/* ═══════════════════════════════════════════════════════════════
   小蓝视频 — Liquid Blueprint Design System
   设计概念：流体蓝图 / 浅色空间 + 网格底纹 + 有机渐变
   配色：暖米白 × 深海蓝 × 珊瑚橙 × 明青
   ═══════════════════════════════════════════════════════════════ */

/* ── 基础重置 ── */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

:root {
    --bg-primary: #F7F4F0;
    --bg-secondary: #EAF0F4;
    --bg-card: #FFFFFF;
    --text-primary: #163240;
    --text-secondary: rgba(22, 50, 64, 0.62);
    --brand-blue: #155E92;
    --brand-blue-light: #4A9BD8;
    --cyan: #2BB6C9;
    --coral: #FF7A59;
    --amber: #F2B84C;
    --border-color: #D6E1E9;
    --shadow-soft: 0 4px 24px rgba(21, 94, 146, 0.07);
    --shadow-hover: 0 16px 48px rgba(21, 94, 146, 0.15);
    --radius: 14px;
    --radius-lg: 22px;
    --transition: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

body {
    font-family: system-ui, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    overflow-x: hidden;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    background-image:
        radial-gradient(ellipse at 88% 8%, rgba(43, 182, 201, 0.12) 0%, transparent 50%),
        radial-gradient(ellipse at 6% 92%, rgba(255, 122, 89, 0.07) 0%, transparent 38%),
        linear-gradient(rgba(21, 94, 146, 0.032) 1px, transparent 1px),
        linear-gradient(90deg, rgba(21, 94, 146, 0.032) 1px, transparent 1px);
    background-size: auto, auto, 52px 52px, 52px 52px;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection {
    background: rgba(255, 122, 89, 0.25);
    color: var(--text-primary);
}

::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--brand-blue), var(--cyan));
    border-radius: 10px;
    border: 2px solid var(--bg-primary);
}

/* ── 核心布局 ── */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    position: relative;
}

.section {
    padding: 96px 0;
    position: relative;
}

.section:nth-child(even) {
    background: rgba(234, 240, 244, 0.55);
    backdrop-filter: blur(2px);
}

/* 分区顶部虚线装饰 */
.section::after {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    border-top: 2px dashed rgba(21, 94, 146, 0.18);
}

/* ── 导航栏 ── */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(247, 244, 240, 0.86);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(214, 225, 233, 0.85);
    transition: box-shadow 0.4s ease;
}

.site-header:hover {
    box-shadow: 0 6px 30px rgba(21, 94, 146, 0.06);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 900;
    font-size: 1.28rem;
    text-decoration: none;
    color: var(--text-primary);
    letter-spacing: -0.02em;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.02);
}

.logo-icon {
    width: 38px;
    height: 38px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    background: linear-gradient(135deg, var(--brand-blue), var(--cyan));
    color: #fff;
    box-shadow: 0 4px 14px rgba(21, 94, 146, 0.35);
    position: relative;
    overflow: hidden;
}

.logo-icon::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 30% 25%, rgba(255,255,255,0.3), transparent 50%);
}

.logo-icon span {
    font-size: 0.95rem;
    color: #fff;
    position: relative;
    z-index: 1;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 30px;
    list-style: none;
}

.main-nav a {
    text-decoration: none;
    font-size: 0.92rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: color 0.3s ease;
    position: relative;
    padding: 6px 2px;
}

.main-nav a:not(.nav-cta)::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--brand-blue), var(--coral));
    border-radius: 2px;
    transition: width 0.35s ease;
}

.main-nav a:not(.nav-cta):hover {
    color: var(--brand-blue);
}

.main-nav a:not(.nav-cta):hover::after {
    width: 100%;
}

.nav-cta {
    padding: 9px 24px;
    border-radius: 100px;
    color: #fff !important;
    font-weight: 600;
    font-size: 0.88rem;
    background: linear-gradient(135deg, var(--brand-blue), var(--cyan));
    box-shadow: 0 4px 18px rgba(21, 94, 146, 0.28);
    transition: transform 0.3s ease, box-shadow 0.3s ease !important;
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 28px rgba(21, 94, 146, 0.38);
    color: #fff !important;
}

.menu-toggle {
    display: none;
    width: 44px;
    height: 44px;
    border: none;
    background: none;
    cursor: pointer;
    padding: 10px;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    border-radius: 8px;
    transition: background 0.3s ease;
}

.menu-toggle:hover {
    background: rgba(21, 94, 146, 0.06);
}

.menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--brand-blue);
    border-radius: 2px;
    transition: all 0.3s ease;
}

