/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background: #0b0d17; /* 深空黑 */
    color: #e0e0e0;
    scroll-behavior: smooth;
}

/* 导航栏 */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 10%;
    background: rgba(0, 0, 0, 0.7);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    letter-spacing: 2px;
    color: #4facfe;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 2rem;
}

nav ul li a {
    text-decoration: none;
    color: white;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: #4facfe;
}

/* 英雄展区 */
.hero {
    height: 100vh;
    background: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), 
                url('https://images.unsplash.com/photo-1446776811953-b23d57bd21aa?auto=format&fit=crop&w=1920&q=80');
    background-size: cover;
    background-position: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 20px;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    background: linear-gradient(to right, #4facfe 0%, #00f2fe 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.cta-btn {
    margin-top: 2rem;
    padding: 1rem 2.5rem;
    background: #4facfe;
    color: white;
    text-decoration: none;
    border-radius: 30px;
    transition: transform 0.3s;
}

.cta-btn:hover {
    transform: scale(1.1);
}

/* 内容网格 */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 5rem 10%;
}

.card {
    background: #161b22;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    transition: translateY 0.3s;
    border: 1px solid #30363d;
}

.card:hover {
    transform: translateY(-10px);
    border-color: #4facfe;
}

.icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

footer {
    text-align: center;
    padding: 2rem;
    background: #050505;
    font-size: 0.9rem;
}