/* style.css - 开云App客户端下载 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
:root {
    --primary: #1a73e8;
    --primary-dark: #1557b0;
    --primary-light: #4a90e2;
    --accent: #00c9a7;
    --bg: #f5f9ff;
    --bg-card: #ffffff;
    --text: #1a1a2e;
    --text-secondary: #4a4a6a;
    --border: #e0e7ff;
    --shadow: 0 8px 32px rgba(26, 115, 232, 0.12);
    --radius: 16px;
    --radius-sm: 8px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --gradient-hero: linear-gradient(135deg, #1a73e8 0%, #00c9a7 100%);
    --glass-bg: rgba(255, 255, 255, 0.72);
    --glass-border: rgba(255, 255, 255, 0.3);
}
body.dark {
    --bg: #0d1117;
    --bg-card: #161b22;
    --text: #e6edf3;
    --text-secondary: #8b949e;
    --border: #30363d;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --glass-bg: rgba(22, 27, 34, 0.85);
    --glass-border: rgba(48, 54, 61, 0.5);
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    transition: background var(--transition), color var(--transition);
    overflow-x: hidden;
}
a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition);
}
a:hover {
    color: var(--primary-dark);
}
img, svg {
    max-width: 100%;
    height: auto;
    display: block;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    transition: background var(--transition), border var(--transition);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
    padding: 0 24px;
    max-width: 1200px;
    margin: 0 auto;
}
.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.5px;
}
.logo svg {
    width: 40px;
    height: 40px;
}
nav {
    display: flex;
    align-items: center;
    gap: 32px;
}
nav a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text);
    position: relative;
    padding: 4px 0;
    transition: color var(--transition);
}
nav a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width var(--transition);
    border-radius: 2px;
}
nav a:hover::after, nav a.active::after {
    width: 100%;
}
nav a.active {
    color: var(--primary);
}
.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}
.dark-toggle {
    background: none;
    border: none;
    font-size: 22px;
    cursor: pointer;
    color: var(--text);
    padding: 8px;
    border-radius: 50%;
    transition: background var(--transition), color var(--transition);
    line-height: 1;
}
.dark-toggle:hover {
    background: var(--border);
}
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: var(--text);
    padding: 8px;
    border-radius: var(--radius-sm);
    transition: background var(--transition);
}
.mobile-menu-btn:hover {
    background: var(--border);
}
.mobile-nav {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
    flex-direction: column;
    gap: 16px;
    z-index: 999;
    box-shadow: var(--shadow);
    max-height: 80vh;
    overflow-y: auto;
}
.mobile-nav.open {
    display: flex;
}
.mobile-nav a {
    font-size: 16px;
    font-weight: 500;
    color: var(--text);
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}
.mobile-nav a:last-child {
    border-bottom: none;
}
.hero {
    padding: 140px 0 80px;
    background: var(--gradient-hero);
    color: #fff;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.08) 0%, transparent 60%);
    animation: heroShift 20s ease-in-out infinite alternate;
}
@keyframes heroShift {
    0% { transform: translate(0, 0); }
    100% { transform: translate(-10%, 10%); }
}
.hero .container {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
}
.hero-text h1 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    letter-spacing: -1px;
}
.hero-text p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 32px;
    line-height: 1.6;
}
.hero-badge {
    display: inline-block;
    background: rgba(255,255,255,0.15);
    backdrop-filter: blur(8px);
    padding: 8px 20px;
    border-radius: 100px;
    font-size: 14px;
    margin-bottom: 20px;
    border: 1px solid rgba(255,255,255,0.2);
}
.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 100px;
    font-weight: 600;
    font-size: 16px;
    border: none;
    cursor: pointer;
    transition: all var(--transition);
    background: #fff;
    color: var(--primary);
    box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}
.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}
.btn-outline {
    background: transparent;
    color: #fff;
    border: 2px solid rgba(255,255,255,0.6);
    box-shadow: none;
}
.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: #fff;
}
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}
.hero-visual svg {
    width: 100%;
    max-width: 480px;
    height: auto;
    filter: drop-shadow(0 20px 40px rgba(0,0,0,0.2));
    animation: float 6s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-16px); }
}
.hero-stats {
    display: flex;
    gap: 40px;
    margin-top: 40px;
    flex-wrap: wrap;
}
.hero-stat {
    text-align: center;
}
.hero-stat .num {
    font-size: 32px;
    font-weight: 800;
    display: block;
}
.hero-stat .label {
    font-size: 14px;
    opacity: 0.75;
}
section {
    padding: 80px 0;
}
.section-title {
    text-align: center;
    margin-bottom: 48px;
}
.section-title h2 {
    font-size: 36px;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}
.section-title p {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}
.section-badge {
    display: inline-block;
    background: var(--primary);
    color: #fff;
    padding: 4px 16px;
    border-radius: 100px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 12px;
    letter-spacing: 0.5px;
}
.grid-2, .grid-3, .grid-4 {
    display: grid;
    gap: 24px;
}
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 32px 24px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(26, 115, 232, 0.15);
}
.card-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    background: var(--primary);
    color: #fff;
}
.card-icon svg {
    width: 28px;
    height: 28px;
}
.card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}
.card p {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.6;
}
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
}
.about-text h2 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 16px;
}
.about-text p {
    margin-bottom: 16px;
    color: var(--text-secondary);
}
.about-visual svg {
    width: 100%;
    max-width: 500px;
    margin: 0 auto;
}
.timeline {
    position: relative;
    padding-left: 32px;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 12px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary);
    opacity: 0.3;
}
.timeline-item {
