/* ========== 全局样式 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #a5b4fc;
    --secondary: #06b6d4;
    --accent: #f59e0b;
    --dark: #0f172a;
    --dark-2: #1e293b;
    --dark-3: #334155;
    --gray: #64748b;
    --gray-light: #cbd5e1;
    --light: #f8fafc;
    --white: #ffffff;
    --gradient-1: linear-gradient(135deg, #6366f1 0%, #06b6d4 100%);
    --gradient-2: linear-gradient(135deg, #f59e0b 0%, #ef4444 100%);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.2);
    --radius: 12px;
    --radius-lg: 20px;
}

html {
    scroll-behavior: smooth;
}

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

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

/* ========== 导航栏 ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: all 0.3s ease;
}

.navbar.scrolled {
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    max-width: 280px;
}

.logo-img {
    height: auto !important;
    max-height: 80px !important;
    width: auto !important;
    max-width: 260px !important;
    display: block;
    object-fit: contain;
}

.footer-brand .logo {
    max-width: 200px;
}

.footer-brand .logo-img {
    height: auto !important;
    max-height: 70px !important;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 8px;
}

.nav-links a {
    text-decoration: none;
    color: var(--gray);
    font-weight: 500;
    font-size: 15px;
    padding: 8px 16px;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
    background: rgba(99, 102, 241, 0.08);
}

.cta-btn {
    background: var(--gradient-1);
    color: white;
    border: none;
    padding: 10px 24px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.cta-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.mobile-menu {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.mobile-menu span {
    width: 24px;
    height: 2px;
    background: var(--dark);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* ========== Hero 区域 ========== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
    padding-top: 72px;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 50%, rgba(6, 182, 212, 0.15) 0%, transparent 50%);
}

.grid-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 60px 60px;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 60px 24px;
    max-width: 900px;
}

.hero-badge {
    display: inline-block;
    background: rgba(99, 102, 241, 0.2);
    border: 1px solid rgba(99, 102, 241, 0.3);
    color: var(--primary-light);
    padding: 8px 20px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 32px;
    animation: fadeInDown 0.8s ease;
}

.hero h1 {
    font-size: 64px;
    font-weight: 700;
    color: var(--white);
    line-height: 1.2;
    margin-bottom: 24px;
    animation: fadeInUp 0.8s ease;
}

.gradient-text {
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 18px;
    color: var(--gray-light);
    line-height: 1.8;
    margin-bottom: 48px;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    margin-bottom: 48px;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

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

.stat-number {
    display: block;
    font-size: 48px;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    display: block;
    font-size: 14px;
    color: var(--gray-light);
    margin-top: 4px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    animation: fadeInUp 0.8s ease 0.6s backwards;
}

.btn-primary {
    background: var(--gradient-1);
    color: white;
    border: none;
    padding: 16px 36px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 16px 36px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-3px);
}

.hero-buttons .btn-secondary {
    display: inline-block;
    text-align: center;
    text-decoration: none;
    background: linear-gradient(135deg, #f97316 0%, #ea580c 100%) !important;
    border: none !important;
    box-shadow: 0 4px 15px rgba(249, 115, 22, 0.4);
}

.hero-buttons .btn-secondary:hover {
    background: linear-gradient(135deg, #ea580c 0%, #c2410c 100%) !important;
    box-shadow: 0 6px 20px rgba(249, 115, 22, 0.5);
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: var(--gray-light);
    font-size: 12px;
    animation: bounce 2s infinite;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    margin: 8px auto 0;
    border-right: 2px solid var(--gray-light);
    border-bottom: 2px solid var(--gray-light);
    transform: rotate(45deg);
}

/* ========== 课程体系 ========== */
.courses-section {
    padding: 120px 0;
    background: var(--light);
}

.section-header {
    text-align: center;
    margin-bottom: 80px;
}

.section-tag {
    display: inline-block;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 3px;
    color: var(--primary);
    margin-bottom: 16px;
}

.section-header h2 {
    font-size: 42px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 16px;
}

.section-header p {
    font-size: 18px;
    color: var(--gray);
}

.stage-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.stage-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all 0.4s ease;
    border: 1px solid rgba(0,0,0,0.06);
}

.stage-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.stage-header {
    padding: 32px;
    color: white;
    position: relative;
    overflow: hidden;
}

