/* ===== 基础样式 reset+字体 ===== */
@import url('https://fonts.googleapis.com/css2?family=Barlow:wght@400;500;600;700&family=Noto+Sans+SC:wght@300;400;500;600;700;800&display=swap');

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

:root {
    --slate-darkest: #020617;
    --slate-dark: #0F172A;
    --slate: #1E293B;
    --slate-light: #334155;
    --blue: #3B82F6;
    --blue-light: #60A5FA;
    --blue-glow: #93C5FD;
    --green: #10B981;
    --gold: #F59E0B;
    --bg-dark: #0F172A;
    --bg-card: #1E293B;
    --text-on-dark: rgba(255,255,255,0.9);
    --text-muted-on-dark: rgba(255,255,255,0.55);
    --border-dark: #334155;
    --radius: 10px;
    --radius-sm: 6px;
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', 'Barlow', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--slate-dark);
    color: var(--text-on-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul, ol {
    list-style: none;
}

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

/* ===== 导航栏（深石板，5项） ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background: rgba(15, 23, 42, 0.97);
    backdrop-filter: blur(12px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 40px;
    border-bottom: 1px solid rgba(59, 130, 246, 0.2);
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.1);
}

.navbar::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--blue), transparent);
    opacity: 0.6;
    animation: glow-line 3s ease-in-out infinite;
}

@keyframes glow-line {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 0.8; }
}

.navbar-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.navbar-logo .logo-icon {
    font-size: 28px;
    color: var(--blue);
    text-shadow: 0 0 20px rgba(59, 130, 246, 0.5);
}

.navbar-logo .logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--blue);
    letter-spacing: 2px;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: 32px;
}

.navbar-nav a {
    font-size: 15px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.85);
    padding: 8px 0;
    position: relative;
    transition: var(--transition);
}

.navbar-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--blue);
    transition: var(--transition);
}

.navbar-nav a:hover {
    color: var(--blue);
}

.navbar-nav a:hover::after {
    width: 100%;
}

.navbar-cta {
    background: linear-gradient(135deg, var(--blue), #2563EB);
    color: white !important;
    padding: 10px 24px !important;
    border-radius: var(--radius-sm);
    font-weight: 600 !important;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
    transition: var(--transition);
}

.navbar-cta::after {
    display: none !important;
}

.navbar-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.5);
    color: white !important;
}

/* 汉堡菜单按钮 */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 10px;
    z-index: 1001;
}

.hamburger span {
    width: 25px;
    height: 2px;
    background: var(--blue);
    transition: var(--transition);
}

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

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

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

/* 移动端导航 */
.mobile-nav {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--slate-dark);
    padding: 20px;
    border-bottom: 1px solid var(--border-dark);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    z-index: 999;
}

.mobile-nav.active {
    display: block;
}

.mobile-nav a {
    display: block;
    padding: 15px 20px;
    color: rgba(255, 255, 255, 0.85);
    font-size: 16px;
    border-bottom: 1px solid var(--border-dark);
    transition: var(--transition);
}

.mobile-nav a:hover {
    color: var(--blue);
    background: rgba(59, 130, 246, 0.1);
}

.mobile-nav .mobile-cta {
    display: block;
    margin-top: 20px;
    background: linear-gradient(135deg, var(--blue), #2563EB);
    color: white;
    text-align: center;
    border-radius: var(--radius-sm);
    font-weight: 600;
    border: none;
}

/* ===== 页脚（深石板，2栏） ===== */
.footer {
    background: var(--slate-dark);
    padding: 60px 40px 30px;
    border-top: 1px solid var(--border-dark);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid var(--border-dark);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-brand .footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.footer-brand .footer-logo-icon {
    font-size: 32px;
    color: var(--blue);
    text-shadow: 0 0 20px rgba(59, 130, 246, 0.5);
}

.footer-brand .footer-logo-text {
    font-size: 24px;
    font-weight: 700;
    color: var(--blue);
    letter-spacing: 2px;
}

.footer-brand .footer-slogan {
    font-size: 15px;
    color: var(--text-muted-on-dark);
    line-height: 1.8;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.footer-links h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-on-dark);
    margin-bottom: 16px;
}

