/* ===== CSS Variables & Reset ===== */
:root {
    --primary: #ff6b35;
    --primary-dark: #e55a2b;
    --secondary: #1a1a2e;
    --accent: #16213e;
    --bg: #0f0f1a;
    --bg-card: rgba(255,255,255,0.05);
    --text: #e0e0e0;
    --text-light: #a0a0b0;
    --glass-bg: rgba(255,255,255,0.08);
    --glass-border: rgba(255,255,255,0.15);
    --shadow: 0 8px 32px rgba(0,0,0,0.4);
    --radius: 20px;
    --radius-sm: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
[data-theme="light"] {
    --primary: #ff6b35;
    --primary-dark: #e55a2b;
    --secondary: #ffffff;
    --accent: #f0f2f5;
    --bg: #f8f9fa;
    --bg-card: rgba(0,0,0,0.03);
    --text: #1a1a2e;
    --text-light: #555;
    --glass-bg: rgba(255,255,255,0.7);
    --glass-border: rgba(0,0,0,0.1);
    --shadow: 0 8px 32px rgba(0,0,0,0.1);
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    scroll-behavior: smooth;
    transition: background 0.3s, color 0.3s;
}
a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}
a:hover {
    color: var(--primary-dark);
}
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header & Nav ===== */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15,15,26,0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    transition: var(--transition);
}
[data-theme="light"] header {
    background: rgba(255,255,255,0.85);
}
header.scrolled {
    box-shadow: var(--shadow);
}
nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
    padding: 0 24px;
    max-width: 1280px;
    margin: 0 auto;
}
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 24px;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: 1px;
}
.logo svg {
    width: 40px;
    height: 40px;
}
.nav-links {
    display: flex;
    gap: 28px;
    list-style: none;
    align-items: center;
}
.nav-links a {
    color: var(--text);
    font-weight: 500;
    font-size: 15px;
    position: relative;
    padding: 4px 0;
}
.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}
.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}
.nav-links a.active {
    color: var(--primary);
}
.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}
.theme-toggle {
    background: none;
    border: none;
    color: var(--text);
    font-size: 22px;
    cursor: pointer;
    padding: 6px;
    border-radius: 50%;
    transition: var(--transition);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.theme-toggle:hover {
    background: var(--glass-bg);
}
.search-box {
    display: flex;
    align-items: center;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 30px;
    padding: 0 16px;
    height: 40px;
    transition: var(--transition);
}
.search-box:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(255,107,53,0.2);
}
.search-box input {
    background: none;
    border: none;
    color: var(--text);
    padding: 8px 0;
    font-size: 14px;
    width: 160px;
    outline: none;
}
.search-box input::placeholder {
    color: var(--text-light);
}
.search-box button {
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    font-size: 18px;
    padding: 4px;
}
.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text);
    font-size: 28px;
    cursor: pointer;
    padding: 4px;
}

/* ===== Hero Banner ===== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, var(--secondary) 0%, var(--accent) 100%);
    position: relative;
    overflow: hidden;
    min-height: 80vh;
    display: flex;
    align-items: center;
}
.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(255,107,53,0.15) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(22,33,62,0.3) 0%, transparent 50%);
    animation: heroGlow 8s ease-in-out infinite alternate;
}
@keyframes heroGlow {
    0% { transform: translate(0,0); }
    100% { transform: translate(-20px,20px); }
}
.hero .container {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}
.hero-content h1 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--primary), #ff9a56);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-content p {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 32px;
    max-width: 500px;
}
.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 16px;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}
.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    box-shadow: 0 4px 20px rgba(255,107,53,0.4);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(255,107,53,0.5);
}
.btn-outline {
    background: transparent;
    color: var(--text);
    border: 2px solid var(--glass-border);
}
.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(255,107,53,0.1);
}
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}
.hero-visual svg {
    width: 100%;
    max-width: 500px;
    height: auto;
    filter: drop-shadow(0 20px 40px rgba(0,0,0,0.3));
    animation: float 6s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

/* ===== Sections ===== */
section {
    padding: 80px 0;
}
.section-title {
    text-align: center;
    margin-bottom: 56px;
}
.section-title h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 12px;
    position: relative;
    display: inline-block;
}
.section-title h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--primary);
    margin: 12px auto 0;
    border-radius: 4px;
}
.section-title p {
    color: var(--text-light);
    font-size: 16px;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Cards ===== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 28px;
}
.card {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    padding: 32px 24px;
    transition: var(--transition);
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}
.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 48px rgba(0,0,0,0.3);
    border-color: var(--primary);
}
.card-icon {
    width: 56px;
    height: 56px;
    margin-bottom: 16px;
}
.card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 12px;
}
.card p {
    color: var(--text-light);
    font-size: 15px;
}

/* ===== Timeline ===== */
.timeline {
    position: relative;
    padding: 20px 0;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--glass-border);
    transform: translateX(-50%);
}
.timeline-item {
    display: flex;
    justify-content: flex-start;
    padding: 20px 0;
    position: relative;
}
.timeline-item:nth-child(even) {
    justify-content: flex-end;
}
.timeline-content {
    width: 45%;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    padding: 20px 24px;
    transition: var(--transition);
}
.timeline-content:hover {
    border-color: var(--primary);
    transform: scale(1.02);
}
.timeline-content .year {
    color: var(--primary);
    font-weight: 700;
    font-size: 18px;
}

