/* 头部样式 */
header {
    background: linear-gradient(90deg, #0c1622 0%, #1a2a40 100%);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    font-size: 28px;
    font-weight: 700;
    color: #4ecca3;
    text-decoration: none;
}

.logo span {
    color: #fff;
}

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

nav ul li {
    margin-left: 30px;
}

nav ul li a {
    color: #e0e0e0;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: color 0.3s;
    padding: 8px 12px;
    border-radius: 4px;
}

nav ul li a:hover, nav ul li a.active {
    color: #4ecca3;
    background-color: rgba(78, 204, 163, 0.1);
}

.search-box {
    display: flex;
    justify-content: center;
    align-items: center;
}

.search-box input {
    padding: 10px 15px;
    border: none;
    border-radius: 30px 0 0 30px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    width: 250px;
}

.search-box button {
    padding: 10px 20px;
    border: none;
    border-radius: 0 30px 30px 0;
    background: #4ecca3;
    color: #000;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
}

.search-box button:hover {
    background: #3da58a;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 20px;
    }

    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }

    nav ul li {
        margin: 5px 10px;
    }

    .search-box {
        width: 100%;
        max-width: 400px;
    }
}

@media (max-width: 480px) {
    .search-box input {
        width: 180px;
    }
}