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

.footer-links ul li a {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    transition: var(--transition);
}

.footer-links ul li a:hover {
    color: var(--blue);
}

.footer-bottom {
    max-width: 1200px;
    margin: 30px auto 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.8;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.6);
    transition: var(--transition);
}

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

/* ===== 公共组件 ===== */

/* 深石板卡片 */
.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 30px;
    position: relative;
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid var(--border-dark);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--blue), var(--blue-light));
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.5);
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% { box-shadow: 0 0 10px rgba(59, 130, 246, 0.3); }
    50% { box-shadow: 0 0 20px rgba(59, 130, 246, 0.6); }
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    border-color: rgba(59, 130, 246, 0.3);
}

/* 亮蓝发光线条 */
.glow-border {
    position: relative;
}

.glow-border::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--blue), var(--blue-light));
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.5);
    animation: pulse-glow 2s ease-in-out infinite;
}

/* 深石板表单 */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-on-dark);
    margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    background: var(--slate-dark);
    border: 1px solid var(--border-dark);
    border-radius: var(--radius-sm);
    color: var(--text-on-dark);
    font-size: 15px;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--blue);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted-on-dark);
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--blue), #2563EB);
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.5);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    border-color: var(--blue);
    color: var(--blue);
    background: rgba(59, 130, 246, 0.1);
}

.btn-green {
    background: linear-gradient(135deg, var(--green), #059669);
    color: white;
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
}

.btn-green:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.5);
}

.btn-gold {
    background: linear-gradient(135deg, var(--gold), #D97706);
    color: white;
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.4);
}

.btn-gold:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(245, 158, 11, 0.5);
}

/* 胶囊标签 */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: rgba(59, 130, 246, 0.15);
    border: 1px solid rgba(59, 130, 246, 0.3);
    border-radius: 20px;
    font-size: 13px;
    color: var(--blue-light);
}

.badge-green {
    background: rgba(16, 185, 129, 0.15);
    border-color: rgba(16, 185, 129, 0.3);
    color: var(--green);
}

.badge-gold {
    background: rgba(245, 158, 11, 0.15);
    border-color: rgba(245, 158, 11, 0.3);
    color: var(--gold);
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 40px;
}

.section {
    padding: 100px 0;
}

.section-dark {
    background: var(--slate-darkest);
}

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

.section-subtitle {
    font-size: 16px;
    color: var(--text-muted-on-dark);
    text-align: center;
    max-width: 600px;
    margin: 0 auto 60px;
}

/* FAQ手风琴 */
.faq-item {
    background: var(--bg-card);
    border-radius: var(--radius);
    margin-bottom: 16px;
    overflow: hidden;
    border: 1px solid var(--border-dark);
}

.faq-question {
    width: 100%;
    padding: 20px 24px;
    background: none;
    border: none;
    color: var(--text-on-dark);
    font-size: 16px;
    font-weight: 600;
    font-family: inherit;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--blue);
}

.faq-question .icon {
    color: var(--blue);
    transition: var(--transition);
}

.faq-item.active .faq-question .icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

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

/* 表格 */
.table-wrapper {
    overflow-x: auto;
    border-radius: var(--radius);
    border: 1px solid var(--border-dark);
}

.table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-card);
}

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

.table th {
    background: var(--slate-dark);
    font-weight: 600;
    color: var(--text-on-dark);
    font-size: 14px;
}

.table td {
    color: var(--text-muted-on-dark);
    font-size: 14px;
}

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

.table tr:hover td {
    background: rgba(59, 130, 246, 0.05);
}

.table .highlight {
    color: var(--blue);
    font-weight: 600;
}

/* 滚动动画 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.fade-in-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.fade-in-right {
    opacity: 0;
    transform: translateX(50px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* ===== 首页专属 ===== */

/* Hero区 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding-top: 72px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 50%;
    height: 100%;
    background: var(--slate-dark);
    z-index: 0;
}

.hero::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: var(--slate);
    z-index: 0;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 40px;
}

