/* ============================================
   PNSEP 官方网站 - 主样式表
   精准营养社交电商平台
   ============================================ */

/* ==================== CSS 变量 ==================== */
:root {
    /* 主色调 - 绿色系 (健康/营养) */
    --color-primary: #16a34a;
    --color-primary-light: #22c55e;
    --color-primary-dark: #15803d;
    --color-primary-bg: #f0fdf4;
    --color-primary-border: #bbf7d0;

    /* 辅助色 */
    --color-accent: #0ea5e9;
    --color-accent-light: #38bdf8;
    --color-warm: #f59e0b;
    --color-danger: #ef4444;

    /* 中性色 */
    --color-white: #ffffff;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    --color-black: #000000;

    /* 渐变 */
    --gradient-hero: linear-gradient(135deg, #064e3b 0%, #065f46 30%, #047857 60%, #059669 100%);
    --gradient-primary: linear-gradient(135deg, #16a34a 0%, #22c55e 100%);
    --gradient-cta: linear-gradient(135deg, #064e3b 0%, #047857 50%, #059669 100%);

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);

    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* 字体 */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
        'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;

    /* 间距 */
    --header-height: 72px;

    /* 过渡 */
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==================== 全局重置 ==================== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    color: var(--color-gray-800);
    background: var(--color-white);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ==================== 按钮系统 ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
    font-family: var(--font-sans);
    white-space: nowrap;
}

.btn-sm {
    padding: 8px 20px;
    font-size: 14px;
}

.btn-lg {
    padding: 14px 32px;
    font-size: 16px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--color-white);
    box-shadow: 0 4px 14px rgba(22, 163, 74, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(22, 163, 74, 0.4);
}

.btn-outline {
    background: transparent;
    color: var(--color-white);
    border: 2px solid rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.7);
}

/* ==================== 导航栏 ==================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    z-index: 1000;
    transition: all var(--transition-base);
    background: transparent;
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-md);
}

.header.scrolled .logo-text,
.header.scrolled .nav-link {
    color: var(--color-gray-800);
}

.header.scrolled .logo-icon { color: var(--color-primary); }
.header.scrolled .logo-icon svg circle:first-child { stroke: var(--color-primary); }
.header.scrolled .logo-icon svg path:first-of-type { fill: var(--color-primary); }

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

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    z-index: 1001;
}

.logo-icon {
    width: 40px;
    height: 40px;
    color: rgba(255, 255, 255, 0.9);
}

.logo-icon svg {
    width: 100%;
    height: 100%;
}

.logo-text {
    font-size: 22px;
    font-weight: 800;
    letter-spacing: 2px;
    color: rgba(255, 255, 255, 0.9);
}

/* 导航菜单 */
.nav-list {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    display: block;
    padding: 8px 16px;
    font-size: 15px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-white);
    background: rgba(255, 255, 255, 0.12);
}

.header.scrolled .nav-link {
    color: var(--color-gray-600);
}

.header.scrolled .nav-link:hover,
.header.scrolled .nav-link.active {
    color: var(--color-primary);
    background: var(--color-primary-bg);
}

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

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-white);
    border-radius: 2px;
    transition: all var(--transition-base);
}

.header.scrolled .menu-toggle span {
    background: var(--color-gray-800);
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ==================== Hero 区域 ==================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 120px 0 80px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
    z-index: 0;
}

.hero-gradient {
    position: absolute;
    top: -50%;
    right: -30%;
    width: 80%;
    height: 120%;
    background: radial-gradient(ellipse, rgba(34, 197, 94, 0.15) 0%, transparent 70%);
    pointer-events: none;
}

.hero-particles {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.particle {
    position: absolute;
    background: rgba(255, 255, 255, 0.06);
    border-radius: 50%;
    animation: float-up linear infinite;
}

@keyframes float-up {
    0% { transform: translateY(100vh) scale(0); opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { transform: translateY(-10vh) scale(1); opacity: 0; }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    color: var(--color-white);
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 6px 18px;
    border-radius: var(--radius-full);
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 28px;
    backdrop-filter: blur(10px);
    animation: fadeInDown 0.6s ease-out;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: #4ade80;
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.hero-title {
    font-size: clamp(36px, 6vw, 60px);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    animation: fadeInUp 0.6s ease-out 0.1s both;
}

.hero-highlight {
    color: #4ade80;
    font-weight: 300;
}

.hero-sub {
    display: block;
    background: linear-gradient(135deg, #4ade80, #86efac);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.hero-desc {
    font-size: clamp(15px, 2vw, 18px);
    color: rgba(255, 255, 255, 0.75);
    line-height: 1.8;
    max-width: 650px;
    margin: 0 auto 36px;
    animation: fadeInUp 0.6s ease-out 0.2s both;
}

.hero-btns {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 60px;
    flex-wrap: wrap;
    animation: fadeInUp 0.6s ease-out 0.3s both;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    flex-wrap: wrap;
    animation: fadeInUp 0.6s ease-out 0.4s both;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.stat-num {
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 800;
    color: #4ade80;
    line-height: 1;
}

