) + 20px);
}

body {
    font-family: var(--font-sans);
    color: var(--color-dark);
    background: var(--color-bg);
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

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

a:hover {
    color: var(--color-primary-dark);
}

ul, ol {
    list-style: none;
}

button {
    cursor: pointer;
    font-family: inherit;
    border: none;
    background: none;
}

/* ---------- 3. 容器与排版 ---------- */
.container {
    width: 100%;
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 80px 0;
}

.section-sm {
    padding: 56px 0;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    text-align: center;
    color: var(--color-dark);
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: 18px;
    color: var(--color-gray);
    text-align: center;
    max-width: 720px;
    margin: 0 auto 56px;
    line-height: 1.7;
}

.section-tag {
    display: inline-block;
    background: var(--color-primary-bg-2);
    color: var(--color-primary-dark);
    font-size: 13px;
    font-weight: 600;
    padding: 6px 14px;
    border-radius: var(--radius-full);
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}

.text-center { text-align: center; }
.text-gradient {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ---------- 4. 按钮 ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 16px;
    font-weight: 600;
    border-radius: var(--radius);
    transition: var(--transition);
    cursor: pointer;
    text-align: center;
    white-space: nowrap;
    border: 2px solid transparent;
    line-height: 1.2;
}

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

.btn-primary:hover {
    background: var(--color-primary-dark);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 14px 36px -10px rgba(22, 163, 74, 0.5);
}

.btn-secondary {
    background: var(--color-bg);
    color: var(--color-dark);
    border: 2px solid var(--color-border);
}

.btn-secondary:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-2px);
}

.btn-ghost {
    background: transparent;
    color: var(--color-primary);
    padding: 10px 18px;
}

.btn-ghost:hover {
    background: var(--color-primary-bg);
    color: var(--color-primary-dark);
}

.btn-lg {
    padding: 16px 36px;
    font-size: 17px;
}

.btn-block {
    width: 100%;
}

.btn .icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

/* ---------- 5. 顶部导航 ---------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-h);
}

.site-header .container {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 20px;
    color: var(--color-dark);
}

.brand:hover { color: var(--color-dark); }

.brand-logo {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    object-fit: cover;
}

.brand-name { letter-spacing: -0.5px; }
.brand-name .accent { color: var(--color-primary); }

.main-nav {
    display: flex;
    align-items: center;
    gap: 4px;
}

.main-nav a {
    color: var(--color-dark-2);
    font-size: 15px;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.main-nav a:hover {
    color: var(--color-primary);
    background: var(--color-primary-bg);
}

.main-nav a.active {
    color: var(--color-primary);
    background: var(--color-primary-bg);
    font-weight: 600;
}

.header-cta {
    display: flex;
    align-items: center;
    gap: 12px;
}

.menu-toggle {
    display: none;
    width: 44px;
    height: 44px;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    border-radius: var(--radius-sm);
}

.menu-toggle span {
    width: 22px;
    height: 2px;
    background: var(--color-dark);
    border-radius: 2px;
    transition: var(--transition);
}

.menu-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}
.menu-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 6. Hero 区 ---------- */
.hero {
    position: relative;
    padding: 80px 0 64px;
    background:
        radial-gradient(circle at 80% 20%, rgba(34, 197, 94, 0.12) 0%, transparent 50%),
        radial-gradient(circle at 20% 80%, rgba(220, 38, 38, 0.06) 0%, transparent 40%),
        linear-gradient(180deg, #F0FDF4 0%, #FFFFFF 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-image:
        linear-gradient(rgba(22, 163, 74, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(22, 163, 74, 0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

.hero .container {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 60px;
    align-items: center;
}

.hero-content { max-width: 600px; }

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid var(--color-primary-bg-2);
    color: var(--color-primary-dark);
    padding: 8px 16px;
    border-radius: var(--radius-full);
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 24px;
    backdrop-filter: blur(8px);
}

.hero-badge .dot {
    width: 8px;
    height: 8px;
    background: var(--color-primary);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.6; transform: scale(1.3); }
}

.hero h1 {
    font-size: 52px;
    line-height: 1.15;
    font-weight: 800;
    color: var(--color-dark);
    margin-bottom: 24px;
    letter-spacing: -0.03em;
}

