/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* 顶部导航 */
.header {
    background: #1f2937;
    color: white;
    padding: 18px 0;
    position: sticky;
    top: 0;
    z-index: 99;
}

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

.logo {
    font-size: 24px;
    font-weight: bold;
    color: #f97316;
}

.nav a {
    color: white;
    text-decoration: none;
    margin-left: 25px;
    font-size: 16px;
}

.nav a:hover {
    color: #f97316;
}

/* 首页横幅 */
.banner {
    background: linear-gradient(135deg, #2563eb, #0ea5e9);
    color: white;
    text-align: center;
    padding: 100px 0;
}

.banner h1 {
    font-size: 42px;
    margin-bottom: 15px;
}

.banner p {
    font-size: 20px;
    margin-bottom: 10px;
}

.banner-desc {
    font-size: 16px;
    opacity: 0.9;
}

/* 通用板块 */
.section {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    font-size: 30px;
    margin-bottom: 40px;
    color: #1f2937;
}

/* 卡片列表 */
.card-list {
    display: flex;
    flex-wrap: wrap;
    gap: 25px;
    justify-content: center;
}

.card {
    width: 300px;
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.15);
}

.card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: #2563eb;
}

.card p {
    color: #4b5563;
    line-height: 1.6;
}

/* 技术板块背景 */
.tech-section {
    background: #f3f4f6;
}

/* 80年代记忆板块 */
.memory-section {
    background: #fffbeb;
}

.memory-section .card h3 {
    color: #f97316;
}

/* 关于我 */
.about-section {
    background: white;
    text-align: center;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: 17px;
    line-height: 1.8;
    color: #374151;
}

.about-content p {
    margin-bottom: 15px;
}

/* 底部 */
.footer {
    background: #1f2937;
    color: white;
    text-align: center;
    padding: 25px 0;
    margin-top: 20px;
}

/* 移动端适配 */
@media (max-width: 768px) {
    .banner h1 {
        font-size: 28px;
    }
    .nav a {
        margin-left: 12px;
        font-size: 14px;
    }
    .card {
        width: 100%;
    }
}