:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #eff6ff;
    --danger: #dc2626;
    --danger-dark: #b91c1c;
    --danger-light: #fef2f2;
    --success: #059669;
    --success-light: #ecfdf5;
    --warning: #d97706;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    --header-height: 60px;
    --radius: 8px;
    --radius-sm: 6px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
    --transition: 0.2s ease;
}

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

[hidden] { display: none !important; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.5;
    color: var(--gray-800);
    background: var(--gray-50);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.3;
}

/* Buttons */
.btn {
    padding: 10px 18px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.875rem;
    font-family: inherit;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    border: 1px solid transparent;
    cursor: pointer;
    white-space: nowrap;
    text-decoration: none;
}

.btn svg { width: 18px; height: 18px; flex-shrink: 0; }

.btn-primary {
    background: var(--primary);
    color: white;
}
.btn-primary:hover { background: var(--primary-dark); }
.btn-primary:disabled { background: var(--gray-300); cursor: not-allowed; }

.btn-ghost {
    background: transparent;
    color: var(--gray-600);
    border-color: transparent;
}
.btn-ghost:hover { background: var(--gray-100); color: var(--gray-800); }

.btn-danger { background: var(--danger); color: white; }
.btn-danger:hover { background: var(--danger-dark); }

.btn-full { width: 100%; }

.btn-icon {
    padding: 8px;
    border: none;
    background: none;
    cursor: pointer;
    color: var(--gray-400);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}
.btn-icon:hover { background: var(--gray-100); color: var(--gray-700); }
.btn-icon svg { width: 18px; height: 18px; }
.btn-icon.danger:hover { background: var(--danger-light); color: var(--danger); }

/* Toast */
.toast {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    background: var(--gray-800);
    color: white;
    padding: 12px 20px;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    z-index: 2000;
    animation: toastIn 0.3s ease;
    box-shadow: var(--shadow-md);
}

.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }

@keyframes toastIn {
    from { transform: translateY(16px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}