.hero h1 .accent {
    color: var(--color-primary);
    position: relative;
}

.hero-desc {
    font-size: 18px;
    color: var(--color-gray);
    margin-bottom: 36px;
    line-height: 1.75;
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

.hero-stats {
    display: flex;
    gap: 40px;
    padding-top: 32px;
    border-top: 1px solid var(--color-border);
}

.hero-stat .num {
    font-size: 28px;
    font-weight: 800;
    color: var(--color-primary);
    letter-spacing: -0.02em;
}

.hero-stat .label {
    font-size: 13px;
    color: var(--color-gray);
    margin-top: 4px;
}

/* Hero 视觉区 */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-mockup {
    width: 100%;
    max-width: 480px;
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    border: 1px solid var(--color-border);
    transform: perspective(1200px) rotateY(-6deg) rotateX(2deg);
    transition: var(--transition);
}

.hero-mockup:hover {
    transform: perspective(1200px) rotateY(0deg) rotateX(0deg);
}

.mockup-bar {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 12px 16px;
    background: var(--color-bg-soft);
    border-bottom: 1px solid var(--color-border);
}

.mockup-bar .dot {
    width: 11px;
    height: 11px;
    border-radius: 50%;
}
.mockup-bar .dot.r { background: #FF5F57; }
.mockup-bar .dot.y { background: #FEBC2E; }
.mockup-bar .dot.g { background: #28C840; }
.mockup-bar .title {
    margin-left: 12px;
    font-size: 12px;
    color: var(--color-gray);
    font-family: var(--font-mono);
}

.mockup-body { padding: 24px; }

.mockup-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--color-dark);
    display: flex;
    align-items: center;
    gap: 10px;
}

.mockup-title .icon {
    width: 22px;
    height: 22px;
    background: var(--color-primary);
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 14px;
}

.mockup-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px dashed var(--color-border);
    font-size: 14px;
}
.mockup-row:last-child { border-bottom: none; }

.mockup-row .label { color: var(--color-gray); }
.mockup-row .value { font-weight: 600; font-family: var(--font-mono); color: var(--color-dark); }
.mockup-row .value.ok { color: var(--color-primary); }
.mockup-row .value.warn { color: var(--color-accent); }

.mockup-progress {
    margin-top: 16px;
    height: 8px;
    background: var(--color-bg-alt);
    border-radius: var(--radius-full);
    overflow: hidden;
}
.mockup-progress .bar {
    height: 100%;
    width: 68%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius-full);
    position: relative;
    animation: progress-shine 2.5s ease-in-out infinite;
}
@keyframes progress-shine {
    0%, 100% { opacity: 0.85; }
    50% { opacity: 1; }
}

.mockup-footer {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--color-gray);
}

/* 浮动徽章 */
.hero-float {
    position: absolute;
    background: var(--color-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    padding: 14px 18px;
    display: flex;
    align-items: center;
    gap: 12px;
    border: 1px solid var(--color-border);
    animation: float 4s ease-in-out infinite;
}

.hero-float.f1 {
    top: 8%;
    left: -4%;
    animation-delay: 0s;
}
.hero-float.f2 {
    bottom: 12%;
    right: -4%;
    animation-delay: 2s;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}

.hero-float .ic {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    background: var(--color-primary-bg);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}

.hero-float .txt {
    font-size: 13px;
}
.hero-float .txt strong {
    display: block;
    color: var(--color-dark);
    font-size: 14px;
}
.hero-float .txt span { color: var(--color-gray); }

/* ---------- 7. 信任栏 ---------- */
.trust-bar {
    background: var(--color-dark);
    color: #fff;
    padding: 28px 0;
}

.trust-bar .container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    text-align: center;
}

.trust-item .num {
    font-size: 30px;
    font-weight: 800;
    color: var(--color-primary-light);
    letter-spacing: -0.02em;
}

.trust-item .label {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.7);
    margin-top: 4px;
}

/* ---------- 8. 功能卡片 ---------- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.feature-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px 28px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 3px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--color-primary-bg-2);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-ic {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    background: var(--color-primary-bg);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    font-size: 24px;
    transition: var(--transition);
}

.feature-card:hover .feature-ic {
    background: var(--color-primary);
    color: #fff;
    transform: scale(1.05);
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--color-dark);
}

.feature-card p {
    color: var(--color-gray);
    font-size: 15px;
    line-height: 1.7;
}

/* ---------- 9. 使用场景 ---------- */
.scenarios {
    background: var(--color-bg-soft);
}

