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

:root {
    --primary: #0066FF;
    --primary-light: #3385FF;
    --primary-dark: #0052CC;
    --text-dark: #1A1A2E;
    --text-gray: #6B7280;
    --text-light: #9CA3AF;
    --bg-white: #FFFFFF;
    --bg-gray: #F7F8FA;
    --bg-light: #F3F4F6;
    --border: #E5E7EB;
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 8px 32px rgba(0, 0, 0, 0.1);
}

html { scroll-behavior: smooth; }

body {
    font-family: 'Noto Sans SC', 'Inter', sans-serif;
    color: var(--text-dark);
    background: var(--bg-white);
    line-height: 1.6;
}

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
}

.navbar .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.logo-icon {
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.logo-icon svg { width: 24px; height: 24px; fill: white; }

.logo-icon img {
    height: 100%;
    width: auto;
    max-width: 160px;
    object-fit: contain;
    display: block;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-dark);
}

.logo-text span { color: var(--primary); }

.nav-links {
    display: flex;
    align-items: center;
    gap: 40px;
}

.nav-links a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-dark);
    transition: color 0.2s;
    position: relative;
}

.nav-links a:hover,
.nav-links a.active { color: var(--primary); }

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: 1px;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.login-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    background: #12B7F5;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    color: white;
    transition: all 0.2s;
    cursor: pointer;
}

.login-btn:hover {
    background: #0E9ED8;
    transform: translateY(-2px);
}

.login-btn svg { width: 18px; height: 18px; fill: white; }

/* 用户头像菜单 */
.user-menu-container {
    position: relative;
    display: flex;
    align-items: center;
}

.user-menu-trigger {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px 6px 6px;
    border-radius: 24px;
    cursor: pointer;
    transition: all 0.2s;
    background: rgba(0, 0, 0, 0.05);
}

.user-menu-trigger:hover {
    background: rgba(0, 0, 0, 0.1);
}

.user-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid rgba(0, 102, 255, 0.3);
}

.nav-avatar-wrap {
    position: relative;
    display: inline-block;
}

.nav-vip-badge {
    position: absolute;
    bottom: -2px;
    right: -2px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    font-size: 9px;
    font-weight: 700;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1.5px solid white;
    line-height: 1;
}
.nav-vip-badge.super { background: linear-gradient(135deg, #FF6B35, #FF8F5E); }
.nav-vip-badge.lifetime { background: linear-gradient(135deg, #FFD700, #FFA500); }
.nav-vip-badge.yearly { background: linear-gradient(135deg, #10B981, #34D399); }

.nav-vip-tag {
    font-size: 11px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 10px;
    line-height: 1.4;
}
.nav-vip-tag.super { background: rgba(255,107,53,0.1); color: #FF6B35; }
.nav-vip-tag.lifetime { background: rgba(255,215,0,0.15); color: #B8860B; }
.nav-vip-tag.yearly { background: rgba(16,185,129,0.1); color: #10B981; }

.user-name {
    font-size: 14px;
    font-weight: 500;
    color: #1A1A2E;
    white-space: nowrap;
    max-width: 80px;
    overflow: hidden;
    text-overflow: ellipsis;
}

.user-menu-arrow {
    width: 14px;
    height: 14px;
    fill: #6B7280;
    transition: transform 0.2s;
}

.user-menu-container:hover .user-menu-arrow {
    transform: rotate(180deg);
}

.user-menu-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 180px;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    padding: 8px 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s;
    z-index: 1000;
}

.user-menu-container:hover .user-menu-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.user-menu-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    font-size: 14px;
    color: #374151;
    text-decoration: none;
    transition: background 0.2s;
    cursor: pointer;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
}

.user-menu-item:hover {
    background: #F3F4F6;
}

.user-menu-item svg {
    width: 18px;
    height: 18px;
    fill: #6B7280;
}

.user-menu-item.logout {
    color: #EF4444;
}

.user-menu-item.logout svg {
    fill: #EF4444;
}

.user-menu-item.logout:hover {
    background: #FEF2F2;
}

.user-menu-divider {
    height: 1px;
    background: #E5E7EB;
    margin: 8px 0;
}

.user-menu-form {
    margin: 0;
    padding: 0;
}

/* 汉堡菜单 */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
}

.menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-dark);
    border-radius: 1px;
    transition: all 0.3s;
}

/* 移动端菜单 */
.mobile-menu {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    max-height: calc(100vh - 72px);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    background: white;
    border-bottom: 1px solid var(--border);
    padding: 20px 24px 40px;
    z-index: 999;
}

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

.mobile-menu a {
    display: block;
    padding: 14px 0;
    font-size: 16px;
    font-weight: 500;
    color: var(--text-dark);
    border-bottom: 1px solid var(--bg-light);
}

.mobile-menu a:last-child { border-bottom: none; }

.mobile-login-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    margin-top: 16px;
    padding: 12px;
    background: #12B7F5;
    border-radius: 8px;
    color: white;
    font-weight: 500;
    font-size: 14px;
}

.mobile-login-btn svg {
    width: 18px;
    height: 18px;
    fill: white;
}

/* 主内容 */
main { padding-top: 72px; }

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

/* 轮播Banner区 */
.banner-slider {
    position: relative;
    height: calc(100vh - 72px);
    min-height: 500px;
    overflow: hidden;
}

.banner-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #0066FF 0%, #00C6FF 50%, #00FF88 100%);
}

.banner-slide.active { display: flex; }

.banner-slide:nth-child(1) {
    background: linear-gradient(135deg, #0066FF 0%, #00C6FF 50%, #00FF88 100%);
}

