/* 全站基础样式 */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: linear-gradient(180deg, #0f172a, #020617);
    color: #e5e7eb;
    min-height: 100vh;
}

/* 顶部导航 */
header {
    background: rgba(15, 23, 42, 0.9);
    border-bottom: 1px solid #1f2937;
    position: sticky;
    top: 0;
    backdrop-filter: blur(10px);
    z-index: 10;
}

.nav {
    max-width: 960px;
    margin: 0 auto;
    padding: 12px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 700;
    letter-spacing: 0.08em;
    font-size: 18px;
    color: #38bdf8;
}

.nav-links a {
    margin-left: 16px;
    text-decoration: none;
    font-size: 14px;
    color: #e5e7eb;
}

.nav-links a:hover {
    color: #38bdf8;
}

/* 主体 */
main {
    max-width: 960px;
    margin: 0 auto;
    padding: 24px 16px 40px;
}

/* hero 区域 */
.hero {
    background: radial-gradient(circle at top, #1d4ed8, #020617);
    border-radius: 20px;
    padding: 24px 20px;
    border: 1px solid #1f2937;
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.8);
    margin-bottom: 28px;
}

.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 999px;
    border: 1px solid rgba(148, 163, 184, 0.7);
    font-size: 12px;
    margin-bottom: 10px;
    background: rgba(15, 23, 42, 0.7);
}

.hero h1 {
    font-size: 26px;
    margin-bottom: 10px;
}

.hero p {
    font-size: 14px;
    line-height: 1.6;
    color: #d1d5db;
}

/* 两个大按钮区块 */
.section-title {
    font-size: 18px;
    margin-bottom: 10px;
}

.card-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
}

.card {
    background: #020617;
    border-radius: 16px;
    border: 1px solid #1f2937;
    padding: 16px 18px 18px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.card p {
    font-size: 14px;
    color: #9ca3af;
    margin-bottom: 14px;
}

.btn-main {
    display: inline-block;
    padding: 8px 14px;
    border-radius: 999px;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    background: #2563eb;
    color: white;
    text-align: center;
}

.btn-main:hover {
    background: #1d4ed8;
}

.tag {
    font-size: 11px;
    color: #9ca3af;
    margin-bottom: 4px;
}

footer {
    text-align: center;
    font-size: 12px;
    color: #6b7280;
    padding: 14px;
    border-top: 1px solid #1f2937;
    background: #020617;
}

/* 手机优化 */
@media (max-width: 640px) {
    .hero {
        padding: 20px 16px;
    }
    .hero h1 {
        font-size: 22px;
    }
}