.hero-content {
    padding-right: 40px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(59, 130, 246, 0.15);
    border: 1px solid rgba(59, 130, 246, 0.3);
    border-radius: 20px;
    font-size: 13px;
    color: var(--blue-light);
    margin-bottom: 24px;
}

.hero-title {
    font-size: 44px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    color: var(--text-on-dark);
}

.hero-title .highlight {
    color: var(--blue);
    text-shadow: 0 0 30px rgba(59, 130, 246, 0.3);
}

.hero-subtitle {
    font-size: 17px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
    margin-bottom: 32px;
}

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

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

.hero-device {
    width: 320px;
    height: 400px;
    background: linear-gradient(145deg, var(--slate-dark), var(--slate));
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border: 2px solid rgba(59, 130, 246, 0.3);
    box-shadow: 0 0 60px rgba(59, 130, 246, 0.2), inset 0 0 60px rgba(59, 130, 246, 0.05);
    position: relative;
}

.hero-device::before {
    content: '';
    position: absolute;
    top: -2px;
    left: 20%;
    right: 20%;
    height: 4px;
    background: linear-gradient(90deg, transparent, var(--blue), transparent);
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.8);
    animation: device-glow 2s ease-in-out infinite;
}

@keyframes device-glow {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

.hero-device-icon {
    font-size: 80px;
    margin-bottom: 20px;
    filter: drop-shadow(0 0 30px rgba(59, 130, 246, 0.5));
}

.hero-device-name {
    font-size: 20px;
    font-weight: 700;
    color: var(--blue);
    margin-bottom: 8px;
}

.hero-device-model {
    font-size: 14px;
    color: var(--text-muted-on-dark);
}

/* 即开即用说明区 */
.easy-start {
    background: var(--slate-dark);
    padding: 100px 0;
}

.easy-start-steps {
    display: flex;
    flex-direction: column;
    gap: 24px;
    max-width: 800px;
    margin: 0 auto;
}

.easy-step {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 32px;
    display: flex;
    align-items: flex-start;
    gap: 24px;
    border-left: 4px solid var(--blue);
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.1);
    position: relative;
}

.easy-step::after {
    content: '';
    position: absolute;
    bottom: -36px;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 24px;
    background: linear-gradient(to bottom, var(--blue), transparent);
}

.easy-step:last-child::after {
    display: none;
}

.easy-step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--blue), #2563EB);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.easy-step-content h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 8px;
}

.easy-step-content p {
    font-size: 15px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
}

.easy-highlight {
    text-align: center;
    margin-top: 50px;
    padding: 24px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius);
    border: 1px dashed rgba(59, 130, 246, 0.3);
}

.easy-highlight p {
    font-size: 16px;
    color: var(--text-muted-on-dark);
}

/* 4G大机优势区 */
.pos-advantages {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.advantage-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.advantage-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 36px;
    text-align: center;
    border: 1px solid var(--border-dark);
    transition: var(--transition);
}

.advantage-card:hover {
    transform: translateY(-5px);
    border-color: rgba(59, 130, 246, 0.3);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.advantage-icon {
    width: 70px;
    height: 70px;
    background: rgba(59, 130, 246, 0.15);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    margin: 0 auto 20px;
}

.advantage-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 12px;
}

.advantage-card p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
}

/* 产品展示区 */
.products {
    background: var(--slate-dark);
    padding: 100px 0;
}

.product-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.product-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--border-dark);
    transition: var(--transition);
    position: relative;
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--blue), var(--blue-light));
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.5);
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.4);
}

.product-image {
    height: 200px;
    background: linear-gradient(145deg, var(--slate-dark), var(--slate));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 64px;
}

.product-info {
    padding: 28px;
}

.product-name {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 4px;
}

.product-model {
    font-size: 13px;
    color: var(--text-muted-on-dark);
    margin-bottom: 16px;
}

.product-tags {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.product-features {
    margin-bottom: 20px;
}

.product-features li {
    font-size: 13px;
    color: var(--text-muted-on-dark);
    padding: 6px 0;
    border-bottom: 1px solid rgba(51, 65, 85, 0.5);
    display: flex;
    align-items: center;
    gap: 8px;
}