.banner-slide:nth-child(2) {
    background: linear-gradient(135deg, #8B5CF6 0%, #A78BFA 50%, #C4B5FD 100%);
}

.banner-slide:nth-child(3) {
    background: linear-gradient(135deg, #10B981 0%, #34D399 50%, #6EE7B7 100%);
}

.banner-slide:nth-child(4) {
    background: linear-gradient(135deg, #F59E0B 0%, #FBBF24 50%, #FCD34D 100%);
}

.banner-slide:nth-child(5) {
    background: linear-gradient(135deg, #EF4444 0%, #F87171 50%, #FCA5A5 100%);
}

.banner-slide:nth-child(6) {
    background: linear-gradient(135deg, #EC4899 0%, #F472B6 50%, #F9A8D4 100%);
}

.banner-content {
    max-width: 1200px;
    width: 100%;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.banner-text h1 {
    font-size: 52px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    color: white;
}

.banner-text h1 span {
    background: rgba(255, 255, 255, 0.9);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.banner-text p {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 32px;
    max-width: 480px;
}

.banner-btns {
    display: flex;
    gap: 16px;
}

.btn-primary {
    padding: 14px 32px;
    background: white;
    color: var(--primary);
    border-radius: 8px;
    font-weight: 600;
    font-size: 15px;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    padding: 14px 32px;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    font-weight: 600;
    font-size: 15px;
    transition: all 0.2s;
    cursor: pointer;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
}

.banner-stats {
    display: flex;
    gap: 40px;
    margin-top: 48px;
}

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

.stat-item h3 {
    font-size: 36px;
    font-weight: 700;
    color: white;
}

.stat-item p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.8);
    margin-top: 4px;
}

.banner-visual {
    position: relative;
}

.banner-visual img {
    width: 100%;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

/* 轮播指示器 */
.slider-dots {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
}

.slider-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s;
}

.slider-dot.active {
    width: 32px;
    border-radius: 6px;
    background: white;
}

/* 轮播箭头 */
.slider-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 56px;
    height: 56px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s;
    z-index: 10;
}

.slider-arrow:hover {
    background: rgba(255, 255, 255, 0.4);
}

.slider-arrow svg {
    width: 24px;
    height: 24px;
    fill: white;
}

.slider-arrow.left { left: 30px; }
.slider-arrow.right { right: 30px; }

/* 公告区 */
.announcement {
    padding: 40px 0;
    border-bottom: 1px solid var(--border);
}

.announcement-content {
    display: flex;
    align-items: center;
    gap: 40px;
}

.announcement-label {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--bg-gray);
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    flex-shrink: 0;
}

.announcement-label svg { width: 16px; height: 16px; fill: var(--primary); }

.announcement-scroll {
    flex: 1;
    overflow: hidden;
    height: 56px;
}

.announcement-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    animation: scroll-up 15s linear infinite;
}

.announcement-list:hover {
    animation-play-state: paused;
}

@keyframes scroll-up {
    0% { transform: translateY(0); }
    100% { transform: translateY(-50%); }
}

.announcement-item {
    font-size: 15px;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 12px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

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

.announcement-category {
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 600;
    flex-shrink: 0;
}

.announcement-category.学院公告 {
    background: #D1FAE5;
    color: #059669;
}

.announcement-category.AI资讯 {
    background: #DBEAFE;
    color: #2563EB;
}

.announcement-category.AI知识笔记 {
    background: #FEF3C7;
    color: #D97706;
}

.announcement-more {
    font-size: 14px;
    color: var(--text-light);
    flex-shrink: 0;
}

/* 福利模块 */
.benefits-section {
    padding: 60px 0;
    background: var(--bg-gray);
}

.benefits-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.benefits-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.benefits-card.orange {
    background: linear-gradient(135deg, #FF6B35 0%, #F7931E 100%);
}

.benefits-card.blue {
    background: linear-gradient(135deg, #0066FF 0%, #00C6FF 100%);
}

.benefits-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.benefits-card-title {
    font-size: 18px;
    font-weight: 700;
    color: white;
}

.benefits-view-more {
    font-size: 14px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    gap: 4px;
}

.benefits-view-more svg {
    width: 14px;
    height: 14px;
    fill: rgba(255, 255, 255, 0.9);
}

.benefits-scroll-wrapper {
    position: relative;
    padding: 0 28px;
}

.benefits-nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    z-index: 10;
}

.benefits-nav-btn:hover {
    background: white;
    transform: translateY(-50%) scale(1.1);
}

.benefits-nav-btn svg {
    width: 18px;
    height: 18px;
    fill: var(--text-dark);
}

.benefits-nav-btn.left {
    left: -18px;
}

.benefits-nav-btn.right {
    right: -18px;
}

.benefits-scroll {
    overflow: hidden;
    touch-action: pan-x;
}

.benefits-list {
    display: flex;
    gap: 16px;
    transition: transform 0.3s ease;
}

.benefit-item {
    flex-shrink: 0;
    width: calc(33.33% - 10px);
    background: rgba(255, 255, 255, 0.95);
    border-radius: 12px;
    padding: 16px;
    display: flex;
    flex-direction: column;
}

.benefit-item h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.benefit-item p {
    font-size: 12px;
    color: var(--text-gray);
    margin-bottom: 12px;
}

.benefit-item-price {
    font-size: 16px;
    font-weight: 700;
    color: #FF6B35;
}

.benefit-item-price span {
    font-size: 10px;
    font-weight: 400;
    color: var(--text-light);
}

.benefit-item-tag {
    display: inline-block;
    padding: 4px 10px;
    background: rgba(0, 102, 255, 0.1);
    border-radius: 4px;
    font-size: 11px;
    font-weight: 500;
    color: var(--primary);
    margin-top: 8px;
}