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

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

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

/* ── Hero 首屏 ── */
.hero {
    min-height: 92vh;
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    align-items: center;
    gap: 60px;
    padding-top: 70px;
    position: relative;
    overflow: hidden;
}

/* 巨大柔性水印字 */
.hero::before {
    content: '視界';
    position: absolute;
    right: 2%;
    bottom: -2%;
    font-size: clamp(160px, 20vw, 340px);
    font-weight: 900;
    letter-spacing: -0.08em;
    line-height: 1;
    color: transparent;
    -webkit-text-stroke: 1.5px rgba(21, 94, 146, 0.07);
    z-index: 0;
    pointer-events: none;
    user-select: none;
}

.hero::after {
    content: '';
    position: absolute;
    top: 20%;
    right: 4%;
    width: 90px;
    height: 90px;
    background-image: radial-gradient(rgba(21, 94, 146, 0.16) 1.5px, transparent 1.5px);
    background-size: 14px 14px;
    border-radius: 50%;
    z-index: 0;
    pointer-events: none;
}

.hero-content {
    max-width: 700px;
    position: relative;
    z-index: 2;
}

.hero-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 4px;
    text-transform: uppercase;
    padding: 7px 20px;
    border-radius: 100px;
    background: rgba(21, 94, 146, 0.07);
    border: 1px solid rgba(21, 94, 146, 0.15);
    color: var(--brand-blue);
    margin-bottom: 26px;
}

.hero-eyebrow::before {
    content: '';
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--coral);
    animation: heroPulse 2s ease-in-out infinite;
}

@keyframes heroPulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(0.72); }
}

.hero h1 {
    font-size: clamp(2.6rem, 5.5vw, 4rem);
    line-height: 1.08;
    font-weight: 900;
    letter-spacing: -0.04em;
    margin-bottom: 22px;
    color: var(--text-primary);
}

.hero h1 .text-accent {
    background: linear-gradient(120deg, var(--brand-blue) 0%, var(--cyan) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.hero p {
    font-size: 1.12rem;
    line-height: 1.75;
    color: var(--text-secondary);
    max-width: 540px;
    margin-bottom: 36px;
}

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

.hero-image {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid rgba(21, 94, 146, 0.14);
    box-shadow: 0 30px 80px rgba(21, 94, 146, 0.16);
    background: linear-gradient(135deg, rgba(21,94,146,0.04), rgba(43,182,201,0.06));
    z-index: 2;
}

.hero-image::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 30px;
    height: 30px;
    border-top: 3px solid var(--coral);
    border-left: 3px solid var(--coral);
    border-top-left-radius: var(--radius-lg);
    z-index: 3;
    pointer-events: none;
}

/* 播放按钮 */
.hero-image::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 76px;
    height: 76px;
    background: rgba(255, 255, 255, 0.92);
    border-radius: 50%;
    box-shadow: 0 10px 36px rgba(22, 50, 64, 0.18);
    backdrop-filter: blur(6px);
    z-index: 3;
    cursor: pointer;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23155E92'%3E%3Cpath d='M8 5v14l11-7z'/%3E%3C/svg%3E");
    background-size: 26px 26px;
    background-repeat: no-repeat;
    background-position: 55% 50%;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-image:hover::after {
    transform: translate(-50%, -50%) scale(1.05);
    box-shadow: 0 14px 44px rgba(21, 94, 146, 0.28);
}

.hero-image img {
    width: 100%;
    height: 100%;
    min-height: 440px;
    object-fit: cover;
    display: block;
    transition: transform 0.6s ease;
}

.hero-image:hover img {
    transform: scale(1.03);
}

/* ── 按钮 ── */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 32px;
    border-radius: 100px;
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    border: none;
    text-decoration: none;
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--brand-blue) 0%, var(--cyan) 100%);
    color: #fff;
    box-shadow: 0 6px 24px rgba(21, 94, 146, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 12px 36px rgba(21, 94, 146, 0.42);
}

.btn-primary:active {
    transform: translateY(-1px) scale(0.99);
}

.btn-primary::after {
    content: '';
    position: absolute;
    top: 0;
    left: -80%;
    width: 60%;
    height: 100%;
    background: linear-gradient(100deg, transparent, rgba(255,255,255,0.28), transparent);
    transform: skewX(-20deg);
    transition: left 0.6s ease;
}

.btn-primary:hover::after {
    left: 130%;
}

.btn-outline {
    background: rgba(255, 255, 255, 0.5);
    border: 1.5px solid var(--brand-blue);
    color: var(--brand-blue);
    backdrop-filter: blur(4px);
}

