:root {
    --primary-color: #00f2ff;
    --secondary-color: #7000ff;
    --bg-dark: #050505;
    --text-light: #e0e0e0;
    --accent-gradient: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-light);
    font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: 0.3s;
}

/* Header & Nav */
header {
    background: rgba(5, 5, 5, 0.8);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 30px;
}

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

/* Search Box */
.search-container {
    padding: 10px 0;
    text-align: center;
}

.search-box {
    width: 100%;
    max-width: 600px;
    padding: 12px 20px;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.05);
    color: white;
    outline: none;
}

/* Banner */
.banner {
    height: 80vh;
    background: url('../images/banner.jpg') center/cover no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
}

.banner::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
}

.banner-content {
    position: relative;
    z-index: 1;
}

.banner h1 {
    font-size: 48px;
    margin-bottom: 20px;
    letter-spacing: 2px;
}

/* Video Cards */
.section-title {
    text-align: center;
    margin: 60px 0 40px;
    font-size: 32px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.video-card {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 15px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: 0.3s;
    position: relative;
}

.video-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary-color);
}

.video-thumb {
    width: 100%;
    height: 200px;
    background-size: cover;
    background-position: center;
    position: relative;
}

.play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background: rgba(0, 242, 255, 0.8);
    border-radius: 50%;
    display: none;
    align-items: center;
    justify-content: center;
}

.video-card:hover .play-btn {
    display: flex;
}

.video-info {
    padding: 20px;
}

.video-stats {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: #888;
    margin-top: 10px;
}

/* FAQ */
.faq-section {
    padding: 60px 0;
}

.faq-item {
    background: rgba(255, 255, 255, 0.02);
    margin-bottom: 15px;
    padding: 20px;
    border-radius: 10px;
}

.faq-q {
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 10px;
}

/* Footer */
footer {
    padding: 60px 0 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: 14px;
    color: #666;
}

/* Responsive */
@media (max-width: 768px) {
    .banner h1 { font-size: 32px; }
    .nav-links { display: none; }
}