.benefit-item-image {
    width: 100%;
    height: 80px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 12px;
}

.benefit-item-link {
    text-decoration: none;
    flex-shrink: 0;
    width: calc(33.33% - 10px);
    display: block;
}

.benefit-item-link .benefit-item {
    width: 100%;
}

.benefits-empty {
    width: 100%;
    text-align: center;
    padding: 30px;
    color: var(--text-gray);
    font-size: 14px;
}

.benefits-indicators {
    display: flex;
    gap: 6px;
    justify-content: center;
    margin-top: 16px;
}

.benefits-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.4);
    cursor: pointer;
    transition: all 0.2s;
}

.benefits-indicator.active {
    width: 20px;
    border-radius: 4px;
    background: white;
}

/* 区块标题 */
.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-header h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 12px;
}

.section-header p {
    font-size: 16px;
    color: var(--text-gray);
}

/* 课程卡片 */
.courses-section {
    padding: 80px 0;
}

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

.course-card {
    background: white;
    border-radius: 16px;
    padding: 32px;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    border: 1px solid var(--border);
}

.course-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

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

.course-card-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.course-card-icon svg { width: 28px; height: 28px; fill: white; }

.course-card-icon.blue { background: linear-gradient(135deg, #0066FF, #3385FF); }
.course-card-icon.purple { background: linear-gradient(135deg, #8B5CF6, #A78BFA); }
.course-card-icon.green { background: linear-gradient(135deg, #10B981, #34D399); }

.course-card h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 0;
}

.course-card p {
    font-size: 14px;
    color: var(--text-gray);
    margin-bottom: 20px;
    line-height: 1.7;
}

.course-card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.course-tag {
    padding: 6px 12px;
    background: var(--bg-gray);
    border-radius: 6px;
    font-size: 12px;
    color: var(--text-gray);
}

.course-card-link {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 6px;
}

.course-card-link svg { width: 16px; height: 16px; fill: var(--primary); }

/* 即将上线新课 */
.upcoming-courses-section {
    padding: 60px 0;
}

.upcoming-courses-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
}

.upcoming-courses-header h2 {
    font-size: 24px;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
}

.upcoming-courses-header h2::before {
    content: '';
    width: 4px;
    height: 20px;
    background: linear-gradient(180deg, var(--primary), var(--primary-light));
    border-radius: 2px;
}

.upcoming-nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 40px;
    background: white;
    border: 1px solid var(--border);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    z-index: 10;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
}

.upcoming-nav-btn:hover {
    background: var(--bg-gray);
    border-color: var(--primary);
}

.upcoming-nav-btn svg {
    width: 18px;
    height: 18px;
    fill: var(--text-gray);
}

.upcoming-nav-btn:hover svg {
    fill: var(--primary);
}

.upcoming-nav-btn.left {
    left: -20px;
}

.upcoming-nav-btn.right {
    right: -20px;
}

.upcoming-scroll-wrapper {
    position: relative;
    padding: 0 30px;
}

.upcoming-scroll {
    overflow: hidden;
    touch-action: pan-x;
}

.upcoming-list {
    display: flex;
    gap: 20px;
    transition: transform 0.3s ease;
}

.upcoming-item-link {
    text-decoration: none;
    flex-shrink: 0;
    width: calc(25% - 15px);
    color: inherit;
}

.upcoming-item-link .upcoming-item {
    width: 100%;
}

.upcoming-item {
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.upcoming-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.upcoming-item-image {
    height: 100px;
    background: linear-gradient(135deg, var(--bg-light), var(--bg-gray));
    border-radius: 8px;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.upcoming-item-image svg {
    width: 36px;
    height: 36px;
    fill: var(--text-light);
}

.upcoming-item-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 8px;
}

.upcoming-empty {
    width: 100%;
    text-align: center;
    padding: 40px;
    color: var(--text-gray);
    font-size: 14px;
}

.upcoming-item h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.upcoming-item p {
    font-size: 13px;
    color: var(--text-gray);
    margin-bottom: 12px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.upcoming-item-date {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    color: var(--text-light);
}

.upcoming-item-date svg {
    width: 14px;
    height: 14px;
    fill: var(--primary);
}

.upcoming-item-date span {
    color: var(--primary);
    font-weight: 500;
}

.upcoming-indicators {
    display: flex;
    gap: 8px;
    justify-content: center;
    margin-top: 20px;
}

.upcoming-indicator {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border);
    cursor: pointer;
    transition: all 0.2s;
}

.upcoming-indicator.active {
    width: 24px;
    border-radius: 5px;
    background: var(--primary);
}

/* 在线课程推荐 */
.online-courses-section {
    padding: 80px 0;
    background: var(--bg-gray);
}

.online-courses-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
}

.online-courses-header h2 {
    font-size: 28px;
    font-weight: 700;
}

.view-more {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
}

.view-more svg { width: 16px; height: 16px; fill: var(--primary); }

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

.online-course-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    border: 1px solid var(--border);
    display: block;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
}

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

.online-course-image {
    height: 140px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.online-course-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.online-course-image svg {
    width: 48px;
    height: 48px;
    fill: rgba(255, 255, 255, 0.8);
}

.online-course-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    padding: 4px 10px;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    color: var(--primary);
}