.btn-outline:hover {
    background: rgba(21, 94, 146, 0.07);
    border-color: var(--cyan);
    transform: translateY(-3px);
    box-shadow: 0 10px 28px rgba(21, 94, 146, 0.12);
}

/* ── 标签 / 标题 ── */
.section-label {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 3.5px;
    text-transform: uppercase;
    color: var(--brand-blue);
    margin-bottom: 16px;
    padding: 7px 18px;
    border-radius: 100px;
    background: rgba(21, 94, 146, 0.06);
    border: 1px solid rgba(21, 94, 146, 0.12);
    position: relative;
}

.section-label::before {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--coral);
    flex-shrink: 0;
}

.section-title {
    font-size: clamp(1.9rem, 3.5vw, 2.5rem);
    line-height: 1.18;
    font-weight: 900;
    letter-spacing: -0.03em;
    margin-bottom: 16px;
    color: var(--text-primary);
    position: relative;
}

.section-title::before {
    content: '';
    display: inline-block;
    width: 10px;
    height: 10px;
    border-radius: 3px;
    background: var(--coral);
    margin-right: 12px;
    transform: rotate(12deg);
}

.section-desc {
    max-width: 600px;
    color: var(--text-secondary);
    margin-bottom: 44px;
    font-size: 1.02rem;
    line-height: 1.75;
}

/* ── 卡片网格 ── */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 28px;
}

.category-card {
    background: var(--bg-card);
    border-radius: 20px;
    padding: 34px 30px;
    border: 1px solid var(--border-color);
    transition: all var(--transition);
    position: relative;
    box-shadow: var(--shadow-soft);
    overflow: hidden;
}

/* 流体内发光 */
.category-card::after {
    content: '';
    position: absolute;
    top: -60px;
    right: -60px;
    width: 140px;
    height: 140px;
    background: radial-gradient(circle, rgba(43, 182, 201, 0.08), transparent 70%);
    border-radius: 50%;
    transition: transform 0.5s ease;
}

/* 注册标记小十字 */
.category-card::before {
    content: '+';
    position: absolute;
    top: 12px;
    right: 16px;
    color: rgba(21, 94, 146, 0.25);
    font-size: 16px;
    font-weight: 300;
    z-index: 1;
}

.category-card:hover {
    transform: translateY(-6px) rotate(-0.4deg);
    box-shadow: var(--shadow-hover);
    border-color: rgba(21, 94, 146, 0.25);
}

.category-card:hover::after {
    transform: scale(1.6);
}

.card-icon {
    width: 54px;
    height: 54px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    margin-bottom: 20px;
    background: linear-gradient(135deg, rgba(21, 94, 146, 0.09), rgba(43, 182, 201, 0.09));
    border: 1px solid rgba(21, 94, 146, 0.1);
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.category-card:hover .card-icon {
    transform: scale(1.08) rotate(-4deg);
}

.card-link {
    font-weight: 600;
    font-size: 0.85rem;
    text-decoration: none;
    color: var(--brand-blue);
    display: inline-flex;
    align-items: center;
    gap: 5px;
    transition: gap 0.3s ease, color 0.3s ease;
}

.card-link::after {
    content: '→';
    transition: transform 0.3s ease;
}

.card-link:hover {
    color: var(--coral);
    gap: 9px;
}

.card-link:hover::after {
    transform: translateX(2px);
}

/* ── 特性块 ── */
.feature-block {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.feature-text {
    position: relative;
}

.feature-text::before {
    content: '◆';
    position: absolute;
    top: -18px;
    left: 0;
    color: var(--coral);
    font-size: 0.7rem;
    opacity: 0.6;
}

.feature-image {
    border-radius: var(--radius-lg);
    overflow: hidden;
    position: relative;
    border: 1px solid var(--border-color);
    box-shadow: 0 24px 64px rgba(21, 94, 146, 0.13);
    background: linear-gradient(135deg, rgba(21,94,146,0.03), rgba(43,182,201,0.05));
}

.feature-image::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(160deg, rgba(255,255,255,0.08), transparent 40%, rgba(21,94,146,0.08));
    z-index: 1;
    pointer-events: none;
}

.feature-image img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.7s ease;
}

.feature-image:hover img {
    transform: scale(1.02);
}

.feature-list {
    list-style: none;
    margin-top: 8px;
}

.feature-list li {
    padding: 9px 0;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.05rem;
    color: var(--text-primary);
    border-bottom: 1px dashed rgba(21, 94, 146, 0.08);
}