.stat-label {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    font-weight: 500;
}

.hero-scroll {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    color: rgba(255, 255, 255, 0.5);
    font-size: 12px;
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(8px); }
}

/* 动画 */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ==================== 通用板块样式 ==================== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    font-size: 13px;
    font-weight: 700;
    color: var(--color-primary);
    background: var(--color-primary-bg);
    padding: 6px 16px;
    border-radius: var(--radius-full);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.section-title {
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 800;
    color: var(--color-gray-900);
    margin-bottom: 16px;
    line-height: 1.3;
}

.section-desc {
    font-size: 17px;
    color: var(--color-gray-500);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ==================== 关于我们 ==================== */
.about {
    padding: 100px 0;
    background: var(--color-white);
}

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

.about-card {
    background: var(--color-gray-50);
    border: 1px solid var(--color-gray-100);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    transition: all var(--transition-smooth);
}

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

.about-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 20px;
    color: var(--color-primary);
}

.about-icon svg {
    width: 100%;
    height: 100%;
}

.about-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 12px;
}

.about-card p {
    font-size: 14px;
    color: var(--color-gray-500);
    line-height: 1.7;
}

/* ==================== 核心功能 ==================== */
.features {
    padding: 100px 0;
    background: var(--color-gray-50);
}

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

.feature-card {
    background: var(--color-white);
    border: 1px solid var(--color-gray-100);
    border-radius: var(--radius-lg);
    padding: 36px 32px;
    transition: all var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-smooth);
}

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

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

.feature-icon-wrap {
    margin-bottom: 20px;
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: var(--color-primary-bg);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
}

.feature-icon svg {
    width: 36px;
    height: 36px;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 14px;
    color: var(--color-gray-500);
    line-height: 1.7;
    margin-bottom: 18px;
}

.feature-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.feature-list li {
    font-size: 12px;
    font-weight: 500;
    color: var(--color-primary-dark);
    background: var(--color-primary-bg);
    padding: 4px 12px;
    border-radius: var(--radius-full);
    border: 1px solid var(--color-primary-border);
}

/* ==================== 商业模式 ==================== */
.business {
    padding: 100px 0;
    background: var(--color-white);
}

/* 流程图 */
.business-flow {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 0;
    margin-bottom: 72px;
    flex-wrap: wrap;
    padding: 0 20px;
}

.flow-node {
    text-align: center;
    padding: 24px 20px;
    min-width: 140px;
    max-width: 160px;
}

.flow-node.highlight {
    background: var(--color-primary-bg);
    border-radius: var(--radius-lg);
    border: 2px solid var(--color-primary);
    box-shadow: 0 0 0 4px rgba(22, 163, 74, 0.08);
}

.flow-icon {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 800;
    margin-bottom: 12px;
}

.flow-icon.supplier { background: #fef3c7; color: #d97706; }
.flow-icon.platform { background: var(--color-primary); color: var(--color-white); font-size: 14px; }
.flow-icon.shop { background: #dbeafe; color: #2563eb; }
.flow-icon.consumer { background: #fce7f3; color: #db2777; }

.flow-node h4 {
    font-size: 15px;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 8px;
}

.flow-node p {
    font-size: 12px;
    color: var(--color-gray-500);
    line-height: 1.7;
}

.flow-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px 4px;
    color: var(--color-gray-300);
    flex-shrink: 0;
}

.flow-arrow svg {
    width: 32px;
    height: 32px;
}

/* 会员等级 */
.member-tiers {
    text-align: center;
}

.tiers-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 36px;
}

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

.tier-card {
    background: var(--color-gray-50);
    border: 2px solid var(--color-gray-100);
    border-radius: var(--radius-lg);
    padding: 28px 20px;
    transition: all var(--transition-smooth);
}

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

.tier-card.highlight {
    border-color: var(--color-primary);
    background: var(--color-primary-bg);
    box-shadow: 0 0 0 4px rgba(22, 163, 74, 0.08);
}

.tier-badge {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: var(--radius-full);
    margin-bottom: 12px;
    background: var(--color-gray-200);
    color: var(--color-gray-600);
}

.tier-badge.v1 { background: #dbeafe; color: #2563eb; }
.tier-badge.v2 { background: #e9d5ff; color: #7c3aed; }
.tier-badge.v3 { background: #fce7f3; color: #db2777; }

.tier-card h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--color-gray-900);
}

.tier-condition {
    font-size: 13px;
    color: var(--color-gray-500);
    margin-bottom: 6px;
}

.tier-benefit {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-primary);
}

/* ==================== 产品优势表格 ==================== */
.advantages {
    padding: 100px 0;
    background: var(--color-gray-50);
}

.compare-table-wrap {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--color-white);
}

.compare-table thead th {
    padding: 18px 24px;
    font-size: 15px;
    font-weight: 700;
    text-align: left;
    background: var(--color-gray-50);
    border-bottom: 2px solid var(--color-gray-200);
    color: var(--color-gray-700);
    white-space: nowrap;
}

.compare-table thead th.highlight-col {
    background: var(--color-primary-bg);
    color: var(--color-primary-dark);
    border-bottom-color: var(--color-primary-border);
}

