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

:root {
    --primary: #1a5cb0;
    --primary-light: #2e8cf0;
    --primary-dark: #134a8e;
    --primary-bg: #f0f6ff;
    --text-primary: #1a2332;
    --text-secondary: #4a5568;
    --text-light: #718096;
    --bg-white: #ffffff;
    --bg-light: #f7f9fc;
    --border: #e2e8f0;
    --border-light: #f0f4f8;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: 0.3s ease;
    --header-height: 68px;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

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

ul {
    list-style: none;
}

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

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

:focus-visible {
    outline: 2px solid var(--primary-light);
    outline-offset: 2px;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.97);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    z-index: 1000;
    transition: box-shadow var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
}

.logo-text {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: 0.5px;
}

.main-nav {
    margin-left: 40px;
}

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

.nav-link {
    display: inline-block;
    padding: 8px 16px;
    font-size: 15px;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    font-weight: 500;
}

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

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

.btn-login {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 20px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    border: 1.5px solid var(--primary);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
}

.btn-login:hover {
    background: var(--primary);
    color: #fff;
}

.mobile-menu-btn {
    display: none;
    color: var(--text-primary);
    padding: 4px;
}

.hero {
    position: relative;
    padding: 120px 0 60px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #0d3b7a 0%, #1a5cb0 30%, #2e8cf0 70%, #4da6ff 100%);
}

.hero-pattern {
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 20% 50%, rgba(255,255,255,0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255,255,255,0.06) 0%, transparent 40%),
        radial-gradient(circle at 60% 80%, rgba(255,255,255,0.04) 0%, transparent 40%);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: #fff;
}

.hero-title {
    font-size: 42px;
    font-weight: 800;
    letter-spacing: 1px;
    margin-bottom: 16px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.hero-subtitle {
    font-size: 18px;
    opacity: 0.9;
    max-width: 640px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

.hero-search {
    max-width: 580px;
    margin: 0 auto 40px;
}

.search-box {
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 50px;
    padding: 6px 6px 6px 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
}

.search-box .icon-search {
    color: var(--text-light);
    flex-shrink: 0;
}

.search-box input {
    flex: 1;
    border: none;
    outline: none;
    padding: 12px 14px;
    font-size: 15px;
    background: transparent;
    color: var(--text-primary);
    font-family: inherit;
    min-width: 0;
}

.search-box input::placeholder {
    color: var(--text-light);
}

.btn-search {
    padding: 12px 28px;
    background: var(--primary);
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    border-radius: 50px;
    transition: background var(--transition);
    flex-shrink: 0;
    white-space: nowrap;
}

.btn-search:hover {
    background: var(--primary-dark);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
}

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

.stat-number {
    display: block;
    font-size: 36px;
    font-weight: 800;
    line-height: 1.2;
}

.stat-label {
    display: block;
    font-size: 14px;
    opacity: 0.8;
    margin-top: 4px;
}

.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: "";
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 48px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    border-radius: 2px;
}

.section-desc {
    font-size: 16px;
    color: var(--text-secondary);
    margin-top: 20px;
}

.categories {
    padding: 80px 0;
    background: var(--bg-light);
}

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

.category-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 28px;
    border: 1px solid var(--border-light);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    opacity: 0;
    transition: opacity var(--transition);
}

.category-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    border-color: transparent;
}

.category-card:hover::before {
    opacity: 1;
}

.category-card-auto .category-certs {
    max-height: none;
    overflow: visible;
}

.category-icon {
    margin-bottom: 16px;
}

.category-name {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.category-count {
    display: inline-block;
    font-size: 13px;
    color: var(--primary);
    background: var(--primary-bg);
    padding: 2px 10px;
    border-radius: 20px;
    margin-bottom: 16px;
    font-weight: 500;
}

.category-certs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    max-height: 76px;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.category-card.expanded .category-certs {
    max-height: 800px;
}

.cert-tag {
    display: inline-block;
    padding: 5px 14px;
    font-size: 13px;
    color: var(--text-secondary);
    background: var(--bg-light);
    border-radius: 20px;
    border: 1px solid var(--border);
    transition: all var(--transition);
    white-space: nowrap;
}

.cert-tag:hover {
    color: var(--primary);
    background: var(--primary-bg);
    border-color: var(--primary-light);
}

.cert-tag.highlighted {
    background: var(--primary) !important;
    color: #fff !important;
    border-color: var(--primary) !important;
    font-weight: 600;
}

.btn-expand {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-top: 12px;
    font-size: 14px;
    color: var(--primary);
    font-weight: 500;
    transition: all var(--transition);
}