.feature-list li:last-child {
    border-bottom: none;
}

.feature-list li::before {
    content: '✓';
    font-weight: 700;
    color: var(--brand-blue);
    background: rgba(21, 94, 146, 0.1);
    width: 26px;
    height: 26px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    flex-shrink: 0;
    transition: background 0.3s ease, color 0.3s ease;
}

.feature-list li:hover::before {
    background: var(--coral);
    color: #fff;
}

/* ── 数据条 ── */
.stats-bar {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
    text-align: center;
}

.stat-item {
    background: var(--bg-card);
    padding: 34px 20px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    position: relative;
    transition: all var(--transition);
    box-shadow: var(--shadow-soft);
    z-index: 1;
}

.stat-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

/* 顶部渐变短条 */
.stat-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 42px;
    height: 3.5px;
    background: linear-gradient(90deg, var(--brand-blue), var(--coral));
    border-radius: 0 0 6px 6px;
    transition: width 0.35s ease;
}

.stat-item:hover::before {
    width: 70px;
}

/* 角标圆点装饰 */
.stat-item::after {
    content: '';
    position: absolute;
    bottom: 12px;
    right: 14px;
    width: 8px;
    height: 8px;
    background-image: radial-gradient(circle, rgba(21,94,146,0.35) 1px, transparent 1px);
    background-size: 4px 4px;
    border-radius: 2px;
}

.stat-number {
    font-size: 2.9rem;
    font-weight: 900;
    line-height: 1;
    color: var(--brand-blue);
    letter-spacing: -0.04em;
    display: block;
}

.stat-number::after {
    content: '+';
    font-size: 1.4rem;
    vertical-align: super;
    color: var(--coral);
    font-weight: 700;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 10px;
    letter-spacing: 1.5px;
    display: block;
}

/* ── 内容墙 ── */
.content-wall {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 26px;
}

.content-wall-item {
    background: var(--bg-card);
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: all var(--transition);
    position: relative;
    box-shadow: var(--shadow-soft);
}

.content-wall-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(21, 94, 146, 0.22);
}

.content-wall-item::after {
    content: '';
    position: absolute;
    inset: 0;
    border: 1px solid transparent;
    border-radius: 20px;
    pointer-events: none;
    transition: border-color 0.4s ease;
}

.content-wall-item:hover::after {
    border-color: rgba(255, 122, 89, 0.3);
}

.content-wall-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
    transition: transform 0.6s ease;
}

.content-wall-item:hover img {
    transform: scale(1.04);
}

.content-wall-body {
    padding: 22px 24px 24px;
}

/* ── FAQ ── */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: 16px;
    margin-bottom: 12px;
    overflow: hidden;
    cursor: pointer;
    background: var(--bg-card);
    transition: all 0.35s ease;
    box-shadow: 0 2px 10px rgba(21, 94, 146, 0.03);
}

.faq-item:hover {
    border-color: rgba(21, 94, 146, 0.3);
    box-shadow: 0 6px 24px rgba(21, 94, 146, 0.07);
}

.faq-item.open {
    border-color: rgba(21, 94, 146, 0.35);
    box-shadow: 0 10px 32px rgba(21, 94, 146, 0.1);
}

.faq-item .faq-question {
    padding: 20px 26px;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1rem;
    color: var(--text-primary);
    letter-spacing: 0.01em;
}

.faq-item .faq-question::after {
    content: '+';
    font-size: 1.2rem;
    font-weight: 300;
    color: var(--brand-blue);
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(21, 94, 146, 0.08);
    border-radius: 50%;
    flex-shrink: 0;
    line-height: 1;
}

.faq-item.open .faq-question::after {
    transform: rotate(180deg);
    background: var(--coral);
    color: #fff;
    content: '−';
}

.faq-item .faq-answer {
    padding: 0 26px 20px;
    display: none;
    color: var(--text-secondary);
    border-top: 1px dashed var(--border-color);
    padding-top: 16px;
    font-size: 0.95rem;
    line-height: 1.7;
}

.faq-item.open .faq-answer {
    display: block;
    animation: faqFade 0.35s ease;
}

@keyframes faqFade {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ── CTA 横幅 ── */
.cta-banner {
    padding: 72px 48px;
    text-align: center;
    border-radius: 28px;
    background: linear-gradient(135deg, var(--brand-blue) 0%, #1A7FB3 45%, var(--cyan) 100%);
    color: #fff;
    position: relative;
    overflow: hidden;
    box-shadow: 0 28px 70px rgba(21, 94, 146, 0.35);
}

/* 气泡装饰 */
.cta-banner::before {
    content: '';
    position: absolute;
    top: -70px;
    right: -30px;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(255,255,255,0.18), transparent 62%);
    border-radius: 50%;
}

