:root {
    --primary: #3b82f6; /* 浅蓝色 */
    --primary-gradient: linear-gradient(135deg, #60a5fa 0%, #3b82f6 100%);
    --primary-light: #eff6ff;
    --primary-dark: #1d4ed8;
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background: var(--bg-main);
    color: var(--text-main);
    margin: 0;
    font-size: 14px;
    -webkit-font-smoothing: antialiased;
}

.wrapper { display: flex; min-height: 100vh; }

/* 侧边栏样式优化 */
.sidebar {
    width: 260px;
    background: var(--bg-card);
    border-right: 1px solid var(--border);
    padding: 1.5rem 0;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
}

.sidebar-header { padding: 0 1.5rem 2rem; text-align: center; }
.sidebar-header h2 { 
    font-size: 1.25rem; 
    font-weight: 800; 
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin: 0; 
}

.nav-menu { list-style: none; padding: 0; margin: 0; }
.nav-section { padding: 1.5rem 1.5rem 0.5rem; font-size: 0.7rem; font-weight: 700; text-uppercase; color: var(--text-muted); letter-spacing: 0.1em; }
.nav-item { padding: 0.25rem 1rem; }
.nav-link {
    display: flex; align-items: center; padding: 0.75rem 1rem;
    color: #64748b; text-decoration: none; border-radius: var(--radius);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1); font-weight: 500;
}
.nav-link i { width: 24px; margin-right: 12px; font-size: 1.1rem; opacity: 0.8; text-align: center; }
.nav-link:hover { background: var(--primary-light); color: var(--primary); }
.nav-link.active { background: var(--primary-gradient); color: #fff; box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3); }
.nav-link.active i { opacity: 1; }

/* 主内容区 */
.main-content { flex-grow: 1; padding: 2rem; background: #fbfcfe; }

.admin-navbar {
    display: flex; justify-content: space-between; align-items: center;
    padding-bottom: 1.5rem; margin-bottom: 2rem; border-bottom: 1px solid var(--border);
}
.admin-navbar h4 { font-weight: 700; margin: 0; font-size: 1.5rem; color: var(--text-main); }

/* 卡片样式 */
.card {
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); box-shadow: var(--shadow);
    overflow: hidden; margin-bottom: 1.5rem; border: none;
}
.card-header { background: #fff; padding: 1.25rem 1.5rem; border-bottom: 1px solid var(--border); font-weight: 700; color: var(--text-main); }
.card-body { padding: 1.5rem; }

/* 按钮样式 */
.btn { font-weight: 600; padding: 0.625rem 1.25rem; border-radius: var(--radius); transition: all 0.2s; border: none; }
.btn-primary { background: var(--primary-gradient); color: #fff; box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 6px 15px rgba(59, 130, 246, 0.3); color: #fff; }

/* 表格样式 */
.table { margin: 0; }
.table thead th { background: #f8fafc; font-size: 0.75rem; font-weight: 700; text-uppercase; color: var(--text-muted); border: none; padding: 1rem 1.5rem; }
.table tbody td { padding: 1.25rem 1.5rem; vertical-align: middle; border-bottom: 1px solid var(--border); color: #475569; }

/* 状态标签 */
.badge { font-weight: 700; padding: 0.5em 0.8em; border-radius: 6px; }

/* 背景色辅助类 */
.bg-primary-gradient { background: var(--primary-gradient) !important; color: #fff !important; }
.text-primary { color: var(--primary) !important; }

@media (max-width: 992px) {
    .sidebar { width: 80px; }
    .sidebar-header h2, .nav-link span, .nav-section { display: none; }
    .nav-link i { margin-right: 0; width: 100%; font-size: 1.25rem; }
    .nav-item { padding: 0.25rem 0.5rem; }
}