* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: #e6edf3;
    background: #0d1117;
    line-height: 1.6;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== 头部毛玻璃特效 ===== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    transition: all 0.3s ease;
}
.header-blur {
    background: rgba(13, 17, 23, 0.65);
    -webkit-backdrop-filter: blur(var(--header-blur-radius, 12px));
    backdrop-filter: blur(var(--header-blur-radius, 12px));
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}
.logo a {
    color: #58a6ff;
    font-size: 22px;
    font-weight: 700;
    text-decoration: none;
}
.nav-menu {
    display: flex;
    gap: 28px;
    align-items: center;
}
.nav-menu a {
    color: #e6edf3;
    text-decoration: none;
    font-size: 15px;
    transition: color 0.2s;
}
.nav-menu a:hover { color: #58a6ff; }
.btn-primary {
    background: #238636;
    color: #fff !important;
    padding: 8px 16px;
    border-radius: 6px;
}
.btn-primary:hover { background: #2ea043; }
.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: #e6edf3;
    font-size: 22px;
    cursor: pointer;
}

/* ===== Hero 区域 ===== */
.hero {
    padding: 140px 0 100px;
    text-align: center;
    background: linear-gradient(180deg, #0d1117 0%, #161b22 100%);
}
.hero h1 {
    font-size: 52px;
    margin-bottom: 20px;
    background: linear-gradient(90deg, #58a6ff, #a371f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero p {
    font-size: 18px;
    color: #8b949e;
    max-width: 700px;
    margin: 0 auto 32px;
}
.hero-buttons { display: flex; gap: 16px; justify-content: center; }
.btn {
    padding: 12px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    display: inline-block;
}
.btn-green { background: #238636; color: #fff; }
.btn-outline { border: 1px solid #30363d; color: #e6edf3; }

/* ===== 特性区块 ===== */
.section { padding: 80px 0; }
.section-title {
    text-align: center;
    font-size: 32px;
    margin-bottom: 48px;
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}
.feature-card {
    background: #161b22;
    border: 1px solid #30363d;
    border-radius: 12px;
    padding: 28px;
    transition: border-color 0.3s;
}
.feature-card:hover { border-color: #58a6ff; }
.feature-card h3 {
    color: #58a6ff;
    margin-bottom: 12px;
    font-size: 20px;
}

/* ===== 表单 ===== */
.auth-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}
.auth-card {
    background: #161b22;
    border: 1px solid #30363d;
    border-radius: 12px;
    padding: 36px;
    width: 100%;
    max-width: 420px;
}
.auth-card h2 {
    text-align: center;
    margin-bottom: 24px;
    color: #58a6ff;
}
.form-group { margin-bottom: 18px; }
.form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 14px;
    color: #8b949e;
}
.form-group input {
    width: 100%;
    padding: 10px 12px;
    background: #0d1117;
    border: 1px solid #30363d;
    border-radius: 6px;
    color: #e6edf3;
    font-size: 14px;
}
.form-group input:focus {
    outline: none;
    border-color: #58a6ff;
}
.btn-submit {
    width: 100%;
    padding: 12px;
    background: #238636;
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 15px;
    cursor: pointer;
}
.alert {
    padding: 10px 14px;
    border-radius: 6px;
    margin-bottom: 16px;
    font-size: 14px;
}
.alert-error { background: rgba(248, 81, 73, 0.15); color: #f85149; }
.alert-success { background: rgba(35, 134, 54, 0.15); color: #3fb950; }

/* ===== 后台样式 ===== */
.admin-layout {
    display: flex;
    min-height: 100vh;
    padding-top: 64px;
}
.admin-sidebar {
    width: 220px;
    background: #161b22;
    border-right: 1px solid #30363d;
    padding: 20px 0;
    position: fixed;
    top: 64px;
    bottom: 0;
    left: 0;
}
.admin-sidebar a {
    display: block;
    padding: 12px 24px;
    color: #e6edf3;
    text-decoration: none;
    border-left: 3px solid transparent;
}
.admin-sidebar a:hover,
.admin-sidebar a.active {
    background: #21262d;
    border-left-color: #58a6ff;
}
.admin-main {
    margin-left: 220px;
    flex: 1;
    padding: 28px;
}
.admin-card {
    background: #161b22;
    border: 1px solid #30363d;
    border-radius: 10px;
    padding: 24px;
    margin-bottom: 20px;
}
.admin-table {
    width: 100%;
    border-collapse: collapse;
}
.admin-table th,
.admin-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #30363d;
}

/* ===== 页脚 ===== */
.site-footer {
    background: #0d1117;
    border-top: 1px solid #30363d;
    padding: 32px 0;
    text-align: center;
    color: #8b949e;
    font-size: 14px;
}

/* ===== 响应式适配（按机型适配模糊特效） ===== */
@media (max-width: 768px) {
    .hero h1 { font-size: 36px; }
    .nav-menu {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: #161b22;
        padding: 16px 20px;
        gap: 12px;
        border-bottom: 1px solid #30363d;
    }
    .nav-menu.open { display: flex; }
    .menu-toggle { display: block; }
    
    /* 移动端降低模糊强度，减少性能消耗 */
    .header-blur {
        -webkit-backdrop-filter: blur(8px);
        backdrop-filter: blur(8px);
        background: rgba(13, 17, 23, 0.8);
    }
    
    .admin-sidebar { width: 180px; }
    .admin-main { margin-left: 180px; }
}

@media (max-width: 480px) {
    .hero h1 { font-size: 28px; }
    .hero-buttons { flex-direction: column; align-items: center; }
    
    /* 低端机型关闭模糊，保证流畅度 */
    .header-blur {
        -webkit-backdrop-filter: none;
        backdrop-filter: none;
        background: rgba(13, 17, 23, 0.95);
    }
    
    .admin-layout { flex-direction: column; }
    .admin-sidebar {
        position: static;
        width: 100%;
        display: flex;
        overflow-x: auto;
        padding: 0;
    }
    .admin-sidebar a {
        white-space: nowrap;
        border-left: none;
        border-bottom: 3px solid transparent;
    }
    .admin-sidebar a.active {
        border-left: none;
        border-bottom-color: #58a6ff;
    }
    .admin-main { margin-left: 0; padding: 16px; }
}

/* 低性能设备降级 */
@media (prefers-reduced-motion: reduce) {
    .site-header { transition: none; }
}
/* 滚动后头部强化效果 */
.header-scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}
.header-blur.header-scrolled {
    background: rgba(13, 17, 23, 0.85);
}