.btn-expand svg {
    transition: transform 0.3s ease;
}

.category-card.expanded .btn-expand svg {
    transform: rotate(180deg);
}

.btn-expand:hover {
    color: var(--primary-dark);
}

.hot-certs {
    padding: 80px 0;
    background: var(--bg-white);
}

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

.hot-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 24px;
    border: 1px solid var(--border-light);
    transition: all var(--transition);
    position: relative;
    display: flex;
    flex-direction: column;
}

.hot-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
    border-color: transparent;
}

.hot-featured {
    grid-column: span 2;
    grid-row: span 2;
    background: linear-gradient(135deg, #0d3b7a, #1a5cb0, #2e8cf0);
    color: #fff;
    border: none;
    padding: 36px;
}

.hot-featured:hover {
    box-shadow: 0 12px 40px rgba(26, 92, 176, 0.3);
}

.hot-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    padding: 3px 12px;
    font-size: 12px;
    font-weight: 600;
    color: #fff;
    background: linear-gradient(135deg, #e8a820, #f0c040);
    border-radius: 20px;
}

.hot-featured .hot-badge {
    top: 24px;
    right: 24px;
}

.hot-icon {
    margin-bottom: 16px;
    color: var(--primary);
}

.hot-featured .hot-icon {
    color: rgba(255, 255, 255, 0.9);
}

.hot-name {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
}

.hot-featured .hot-name {
    font-size: 24px;
    margin-bottom: 14px;
}

.hot-desc {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 16px;
    flex: 1;
}

.hot-featured .hot-desc {
    color: rgba(255, 255, 255, 0.85);
    font-size: 15px;
}

.hot-meta {
    margin-bottom: 16px;
}

.hot-category {
    font-size: 12px;
    color: var(--text-light);
    background: var(--bg-light);
    padding: 3px 10px;
    border-radius: 12px;
}

.hot-featured .hot-category {
    background: rgba(255, 255, 255, 0.15);
    color: rgba(255, 255, 255, 0.9);
}

.btn-hot-apply {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    background: var(--primary-bg);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    align-self: flex-start;
}

.btn-hot-apply:hover {
    background: var(--primary);
    color: #fff;
}

.hot-featured .btn-hot-apply {
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.hot-featured .btn-hot-apply:hover {
    background: #fff;
    color: var(--primary);
    border-color: #fff;
}

.process {
    padding: 80px 0;
    background: var(--bg-light);
}

.process-steps {
    display: flex;
    align-items: flex-start;
    justify-content: center;
}

.step-item {
    flex: 1;
    max-width: 240px;
    text-align: center;
    padding: 0 16px;
}

.step-number {
    font-size: 14px;
    font-weight: 700;
    color: var(--primary-light);
    margin-bottom: 12px;
    letter-spacing: 1px;
}

.step-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    height: 80px;
    background: var(--primary-bg);
    border-radius: 50%;
    color: var(--primary);
    margin-bottom: 20px;
    transition: all var(--transition);
}

.step-item:hover .step-icon {
    background: var(--primary);
    color: #fff;
    transform: scale(1.05);
}

.step-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.step-desc {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

.step-connector {
    display: flex;
    align-items: center;
    padding-top: 60px;
    flex-shrink: 0;
}

.advantages {
    padding: 80px 0;
    background: var(--bg-white);
}

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

.advantage-item {
    text-align: center;
    padding: 36px 24px;
    border-radius: var(--radius-lg);
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    transition: all var(--transition);
}

.advantage-item:hover {
    background: var(--bg-white);
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
    border-color: transparent;
}

.advantage-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 72px;
    height: 72px;
    background: var(--primary-bg);
    border-radius: 50%;
    color: var(--primary);
    margin-bottom: 20px;
    transition: all var(--transition);
}

.advantage-item:hover .advantage-icon {
    background: var(--primary);
    color: #fff;
}

.advantage-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.advantage-desc {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

.faq {
    padding: 80px 0;
    background: var(--bg-light);
}

.faq-list {
    max-width: 760px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-white);
    border-radius: var(--radius-md);
    margin-bottom: 12px;
    border: 1px solid var(--border-light);
    overflow: hidden;
    transition: all var(--transition);
}

.faq-item:hover {
    border-color: var(--primary-light);
}

.faq-item.active {
    border-color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 18px 24px;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    text-align: left;
    transition: color var(--transition);
}

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

.faq-item.active .faq-question {
    color: var(--primary);
}

.faq-arrow {
    flex-shrink: 0;
    transition: transform 0.3s ease;
    margin-left: 12px;
}

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

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
}

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

.faq-answer p {
    padding: 0 24px 20px;
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.cta {
    padding: 80px 0;
    background: linear-gradient(135deg, #0d3b7a 0%, #1a5cb0 50%, #2e8cf0 100%);
    position: relative;
    overflow: hidden;
}