/* 会员专享角标 */
.course-vip-badge {
    position: absolute;
    right: 8px;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 700;
    color: #fff;
    z-index: 2;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
    letter-spacing: 0.5px;
}
.course-vip-badge:nth-of-type(1) { top: 8px; }
.course-vip-badge:nth-of-type(2) { top: 0px; }
.course-vip-badge:nth-of-type(3) { top: 52px; }
.course-vip-badge.super { background: linear-gradient(135deg, #FF6B35, #FF8F5E); }
.course-vip-badge.lifetime { background: linear-gradient(135deg, #0066FF, #3385FF); }
.course-vip-badge.yearly { background: linear-gradient(135deg, #10B981, #34D399); }

.online-course-content {
    padding: 16px;
}

.online-course-content h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.online-course-content p {
    font-size: 13px;
    color: var(--text-gray);
    margin-bottom: 12px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.online-course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.online-course-price {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
}

.online-course-btn {
    padding: 6px 14px;
    background: var(--bg-gray);
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    color: var(--text-dark);
    transition: all 0.2s;
}

.online-course-btn:hover {
    background: var(--primary);
    color: white;
}

/* 作品展示 */
.works-section {
    padding: 80px 0;
}

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

.work-item {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    cursor: pointer;
}

.work-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.work-item-image {
    height: 160px;
    background: linear-gradient(135deg, var(--bg-light), var(--bg-gray));
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.work-item-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.work-item-image svg {
    width: 48px;
    height: 48px;
    fill: var(--text-light);
}

.work-item-content {
    padding: 16px;
}

.work-item-content h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 6px;
}

.work-item-content p {
    font-size: 12px;
    color: var(--text-light);
}

.works-more {
    text-align: center;
    margin-top: 40px;
}

/* VIP会员卡片 */
.vip-section {
    padding: 80px 0;
}

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

.vip-card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

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

.vip-card.yearly {
    background: linear-gradient(135deg, #667EEA, #764BA2);
    border: none;
}

.vip-card.lifetime {
    background: linear-gradient(135deg, #F093FB, #F5576C);
    border: none;
    transform: scale(1.05);
    box-shadow: 0 12px 40px rgba(240, 147, 251, 0.3);
}

.vip-card.premium {
    background: linear-gradient(135deg, #4FACFE, #00F2FE);
    border: none;
}

.vip-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.vip-card.yearly .vip-badge {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.vip-card.lifetime .vip-badge {
    background: linear-gradient(135deg, #FFD700, #FFA500);
    color: #1A1A2E;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.vip-card.premium .vip-badge {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.vip-card h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 8px;
}

.vip-card.yearly h3 { color: white; }
.vip-card.lifetime h3 { color: white; }
.vip-card.premium h3 { color: white; }

.vip-price {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 20px;
    color: white;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.vip-price .amount {
    font-size: 48px;
    color: #FF4757;
    -webkit-text-fill-color: #FF4757;
    text-shadow: 0 2px 8px rgba(255, 71, 87, 0.3);
}

.vip-price .vip-original-price {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.5);
    text-decoration: line-through;
    margin-left: 8px;
    font-weight: 400;
    vertical-align: middle;
}

.vip-price .vip-save-tag {
    display: inline-block;
    font-size: 11px;
    background: #FF4757;
    color: #fff;
    padding: 2px 8px;
    border-radius: 10px;
    margin-left: 6px;
    font-weight: 500;
    vertical-align: middle;
}

.vip-card p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 20px;
}

.vip-card.yearly p { color: rgba(255, 255, 255, 0.8); }
.vip-card.lifetime p { color: rgba(255, 255, 255, 0.9); }
.vip-card.premium p { color: rgba(255, 255, 255, 0.8); }

.vip-features {
    list-style: none;
    margin-bottom: 28px;
    min-height: 140px;
}

.vip-features li {
    font-size: 14px;
    padding: 10px 0;
    display: flex;
    align-items: flex-start;
    gap: 10px;
    line-height: 1.5;
    word-break: break-all;
}

.vip-card.yearly .vip-features li { color: rgba(255, 255, 255, 0.9); }
.vip-card.lifetime .vip-features li { color: rgba(255, 255, 255, 0.95); }
.vip-card.premium .vip-features li { color: rgba(255, 255, 255, 0.9); }

.vip-features li svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.vip-card.yearly .vip-features li svg { fill: #A7F3D0; }
.vip-card.lifetime .vip-features li svg { fill: #FFD700; }
.vip-card.premium .vip-features li svg { fill: #67E8F9; }

.btn-vip {
    width: 100%;
    padding: 14px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.vip-card.yearly .btn-vip {
    background: white;
    color: #667EEA;
}

.vip-card.yearly .btn-vip:hover {
    background: rgba(255, 255, 255, 0.9);
}

.vip-card.lifetime .btn-vip {
    background: linear-gradient(135deg, #FFD700, #FFA500);
    color: #1A1A2E;
}

.vip-card.lifetime .btn-vip:hover {
    transform: scale(1.02);
    box-shadow: 0 4px 16px rgba(255, 215, 0, 0.4);
}

.vip-card.premium .btn-vip {
    background: white;
    color: #4FACFE;
}

.vip-card.premium .btn-vip:hover {
    background: rgba(255, 255, 255, 0.9);
}

/* 页脚 */
footer {
    background: #1A1A2E;
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-links-group {
    display: contents;
}

.footer-brand h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-brand p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    line-height: 1.8;
    margin-bottom: 20px;
}

.qr-codes {
    display: flex;
    gap: 16px;
}

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

.qr-box {
    width: 100px;
    height: 100px;
    background: white;
    border-radius: 8px;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

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

.qr-box svg { width: 60px; height: 60px; fill: var(--text-light); }

.qr-item p {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.6);
}

.footer-links h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 20px;
    color: white;
}

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

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

.footer-links a {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    transition: color 0.2s;
}

