/* ============================================
   Server Guardian - Professional UI Stylesheet
   Mobile-First Responsive Design
   ============================================ */

:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;
    --secondary: #8b5cf6;
    --success: #10b981;
    --success-dark: #059669;
    --warning: #f59e0b;
    --warning-dark: #d97706;
    --danger: #ef4444;
    --danger-dark: #dc2626;
    --info: #06b6d4;
    
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --bg-card-hover: #334155;
    --bg-input: #0f172a;
    
    --border: #475569;
    --border-light: #64748b;
    
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.2);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.3);
    --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.3);
    
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   HEADER
   ============================================ */
.header {
    background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-card-hover) 100%);
    padding: 1rem;
    box-shadow: var(--shadow-lg);
    border-bottom: 2px solid var(--primary);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

.header-content {
    max-width: 1600px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-brand .logo {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    object-fit: cover;
}

.header-brand h1 {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-brand .subtitle {
    display: none;
    color: var(--text-muted);
    font-size: 0.75rem;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    border-radius: var(--radius-md);
    border: none;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

.btn:active {
    transform: scale(0.98);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
}

.btn-primary:hover {
    box-shadow: var(--shadow-glow);
    transform: translateY(-1px);
}

.btn-success {
    background: linear-gradient(135deg, var(--success), var(--success-dark));
    color: white;
}

.btn-success:hover {
    box-shadow: 0 0 20px rgba(16, 185, 129, 0.3);
}

.btn-danger {
    background: rgba(239, 68, 68, 0.15);
    color: var(--danger);
    border: 1px solid var(--danger);
}

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

.btn-ghost {
    background: rgba(255,255,255,0.05);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.btn-ghost:hover {
    background: rgba(255,255,255,0.1);
    color: var(--text-primary);
}

.btn-sm {
    padding: 0.5rem 0.75rem;
    font-size: 0.8rem;
}

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
    border-radius: var(--radius-sm);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* ============================================
   STATS GRID
   ============================================ */
.stats-section {
    padding: 1rem;
    max-width: 1600px;
    margin: 0 auto;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

.stat-card {
    background: linear-gradient(145deg, var(--bg-card), var(--bg-card-hover));
    border-radius: var(--radius-lg);
    padding: 1rem;
    border: 1px solid var(--border);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    opacity: 0;
    transition: var(--transition);
}

.stat-card:hover::before {
    opacity: 1;
}

.stat-card .stat-icon {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.stat-card .stat-label {
    color: var(--text-muted);
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}

.stat-card .stat-value {
    font-size: 1.75rem;
    font-weight: 800;
    line-height: 1.2;
    margin: 0.25rem 0;
}

.stat-card .stat-change {
    font-size: 0.75rem;
    color: var(--text-muted);
}

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

/* ============================================
   MAIN CONTENT GRID
   ============================================ */
.main-content {
    padding: 1rem;
    max-width: 1600px;
    margin: 0 auto;
}

.content-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

/* ============================================
   CARDS
   ============================================ */
.card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    overflow: hidden;
}

.card-header {
    padding: 1rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.card-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.card-body {
    padding: 1rem;
}

.card-footer {
    padding: 1rem;
    border-top: 1px solid var(--border);
    background: rgba(0,0,0,0.2);
}

/* ============================================
   SERVER LIST
   ============================================ */
.server-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.server-item {
    background: var(--bg-dark);
    border-radius: var(--radius-md);
    padding: 1rem;
    border-left: 4px solid var(--border);
    transition: var(--transition);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.server-item:hover {
    background: var(--bg-card-hover);
    transform: translateX(4px);
}

.server-item:active {
    transform: translateX(2px);
}

.server-item.online { border-left-color: var(--success); }
.server-item.warning { border-left-color: var(--warning); }
.server-item.critical { border-left-color: var(--danger); }
.server-item.offline { border-left-color: var(--border-light); }

.server-item-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 0.5rem;
}

.server-name {
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-primary);
    word-break: break-word;
}

.server-metrics {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
}

.metric-item {
    background: rgba(0,0,0,0.3);
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    text-align: center;
}

.metric-label {
    font-size: 0.65rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.metric-value {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* ============================================
   ALERTS LIST
   ============================================ */
.alert-list {
    max-height: 400px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.alert-list::-webkit-scrollbar {
    width: 6px;
}

.alert-list::-webkit-scrollbar-track {
    background: var(--bg-dark);
}

.alert-list::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.alert-item {
    background: var(--bg-dark);
    border-radius: var(--radius-md);
    padding: 0.875rem;
    border-left: 4px solid;
    transition: var(--transition);
}

.alert-item:hover {
    transform: translateX(4px);
}

.alert-item.critical { 
    border-left-color: var(--danger); 
    background: rgba(239, 68, 68, 0.05);
}
.alert-item.warning { 
    border-left-color: var(--warning); 
    background: rgba(245, 158, 11, 0.05);
}
.alert-item.info { 
    border-left-color: var(--primary); 
    background: rgba(59, 130, 246, 0.05);
}

.alert-title {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.alert-message {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.alert-time {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

/* ============================================
   STATUS BADGES
   ============================================ */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.25rem 0.625rem;
    border-radius: 999px;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.badge-success { background: var(--success); color: white; }
.badge-warning { background: var(--warning); color: #000; }
.badge-danger { background: var(--danger); color: white; }
.badge-muted { background: var(--border-light); color: white; }
.badge-info { background: var(--primary); color: white; }

