/* REA Attendance - Mobile-First App Design System */

:root {
    /* Colors */
    --primary: #667eea;
    --primary-dark: #5568d3;
    --secondary: #764ba2;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    /* Neutrals */
    --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;
    
    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background: var(--gray-50);
    color: var(--gray-900);
    line-height: 1.5;
    min-height: 100vh;
}

/* App Container */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.app-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: var(--space-md);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-md);
}

.app-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 20px;
    font-weight: 700;
    text-decoration: none;
    color: white;
}

.logo-icon {
    font-size: 28px;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}

.user-info {
    text-align: right;
}

.user-name {
    font-weight: 600;
    font-size: 14px;
}

.user-role {
    font-size: 12px;
    opacity: 0.9;
}

/* Main Content */
.app-main {
    flex: 1;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: var(--space-lg) var(--space-md);
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
}

.card-icon {
    font-size: 32px;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--gray-900);
}

.card-description {
    color: var(--gray-600);
    font-size: 14px;
    margin-bottom: var(--space-md);
}

/* Grid */
.grid {
    display: grid;
    gap: var(--space-lg);
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 768px) {
    .grid-cols-2,
    .grid-cols-3,
    .grid-cols-4 {
        grid-template-columns: 1fr;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .grid-cols-3,
    .grid-cols-4 {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 14px;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: 44px;
    min-width: 44px;
    -webkit-tap-highlight-color: transparent;
}

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

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

.btn-primary:hover {
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: white;
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

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

.btn-outline {
    background: transparent;
    border: 2px solid var(--gray-300);
    color: var(--gray-700);
}

.btn-block {
    width: 100%;
}

.btn-lg {
    padding: 16px 32px;
    font-size: 16px;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 12px;
}

/* Forms */
.form-group {
    margin-bottom: var(--space-md);
}

.form-label {
    display: block;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: var(--space-sm);
    font-size: 14px;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: 16px;
    font-family: var(--font-sans);
    transition: all 0.2s ease;
    background: white;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 100px;
}

/* Alerts */
.alert {
    padding: var(--space-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
    border-left: 4px solid var(--success);
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border-left: 4px solid var(--danger);
}

.alert-warning {
    background: #fef3c7;
    color: #92400e;
    border-left: 4px solid var(--warning);
}

.alert-info {
    background: #dbeafe;
    color: #1e40af;
    border-left: 4px solid var(--info);
}

/* Bottom Navigation (Mobile) */
.bottom-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: white;
    border-top: 1px solid var(--gray-200);
    padding: var(--space-sm) 0;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
    z-index: 100;
}

@media (max-width: 768px) {
    .bottom-nav {
        display: flex;
    }
    
    .app-main {
        padding-bottom: 80px;
    }
}

.nav-items {
    display: flex;
    justify-content: space-around;
    align-items: center;
    max-width: 600px;
    margin: 0 auto;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: var(--space-sm);
    color: var(--gray-600);
    text-decoration: none;
    font-size: 11px;
    min-width: 60px;
    transition: all 0.2s;
}

.nav-item.active {
    color: var(--primary);
}

.nav-icon {
    font-size: 24px;
}

/* PWA Install Banner */
.pwa-install-banner {
    position: fixed;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    display: none;
    align-items: center;
    gap: var(--space-md);
    max-width: 90%;
    z-index: 1000;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        transform: translateX(-50%) translateY(100px);
        opacity: 0;
    }
    to {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
}

.pwa-install-banner.show {
    display: flex;
}

.banner-icon {
    font-size: 32px;
}

.banner-content {
    flex: 1;
}

.banner-title {
    font-weight: 600;
    margin-bottom: 4px;
}

.banner-text {
    font-size: 13px;
    opacity: 0.9;
}

.banner-actions {
    display: flex;
    gap: var(--space-sm);
}

.banner-btn {
    padding: 8px 16px;
    border-radius: var(--radius-md);
    border: none;
    font-weight: 600;
    cursor: pointer;
    font-size: 13px;
}

.banner-btn-primary {
    background: white;
    color: var(--primary);
}

.banner-btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

/* Loading */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.6s linear infinite;
}

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

/* Utilities */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }

.hidden { display: none; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }

/* Responsive */
@media (max-width: 768px) {
    .app-header {
        padding: var(--space-sm) var(--space-md);
    }
    
    .app-logo {
        font-size: 16px;
    }
    
    .logo-icon {
        font-size: 24px;
    }
    
    .user-info {
        display: none;
    }
    
    .card {
        padding: var(--space-md);
    }
}

/* iOS Safe Area */
@supports (padding: max(0px)) {
    .app-header {
        padding-top: max(var(--space-md), env(safe-area-inset-top));
    }
    
    .bottom-nav {
        padding-bottom: max(var(--space-sm), env(safe-area-inset-bottom));
    }
}