:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #1e293b;
    --bg-card-hover: #253347;
    --bg-input: #0f172a;
    --border: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #06b6d4;
    --purple: #a855f7;
    --gradient-accent: linear-gradient(135deg, #3b82f6, #8b5cf6);
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.4);
    --radius: 12px;
    --radius-sm: 8px;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

/* Layout */
.app { display: flex; min-height: 100vh; }

.sidebar {
    width: 260px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    padding: 24px 16px;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 100;
}

.sidebar-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0 8px 24px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 24px;
}

.sidebar-logo .logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-accent);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 700;
    color: white;
}

.sidebar-logo h1 {
    font-size: 18px;
    font-weight: 700;
}

.sidebar-logo span {
    font-size: 11px;
    color: var(--text-muted);
    display: block;
}

.nav-section {
    margin-bottom: 24px;
}

.nav-section-title {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    padding: 0 8px;
    margin-bottom: 8px;
    font-weight: 600;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
    font-size: 14px;
    margin-bottom: 2px;
}

.nav-item:hover { background: var(--bg-card-hover); color: var(--text-primary); }
.nav-item.active { background: rgba(59,130,246,0.15); color: var(--accent); font-weight: 500; }
.nav-item svg { width: 18px; height: 18px; flex-shrink: 0; }

.main-content {
    flex: 1;
    margin-left: 260px;
    padding: 32px;
    max-width: 1400px;
}

/* Page header */
.page-header {
    margin-bottom: 32px;
}

.page-header h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 4px;
}

.page-header p {
    color: var(--text-secondary);
    font-size: 14px;
}

/* Cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    transition: all 0.2s;
}

.stat-card:hover { border-color: var(--accent); transform: translateY(-1px); }

.stat-card .stat-label {
    font-size: 12px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.stat-card .stat-value {
    font-size: 28px;
    font-weight: 700;
}

.stat-card .stat-sub {
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 4px;
}

.stat-card.accent .stat-value { color: var(--accent); }
.stat-card.success .stat-value { color: var(--success); }
.stat-card.warning .stat-value { color: var(--warning); }
.stat-card.danger .stat-value { color: var(--danger); }
.stat-card.purple .stat-value { color: var(--purple); }
.stat-card.info .stat-value { color: var(--info); }

/* Content panels */
.panel {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 24px;
    overflow: hidden;
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
}

.panel-header h3 {
    font-size: 16px;
    font-weight: 600;
}

.panel-body { padding: 20px; }

/* Forms */
.form-group { margin-bottom: 16px; }

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

.form-control {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 14px;
    transition: border-color 0.15s;
}

.form-control:focus { outline: none; border-color: var(--accent); }
.form-control::placeholder { color: var(--text-muted); }

textarea.form-control { resize: vertical; min-height: 100px; font-family: monospace; }

/* Buttons */
.btn {
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: all 0.15s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); }
.btn-success { background: var(--success); color: white; }
.btn-success:hover { opacity: 0.9; }
.btn-warning { background: var(--warning); color: #000; }
.btn-danger { background: var(--danger); color: white; }
.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-primary);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }
.btn-sm { padding: 6px 14px; font-size: 13px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Tables */
.table-container { overflow-x: auto; }

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

th, td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border);
    font-size: 14px;
}

th {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

tr:hover { background: var(--bg-card-hover); }

/* Badges */
.badge {
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
    display: inline-block;
}

.badge-success { background: rgba(34,197,94,0.15); color: var(--success); }
.badge-warning { background: rgba(245,158,11,0.15); color: var(--warning); }
.badge-danger { background: rgba(239,68,68,0.15); color: var(--danger); }
.badge-info { background: rgba(6,182,212,0.15); color: var(--info); }
.badge-neutral { background: rgba(148,163,184,0.15); color: var(--text-secondary); }

/* Progress bar */
.progress-bar {
    height: 8px;
    background: var(--bg-input);
    border-radius: 4px;
    overflow: hidden;
    margin-top: 8px;
}

.progress-bar .fill {
    height: 100%;
    border-radius: 4px;
    transition: width 0.5s ease;
}