.footer-links a:hover { color: white; }

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.5);
}

/* 返回顶部 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s;
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    box-shadow: 0 4px 16px rgba(0, 102, 255, 0.3);
}

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

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 20px rgba(0, 102, 255, 0.4);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
    fill: white;
}

/* 客服按钮 */
.customer-service {
    position: fixed;
    bottom: 90px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #FF6B35, #F7931E);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s;
    z-index: 100;
    box-shadow: 0 4px 16px rgba(255, 107, 53, 0.3);
}

.customer-service:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 20px rgba(255, 107, 53, 0.4);
}

.customer-service svg {
    width: 24px;
    height: 24px;
    fill: white;
}

.customer-popup {
    position: fixed;
    bottom: 150px;
    right: 30px;
    width: 220px;
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
    z-index: 99;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s;
}

.customer-popup.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.customer-popup h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 16px;
    text-align: center;
}

.customer-qr {
    width: 140px;
    height: 140px;
    background: var(--bg-gray);
    border-radius: 8px;
    margin: 0 auto 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

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

.customer-qr svg {
    width: 80px;
    height: 80px;
    fill: var(--text-light);
}

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

.customer-info p {
    font-size: 14px;
    color: var(--text-gray);
    margin-bottom: 8px;
}

.customer-info .qq-number {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.customer-info .qq-number svg {
    width: 20px;
    height: 20px;
    fill: var(--primary);
}

/* 响应式 */
@media (max-width: 1024px) {
    .banner-content { grid-template-columns: 1fr; text-align: center; }
    .banner-text p { margin: 0 auto 32px; }
    .banner-btns { justify-content: center; }
    .banner-stats { justify-content: center; }
    .banner-visual { max-width: 600px; margin: 0 auto; }
    .works-grid { grid-template-columns: repeat(2, 1fr); }
    .online-courses-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-content { grid-template-columns: repeat(2, 1fr); gap: 30px; }
    .benefits-nav-btn.left { left: -12px; }
    .benefits-nav-btn.right { right: -12px; }
    .upcoming-nav-btn.left { left: -15px; }
    .upcoming-nav-btn.right { right: -15px; }
}

@media (max-width: 1024px) {
    .vip-cards { grid-template-columns: repeat(2, 1fr); }
    .vip-card.lifetime { transform: scale(1); box-shadow: var(--shadow); }
}

@media (max-width: 768px) {
    .nav-links, .nav-right { display: none; }
    .menu-toggle { display: flex; }
    .logo-icon { height: 38px; }
    .logo-icon img { max-width: 130px; }
    .banner-text h1 { font-size: 36px; }
    .banner-stats { gap: 24px; }
    .stat-item h3 { font-size: 28px; }
    .course-cards { grid-template-columns: 1fr; }
    .vip-cards { grid-template-columns: 1fr; }
    .vip-card.lifetime { transform: scale(1); box-shadow: var(--shadow); }
    .works-grid { grid-template-columns: 1fr; }
    .online-courses-grid { grid-template-columns: 1fr; }
    .footer-content { grid-template-columns: 1fr; gap: 24px; }
    .footer-links-group {
        display: flex;
        justify-content: space-around;
        gap: 16px;
    }
    .footer-links { flex: 1; }
    footer { padding: 40px 0 20px; }
    .footer-brand p { margin-bottom: 12px; }
    .qr-codes { justify-content: center; }
    .footer-links h4 { margin-bottom: 8px; font-size: 13px; }
    .footer-links li { margin-bottom: 6px; }
    .footer-links a { font-size: 12px; }
    .benefits-grid { grid-template-columns: 1fr; }
    .benefits-card { padding: 20px; }
    .benefits-nav-btn.left { left: -10px; }
    .benefits-nav-btn.right { right: -10px; }
    .benefits-nav-btn { width: 32px; height: 32px; }
    .benefit-item-link { width: calc(100% - 10px); }
    .benefit-item { width: calc(100% - 10px); }
    .upcoming-nav-btn { width: 32px; height: 32px; }
    .upcoming-nav-btn.left { left: -12px; }
    .upcoming-nav-btn.right { right: -12px; }
    .upcoming-item-link { width: calc(50% - 10px); }
    /* 修复移动端学院公告：改为竖向列表，完整显示新闻标题 */
    .announcement { padding: 20px 0; }
    .announcement-content { gap: 10px; flex-wrap: wrap; }
    .announcement-label { padding: 6px 10px; font-size: 12px; }
    .announcement-scroll { height: auto; min-width: 0; flex: 1 1 100%; order: 3; max-height: 120px; overflow-y: auto; -webkit-overflow-scrolling: touch; }
    .announcement-list { animation: none; flex-direction: column; gap: 10px; }
    .announcement-item { white-space: normal; font-size: 14px; line-height: 1.5; overflow: visible; text-overflow: clip; }
    .announcement-more { font-size: 12px; }
    /* 修复移动端首页体系课专区文字拥挤 */
    .system-courses-section { padding: 24px 0 !important; }
    .system-courses-section .section-header { margin-bottom: 16px !important; }
    .system-courses-section .section-header h2 { font-size: 18px !important; }
    .system-courses-section .section-header p { font-size: 12px !important; }
    .system-course-bar-list { gap: 10px !important; }
    .system-course-bar { flex-direction: column !important; align-items: stretch !important; gap: 12px !important; padding: 14px !important; }
    .system-course-bar > div:first-child { width: 100% !important; height: 120px !important; }
    .system-course-bar > div:first-child img { width: 100% !important; height: 100% !important; object-fit: cover !important; }
    .system-course-bar > div:nth-child(2) { width: 100% !important; }
    .system-course-bar > div:nth-child(2) h3 { font-size: 15px !important; white-space: normal !important; }
    .system-course-bar > div:nth-child(2) p { font-size: 12px !important; white-space: normal !important; line-height: 1.5 !important; }
    .system-course-bar > div:nth-child(2) > div:first-child { gap: 6px !important; }
    .system-course-bar > div:nth-child(2) > div:last-child { gap: 10px !important; font-size: 11px !important; }
    .system-course-bar > div:last-child { text-align: left !important; display: flex !important; align-items: center !important; gap: 10px !important; padding-top: 8px !important; border-top: 1px solid #f0f0f0 !important; }
    .system-course-bar > div:last-child > div:first-child { font-size: 18px !important; }
}