.scenarios-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.scenario-card {
    background: var(--color-bg);
    border-radius: var(--radius-md);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    display: flex;
    gap: 20px;
    transition: var(--transition);
}

.scenario-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.scenario-ic {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
}

.scenario-ic.alt {
    background: linear-gradient(135deg, var(--color-dark), var(--color-dark-2));
}
.scenario-ic.acc {
    background: linear-gradient(135deg, var(--color-accent), #B91C1C);
}
.scenario-ic.warn {
    background: linear-gradient(135deg, var(--color-warn), #D97706);
}

.scenario-body h3 {
    font-size: 19px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--color-dark);
}

.scenario-body p {
    color: var(--color-gray);
    font-size: 15px;
    line-height: 1.7;
    margin-bottom: 12px;
}

.scenario-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.scenario-tags span {
    font-size: 12px;
    color: var(--color-primary-dark);
    background: var(--color-primary-bg);
    padding: 3px 10px;
    border-radius: var(--radius-full);
    font-weight: 500;
}

/* ---------- 10. 用户评价 ---------- */
.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.testimonial {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 28px;
    transition: var(--transition);
    position: relative;
}

.testimonial:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-3px);
}

.testimonial .quote-mark {
    position: absolute;
    top: 16px;
    right: 24px;
    font-size: 56px;
    line-height: 1;
    color: var(--color-primary-bg-2);
    font-family: Georgia, serif;
    font-weight: 700;
}

.testimonial .stars {
    color: #F59E0B;
    margin-bottom: 14px;
    font-size: 16px;
    letter-spacing: 2px;
}

.testimonial .text {
    color: var(--color-dark-2);
    font-size: 15px;
    line-height: 1.75;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
}

.testimonial .author {
    display: flex;
    align-items: center;
    gap: 12px;
    padding-top: 16px;
    border-top: 1px solid var(--color-border);
}

.testimonial .avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 16px;
    flex-shrink: 0;
}

.testimonial .author-info .name {
    font-weight: 700;
    color: var(--color-dark);
    font-size: 15px;
}

.testimonial .author-info .meta {
    font-size: 12px;
    color: var(--color-gray);
}

/* ---------- 11. CTA 区 ---------- */
.cta-section {
    padding: 80px 0;
    background:
        radial-gradient(circle at 30% 50%, rgba(34, 197, 94, 0.15) 0%, transparent 60%),
        linear-gradient(135deg, #14532D 0%, #166534 100%);
    color: #fff;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
}

.cta-section .container {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
}

.cta-section h2 {
    font-size: 40px;
    font-weight: 800;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.cta-section p {
    font-size: 18px;
    opacity: 0.92;
    margin-bottom: 32px;
}

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

.cta-section .btn-primary:hover {
    background: var(--color-primary-bg-2);
    transform: translateY(-2px);
}

.cta-section .btn-secondary {
    background: transparent;
    color: #fff;
    border-color: rgba(255, 255, 255, 0.4);
}

.cta-section .btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: #fff;
    color: #fff;
}

.cta-meta {
    margin-top: 28px;
    display: flex;
    justify-content: center;
    gap: 32px;
    font-size: 14px;
    opacity: 0.85;
    flex-wrap: wrap;
}

.cta-meta span {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

/* ---------- 12. 下载弹窗 ---------- */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    max-width: 640px;
    width: 100%;
    box-shadow: var(--shadow-xl);
    transform: translateY(20px) scale(0.96);
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    max-height: 90vh;
    overflow-y: auto;
}

.modal-overlay.active .modal {
    transform: translateY(0) scale(1);
}

.modal-header {
    padding: 28px 32px 20px;
    border-bottom: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    background: linear-gradient(180deg, var(--color-primary-bg) 0%, transparent 100%);
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.modal-header h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 4px;
}

.modal-header p {
    color: var(--color-gray);
    font-size: 14px;
}

.modal-close {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--color-bg);
    color: var(--color-gray);
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    flex-shrink: 0;
}

.modal-close:hover {
    background: var(--color-bg-alt);
    color: var(--color-dark);
    transform: rotate(90deg);
}

.modal-body {
    padding: 28px 32px 32px;
}

.qr-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 24px;
}

.qr-item {
    text-align: center;
    padding: 24px 16px;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: var(--transition);
    background: var(--color-bg-soft);
}