.progress-bar .fill.blue { background: var(--accent); }
.progress-bar .fill.green { background: var(--success); }
.progress-bar .fill.yellow { background: var(--warning); }
.progress-bar .fill.red { background: var(--danger); }

/* DNS check results */
.dns-result {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px;
    border-radius: var(--radius-sm);
    background: var(--bg-input);
    margin-bottom: 10px;
}

.dns-result .icon {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    flex-shrink: 0;
    margin-top: 2px;
}

.dns-result .icon.pass { background: rgba(34,197,94,0.2); color: var(--success); }
.dns-result .icon.fail { background: rgba(239,68,68,0.2); color: var(--danger); }

.dns-result .info h4 { font-size: 14px; font-weight: 600; margin-bottom: 4px; }
.dns-result .info p { font-size: 13px; color: var(--text-secondary); }
.dns-result .info .value {
    font-family: monospace;
    font-size: 12px;
    color: var(--text-muted);
    word-break: break-all;
    margin-top: 4px;
}

.dns-result .info .recommendations {
    margin-top: 8px;
    padding: 8px 12px;
    background: rgba(245,158,11,0.1);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--warning);
}

.dns-result .info .recommendations li {
    font-size: 12px;
    color: var(--warning);
    margin-bottom: 4px;
    list-style: none;
}

/* Score circle */
.score-circle {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
}

.score-circle .number { font-size: 36px; font-weight: 700; }
.score-circle .label { font-size: 12px; color: var(--text-secondary); }

.score-circle.excellent { border: 4px solid var(--success); }
.score-circle.good { border: 4px solid var(--accent); }
.score-circle.fair { border: 4px solid var(--warning); }
.score-circle.poor { border: 4px solid var(--danger); }

/* Warmup timeline */
.warmup-timeline {
    position: relative;
    padding-left: 24px;
}

.warmup-timeline::before {
    content: '';
    position: absolute;
    left: 8px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.warmup-step {
    position: relative;
    padding: 12px 0 12px 20px;
}

.warmup-step::before {
    content: '';
    position: absolute;
    left: -20px;
    top: 16px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--border);
}

.warmup-step.completed::before { background: var(--success); }
.warmup-step.current::before { background: var(--accent); box-shadow: 0 0 0 4px rgba(59,130,246,0.2); }

.warmup-step .step-header { display: flex; justify-content: space-between; align-items: center; }
.warmup-step .step-day { font-weight: 600; font-size: 14px; }
.warmup-step .step-volume { color: var(--accent); font-weight: 600; }
.warmup-step .step-details { font-size: 13px; color: var(--text-secondary); margin-top: 4px; }

/* Tabs */
.tabs {
    display: flex;
    gap: 4px;
    padding: 4px;
    background: var(--bg-input);
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
}

.tab {
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all 0.15s;
}

.tab:hover { color: var(--text-primary); }
.tab.active { background: var(--accent); color: white; }

/* File upload */
.file-upload {
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
}

.file-upload:hover { border-color: var(--accent); background: rgba(59,130,246,0.05); }
.file-upload.dragover { border-color: var(--accent); background: rgba(59,130,246,0.1); }
.file-upload svg { width: 40px; height: 40px; color: var(--text-muted); margin-bottom: 12px; }
.file-upload p { color: var(--text-secondary); font-size: 14px; }
.file-upload .hint { font-size: 12px; color: var(--text-muted); margin-top: 4px; }

/* Loading */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
    color: var(--text-muted);
    gap: 8px;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* Toast notifications */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toast {
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    color: white;
    font-size: 14px;
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease;
    max-width: 400px;
}

.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }
.toast.warning { background: var(--warning); color: #000; }
.toast.info { background: var(--accent); }

@keyframes slideIn { from { transform: translateX(100%); opacity: 0; } }

/* Grid layout helpers */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 16px; }

/* Section hidden/shown */
.section { display: none; }
.section.active { display: block; }

/* Responsive */
@media (max-width: 768px) {
    .sidebar { display: none; }
    .main-content { margin-left: 0; padding: 16px; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
}