/* VIP支付弹窗 */
.vip-payment-modal { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; z-index: 2000; justify-content: center; align-items: center; }
.vip-payment-modal.active { display: flex; }
.vip-payment-overlay { position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); }
.vip-payment-content { position: relative; width: 90%; max-width: 480px; background: white; border-radius: 20px; padding: 32px; box-shadow: 0 20px 60px rgba(0,0,0,0.2); }
.vip-payment-close { position: absolute; top: 16px; right: 16px; width: 36px; height: 36px; border: none; background: #F3F4F6; border-radius: 50%; cursor: pointer; display: flex; align-items: center; justify-content: center; }
.vip-payment-close svg { width: 20px; height: 20px; fill: #6B7280; }
.vip-payment-header { text-align: center; margin-bottom: 24px; }
.vip-payment-header h3 { font-size: 20px; font-weight: 600; margin-bottom: 8px; }
.vip-payment-header p { font-size: 14px; color: #6B7280; }
.vip-payment-form { display: flex; flex-direction: column; gap: 16px; }
.vip-payment-form label { font-size: 14px; font-weight: 500; color: #1A1A2E; }
.vip-payment-form input { padding: 12px 16px; border: 1px solid #E5E7EB; border-radius: 8px; font-size: 14px; }
.vip-payment-form input:focus { outline: none; border-color: #0066FF; }
.vip-payment-methods { display: flex; gap: 12px; }
.vip-payment-method { flex: 1; padding: 12px; border: 2px solid #E5E7EB; border-radius: 8px; text-align: center; cursor: pointer; transition: all 0.2s; display: flex; flex-direction: column; align-items: center; gap: 4px; }
.vip-payment-method.active { border-color: #0066FF; background: rgba(0,102,255,0.05); }
.vip-payment-method svg { width: 24px; height: 24px; fill: #6B7280; }
.vip-payment-method.active svg { fill: #0066FF; }
.vip-payment-method span { font-size: 12px; color: #6B7280; }
.vip-qr-container { display: flex; flex-direction: column; align-items: center; padding: 20px; background: #F3F4F6; border-radius: 12px; }
.vip-qr-container h4 { font-size: 14px; font-weight: 600; margin-bottom: 12px; color: #1A1A2E; }
.vip-qr-image { width: 180px; height: 180px; background: white; border-radius: 12px; display: flex; align-items: center; justify-content: center; border: 2px dashed #E5E7EB; }
.vip-qr-image svg { width: 120px; height: 120px; fill: #9CA3AF; }
.vip-customer-info { text-align: center; padding: 16px; background: rgba(255,107,53,0.05); border-radius: 8px; }
.vip-customer-info h4 { font-size: 14px; font-weight: 600; color: #FF6B35; margin-bottom: 8px; }
.vip-customer-info p { font-size: 13px; color: #6B7280; line-height: 1.8; }
.vip-payment-btn { width: 100%; padding: 14px; background: #0066FF; color: white; border: none; border-radius: 12px; font-size: 16px; font-weight: 600; cursor: pointer; }
.vip-payment-btn:hover { background: #0052CC; }
.vip-payment-btn:disabled { background: #9CA3AF; cursor: not-allowed; }

/* =========================================
   支付弹窗统一组件样式
   课程购买、VIP开通、首页VIP开通共用
   ========================================= */

/* 弹窗主体统一优化 */
.payment-content,
.vip-payment-content {
    width: 92%;
    max-width: 460px;
    max-height: 90vh;
    overflow-y: auto;
    padding: 32px;
    border-radius: 24px;
    box-shadow: 0 30px 90px rgba(0, 0, 0, 0.28);
    background: white;
    position: relative;
}

.payment-overlay,
.vip-payment-overlay {
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
}

.payment-close,
.vip-payment-close {
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    transition: all 0.25s;
    border: none;
    background: #F3F4F6;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.payment-close:hover,
.vip-payment-close:hover { 
    background: #E5E7EB; 
    transform: rotate(90deg);
}

.payment-close svg,
.vip-payment-close svg { width: 18px; height: 18px; fill: #6B7280; }

.payment-header,
.vip-payment-header { margin-bottom: 26px; text-align: center; }

.payment-header h3,
.vip-payment-header h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 8px;
    color: #1A1A2E;
}

.payment-header p,
.vip-payment-header p { font-size: 14px; color: #6B7280; }

.payment-body,
.payment-form,
.vip-payment-form { display: flex; flex-direction: column; gap: 20px; }

.payment-form label,
.vip-payment-form label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: #1A1A2E;
    margin-bottom: 8px;
}

.payment-form input,
.vip-payment-form input {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid #E5E7EB;
    border-radius: 12px;
    font-size: 14px;
    transition: all 0.25s;
    background: #FAFAFA;
}

.payment-form input:focus,
.vip-payment-form input:focus { 
    outline: none; 
    border-color: #0066FF; 
    background: white;
    box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.08);
}