.product-features li:last-child {
    border-bottom: none;
}

.product-features li::before {
    content: '✓';
    color: var(--blue);
    font-weight: bold;
}

.products-footer {
    text-align: center;
    margin-top: 50px;
}

.products-footer p {
    font-size: 15px;
    color: var(--text-muted-on-dark);
    margin-bottom: 20px;
}

.products-footer a {
    color: var(--blue);
    font-weight: 600;
}

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

/* 安全可靠说明区 */
.safety {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.safety-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.safety-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 36px;
    border: 1px solid var(--border-dark);
    transition: var(--transition);
}

.safety-card:hover {
    transform: translateY(-5px);
    border-color: rgba(16, 185, 129, 0.3);
}

.safety-icon {
    width: 60px;
    height: 60px;
    background: rgba(16, 185, 129, 0.15);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin-bottom: 20px;
}

.safety-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 12px;
}

.safety-card p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
}

.safety-highlight {
    text-align: center;
    margin-top: 50px;
    padding: 20px;
    background: rgba(16, 185, 129, 0.1);
    border-radius: var(--radius);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.safety-highlight p {
    font-size: 15px;
    color: var(--green);
    font-weight: 500;
}

/* 为什么选瑞银信 */
.why-us {
    background: var(--slate-dark);
    padding: 100px 0;
}

.why-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.why-card {
    text-align: center;
    padding: 40px 24px;
}

.why-number {
    font-size: 48px;
    font-weight: 800;
    font-family: 'Barlow', sans-serif;
    color: var(--blue);
    margin-bottom: 16px;
    text-shadow: 0 0 30px rgba(59, 130, 246, 0.3);
}

.why-icon {
    font-size: 40px;
    margin-bottom: 16px;
}

.why-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 12px;
}

.why-card p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
}

/* 底部CTA申请区 */
.cta-section {
    background: var(--slate-dark);
    padding: 100px 0;
}

.cta-container {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.cta-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 20px;
}

.cta-features {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.cta-features span {
    font-size: 14px;
    color: var(--text-muted-on-dark);
}

.cta-features span::before {
    content: '|';
    margin-right: 12px;
    color: var(--blue);
}

.cta-features span:first-child::before {
    display: none;
}

.cta-form {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 40px;
    border: 1px solid var(--border-dark);
}

.cta-form .form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.cta-form .btn {
    width: 100%;
    margin-top: 10px;
}

.cta-note {
    margin-top: 20px;
    font-size: 13px;
    color: var(--text-muted-on-dark);
}

/* ===== 4G大机页专属 ===== */
.page-hero {
    padding: 140px 0 80px;
    background: var(--slate-dark);
    text-align: left;
}

.page-hero .container {
    max-width: 800px;
}

.page-hero h1 {
    font-size: 42px;
    font-weight: 800;
    color: var(--text-on-dark);
    margin-bottom: 16px;
}

.page-hero p {
    font-size: 17px;
    color: var(--text-muted-on-dark);
}

/* 即开即用技术解析 */
.tech-analysis {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.tech-points {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.tech-point {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 32px;
    border: 1px solid var(--border-dark);
    transition: var(--transition);
}

.tech-point:hover {
    border-color: rgba(59, 130, 246, 0.3);
    transform: translateY(-5px);
}

.tech-point-icon {
    width: 56px;
    height: 56px;
    background: rgba(59, 130, 246, 0.15);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
    margin-bottom: 20px;
}

.tech-point h3 {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 10px;
}

.tech-point p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
}

.tech-emphasis {
    text-align: center;
    margin-top: 50px;
    padding: 24px;
    background: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius);
    border: 1px dashed rgba(59, 130, 246, 0.3);
}

.tech-emphasis p {
    font-size: 16px;
    color: var(--blue);
    font-weight: 500;
}

/* 4G大机对比 */
.comparison {
    background: var(--slate-dark);
    padding: 100px 0;
}

.comparison-table {
    margin-bottom: 40px;
}

.comparison-table .table th:first-child,
.comparison-table .table td:first-child {
    font-weight: 600;
    color: var(--text-on-dark);
}

