/* style.css - 开云网页版 (KAIYUN OFFICIAL) */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: #f5f7fa;
    color: #1a2a3a;
    line-height: 1.6;
}

.dark-mode {
    background: #0f1a2a;
    color: #e0e8f0;
}

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

ul {
    list-style: none;
}

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

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}

/* Header */
header {
    background: linear-gradient(135deg, #1a3a5c 0%, #2a5a8c 100%);
    color: white;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0,0,0,0.2);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.logo span {
    color: #ffd700;
}

nav ul {
    display: flex;
    gap: 1.5rem;
}

nav a {
    padding: 0.5rem 0;
    position: relative;
    transition: color 0.3s;
}

nav a:hover, nav a.active {
    color: #ffd700;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

.search-box {
    display: flex;
    gap: 0.5rem;
}

.search-box input {
    padding: 0.4rem 0.8rem;
    border: none;
    border-radius: 20px;
    background: rgba(255,255,255,0.15);
    color: white;
    outline: none;
    width: 180px;
}

.search-box input::placeholder {
    color: rgba(255,255,255,0.6);
}

.search-box button {
    background: #ffd700;
    border: none;
    border-radius: 20px;
    padding: 0.4rem 1rem;
    cursor: pointer;
    color: #1a3a5c;
    font-weight: 600;
}

.dark-mode-toggle {
    background: none;
    border: 2px solid rgba(255,255,255,0.3);
    color: white;
    border-radius: 30px;
    padding: 0.3rem 0.8rem;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.3s;
}

.dark-mode-toggle:hover {
    background: rgba(255,255,255,0.1);
}

/* Breadcrumb */
.breadcrumb {
    padding: 0.5rem 0;
    font-size: 0.9rem;
    opacity: 0.8;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

/* Hero */
.hero {
    background: linear-gradient(135deg, #1a3a5c 0%, #2a5a8c 50%, #1a3a5c 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,215,0,0.05) 0%, transparent 70%);
    animation: heroGlow 8s ease-in-out infinite;
}

@keyframes heroGlow {
    0%,100% { transform: translate(0,0); }
    50% { transform: translate(20%,20%); }
}

.hero h1 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    position: relative;
}

.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    opacity: 0.9;
    position: relative;
}

.hero .btn {
    display: inline-block;
    background: #ffd700;
    color: #1a3a5c;
    padding: 0.8rem 2rem;
    border-radius: 30px;
    font-weight: 700;
    transition: transform 0.3s, box-shadow 0.3s;
}

.hero .btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(255,215,0,0.3);
}

/* Carousel */
.carousel {
    display: flex;
    overflow: hidden;
    position: relative;
    min-height: 400px;
}

.carousel-slide {
    min-width: 100%;
    transition: transform 0.5s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    padding: 2rem;
}

.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255,255,255,0.2);
    border: none;
    color: white;
    font-size: 2rem;
    padding: 0.5rem 1rem;
    cursor: pointer;
    border-radius: 50%;
    backdrop-filter: blur(5px);
    z-index: 10;
}

.carousel-btn.prev {
    left: 20px;
}

.carousel-btn.next {
    right: 20px;
}

/* Sections */
section {
    padding: 4rem 0;
}

section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
    position: relative;
}

section h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: #ffd700;
    margin: 0.5rem auto;
    border-radius: 2px;
}

/* Glass */
.glass {
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid rgba(255,255,255,0.2);
}

.dark-mode .glass {
    background: rgba(0,0,0,0.3);
    border-color: rgba(255,255,255,0.1);
}

/* Cards */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.card {
    background: white;
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    transition: transform 0.3s, box-shadow 0.3s;
}

.dark-mode .card {
    background: #1a2a3a;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

.card svg {
    display: block;
    margin: 0 auto 1rem;
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1.5rem;
    text-align: center;
}

.stat-item {
    padding: 1.5rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #ffd700;
}

/* FAQ */
.faq-item {
    margin-bottom: 1rem;
    border-radius: 12px;
    overflow: hidden;
}

.faq-question {
    background: rgba(255,255,255,0.05);
    padding: 1rem 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    transition: background 0.3s;
}

.faq-question:hover {
    background: rgba(255,215,0,0.1);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0 1.5rem;
    background: rgba(0,0,0,0.02);
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 1rem 1.5rem;
}

.dark-mode .faq-answer {
    background: rgba(255,255,255,0.05);
}

/* Footer */
.footer {
    background: #1a3a5c;
    color: white;
    padding: 3rem 0 1.5rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.footer h3 {
    margin-bottom: 1rem;
    color: #ffd700;
}

.footer a {
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 0.9rem;
    opacity: 0.7;
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: #ffd700;
    color: #1a3a5c;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: transform 0.3s, opacity 0.3s;
    opacity: 0;
    pointer-events: none;
    z-index: 999;
}

.back-to-top.show {
    opacity: 1;
    pointer-events: auto;
}

.back-to-top:hover {
    transform: scale(1.1);
}

/* Scroll Animation */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    nav ul {
        display: none;
        flex-direction: column;
        background: #1a3a5c;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        padding: 1rem;
        gap: 0.5rem;
    }

    nav ul.open {
        display: flex;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .search-box input {
        width: 120px;
    }

    .carousel-btn {
        font-size: 1.2rem;
        padding: 0.3rem 0.6rem;
    }
}