:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f7fa;
    --surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --border: #e2e8f0;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --code-bg: #f1f5f9;
    --sidebar-bg: #f8fafc;
    --card-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05);
    --btn-outline: #cbd5e1;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --surface: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --border: #334155;
    --accent: #60a5fa;
    --accent-hover: #3b82f6;
    --code-bg: #0f172a;
    --sidebar-bg: #111827;
    --card-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --btn-outline: #475569;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: background-color 0.2s, color 0.2s;
}

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
    height: 64px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 10;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    font-size: 1.3rem;
}

.logo-area i {
    font-size: 1.6rem;
    color: var(--accent);
}

.logo-text {
    background: linear-gradient(135deg, var(--accent), #8b5cf6);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
}

.tagline {
    font-size: 0.8rem;
    font-weight: normal;
    color: var(--text-secondary);
    margin-left: 8px;
}

.header-actions {
    display: flex;
    gap: 12px;
    align-items: center;
}

.icon-btn, .btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    padding: 8px 12px;
    border-radius: 40px;
    cursor: pointer;
    color: var(--text-primary);
    transition: all 0.2s;
    font-size: 0.9rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.icon-btn {
    border-radius: 40px;
    aspect-ratio: 1;
    padding: 8px;
}

.btn-outline:hover, .icon-btn:hover {
    background: var(--bg-secondary);
    border-color: var(--accent);
}

.main-layout {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.sidebar {
    width: 280px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    padding: 1.5rem 0;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 1.8rem;
}

.nav-group .group-title {
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    padding: 0 1.2rem 0.5rem 1.2rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-list {
    list-style: none;
    margin-top: 4px;
}

.nav-item a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 1.2rem 8px 2rem;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    border-radius: 0 24px 24px 0;
    transition: background 0.15s;
}

.nav-item a i {
    width: 20px;
    color: var(--text-secondary);
}

.nav-item.active a {
    background: var(--accent);
    color: white;
    font-weight: 500;
}

.nav-item.active a i {
    color: white;
}

.nav-item a:hover:not(.active) {
    background: var(--bg-secondary);
}

.content-area {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
}

.content-card {
    max-width: 900px;
    margin: 0 auto;
    background: var(--surface);
    border-radius: 28px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border);
    overflow: hidden;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.8rem 2rem;
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
    gap: 12px;
}

.page-header h1 {
    font-size: 1.8rem;
    font-weight: 600;
}

.page-content {
    padding: 2rem;
    line-height: 1.65;
}

.page-content h1, .page-content h2, .page-content h3 {
    margin-top: 1.5em;
    margin-bottom: 0.5em;
}

.code-block {
    position: relative;
    margin: 1.5rem 0;
    border-radius: 16px;
    overflow: hidden;
    background: var(--code-bg);
    border: 1px solid var(--border);
}

.code-block pre {
    padding: 1.2rem;
    overflow-x: auto;
    margin: 0;
    font-size: 0.85rem;
}

.copy-btn {
    position: absolute;
    top: 12px;
    right: 12px;
    background: rgba(0,0,0,0.5);
    border: none;
    border-radius: 40px;
    padding: 6px 12px;
    color: white;
    font-size: 0.7rem;
    cursor: pointer;
    backdrop-filter: blur(4px);
    transition: 0.1s;
}

.copy-btn:hover {
    background: var(--accent);
}

/* 管理员后台样式 */
.admin-login-body, .admin-body {
    background: var(--bg-secondary);
}

.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.login-card {
    background: var(--surface);
    border-radius: 32px;
    padding: 2.5rem;
    width: 360px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border);
}

.admin-header {
    background: var(--surface);
    padding: 1rem 2rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.admin-container {
    display: flex;
    padding: 2rem;
    gap: 2rem;
}

.admin-sidebar {
    width: 200px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.btn-sidebar {
    padding: 10px 16px;
    border-radius: 40px;
    background: transparent;
    text-decoration: none;
    color: var(--text-primary);
}

.btn-sidebar.active, .btn-sidebar:hover {
    background: var(--accent);
    color: white;
}

.admin-main {
    flex: 1;
}

.card {
    background: var(--surface);
    border-radius: 28px;
    padding: 1.8rem;
    border: 1px solid var(--border);
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom: 1.2rem;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
}

input, textarea, select {
    width: 100%;
    padding: 10px 14px;
    border-radius: 20px;
    border: 1px solid var(--border);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: inherit;
}

textarea.code-editor {
    font-family: monospace;
    font-size: 14px;
}

.btn-primary, .btn-secondary {
    padding: 10px 20px;
    border-radius: 40px;
    border: none;
    background: var(--accent);
    color: white;
    cursor: pointer;
    font-weight: 500;
    text-decoration: none;
    display: inline-block;
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table th, .data-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.actions {
    display: flex;
    gap: 10px;
}

.btn-icon {
    color: var(--text-secondary);
    text-decoration: none;
}
.btn-icon.delete { color: #ef4444; }

.alert {
    padding: 12px 16px;
    border-radius: 20px;
    margin-bottom: 20px;
}
.alert.success { background: #10b98120; color: #10b981; border: 1px solid #10b98140; }
.alert.error { background: #ef444420; color: #ef4444; border: 1px solid #ef444440; }

@media (max-width: 768px) {
    .sidebar { display: none; }
    .content-area { padding: 1rem; }
    .top-bar { padding: 0 1rem; }
    .page-header { flex-direction: column; align-items: flex-start; }
}