.qr-item:hover {
    border-color: var(--color-primary);
    background: var(--color-primary-bg);
    transform: translateY(-3px);
}

.qr-img {
    width: 180px;
    height: 180px;
    margin: 0 auto 14px;
    background: #fff;
    border-radius: var(--radius);
    padding: 10px;
    box-shadow: var(--shadow-sm);
}

.qr-img img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.qr-item .platform {
    font-weight: 700;
    font-size: 16px;
    color: var(--color-dark);
    margin-bottom: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.qr-item .desc {
    font-size: 13px;
    color: var(--color-gray);
}

.qr-item .size {
    margin-top: 6px;
    display: inline-block;
    font-size: 12px;
    color: var(--color-primary-dark);
    background: var(--color-primary-bg-2);
    padding: 2px 10px;
    border-radius: var(--radius-full);
}

.modal-footer {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px dashed var(--color-border);
    font-size: 13px;
    color: var(--color-gray);
    text-align: center;
    line-height: 1.7;
}

.modal-footer a {
    color: var(--color-primary);
    font-weight: 600;
}

/* ---------- 13. 步骤 / 教程 ---------- */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    counter-reset: step;
}

.step-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px 24px;
    text-align: center;
    position: relative;
    transition: var(--transition);
}

.step-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-bg-2);
    transform: translateY(-3px);
}

.step-card .step-num {
    counter-increment: step;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 800;
    margin: 0 auto 20px;
    box-shadow: var(--shadow-green);
}

.step-card .step-num::before {
    content: counter(step);
}

.step-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--color-dark);
}

.step-card p {
    color: var(--color-gray);
    font-size: 14px;
    line-height: 1.7;
}

/* 详细教程页 */
.tutorial-content {
    max-width: 820px;
    margin: 0 auto;
}

.tutorial-step {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 24px;
    padding: 32px 0;
    border-bottom: 1px solid var(--color-border);
}

.tutorial-step:last-child { border-bottom: none; }

.tutorial-step .num {
    width: 56px;
    height: 56px;
    background: var(--color-primary-bg);
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    font-weight: 800;
    flex-shrink: 0;
}

.tutorial-step h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 12px;
}

.tutorial-step p {
    color: var(--color-dark-2);
    font-size: 15px;
    line-height: 1.8;
    margin-bottom: 12px;
}

.tutorial-step .tip {
    background: var(--color-primary-bg);
    border-left: 3px solid var(--color-primary);
    padding: 12px 16px;
    border-radius: 0 var(--radius) var(--radius) 0;
    font-size: 14px;
    color: var(--color-primary-dark);
    margin-top: 12px;
}

.tutorial-step .tip strong { color: var(--color-dark); }

.code-block {
    background: var(--color-dark);
    color: #E5E7EB;
    padding: 16px 20px;
    border-radius: var(--radius);
    font-family: var(--font-mono);
    font-size: 13px;
    overflow-x: auto;
    margin: 12px 0;
}

.code-block .key { color: #93C5FD; }
.code-block .val { color: #86EFAC; }

/* ---------- 14. 下载页 ---------- */
.download-options {
    display: grid;
    grid-template-columns: repeat(1, 1fr);
    gap: 28px;
    max-width: 580px;
    margin: 0 auto;
}

.download-card {
    background: var(--color-bg);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 40px 32px;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.download-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.download-card.featured {
    border-color: var(--color-primary);
    background: linear-gradient(180deg, var(--color-primary-bg) 0%, var(--color-bg) 50%);
}

.download-card .badge-top {
    position: absolute;
    top: 16px;
    right: -32px;
    background: var(--color-primary);
    color: #fff;
    font-size: 12px;
    font-weight: 700;
    padding: 4px 36px;
    transform: rotate(45deg);
    letter-spacing: 0.5px;
}

.download-card .os-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: var(--color-primary-bg);
    color: var(--color-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
}

.download-card h3 {
    font-size: 24px;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 8px;
}

.download-card .ver {
    color: var(--color-gray);
    font-size: 14px;
    margin-bottom: 24px;
}

.download-card .specs {
    margin-bottom: 28px;
    text-align: left;
    background: var(--color-bg-soft);
    border-radius: var(--radius);
    padding: 16px 20px;
}