.comparison-note {
    text-align: center;
    padding: 24px;
    background: var(--bg-card);
    border-radius: var(--radius);
    border: 1px solid var(--border-dark);
}

.comparison-note p {
    font-size: 15px;
    color: var(--text-muted-on-dark);
}

/* 产品详情 */
.product-details {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.product-detail {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 40px;
    margin-bottom: 40px;
    border: 1px solid var(--border-dark);
}

.product-detail-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 24px;
}

.product-detail-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(145deg, var(--slate-dark), var(--slate));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.product-detail-title h3 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-on-dark);
}

.product-detail-title p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
}

.product-detail-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.product-specs h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-on-dark);
    margin-bottom: 16px;
}

.product-specs ul li {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    padding: 8px 0;
    border-bottom: 1px solid rgba(51, 65, 85, 0.5);
    display: flex;
    align-items: center;
    gap: 10px;
}

.product-specs ul li::before {
    content: '✓';
    color: var(--blue);
}

.product-suitable h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-on-dark);
    margin-bottom: 16px;
}

.product-suitable p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
}

/* 参数对比表 */
.specs-table {
    background: var(--slate-dark);
    padding: 100px 0;
}

.specs-table .table-wrapper {
    background: var(--bg-card);
}

/* ===== 安全可靠页专属 ===== */
.safety-intro {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.safety-guarantees {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.safety-guarantee {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 36px;
    border: 1px solid var(--border-dark);
    transition: var(--transition);
}

.safety-guarantee:hover {
    transform: translateY(-5px);
    border-color: rgba(16, 185, 129, 0.3);
}

.safety-guarantee-icon {
    width: 64px;
    height: 64px;
    background: rgba(16, 185, 129, 0.15);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 30px;
    margin-bottom: 24px;
}

.safety-guarantee h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 12px;
}

.safety-guarantee > p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
    margin-bottom: 16px;
}

.safety-guarantee .detail {
    font-size: 14px;
    color: var(--green);
    line-height: 1.7;
    padding-top: 16px;
    border-top: 1px solid var(--border-dark);
}

/* 安全对比表 */
.safety-compare {
    background: var(--slate-dark);
    padding: 100px 0;
}

/* 安全FAQ */
.safety-faq {
    background: var(--slate-darkest);
    padding: 100px 0;
}

/* ===== 办理入口页专属 ===== */
.notice-section {
    background: var(--slate-dark);
    padding: 100px 0;
}

.notice-list {
    max-width: 800px;
    margin: 0 auto;
}

.notice-item {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 24px 28px;
    margin-bottom: 20px;
    border-left: 4px solid var(--blue);
    display: flex;
    align-items: flex-start;
    gap: 20px;
}

.notice-icon {
    width: 48px;
    height: 48px;
    background: rgba(59, 130, 246, 0.15);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    flex-shrink: 0;
}

.notice-content h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-on-dark);
    margin-bottom: 6px;
}

.notice-content p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
}

/* 办理流程 */
.process-section {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.process-steps {
    display: flex;
    flex-direction: column;
    gap: 24px;
    max-width: 600px;
    margin: 0 auto;
}

.process-step {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 28px;
    display: flex;
    align-items: center;
    gap: 24px;
    border: 1px solid var(--border-dark);
    position: relative;
}

.process-step::after {
    content: '↓';
    position: absolute;
    bottom: -32px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 24px;
    color: var(--blue);
}

.process-step:last-child::after {
    display: none;
}

.process-number {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--blue), #2563EB);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.process-content h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 6px;
}

.process-content p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
}

/* 申请表单 */
.apply-section {
    background: var(--slate-dark);
    padding: 100px 0;
}

.apply-form {
    max-width: 700px;
    margin: 0 auto;
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 40px;
    border: 1px solid var(--border-dark);
}

.apply-form h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-on-dark);
    text-align: center;
    margin-bottom: 32px;
}

.apply-form .form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.apply-form textarea {
    resize: vertical;
    min-height: 100px;
}

.apply-form .btn {
    width: 100%;
    margin-top: 10px;
    font-size: 16px;
    padding: 16px;
}