.badge-outline {
    background: transparent;
    border: 1px solid currentColor;
}

.badge-outline.badge-success { color: var(--success); }
.badge-outline.badge-warning { color: var(--warning); }
.badge-outline.badge-danger { color: var(--danger); }

/* ============================================
   FORMS
   ============================================ */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.form-input {
    width: 100%;
    padding: 0.875rem 1rem;
    border-radius: var(--radius-md);
    border: 2px solid var(--border);
    background: var(--bg-input);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-input::placeholder {
    color: var(--text-muted);
}

.form-checkbox {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
}

.form-checkbox input {
    width: 20px;
    height: 20px;
    accent-color: var(--primary);
}

/* ============================================
   MODALS
   ============================================ */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.8);
    backdrop-filter: blur(4px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    overflow-y: auto;
}

.modal {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 25px 50px rgba(0,0,0,0.5);
    border: 1px solid var(--border);
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    padding: 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    font-size: 1.125rem;
    font-weight: 700;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.25rem;
    line-height: 1;
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 1.25rem;
}

.modal-footer {
    padding: 1.25rem;
    border-top: 1px solid var(--border);
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
}

/* ============================================
   CHARTS
   ============================================ */
.chart-container {
    position: relative;
    height: 250px;
    width: 100%;
}

/* ============================================
   LOADING STATES
   ============================================ */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    color: var(--text-muted);
    text-align: center;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

.skeleton {
    background: linear-gradient(90deg, var(--bg-card) 25%, var(--bg-card-hover) 50%, var(--bg-card) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-sm);
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-danger { color: var(--danger); }
.text-muted { color: var(--text-muted); }
.text-primary { color: var(--primary); }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }

.hidden { display: none !important; }
.visible { display: block; }

/* ============================================
   USER MENU
   ============================================ */
.user-menu {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.user-avatar {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 700;
}

.user-name {
    display: none;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* ============================================
   PROGRESS BARS
   ============================================ */
.progress {
    height: 6px;
    background: var(--bg-dark);
    border-radius: 3px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    border-radius: 3px;
    transition: width 0.5s ease;
}

.progress-bar.success { background: var(--success); }
.progress-bar.warning { background: var(--warning); }
.progress-bar.danger { background: var(--danger); }

/* ============================================
   TABS
   ============================================ */
.tabs {
    display: flex;
    gap: 0.25rem;
    padding: 0.25rem;
    background: var(--bg-dark);
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
}

.tab {
    flex: 1;
    padding: 0.625rem 1rem;
    border: none;
    background: transparent;
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.tab:hover {
    color: var(--text-secondary);
}

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

/* ============================================
   EMPTY STATE
   ============================================ */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.empty-state-text {
    font-size: 0.9rem;
}

/* ============================================
   RESPONSIVE - TABLET
   ============================================ */
@media (min-width: 640px) {
    .header {
        padding: 1rem 1.5rem;
    }
    
    .header-brand h1 {
        font-size: 1.5rem;
    }
    
    .header-brand .subtitle {
        display: block;
    }
    
    .stats-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 1rem;
    }
    
    .stat-card {
        padding: 1.25rem;
    }
    
    .stat-card .stat-value {
        font-size: 2rem;
    }
    
    .main-content {
        padding: 1.5rem;
    }
    
    .server-metrics {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .user-name {
        display: block;
    }
    
    .chart-container {
        height: 300px;
    }
}

/* ============================================
   RESPONSIVE - DESKTOP
   ============================================ */
@media (min-width: 1024px) {
    .header {
        padding: 1rem 2rem;
    }
    
    .stats-section {
        padding: 1.5rem 2rem;
    }
    
    .main-content {
        padding: 0 2rem 2rem;
    }
    
    .content-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
    
    .stat-card:hover {
        transform: translateY(-4px);
        box-shadow: var(--shadow-lg);
    }
    
    .server-item:hover {
        transform: translateX(8px);
    }
}

/* ============================================
   RESPONSIVE - LARGE DESKTOP
   ============================================ */
@media (min-width: 1400px) {
    .stats-grid {
        gap: 1.5rem;
    }
    
    .stat-card .stat-value {
        font-size: 2.5rem;
    }
}

/* ============================================
   TOUCH DEVICE OPTIMIZATIONS
   ============================================ */
@media (hover: none) {
    .stat-card:hover,
    .server-item:hover,
    .alert-item:hover,
    .btn:hover {
        transform: none;
    }
    
    .btn:active {
        transform: scale(0.98);
    }
    
    .server-item:active {
        background: var(--bg-card-hover);
    }
}

/* ============================================
   SAFE AREA (iPhone X+)
   ============================================ */
@supports (padding-bottom: env(safe-area-inset-bottom)) {
    body {
        padding-bottom: env(safe-area-inset-bottom);
    }
    
    .header {
        padding-top: calc(1rem + env(safe-area-inset-top));
    }
}

/* ============================================
   REDUCED MOTION
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ============================================
   DARK MODE SCROLLBARS
   ============================================ */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-dark);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-light);
}

/* Firefox */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--border) var(--bg-dark);
}