.download-card .specs div {
    display: flex;
    justify-content: space-between;
    padding: 6px 0;
    font-size: 14px;
    border-bottom: 1px dashed var(--color-border);
}
.download-card .specs div:last-child { border-bottom: none; }
.download-card .specs .l { color: var(--color-gray); }
.download-card .specs .v { font-weight: 600; color: var(--color-dark); font-family: var(--font-mono); }

/* 系统要求表 */
.specs-table {
    width: 100%;
    max-width: 880px;
    margin: 0 auto;
    border-collapse: collapse;
    background: var(--color-bg);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.specs-table th, .specs-table td {
    padding: 16px 20px;
    text-align: left;
    border-bottom: 1px solid var(--color-border);
    font-size: 15px;
}

.specs-table th {
    background: var(--color-dark);
    color: #fff;
    font-weight: 600;
}

.specs-table tr:last-child td { border-bottom: none; }
.specs-table tr:nth-child(even) td { background: var(--color-bg-soft); }
.specs-table td:first-child { font-weight: 600; color: var(--color-dark); }
.specs-table td:last-child { color: var(--color-gray); }

/* 版本历史 */
.changelog {
    max-width: 880px;
    margin: 0 auto;
}

.changelog-item {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 24px 28px;
    margin-bottom: 16px;
    transition: var(--transition);
}

.changelog-item:hover {
    box-shadow: var(--shadow-sm);
}

.changelog-item .head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    flex-wrap: wrap;
    gap: 8px;
}

.changelog-item .ver {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-primary);
    font-family: var(--font-mono);
}

.changelog-item .date {
    color: var(--color-gray);
    font-size: 13px;
}

.changelog-item ul {
    list-style: none;
}

.changelog-item li {
    padding: 6px 0;
    color: var(--color-dark-2);
    font-size: 14px;
    padding-left: 22px;
    position: relative;
}

.changelog-item li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

/* ---------- 15. FAQ ---------- */
.faq-list {
    max-width: 820px;
    margin: 0 auto;
}

.faq-item {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    margin-bottom: 12px;
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: var(--color-primary-bg-2);
}

.faq-item summary {
    padding: 20px 24px;
    font-size: 16px;
    font-weight: 600;
    color: var(--color-dark);
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    transition: var(--transition);
}

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

.faq-item summary::after {
    content: '+';
    font-size: 24px;
    color: var(--color-primary);
    flex-shrink: 0;
    transition: var(--transition);
    font-weight: 300;
    line-height: 1;
}

.faq-item[open] summary::after {
    transform: rotate(45deg);
}

.faq-item[open] summary {
    background: var(--color-primary-bg);
    color: var(--color-primary-dark);
}

.faq-answer {
    padding: 0 24px 20px;
    color: var(--color-dark-2);
    font-size: 15px;
    line-height: 1.8;
}

.faq-answer p { margin-bottom: 10px; }
.faq-answer p:last-child { margin-bottom: 0; }

/* ---------- 16. 通用页面横幅 ---------- */
.page-hero {
    background:
        radial-gradient(circle at 80% 30%, rgba(34, 197, 94, 0.1) 0%, transparent 50%),
        linear-gradient(180deg, var(--color-primary-bg) 0%, var(--color-bg) 100%);
    padding: 64px 0 48px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(22, 163, 74, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(22, 163, 74, 0.04) 1px, transparent 1px);
    background-size: 32px 32px;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 75%);
    pointer-events: none;
}

.page-hero .container { position: relative; z-index: 1; }

.breadcrumb {
    font-size: 13px;
    color: var(--color-gray);
    margin-bottom: 16px;
}

.breadcrumb a { color: var(--color-gray); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb .sep { margin: 0 8px; opacity: 0.5; }

.page-hero h1 {
    font-size: 40px;
    font-weight: 800;
    color: var(--color-dark);
    margin-bottom: 14px;
    letter-spacing: -0.02em;
}

.page-hero .lead {
    font-size: 17px;
    color: var(--color-gray);
    max-width: 720px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ---------- 17. Footer ---------- */
.site-footer {
    background: var(--color-dark);
    color: rgba(255, 255, 255, 0.75);
    padding: 64px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 40px;
    padding-bottom: 48px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand .brand {
    color: #fff;
    margin-bottom: 16px;
}

.footer-brand p {
    font-size: 14px;
    line-height: 1.7;
    margin-bottom: 16px;
    max-width: 320px;
}