/* 支付选项卡 */
.payment-tabs {
    display: flex;
    gap: 10px;
    padding: 6px;
    background: #F5F6F7;
    border-radius: 16px;
}

.payment-tab {
    flex: 1;
    padding: 14px 16px;
    border: none;
    border-radius: 12px;
    background: transparent;
    color: #6B7280;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.payment-tab:hover { 
    color: #374151; 
    background: rgba(255, 255, 255, 0.6);
}

.payment-tab.active {
    background: white;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

.payment-tab.active.wechat {
    color: #07C160;
    border: 1px solid rgba(7, 193, 96, 0.2);
}

.payment-tab.active.alipay {
    color: #1677FF;
    border: 1px solid rgba(22, 119, 255, 0.2);
}

.payment-tab-icon {
    width: 20px;
    height: 20px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
    color: white;
}

.payment-tab.wechat .payment-tab-icon {
    background: #07C160;
}

.payment-tab.alipay .payment-tab-icon {
    background: #1677FF;
}

/* 二维码面板 */
.qr-panel {
    display: none;
    flex-direction: column;
    align-items: center;
    padding: 28px 24px;
    background: linear-gradient(145deg, #FFFFFF 0%, #F8FAFC 50%, #F1F5F9 100%);
    border-radius: 20px;
    border: 1px solid #E2E8F0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.qr-panel::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
}

.qr-panel.wechat::before {
    background: linear-gradient(90deg, #07C160, #10B981);
}

.qr-panel.alipay::before {
    background: linear-gradient(90deg, #1677FF, #3B82F6);
}

.qr-panel.active { display: flex; }

.qr-panel h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
}

.qr-panel.wechat h4 { color: #07C160; }
.qr-panel.alipay h4 { color: #1677FF; }

.qr-image-wrap {
    width: 220px;
    height: 220px;
    background: white;
    border-radius: 20px;
    padding: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08), 0 0 0 1px rgba(0, 0, 0, 0.04);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 18px;
    position: relative;
}

.qr-image-wrap::after {
    content: '';
    position: absolute;
    top: 8px;
    left: 8px;
    right: 8px;
    bottom: 8px;
    border: 2px dashed #E2E8F0;
    border-radius: 14px;
}

.qr-image-wrap img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 12px;
    z-index: 1;
}

.qr-desc {
    font-size: 14px;
    color: #6B7280;
    line-height: 1.8;
    margin: 0;
    padding: 0 8px;
}

.qr-desc strong {
    color: #374151;
    font-weight: 500;
}

/* 支付流水号输入框 */
.payment-input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.payment-input-group label {
    font-size: 14px;
    font-weight: 600;
    color: #1A1A2E;
    display: flex;
    align-items: center;
    gap: 4px;
}

.payment-input-group label .required {
    color: #EF4444;
    font-size: 16px;
    font-weight: 700;
}

.payment-input-group input {
    width: 100%;
    padding: 16px 20px;
    border: 2px solid #E2E8F0;
    border-radius: 14px;
    font-size: 15px;
    font-weight: 500;
    color: #1A1A2E;
    background: #FAFBFC;
    transition: all 0.3s ease;
    box-sizing: border-box;
}

.payment-input-group input::placeholder {
    color: #9CA3AF;
    font-weight: 400;
}

.payment-input-group input:focus {
    outline: none;
    border-color: #0066FF;
    background: white;
    box-shadow: 0 0 0 4px rgba(0, 102, 255, 0.08);
    transform: translateY(-1px);
}

.payment-input-group input:hover {
    border-color: #CBD5E1;
    background: white;
}

.payment-input-error {
    display: none;
    padding: 10px 14px;
    background: rgba(239, 68, 68, 0.08);
    border: 1px solid rgba(239, 68, 68, 0.2);
    border-radius: 10px;
    font-size: 13px;
    color: #EF4444;
    font-weight: 500;
    text-align: center;
}

/* 客服信息 */
.payment-service {
    text-align: center;
    padding: 16px;
    background: rgba(255, 107, 53, 0.06);
    border-radius: 12px;
    border: 1px dashed rgba(255, 107, 53, 0.2);
}

.payment-service h4 {
    font-size: 14px;
    font-weight: 600;
    color: #FF6B35;
    margin-bottom: 8px;
}

.payment-service p {
    font-size: 13px;
    color: #6B7280;
    line-height: 1.8;
    margin: 0;
}

/* 订单信息 */
.payment-summary,
.payment-info {
    background: #F9FAFB;
    border-radius: 12px;
    padding: 16px;
}

.payment-summary .summary-row,
.payment-info .info-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 0;
    border-bottom: 1px solid #E5E7EB;
}

.payment-summary .summary-row:last-child,
.payment-info .info-row:last-child { border-bottom: none; }

.payment-summary .summary-label,
.payment-info .info-label { font-size: 14px; color: #6B7280; }

.payment-summary .summary-value,
.payment-info .info-value { font-size: 15px; font-weight: 600; color: #1A1A2E; }

.payment-summary .summary-value.price,
.payment-info .price { color: #FF6B35; font-size: 18px; }

/* 提交按钮 */
.payment-submit-btn,
.payment-btn,
.vip-payment-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #0066FF 0%, #0052CC 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s;
}

.payment-submit-btn:hover,
.payment-btn:hover,
.vip-payment-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 20px rgba(0, 102, 255, 0.3);
}

.payment-submit-btn:disabled,
.payment-btn:disabled,
.vip-payment-btn:disabled {
    background: #9CA3AF;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* 提示文字 */
.payment-notice,
.payment-tip {
    font-size: 12px;
    color: #F59E0B;
    text-align: center;
    margin: 4px 0;
    line-height: 1.5;
}