.stage-1 {
    background: linear-gradient(135deg, #6366f1 0%, #818cf8 100%);
}

.stage-2 {
    background: linear-gradient(135deg, #06b6d4 0%, #22d3ee 100%);
}

.stage-3 {
    background: linear-gradient(135deg, #f59e0b 0%, #fbbf24 100%);
}

.stage-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 16px;
}

.stage-header h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 12px;
}

.stage-meta {
    font-size: 14px;
    opacity: 0.9;
}

.stage-body {
    padding: 32px;
}

.stage-goal {
    font-size: 14px;
    color: var(--gray);
    line-height: 1.8;
    margin-bottom: 24px;
    padding-bottom: 24px;
    border-bottom: 1px solid rgba(0,0,0,0.06);
}

.stage-goal strong {
    color: var(--dark);
}

.module-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.module-item {
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

.module-icon {
    font-size: 24px;
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--light);
    border-radius: 10px;
}

.module-item strong {
    display: block;
    font-size: 14px;
    color: var(--dark);
    margin-bottom: 4px;
}

.module-item p {
    font-size: 13px;
    color: var(--gray);
    line-height: 1.5;
}

.stage-topics {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.topic-tag {
    display: inline-block;
    background: var(--light);
    color: var(--primary);
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    border: 1px solid rgba(99, 102, 241, 0.1);
}

/* ========== 企业简介 ========== */
.about-section {
    padding: 120px 0;
    background: var(--dark);
    color: var(--white);
}

.about-section .section-header.light h2,
.about-section .section-header.light p {
    color: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.about-text h3 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 20px;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.about-text p {
    font-size: 16px;
    color: var(--gray-light);
    line-height: 1.8;
    margin-bottom: 16px;
}

.about-features {
    margin-top: 32px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.feature-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.feature-icon {
    font-size: 28px;
    flex-shrink: 0;
}

.feature-item strong {
    display: block;
    font-size: 16px;
    color: var(--white);
    margin-bottom: 4px;
}

.feature-item p {
    font-size: 14px;
    color: var(--gray);
    margin: 0;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.about-stat-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius);
    padding: 32px;
    text-align: center;
    transition: all 0.3s ease;
}

.about-stat-card:hover {
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-4px);
}

.stat-number-large {
    font-size: 48px;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.stat-desc {
    font-size: 14px;
    color: var(--gray-light);
}

/* ========== 联系我们 ========== */
.contact-section {
    padding: 120px 0;
    background: var(--light);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(0,0,0,0.06);
    transition: all 0.3s ease;
}

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

.contact-icon {
    font-size: 32px;
    margin-bottom: 12px;
}

.contact-card h4 {
    font-size: 18px;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 8px;
}

.contact-card p {
    font-size: 16px;
    color: var(--dark);
    font-weight: 500;
}

.contact-detail {
    display: block;
    font-size: 13px;
    color: var(--gray);
    margin-top: 8px;
}

.contact-form-wrapper {
    position: sticky;
    top: 96px;
}

.contact-form {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(0,0,0,0.06);
}

.contact-form h3 {
    font-size: 24px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 32px;
}

.form-group {
    margin-bottom: 20px;
}

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid rgba(0,0,0,0.1);
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    transition: all 0.2s ease;
    background: var(--light);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--white);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    resize: vertical;
}

.full-width {
    width: 100%;
}

/* ========== 页脚 ========== */
.footer {
    background: var(--dark-2);
    color: var(--white);
    padding: 80px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-brand p {
    font-size: 14px;
    color: var(--gray-light);
    line-height: 1.8;
    margin-top: 16px;
}

.footer-links h4,
.footer-contact h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
}

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

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: var(--gray-light);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s ease;
}

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

.footer-contact p {
    font-size: 14px;
    color: var(--gray-light);
    margin-bottom: 12px;
}

.footer-bottom {
    padding: 24px 0;
    text-align: center;
    font-size: 13px;
    color: var(--gray);
}

.footer-bottom a {
    color: var(--gray-light);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

/* ========== 回到顶部 ========== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-1);
    color: white;
    border: none;
    font-size: 20px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
    box-shadow: var(--shadow-md);
}

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

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

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

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* ========== 响应式设计 ========== */
@media (max-width: 1024px) {
    .stage-cards {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .cta-btn {
        display: none;
    }
    
    .mobile-menu {
        display: flex;
    }
    
    .hero h1 {
        font-size: 36px;
    }
    
    .hero-desc {
        font-size: 16px;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .section-header h2 {
        font-size: 32px;
    }
    