.compare-table tbody td {
    padding: 16px 24px;
    font-size: 14px;
    border-bottom: 1px solid var(--color-gray-100);
    color: var(--color-gray-600);
}

.compare-table tbody td.highlight-col {
    font-weight: 600;
    color: var(--color-primary-dark);
    background: rgba(240, 253, 244, 0.4);
}

.compare-table tbody tr:hover td {
    background: var(--color-gray-50);
}

.compare-table tbody tr:hover td.highlight-col {
    background: var(--color-primary-bg);
}

.check { color: var(--color-primary); font-weight: 700; }
.cross { color: var(--color-gray-400); }
.warn { color: var(--color-warm); }

/* ==================== 生态伙伴 ==================== */
.ecosystem {
    padding: 100px 0;
    background: var(--color-white);
}

.eco-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.eco-card {
    background: var(--color-gray-50);
    border: 1px solid var(--color-gray-100);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    text-align: center;
    transition: all var(--transition-smooth);
}

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

.eco-avatar {
    width: 64px;
    height: 64px;
    margin: 0 auto 18px;
    color: var(--color-primary);
}

.eco-avatar svg {
    width: 100%;
    height: 100%;
}

.eco-card h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 8px;
}

.eco-card p {
    font-size: 14px;
    color: var(--color-gray-500);
    line-height: 1.6;
}

/* ==================== CTA 下载区 ==================== */
.cta {
    padding: 100px 0;
    background: var(--gradient-cta);
    color: var(--color-white);
    text-align: center;
}

.cta-content h2 {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 800;
    margin-bottom: 16px;
}

.cta-content > p {
    font-size: 17px;
    color: rgba(255, 255, 255, 0.75);
    max-width: 600px;
    margin: 0 auto 48px;
    line-height: 1.7;
}

.cta-platforms {
    display: flex;
    justify-content: center;
    gap: 32px;
    margin-bottom: 48px;
    flex-wrap: wrap;
}

.platform-item {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    min-width: 180px;
    backdrop-filter: blur(10px);
    transition: all var(--transition-base);
}

.platform-item:hover {
    background: rgba(255, 255, 255, 0.14);
    transform: translateY(-4px);
}

.platform-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
    color: #4ade80;
}

.platform-icon svg {
    width: 100%;
    height: 100%;
}

.platform-item h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 6px;
}

.platform-item p {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 12px;
}

.platform-status {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    padding: 3px 12px;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.12);
    color: #4ade80;
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--color-gray-900);
    color: var(--color-gray-400);
    padding: 64px 0 32px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand p {
    margin-top: 12px;
    font-size: 14px;
    line-height: 1.7;
}

.footer-logo .logo-text {
    color: var(--color-gray-300);
}

.footer-logo .logo-icon {
    color: var(--color-gray-400);
}

.footer-links h4 {
    font-size: 15px;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: 20px;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    font-size: 14px;
    color: var(--color-gray-400);
    transition: color var(--transition-base);
}

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

.footer-bottom {
    padding-top: 32px;
    border-top: 1px solid var(--color-gray-800);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 13px;
}

.footer-legal {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.footer-legal a {
    color: var(--color-gray-400);
    transition: color var(--transition-base);
}

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

.sep {
    color: var(--color-gray-700);
}

/* ==================== 滚动动画 ==================== */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ==================== 响应式设计 ==================== */

/* 平板端 */
@media (max-width: 1024px) {
    .about-grid { grid-template-columns: repeat(2, 1fr); }
    .tiers-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

/* 移动端 */
@media (max-width: 768px) {
    .header-actions { display: none; }

    .menu-toggle { display: flex; }

    .nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--color-white);
        box-shadow: var(--shadow-xl);
        padding: 100px 32px 40px;
        transition: right var(--transition-smooth);
    }

    .nav.active { right: 0; }

    .nav-list {
        flex-direction: column;
        gap: 4px;
    }

    .nav-link {
        color: var(--color-gray-700) !important;
        padding: 12px 16px;
        font-size: 16px;
    }

    .nav-link:hover,
    .nav-link.active {
        color: var(--color-primary) !important;
        background: var(--color-primary-bg) !important;
    }

    .hero-stats { gap: 24px; }

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

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

    .business-flow {
        flex-direction: column;
        align-items: center;
        gap: 8px;
    }

    .flow-arrow { transform: rotate(90deg); padding: 8px; }

    .flow-node { max-width: 240px; }

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

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

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

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .footer-legal { justify-content: center; }
}

@media (max-width: 480px) {
    .hero-btns { flex-direction: column; align-items: center; }

    .hero-stats {
        flex-direction: column;
        gap: 16px;
    }

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

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

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

    .cta-platforms { flex-direction: column; align-items: center; }

    .platform-item { width: 100%; max-width: 280px; }

    .compare-table thead th,
    .compare-table tbody td {
        padding: 12px 16px;
        font-size: 13px;
    }
}

/* 移动端导航遮罩 */
.nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 999;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.nav-overlay.active {
    display: block;
    opacity: 1;
}