    position: relative;
    margin-bottom: 32px;
    padding-left: 20px;
}
.timeline-item::before {
    content: '';
    position: absolute;
    left: -24px;
    top: 6px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary);
    border: 3px solid var(--bg);
    box-shadow: 0 0 0 2px var(--primary);
}
.timeline-item h4 {
    font-size: 18px;
    font-weight: 600;
}
.timeline-item p {
    color: var(--text-secondary);
    font-size: 14px;
}
.team-card {
    text-align: center;
}
.team-card .avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    margin: 0 auto 16px;
    background: var(--primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 32px;
    font-weight: 700;
}
.team-card h4 {
    font-size: 18px;
    font-weight: 600;
}
.team-card p {
    color: var(--text-secondary);
    font-size: 14px;
}
.banner-carousel {
    position: relative;
    overflow: hidden;
    border-radius: var(--radius);
    background: var(--bg-card);
    box-shadow: var(--shadow);
}
.carousel-slides {
    display: flex;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}
.carousel-slide {
    min-width: 100%;
    padding: 48px 32px;
    display: flex;
    align-items: center;
    gap: 32px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: #fff;
}
.carousel-slide:nth-child(2) {
    background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
}
.carousel-slide:nth-child(3) {
    background: linear-gradient(135deg, #141e30, #243b55);
}
.carousel-slide svg {
    width: 120px;
    height: 120px;
    flex-shrink: 0;
    filter: drop-shadow(0 4px 12px rgba(0,0,0,0.2));
}
.carousel-slide h3 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
}
.carousel-slide p {
    opacity: 0.9;
    font-size: 16px;
}
.carousel-controls {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-top: 16px;
}
.carousel-controls button {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text);
    cursor: pointer;
    font-size: 18px;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}
.carousel-controls button:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.carousel-dots {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 12px;
}
.carousel-dots span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border);
    cursor: pointer;
    transition: all var(--transition);
}
.carousel-dots span.active {
    background: var(--primary);
    width: 28px;
    border-radius: 5px;
}
.faq-item {
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
    cursor: pointer;
}
.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    font-size: 16px;
    color: var(--text);
    user-select: none;
}
.faq-question .icon {
    transition: transform 0.3s;
    font-size: 20px;
}
.faq-item.open .faq-question .icon {
    transform: rotate(45deg);
}
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s;
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.7;
}
.faq-item.open .faq-answer {
    max-height: 400px;
    padding-top: 12px;
}
.howto-steps {
    counter-reset: step;
}
.howto-step {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
    align-items: flex-start;
}
.howto-step::before {
    counter-increment: step;
    content: counter(step);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
    font-size: 16px;
}
.howto-step h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
}
.howto-step p {
    color: var(--text-secondary);
    font-size: 14px;
}
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
}
.contact-info p {
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 12px;
}
.contact-info svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    color: var(--primary);
}
footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 48px 0 24px;
    margin-top: 40px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 32px;
    margin-bottom: 32px;
}
.footer-brand p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-top: 8px;
}
.footer-links h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 12px;
}
.footer-links a {
    display: block;
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 8px;
    transition: color var(--transition);
}
.footer-links a:hover {
    color: var(--primary);
}
.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 13px;
    color: var(--text-secondary);
}
.footer-bottom a {
    color: var(--text-secondary);
}
.scroll-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 20px;
    box-shadow: 0 4px 16px rgba(26,115,232,0.3);
    transition: all var(--transition);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
}
.scroll-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.scroll-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}
@media (max-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero-text h1 { font-size: 36px; }
    .hero-buttons { justify-content: center; }
    .hero-stats { justify-content: center; }
    .about-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
    nav { display: none; }
    .mobile-menu-btn { display: block; }
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .hero-text h1 { font-size: 28px; }
    .hero { padding: 120px 0 60px; }
    section { padding: 48px 0; }
    .section-title h2 { font-size: 26px; }
    .footer-grid { grid-template-columns: 1fr; }
    .carousel-slide { flex-direction: column; text-align: center; }
    .carousel-slide svg { width: 80px; height: 80px; }
}
.fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}
.search-box {
    display: flex;
    gap: 8px;
    max-width: 400px;
    margin: 0 auto 32px;
}
.search-box input {
    flex: 1;
    padding: 12px 16px;
    border-radius: 100px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text);
    font-size: 15px;
    outline: none;
    transition: border var(--transition);
}
.search-box input:focus {
    border-color: var(--primary);
}
.search-box button {
    padding: 12px 24px;
    border-radius: 100px;
    border: none;
    background: var(--primary);
    color: #fff;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--transition);
}
.search-box button:hover {
    background: var(--primary-dark);
}
.breadcrumb {
    display: flex;
    gap: 8px;
    font-size: 14px;
    color: var(--text-secondary);
    padding: 16px 0;
    flex-wrap: wrap;
}
.breadcrumb a {
    color: var(--primary);
}
.breadcrumb span {
    color: var(--text-secondary);
}
.dark-toggle .light-icon { display: inline; }
.dark-toggle .dark-icon { display: none; }
body.dark .dark-toggle .light-icon { display: none; }
body.dark .dark-toggle .dark-icon { display: inline; }