.payment-footer { margin-top: 4px; }

/* 升级提示 */
.payment-upgrade-tip,
#upgradeTip,
#vipUpgradeTip {
    padding: 10px 16px;
    border-radius: 8px;
    background: rgba(245, 158, 11, 0.1);
    font-size: 13px;
    text-align: center;
    color: #B45309;
}

/* 移动端适配 */
@media (max-width: 480px) {
    .payment-content,
    .vip-payment-content {
        width: 95%;
        padding: 22px 18px;
    }

    .payment-header h3,
    .vip-payment-header h3 { font-size: 20px; }

    .qr-image-wrap { width: 170px; height: 170px; }

    .payment-tab { font-size: 13px; padding: 10px 12px; }
}

.vip-success-modal { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; z-index: 2001; justify-content: center; align-items: center; }
.vip-success-modal.active { display: flex; }
.vip-success-content { width: 90%; max-width: 360px; background: white; border-radius: 20px; padding: 40px 32px; text-align: center; position: relative; }
.vip-success-icon { width: 80px; height: 80px; margin: 0 auto 24px; background: linear-gradient(135deg, #10B981, #059669); border-radius: 50%; display: flex; align-items: center; justify-content: center; }
.vip-success-icon svg { width: 40px; height: 40px; fill: white; }
.vip-success-content h3 { font-size: 20px; font-weight: 600; margin-bottom: 12px; }
.vip-success-content p { font-size: 14px; color: #6B7280; margin-bottom: 24px; }
.vip-success-btn { width: 100%; padding: 14px; background: #0066FF; color: white; border: none; border-radius: 12px; font-size: 16px; font-weight: 600; cursor: pointer; }

.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    padding: 16px 0;
    flex-wrap: wrap;
}
.pagination li {
    list-style: none;
}
.pagination a, .pagination span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 36px;
    padding: 0 12px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
}
.pagination a {
    background: #fff;
    color: var(--text-gray);
    border: 1px solid var(--border);
}
.pagination a:hover {
    background: rgba(0, 102, 255, 0.05);
    color: var(--primary);
    border-color: var(--primary);
}
.pagination span.current {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.pagination span.disabled {
    background: #f5f5f5;
    color: var(--text-light);
    border-color: var(--border);
    cursor: not-allowed;
}

@media (max-width: 480px) {
    .logo-icon { height: 34px; }
    .logo-icon img { max-width: 110px; }
    .banner-text h1 { font-size: 28px; }
    .benefit-item { width: calc(100% - 8px); }
    .upcoming-item-link { width: calc(100% - 10px); }
    .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
    .section-header h2 { font-size: 28px; }
    .slider-arrow { display: none; }
    .customer-service { right: 20px; bottom: 80px; width: 44px; height: 44px; }
    .customer-popup { right: 20px; bottom: 130px; width: 200px; padding: 16px; }
    .customer-qr { width: 120px; height: 120px; }
    .back-to-top { right: 20px; bottom: 30px; width: 44px; height: 44px; }
}

/* ========== 广告Banner通用样式 ========== */
.ad-banner { position: relative; display: block; width: 100%; overflow: hidden; }
.ad-banner .ad-banner-link { display: block; }
.ad-banner .ad-banner-img { display: block; width: 100%; height: auto; object-fit: cover; }
.ad-banner .ad-banner-close {
    position: absolute; top: 4px; right: 4px; width: 24px; height: 24px;
    background: rgba(0,0,0,0.45); border: none; border-radius: 50%;
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    z-index: 10; transition: background 0.2s;
}
.ad-banner .ad-banner-close:hover { background: rgba(0,0,0,0.7); }
.ad-banner .ad-banner-close svg { width: 14px; height: 14px; fill: #fff; }

/* 首页顶部Banner */
.ad-banner.ad-pos-homepage_top { background: #f5f5f5; border-bottom: 1px solid #eee; }
.ad-banner.ad-pos-homepage_top .ad-banner-img { max-height: 60px; }

/* 首页固定底部广告条 */
.ad-banner.ad-pos-homepage_bottom {
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 998;
    background: #fff; box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
}
.ad-banner.ad-pos-homepage_bottom .ad-banner-img { max-height: 56px; }

/* 内容区广告 */
.ad-banner.ad-pos-system_course_detail_top,
.ad-banner.ad-pos-course_detail_recommend,
.ad-banner.ad-pos-ebook_detail_recommend,
.ad-banner.ad-pos-news_list_top,
.ad-banner.ad-pos-news_detail_bottom,
.ad-banner.ad-pos-ai_tool_detail,
.ad-banner.ad-pos-student_work_detail {
    margin: 20px 0; border-radius: 8px;
}
.ad-banner.ad-pos-system_course_detail_top .ad-banner-img,
.ad-banner.ad-pos-course_detail_recommend .ad-banner-img,
.ad-banner.ad-pos-ebook_detail_recommend .ad-banner-img,
.ad-banner.ad-pos-news_list_top .ad-banner-img,
.ad-banner.ad-pos-news_detail_bottom .ad-banner-img,
.ad-banner.ad-pos-ai_tool_detail .ad-banner-img,
.ad-banner.ad-pos-student_work_detail .ad-banner-img {
    max-height: 100px; border-radius: 8px;
}

@media (max-width: 768px) {
    .ad-banner.ad-pos-homepage_top .ad-banner-img { max-height: 50px; }
    .ad-banner.ad-pos-homepage_bottom .ad-banner-img { max-height: 50px; }
}