/* ===== FAQ ===== */
.faq-item {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    margin-bottom: 12px;
    overflow: hidden;
    transition: var(--transition);
}
.faq-question {
    padding: 20px 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    font-size: 16px;
    transition: var(--transition);
}
.faq-question:hover {
    background: rgba(255,107,53,0.08);
}
.faq-question .icon {
    font-size: 22px;
    transition: var(--transition);
}
.faq-item.active .faq-question .icon {
    transform: rotate(45deg);
}
.faq-answer {
    max-height: 0;
    padding: 0 24px;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.8;
}
.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 24px 20px;
}

/* ===== Testimonials ===== */
.testimonial-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    padding: 28px;
    transition: var(--transition);
    position: relative;
}
.testimonial-card::before {
    content: '"';
    font-size: 64px;
    color: var(--primary);
    opacity: 0.2;
    position: absolute;
    top: 10px;
    left: 20px;
    font-family: Georgia, serif;
}
.testimonial-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}
.testimonial-card .author {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 16px;
}
.testimonial-card .author svg {
    width: 44px;
    height: 44px;
    border-radius: 50%;
}

/* ===== Partners ===== */
.partner-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 32px;
    align-items: center;
}
.partner-item {
    opacity: 0.6;
    transition: var(--transition);
    filter: grayscale(0.5);
}
.partner-item:hover {
    opacity: 1;
    filter: grayscale(0);
}

/* ===== Articles ===== */
.article-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: var(--transition);
}
.article-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}
.article-card .article-body {
    padding: 20px 24px 24px;
}
.article-card .article-body .date {
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 8px;
}
.article-card .article-body h3 {
    font-size: 18px;
    margin-bottom: 8px;
}
.article-card .article-body p {
    color: var(--text-light);
    font-size: 14px;
    margin-bottom: 12px;
}
.article-card .article-body .read-more {
    color: var(--primary);
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    display: inline-block;
}

/* ===== HowTo ===== */
.howto-steps {
    counter-reset: step;
}
.howto-step {
    display: flex;
    gap: 20px;
    margin-bottom: 28px;
    align-items: flex-start;
}
.howto-step .step-number {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}
.howto-step .step-content h4 {
    font-size: 18px;
    margin-bottom: 6px;
}
.howto-step .step-content p {
    color: var(--text-light);
}

/* ===== Footer ===== */
footer {
    background: var(--secondary);
    border-top: 1px solid var(--glass-border);
    padding: 60px 0 30px;
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}
.footer-col h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--primary);
}
.footer-col ul {
    list-style: none;
}
.footer-col ul li {
    margin-bottom: 10px;
}
.footer-col ul li a {
    color: var(--text-light);
    font-size: 14px;
}
.footer-col ul li a:hover {
    color: var(--primary);
}
.footer-bottom {
    border-top: 1px solid var(--glass-border);
    padding-top: 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 13px;
    color: var(--text-light);
}
.footer-bottom a {
    color: var(--text-light);
}
.footer-bottom a:hover {
    color: var(--primary);
}

/* ===== Back to top ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(255,107,53,0.4);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    z-index: 999;
}
.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(255,107,53,0.5);
}

/* ===== Breadcrumb ===== */
.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 16px 0;
    font-size: 14px;
    color: var(--text-light);
}
.breadcrumb a {
    color: var(--text-light);
}
.breadcrumb a:hover {
    color: var(--primary);
}
.breadcrumb .sep {
    color: var(--text-light);
}

/* ===== Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}
.count-number {
    font-size: 40px;
    font-weight: 800;
    color: var(--primary);
    line-height: 1.2;
}
.count-label {
    font-size: 14px;
    color: var(--text-light);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero-content p {
        margin: 0 auto 32px;
    }
    .hero-buttons {
        justify-content: center;
    }
    .hero-visual {
        order: -1;
    }
    .hero-visual svg {
        max-width: 350px;
    }
    .timeline::before {
        left: 20px;
    }
    .timeline-item,
    .timeline-item:nth-child(even) {
        justify-content: flex-start;
        padding-left: 50px;
    }
    .timeline-content {
        width: 100%;
    }
}
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg);
        flex-direction: column;
        padding: 20px 24px;
        border-bottom: 1px solid var(--glass-border);
        box-shadow: var(--shadow);
    }
    .nav-links.open {
        display: flex;
    }
    .mobile-toggle {
        display: block;
    }
    .search-box input {
        width: 120px;
    }
    .hero {
        padding: 120px 0 60px;
        min-height: auto;
    }
    .hero-content h1 {
        font-size: 32px;
    }
    .section-title h2 {
        font-size: 28px;
    }
    .card-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}
@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 26px;
    }
    .hero-buttons .btn {
        width: 100%;
        justify-content: center;
    }
    .footer-grid {
        grid-template-columns: 1fr;
    }
}