.footer-social {
    display: flex;
    gap: 10px;
}

.footer-social a {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.08);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--color-primary);
    transform: translateY(-2px);
}

.footer-col h4 {
    color: #fff;
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 18px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: var(--color-primary-light);
    padding-left: 4px;
}

.footer-bottom {
    padding: 24px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.55);
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.7);
}

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

.footer-bottom .icp {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

/* ---------- 18. 回到顶部 ---------- */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    box-shadow: var(--shadow-green);
    cursor: pointer;
    z-index: 900;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--color-primary-dark);
    transform: translateY(-3px);
}

/* ---------- 19. 浮动下载条 (移动端) ---------- */
.float-download {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 12px 16px;
    box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.08);
    z-index: 800;
    display: none;
}

.float-download .btn {
    width: 100%;
}

/* ---------- 20. 响应式 ---------- */
@media (max-width: 992px) {
    .hero .container {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    .hero h1 { font-size: 42px; }
    .hero-visual { order: -1; }
    .hero-mockup { max-width: 420px; }
    .hero-float { display: none; }

    .features-grid,
    .testimonials-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .scenarios-grid {
        grid-template-columns: 1fr;
    }
    .steps-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .section { padding: 56px 0; }
    .section-title { font-size: 28px; }
    .section-subtitle { font-size: 16px; margin-bottom: 40px; }

    .main-nav {
        position: fixed;
        top: var(--header-h);
        left: 0;
        right: 0;
        background: var(--color-bg);
        flex-direction: column;
        align-items: stretch;
        padding: 16px;
        gap: 4px;
        box-shadow: var(--shadow-md);
        border-bottom: 1px solid var(--color-border);
        transform: translateY(-120%);
        transition: transform 0.3s ease;
        max-height: calc(100vh - var(--header-h));
        overflow-y: auto;
    }
    .main-nav.active {
        transform: translateY(0);
    }
    .main-nav a {
        padding: 14px 16px;
        font-size: 15px;
    }
    .menu-toggle { display: flex; }
    .header-cta .btn-text { display: none; }
    .header-cta .btn { padding: 10px 14px; }

    .hero { padding: 48px 0 40px; }
    .hero h1 { font-size: 32px; }
    .hero-desc { font-size: 16px; }
    .hero-stats { gap: 24px; }
    .hero-stat .num { font-size: 22px; }

    .trust-bar .container {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    .features-grid,
    .testimonials-grid {
        grid-template-columns: 1fr;
    }

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

    .cta-section h2 { font-size: 28px; }
    .cta-section p { font-size: 16px; }
    .cta-meta { gap: 16px; font-size: 13px; }

    .page-hero { padding: 48px 0 32px; }
    .page-hero h1 { font-size: 30px; }

    .qr-grid { grid-template-columns: 1fr; }
    .qr-img { width: 160px; height: 160px; }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 28px;
    }
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .tutorial-step {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .tutorial-step .num {
        width: 48px;
        height: 48px;
        font-size: 18px;
    }

    .back-to-top {
        bottom: 80px;
        right: 20px;
        width: 44px;
        height: 44px;
    }

    .float-download { display: block; }
}

@media (max-width: 480px) {
    .container { padding: 0 16px; }
    .hero h1 { font-size: 28px; }
    .hero-actions { flex-direction: column; }
    .hero-actions .btn { width: 100%; }
    .hero-stats {
        flex-direction: column;
        gap: 16px;
    }

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

/* ---------- 21. 工具类 ---------- */
.mt-0 { margin-top: 0; }
.mt-2 { margin-top: 16px; }
.mt-4 { margin-top: 32px; }
.mb-0 { margin-bottom: 0; }
.mb-2 { margin-bottom: 16px; }
.mb-4 { margin-bottom: 32px; }
.text-center { text-align: center; }
.hidden { display: none !important; }

.bg-soft { background: var(--color-bg-soft); }
.bg-alt { background: var(--color-bg-alt); }
.bg-primary-soft { background: var(--color-primary-bg); }

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
::-webkit-scrollbar-track {
    background: var(--color-bg-soft);
}
::-webkit-scrollbar-thumb {
    background: var(--color-gray-light);
    border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--color-gray);
}

/* 文本选中 */
::selection {
    background: var(--color-primary-bg-2);
    color: var(--color-primary-dark);
}