/* GBUK Booking System - Modern Design (GearBlast-Inspired) */

/* ============================================
   COLOR PALETTE
   ============================================ */
:root {
    /* Primary Orange (replaces blue) */
    --primary: #ff6600;
    --primary-light: #ff8533;
    --primary-dark: #cc5200;
    --primary-glow: rgba(255, 102, 0, 0.3);
    
    /* Dark Theme */
    --bg-primary: #0a0a0f;
    --bg-secondary: #13131a;
    --bg-tertiary: #1a1a24;
    --bg-card: #1e1e2e;
    
    /* Text */
    --text-primary: #ffffff;
    --text-secondary: #b4b4c8;
    --text-muted: #6e6e8f;
    
    /* Borders & Dividers */
    --border-color: rgba(255, 255, 255, 0.08);
    --border-highlight: rgba(255, 102, 0, 0.2);
    
    /* Status Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;
    
    /* Shadows & Glows */
    --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, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4);
    --glow-orange: 0 0 20px var(--primary-glow);
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   HEADER / NAVIGATION
   ============================================ */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-lg) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--primary), transparent);
    opacity: 0.5;
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.header-actions {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width var(--transition-fast), height var(--transition-fast);
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--text-primary);
    box-shadow: 0 4px 14px 0 var(--primary-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px 0 var(--primary-glow);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-card);
    color: var(--text-primary);
    border-color: var(--border-highlight);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}

.btn-ghost:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

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

/* ============================================
   CONTAINER & LAYOUT
   ============================================ */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-2xl) var(--spacing-xl);
}

/* ============================================
   TABS
   ============================================ */
.tabs {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    margin-bottom: var(--spacing-2xl);
    border: 1px solid var(--border-color);
    overflow-x: auto;
    scrollbar-width: none;
}

.tabs::-webkit-scrollbar {
    display: none;
}

.tab {
    flex: 1;
    min-width: 120px;
    padding: 0.75rem 1.5rem;
    background: transparent;
    color: var(--text-secondary);
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    white-space: nowrap;
}

.tab::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary);
    transform: translateX(-50%);
    transition: width var(--transition-base);
}

.tab:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.tab.active {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--text-primary);
    box-shadow: var(--glow-orange);
}

.tab.active::before {
    width: 100%;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn var(--transition-base);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   FILTERS
   ============================================ */
.day-filters {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.day-filter {
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
}

.day-filter:hover {
    background: var(--bg-card);
    color: var(--text-primary);
    border-color: var(--border-highlight);
}

.day-filter.active {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--text-primary);
    border-color: var(--primary);
    box-shadow: var(--glow-orange);
}

/* ============================================
   CARDS / SLOTS GRID
   ============================================ */
.slots-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.slot-card,
.room-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.slot-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--primary-light) 100%);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.slot-card:hover {
    border-color: var(--border-highlight);
    box-shadow: var(--shadow-xl), var(--glow-orange);
    transform: translateY(-4px);
}

.slot-card:hover::before {
    transform: scaleX(1);
}

.slot-header {
    margin-bottom: var(--spacing-lg);
}

.slot-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

.slot-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.meta-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.25rem 0.75rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.slot-description {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
}

/* ============================================
   AVAILABILITY INDICATORS
   ============================================ */
.slot-availability {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
    font-size: 0.875rem;
    font-weight: 600;
}

.slots-full {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: var(--success);
}

.slots-limited {
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid rgba(245, 158, 11, 0.3);
    color: var(--warning);
}

.slots-available {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--error);
}

/* ============================================
   PARTICIPANTS LIST
   ============================================ */
.participants-list {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    max-height: 180px;
    overflow-y: auto;
}

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

.participants-list::-webkit-scrollbar-track {
    background: var(--bg-card);
    border-radius: 3px;
}

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

.participants-list-title {
    color: var(--primary);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
}

.participant-name {
    color: var(--text-secondary);
    font-size: 0.875rem;
    padding: var(--spacing-xs) 0;
}

.no-participants {
    color: var(--text-muted);
    font-size: 0.875rem;
    font-style: italic;
}

/* ============================================
   MODAL
   ============================================ */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(4px);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
}

.modal.active {
    display: flex;
    animation: fadeIn var(--transition-base);
}

.modal-content {
    background: var(--bg-card);
    border: 1px solid var(--border-highlight);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-2xl);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl), var(--glow-orange);
    animation: slideUp var(--transition-base);
}

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

.modal-header {
    margin-bottom: var(--spacing-xl);
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

/* ============================================
   FORMS
   ============================================ */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    font-size: 0.875rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: all var(--transition-base);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
    background: var(--bg-card);
}

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

/* ============================================
   WARNING BOX
   ============================================ */
.warning-box {
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.warning-box h4 {
    color: var(--warning);
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    font-weight: 700;
}

.warning-box ul {
    color: var(--warning);
    margin-left: var(--spacing-xl);
    font-size: 0.875rem;
    line-height: 1.6;
}

/* ============================================
   MESSAGES & ALERTS
   ============================================ */
.message,
.success {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: var(--success);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xl);
    font-size: 0.875rem;
}

.error {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--error);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xl);
    font-size: 0.875rem;
}

.info {
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.3);
    color: var(--info);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xl);
    font-size: 0.875rem;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
    .header h1 {
        font-size: 1.25rem;
    }
    
    .header-actions {
        flex-wrap: wrap;
    }
    
    .slots-grid {
        grid-template-columns: 1fr;
    }
    
    .tabs {
        overflow-x: auto;
    }
    
    .day-filters {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .container {
        padding: var(--spacing-xl) var(--spacing-md);
    }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.glow-effect {
    box-shadow: var(--glow-orange);
}

.backdrop-blur {
    backdrop-filter: blur(10px);
}

/* ============================================
   LOADING STATES & ANIMATIONS
   ============================================ */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

.skeleton {
    background: linear-gradient(90deg, var(--bg-tertiary) 25%, var(--bg-card) 50%, var(--bg-tertiary) 75%);
    background-size: 1000px 100%;
    animation: shimmer 2s infinite;
}