:root {
    --color-primary: #2563eb;
    --color-primary-light: #3b82f6;
    --color-primary-hover: #1d4ed8;
    --color-primary-active: #1e40af;
    --color-primary-bg: #eff6ff;
    --color-primary-border: #bfdbfe;

    --color-success: #10b981;
    --color-success-bg: #ecfdf5;
    --color-success-border: #a7f3d0;
    --color-warning: #f59e0b;
    --color-warning-bg: #fffbeb;
    --color-warning-border: #fde68a;
    --color-danger: #ef4444;
    --color-danger-bg: #fef2f2;
    --color-danger-border: #fecaca;
    --color-info: #6366f1;
    --color-info-bg: #eef2ff;
    --color-info-border: #c7d2fe;

    --bg-body: #f8fafc;
    --bg-white: #ffffff;
    --bg-subtle: #f1f5f9;
    --bg-hover: #f8fafc;
    --bg-active: #eff6ff;
    --bg-muted: #e2e8f0;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #94a3b8;
    --text-disabled: #cbd5e1;
    --text-white: #ffffff;

    --border-color: #e2e8f0;
    --border-color-light: #f1f5f9;
    --border-color-focus: #2563eb;

    --shadow-xs: 0 1px 2px 0 rgba(0,0,0,0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0,0,0,0.1), 0 1px 2px -1px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);

    --radius-sm: 6px;
    --radius-base: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-base: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 40px;

    --header-height: 60px;
    --sidebar-width: 200px;
    --sidebar-collapsed-width: 72px;

    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);

    font-family: -apple-system, 'SF Pro SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    font-size: 14px;
    color: var(--text-primary);
}

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

body {
    background: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-primary-hover); }

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 7px 16px;
    font-size: 14px;
    font-weight: 500;
    line-height: 1.4;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-white);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition-fast);
    white-space: nowrap;
    user-select: none;
}
.btn:hover { border-color: var(--color-primary-border); background: var(--bg-hover); }
.btn:active { transform: scale(0.97); }

.btn-primary {
    background: var(--color-primary);
    color: var(--text-white);
    border-color: var(--color-primary);
}
.btn-primary:hover { background: var(--color-primary-hover); border-color: var(--color-primary-hover); }

.btn-success { background: var(--color-success); color: var(--text-white); border-color: var(--color-success); }
.btn-warning { background: var(--color-warning); color: var(--text-white); border-color: var(--color-warning); }
.btn-danger { background: var(--color-danger); color: var(--text-white); border-color: var(--color-danger); }

.btn-sm { padding: 4px 12px; font-size: 12px; }
.btn-ghost { background: transparent; border-color: transparent; color: var(--text-secondary); }
.btn-ghost:hover { background: rgba(255,255,255,0.1); color: var(--text-white); }
.btn-block { width: 100%; }

.input, .select {
    width: 100%;
    padding: 8px 12px;
    font-size: 14px;
    line-height: 1.4;
    color: var(--text-primary);
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    outline: none;
    transition: var(--transition-fast);
}
.input:focus, .select:focus {
    border-color: var(--border-color-focus);
    box-shadow: 0 0 0 3px var(--color-primary-bg);
}
.input::placeholder { color: var(--text-tertiary); }

.card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-xs);
}

.stat-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-xs);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}
.stat-card .stat-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.2;
}
.stat-card .stat-label {
    font-size: 13px;
    color: var(--text-secondary);
}
.stat-card .stat-change {
    font-size: 12px;
    font-weight: 500;
}
.stat-card .stat-change.up { color: var(--color-success); }
.stat-card .stat-change.down { color: var(--color-danger); }

.tag {
    display: inline-flex;
    align-items: center;
    padding: 2px 10px;
    font-size: 12px;
    font-weight: 500;
    border-radius: 100px;
    line-height: 1.6;
}
.tag-red { background: var(--color-danger-bg); color: #dc2626; }
.tag-orange { background: var(--color-warning-bg); color: #d97706; }
.tag-green { background: var(--color-success-bg); color: #059669; }
.tag-blue { background: var(--color-primary-bg); color: var(--color-primary); }

.status-tag--active { background: var(--color-success-bg); color: var(--color-success); }
.status-tag--paused { background: var(--color-warning-bg); color: var(--color-warning); }
.status-tag--error { background: var(--color-danger-bg); color: var(--color-danger); }

.form-group { margin-bottom: var(--spacing-base); }
.form-label {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.text-center { text-align: center; }
.text-right { text-align: right; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--spacing-sm); }
.gap-base { gap: var(--spacing-base); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-base { margin-top: var(--spacing-base); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-base { margin-bottom: var(--spacing-base); }