.cta::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 30% 40%, rgba(255,255,255,0.06) 0%, transparent 50%),
        radial-gradient(circle at 70% 60%, rgba(255,255,255,0.04) 0%, transparent 40%);
}

.cta-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: #fff;
}

.cta-title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 14px;
}

.cta-desc {
    font-size: 16px;
    opacity: 0.85;
    margin-bottom: 32px;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 36px;
    font-size: 16px;
    font-weight: 600;
    color: #fff;
    background: var(--primary);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    box-shadow: 0 4px 12px rgba(26, 92, 176, 0.3);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(26, 92, 176, 0.4);
}

.cta .btn-primary {
    background: #fff;
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.cta .btn-primary:hover {
    background: #f0f6ff;
    color: var(--primary-dark);
}

.btn-outline {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 36px;
    font-size: 16px;
    font-weight: 600;
    color: #fff;
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: #fff;
}

.footer {
    background: #1a2332;
    color: rgba(255, 255, 255, 0.7);
    padding-top: 60px;
}

.footer-top {
    display: flex;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-info {
    flex: 1;
    min-width: 260px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo span {
    font-size: 18px;
    font-weight: 700;
    color: #fff;
}

.footer-desc {
    font-size: 14px;
    line-height: 1.7;
    max-width: 320px;
}

.footer-links {
    display: flex;
    gap: 48px;
    flex: 1;
    justify-content: flex-end;
}

.footer-col h4 {
    font-size: 15px;
    font-weight: 600;
    color: #fff;
    margin-bottom: 16px;
}

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

.footer-col ul li a {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    transition: color var(--transition);
}

.footer-col ul li a:hover {
    color: var(--primary-light);
}

.footer-notice {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    padding: 20px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 14px;
    color: #e6a23c;
    line-height: 1.6;
}

.footer-notice .notice-icon {
    flex-shrink: 0;
    margin-top: 2px;
}

.footer-bottom {
    padding: 20px 0;
    text-align: center;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.4);
    line-height: 1.8;
}

.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 44px;
    height: 44px;
    background: var(--primary);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.animate-wait {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

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

@supports not (backdrop-filter: blur(12px)) {
    .header {
        background: rgba(255, 255, 255, 1);
    }
    .main-nav {
        background: rgba(255, 255, 255, 1);
    }
}

@media (max-width: 1024px) {
    .category-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

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

    .hot-featured {
        grid-column: span 2;
        grid-row: span 1;
    }

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

    .process-steps {
        flex-wrap: wrap;
        gap: 20px;
        justify-content: center;
    }

    .step-connector {
        display: none;
    }

    .step-item {
        flex: 0 0 calc(50% - 10px);
        max-width: none;
    }

    .footer-top {
        flex-direction: column;
        gap: 40px;
    }

    .footer-links {
        justify-content: flex-start;
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 60px;
    }

    .main-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        -webkit-backdrop-filter: blur(12px);
        backdrop-filter: blur(12px);
        border-bottom: 1px solid var(--border);
        padding: 16px 20px;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        margin-left: 0;
        z-index: 999;
    }

    .main-nav.open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

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

    .nav-link {
        display: block;
        padding: 12px 16px;
        font-size: 15px;
    }

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

    .hero {
        padding: 100px 0 48px;
    }

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

    .hero-subtitle {
        font-size: 15px;
        margin-bottom: 28px;
    }

    .hero-stats {
        gap: 32px;
    }

    .stat-number {
        font-size: 28px;
    }

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

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

    .hot-featured {
        grid-column: span 1;
    }

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

    .step-item {
        flex: 0 0 100%;
    }

    .section-title {
        font-size: 26px;
    }

    .cta-title {
        font-size: 26px;
    }

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

    .footer-links {
        flex-direction: column;
        gap: 32px;
    }

    .footer-notice {
        font-size: 13px;
    }

    .footer-bottom {
        font-size: 12px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 24px;
    }

    .hero-subtitle {
        font-size: 14px;
    }

    .search-box {
        flex-direction: column;
        border-radius: var(--radius-md);
        padding: 12px;
        gap: 8px;
    }

    .search-box input {
        width: 100%;
        padding: 10px 12px;
    }

    .btn-search {
        width: 100%;
        justify-content: center;
    }

    .hero-stats {
        gap: 24px;
    }

    .stat-number {
        font-size: 24px;
    }

    .category-card {
        padding: 20px;
    }

    .category-name {
        font-size: 17px;
    }

    .cert-tag {
        font-size: 12px;
        padding: 4px 10px;
    }
}

@media print {
    .header,
    .hero-search,
    .back-to-top,
    .btn-expand,
    .cta {
        display: none;
    }

    .hero {
        padding-top: 0;
    }

    body {
        color: #000;
    }
}