:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #eff6ff;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --sidebar-width: 260px;
    --border-radius: 12px;
    --shadow-sm: 0 1px 2px 0 rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
}
* { margin:0; padding:0; box-sizing:border-box; }
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gray-100);
    color: var(--gray-800);
    line-height: 1.5;
}
.login-box {
    max-width: 420px;
    margin: 10vh auto;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    padding: 2rem;
}
.login-box h2 { text-align:center; margin-bottom:1.5rem; font-weight:600; }
.login-box input { width:100%; padding:0.75rem 1rem; margin-bottom:1rem; border:1px solid var(--gray-300); border-radius:8px; }
.login-box input:focus { outline:none; border-color:var(--primary); box-shadow:0 0 0 3px rgba(59,130,246,0.1); }
.login-box button { width:100%; padding:0.75rem; background:var(--primary); color:white; border:none; border-radius:8px; font-weight:500; cursor:pointer; }
.login-box button:hover { background:var(--primary-dark); }
.captcha-row { display:flex; gap:10px; align-items:center; }
.captcha-img { height:42px; border-radius:8px; cursor:pointer; }
.admin-container { display:flex; min-height:100vh; }
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, var(--gray-800) 0%, var(--gray-900) 100%);
    color: var(--gray-300);
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 10;
}
.sidebar h2 { font-size:1.25rem; font-weight:600; padding:1.5rem 1.5rem 1rem; margin-bottom:0.5rem; border-bottom:1px solid rgba(255,255,255,0.1); color:white; }
.sidebar ul { list-style:none; }
.sidebar ul li a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0.75rem 1.5rem;
    color: var(--gray-300);
    text-decoration: none;
    transition: all 0.2s;
}
.sidebar ul li a i { width:20px; }
.sidebar ul li a:hover { background:rgba(255,255,255,0.1); color:white; }
.sidebar ul li a.active { background:var(--primary); color:white; }
.content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 1.5rem;
    min-height: 100vh;
}
.content h1 { font-size:1.875rem; font-weight:600; margin-bottom:1.5rem; color:var(--gray-800); }
.stats { display:grid; grid-template-columns:repeat(auto-fit, minmax(240px,1fr)); gap:1.5rem; margin-bottom:2rem; }
.stat-box { background:white; border-radius:var(--border-radius); padding:1.5rem; box-shadow:var(--shadow-sm); border:1px solid var(--gray-200); transition:transform 0.2s; }
.stat-box:hover { transform:translateY(-2px); box-shadow:var(--shadow-md); }
.stat-box .stat-number { font-size:2rem; font-weight:700; color:var(--primary); margin-bottom:0.25rem; }
.stat-box .stat-label { font-size:0.875rem; color:var(--gray-500); text-transform:uppercase; letter-spacing:0.5px; }
table { width:100%; background:white; border-radius:var(--border-radius); overflow:hidden; box-shadow:var(--shadow-sm); border-collapse:collapse; margin-bottom:1.5rem; }
table th { background:var(--gray-50); padding:1rem; text-align:left; font-weight:600; color:var(--gray-700); border-bottom:1px solid var(--gray-200); }
table td { padding:0.875rem 1rem; border-bottom:1px solid var(--gray-100); vertical-align:middle; }
table tr:hover { background:var(--gray-50); }
table a { color:var(--primary); text-decoration:none; margin-right:0.75rem; }
form { background:white; border-radius:var(--border-radius); padding:1.5rem; margin-bottom:2rem; box-shadow:var(--shadow-sm); border:1px solid var(--gray-200); }
form div { margin-bottom:1.25rem; }
form label { display:block; margin-bottom:0.5rem; font-weight:500; color:var(--gray-700); }
form input, form select, form textarea { width:100%; padding:0.625rem 0.875rem; border:1px solid var(--gray-300); border-radius:8px; transition:all 0.2s; }
form input:focus, form select:focus, form textarea:focus { outline:none; border-color:var(--primary); box-shadow:0 0 0 3px rgba(59,130,246,0.1); }
form button { background:var(--primary); color:white; padding:0.625rem 1.5rem; border:none; border-radius:8px; font-weight:500; cursor:pointer; }
form button:hover { background:var(--primary-dark); }
.alert { background:#d1fae5; color:#065f46; padding:0.75rem 1rem; border-radius:8px; margin-bottom:1rem; border-left:4px solid var(--success); }
.error { background:#fee2e2; color:#991b1b; padding:0.75rem 1rem; border-radius:8px; margin-bottom:1rem; border-left:4px solid var(--danger); }
.btn { display:inline-flex; align-items:center; gap:0.5rem; padding:0.5rem 1rem; border-radius:8px; font-size:0.875rem; font-weight:500; text-decoration:none; cursor:pointer; border:none; }
.btn-primary { background:var(--primary); color:white; }
.btn-primary:hover { background:var(--primary-dark); }
.btn-outline { background:transparent; border:1px solid var(--gray-300); color:var(--gray-700); }
.btn-outline:hover { border-color:var(--primary); color:var(--primary); background:var(--primary-light); }
.btn-sm { padding:0.25rem 0.75rem; font-size:0.75rem; }
@media (max-width:768px) { .sidebar { width:0; transform:translateX(-100%); } .content { margin-left:0; } }