.cta-banner::after {
    content: '';
    position: absolute;
    bottom: -110px;
    left: -50px;
    width: 260px;
    height: 260px;
    background: radial-gradient(circle, rgba(255,255,255,0.1), transparent 58%);
    border-radius: 50%;
}

/* 网格底纹 */
.cta-banner .container {
    position: relative;
    z-index: 1;
}

.cta-banner h2 {
    font-size: clamp(1.8rem, 3vw, 2.4rem);
    font-weight: 900;
    color: #fff;
    margin-bottom: 10px;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.cta-banner .btn-primary {
    background: #fff;
    color: var(--brand-blue);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
}

.cta-banner .btn-primary:hover {
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    transform: translateY(-3px) scale(1.02);
}

.cta-banner .btn-primary::after {
    background: linear-gradient(100deg, transparent, rgba(21, 94, 146, 0.15), transparent);
}

/* ── 页脚 ── */
.site-footer {
    padding: 68px 0 32px;
    background: linear-gradient(180deg, rgba(234, 240, 244, 0.6), rgba(234, 240, 244, 0.95));
    border-top: 1px solid rgba(214, 225, 233, 0.8);
    margin-top: 40px;
    position: relative;
}

.site-footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(21, 94, 146, 0.25), transparent);
}

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

.footer-brand .logo {
    margin-bottom: 16px;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.75;
    max-width: 280px;
}

.footer-col h4 {
    font-size: 0.82rem;
    font-weight: 800;
    letter-spacing: 2.5px;
    text-transform: uppercase;
    margin-bottom: 20px;
    color: var(--text-primary);
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 22px;
    height: 2px;
    background: linear-gradient(90deg, var(--brand-blue), var(--coral));
    border-radius: 2px;
}

.footer-col ul {
    list-style: none;
}

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

.footer-col ul li a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
}

.footer-col ul li a::before {
    content: '';
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--coral);
    margin-right: 0;
    opacity: 0;
    transition: all 0.3s ease;
}

.footer-col ul li a:hover {
    color: var(--brand-blue);
    transform: translateX(3px);
}

.footer-col ul li a:hover::before {
    opacity: 1;
    margin-right: 8px;
}

.footer-bottom {
    border-top: 1px solid rgba(21, 94, 146, 0.1);
    margin-top: 48px;
    padding-top: 24px;
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ── 工具类 ── */
.text-accent {
    color: var(--brand-blue);
    font-weight: inherit;
}

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

.seo-description {
    max-width: 600px;
    margin: 0 auto 48px;
    color: var(--text-secondary);
    line-height: 1.75;
}

.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }

/* ── 响应式 768px ── */
@media (max-width: 768px) {
    .hero {
        grid-template-columns: 1fr;
        padding-top: 100px;
        gap: 40px;
    }

    .hero-content {
        text-align: center;
        margin: 0 auto;
    }

    .hero p {
        margin-left: auto;
        margin-right: auto;
    }

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

    .hero-image img {
        min-height: 280px;
    }

    .hero::before {
        font-size: 7rem;
    }

    .feature-block {
        grid-template-columns: 1fr;
        gap: 40px;
    }

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

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

    .section {
        padding: 72px 0;
    }

    .main-nav {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(247, 244, 240, 0.98);
        backdrop-filter: blur(18px);
        padding: 24px 24px 32px;
        gap: 18px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 12px 32px rgba(21, 94, 146, 0.08);
    }

    .main-nav.open {
        display: flex;
        align-items: stretch;
    }

    .main-nav a {
        font-size: 1rem;
        padding: 8px 0;
        border-bottom: 1px dashed rgba(21, 94, 146, 0.08);
    }

    .main-nav a:not(.nav-cta)::after {
        display: none;
    }

    .nav-cta {
        text-align: center;
        border-bottom: none !important;
    }

    .menu-toggle {
        display: flex;
    }

    .cta-banner {
        padding: 56px 24px;
    }
}

/* ── 响应式 480px ── */
@media (max-width: 480px) {
    .cards-grid,
    .content-wall,
    .stats-bar {
        grid-template-columns: 1fr;
    }

    .stats-bar {
        gap: 16px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 36px;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .hero-buttons .btn {
        justify-content: center;
    }

    .hero h1 {
        font-size: 2.2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .category-card {
        padding: 26px 22px;
    }
}

/* ── 仅在支持 hover 的设备增强 ── */
@media (hover: hover) {
    .category-card {
        will-change: transform, box-shadow;
    }
}