.form-success {
    display: none;
    text-align: center;
    padding: 40px;
}

.form-success.show {
    display: block;
}

.form-success-icon {
    font-size: 64px;
    margin-bottom: 20px;
}

.form-success h4 {
    font-size: 22px;
    font-weight: 700;
    color: var(--green);
    margin-bottom: 12px;
}

.form-success p {
    font-size: 15px;
    color: var(--text-muted-on-dark);
}

/* 申请FAQ */
.apply-faq {
    background: var(--slate-darkest);
    padding: 100px 0;
}

/* ===== 关于页专属 ===== */
.brand-intro {
    background: var(--slate-dark);
    padding: 100px 0;
    text-align: center;
}

.brand-intro p {
    max-width: 800px;
    margin: 0 auto;
    font-size: 17px;
    color: var(--text-muted-on-dark);
    line-height: 1.9;
}

.brand-advantages {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.brand-advantage-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.brand-advantage-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 36px;
    text-align: center;
    border: 1px solid var(--border-dark);
    transition: var(--transition);
}

.brand-advantage-card:hover {
    transform: translateY(-5px);
    border-color: rgba(59, 130, 246, 0.3);
}

.brand-advantage-number {
    font-size: 14px;
    font-weight: 700;
    color: var(--blue);
    margin-bottom: 12px;
}

.brand-advantage-icon {
    font-size: 40px;
    margin-bottom: 16px;
}

.brand-advantage-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 12px;
}

.brand-advantage-card p {
    font-size: 14px;
    color: var(--text-muted-on-dark);
    line-height: 1.7;
}

/* 品牌数据 */
.brand-stats {
    background: var(--slate-dark);
    padding: 80px 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

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

.stat-icon {
    font-size: 40px;
    margin-bottom: 12px;
}

.stat-value {
    font-size: 36px;
    font-weight: 800;
    font-family: 'Barlow', sans-serif;
    color: var(--blue);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 15px;
    color: var(--text-muted-on-dark);
}

/* 资质展示 */
.qualifications {
    background: var(--slate-darkest);
    padding: 100px 0;
}

.qualifications-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.qualification-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 32px;
    text-align: center;
    border: 1px solid var(--border-dark);
    transition: var(--transition);
}

.qualification-card:hover {
    transform: translateY(-5px);
    border-color: rgba(59, 130, 246, 0.3);
}

.qualification-icon {
    width: 64px;
    height: 64px;
    background: rgba(59, 130, 246, 0.15);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 30px;
    margin: 0 auto 16px;
}

.qualification-card h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-on-dark);
}

/* 联系CTA */
.contact-cta {
    background: var(--slate-dark);
    padding: 100px 0;
    text-align: center;
}

.contact-cta h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-on-dark);
    margin-bottom: 24px;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .hero-container {
        grid-template-columns: 1fr;
        gap: 60px;
        text-align: center;
    }

    .hero-content {
        padding-right: 0;
    }

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

    .advantage-cards,
    .product-cards,
    .safety-cards,
    .why-cards,
    .tech-points,
    .safety-guarantees,
    .brand-advantage-cards,
    .stats-grid,
    .qualifications-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .product-detail-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 0 20px;
    }

    .navbar-nav {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    .container {
        padding: 0 20px;
    }

    .section {
        padding: 70px 0;
    }

    .hero {
        min-height: auto;
        padding: 120px 0 60px;
    }

    .hero-title {
        font-size: 32px;
    }

    .hero-device {
        width: 260px;
        height: 320px;
    }

    .section-title {
        font-size: 28px;
    }

    .advantage-cards,
    .product-cards,
    .safety-cards,
    .why-cards,
    .tech-points,
    .safety-guarantees,
    .brand-advantage-cards,
    .stats-grid,
    .qualifications-grid {
        grid-template-columns: 1fr;
    }

    .cta-form {
        padding: 24px;
    }

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

    .apply-form {
        padding: 24px;
    }

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

    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

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

    .page-hero h1 {
        font-size: 32px;
    }

    .product-detail {
        padding: 24px;
    }

    .table th,
    .table td {
        padding: 12px 14px;
        font-size: 13px;
    }
}