    .about-stats {
        grid-template-columns: 1fr 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 28px;
    }
    
    .stat-number {
        font-size: 36px;
    }
    
    .contact-form {
        padding: 24px;
    }
}

/* ========== 为什么选择 AI Infra ========== */
.why-section {
    padding: 120px 0;
    background: var(--white);
}

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

.why-card {
    background: var(--light);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid rgba(0,0,0,0.06);
}

.why-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.why-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

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

.why-card p {
    font-size: 14px;
    color: var(--gray);
    line-height: 1.8;
}

.why-card strong {
    color: var(--primary);
    font-weight: 700;
}

/* ========== 学习收获 ========== */
.outcomes-section {
    padding: 120px 0;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

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

.outcome-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 36px;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    border: 1px solid rgba(0,0,0,0.06);
    position: relative;
    overflow: hidden;
}

.outcome-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-1);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

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

.outcome-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.outcome-number {
    font-size: 48px;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 16px;
}

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

.outcome-card p {
    font-size: 14px;
    color: var(--gray);
    line-height: 1.8;
}

/* ========== 学员案例 ========== */
.testimonials-section {
    padding: 120px 0;
    background: var(--dark);
    color: var(--white);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.testimonial-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all 0.3s ease;
}

.testimonial-card:hover {
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-4px);
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}

.testimonial-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
}

.testimonial-avatar {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--gradient-1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
}

.testimonial-name {
    font-size: 18px;
    font-weight: 600;
    color: var(--white);
    margin-bottom: 4px;
}

.testimonial-title {
    font-size: 13px;
    color: var(--gray-light);
}

.testimonial-content {
    font-size: 15px;
    color: var(--gray-light);
    line-height: 1.8;
    margin-bottom: 16px;
    font-style: italic;
}

.testimonial-tag {
    display: inline-block;
    background: rgba(99, 102, 241, 0.2);
    border: 1px solid rgba(99, 102, 241, 0.3);
    color: var(--primary-light);
    padding: 6px 16px;
    border-radius: 50px;
    font-size: 13px;
    font-weight: 500;
}

/* ========== 限时优惠 ========== */
.offer-section {
    padding: 80px 0;
    background: var(--light);
}

.offer-banner {
    background: var(--gradient-2);
    border-radius: var(--radius-lg);
    padding: 64px;
    text-align: center;
    color: white;
    position: relative;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(245, 158, 11, 0.3);
}

.offer-banner::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 500px;
    height: 500px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
}

.offer-banner::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 400px;
    height: 400px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 50%;
}

.offer-content {
    position: relative;
    z-index: 2;
}

.offer-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    padding: 8px 24px;
    border-radius: 50px;
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 24px;
}

.offer-banner h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
}

.highlight {
    background: rgba(255, 255, 255, 0.25);
    padding: 4px 16px;
    border-radius: 8px;
    font-weight: 800;
}

.offer-banner p {
    font-size: 18px;
    opacity: 0.95;
    margin-bottom: 24px;
    line-height: 1.8;
}

.offer-countdown {
    font-size: 18px;
    margin-bottom: 8px;
}

.countdown-number {
    display: inline-block;
    background: rgba(255, 255, 255, 0.25);
    padding: 4px 16px;
    border-radius: 8px;
    font-weight: 800;
    font-size: 24px;
    margin: 0 8px;
}

.offer-banner .btn-primary {
    background: white;
    color: var(--accent);
    font-weight: 700;
    font-size: 18px;
    padding: 18px 48px;
}

.offer-banner .btn-primary:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(255, 255, 255, 0.4);
}

/* ========== 响应式优化 ========== */
@media (max-width: 1024px) {
    .why-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .outcomes-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .why-grid {
        grid-template-columns: 1fr;
    }
    
    .outcomes-grid {
        grid-template-columns: 1fr;
    }
    
    .offer-banner {
        padding: 48px 24px;
    }
    
    .offer-banner h2 {
        font-size: 32px;
    }
}

@media (max-width: 480px) {
    .why-card {
        padding: 28px 20px;
    }
    
    .outcome-card {
        padding: 28px;
    }
    
    .testimonial-card {
        padding: 24px;
    }
    
    .offer-banner h2 {
        font-size: 24px;
    }
    
    .highlight {
        font-size: 20px;
    }
}