/* ============================================
   RoomFinder — Design System & Components
   Mobile-first dark theme with glassmorphism
   ============================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* --- CSS Custom Properties (Design Tokens) --- */
:root {
    /* Colors */
    --bg-primary: hsl(220, 20%, 8%);
    --bg-secondary: hsl(220, 18%, 11%);
    --bg-tertiary: hsl(220, 15%, 15%);
    --bg-card: rgba(255, 255, 255, 0.04);
    --bg-card-hover: rgba(255, 255, 255, 0.07);
    --bg-glass: rgba(255, 255, 255, 0.06);
    --border-glass: rgba(255, 255, 255, 0.08);
    --border-subtle: rgba(255, 255, 255, 0.06);

    --text-primary: hsl(0, 0%, 92%);
    --text-secondary: hsl(0, 0%, 60%);
    --text-tertiary: hsl(0, 0%, 42%);

    --accent: hsl(200, 85%, 55%);
    --accent-glow: hsla(200, 85%, 55%, 0.25);
    --accent-dim: hsl(200, 50%, 35%);

    --free: hsl(152, 69%, 45%);
    --free-glow: hsla(152, 69%, 45%, 0.2);
    --free-bg: hsla(152, 69%, 45%, 0.1);

    --occupied: hsl(0, 72%, 55%);
    --occupied-glow: hsla(0, 72%, 55%, 0.2);
    --occupied-bg: hsla(0, 72%, 55%, 0.1);

    --warning: hsl(38, 92%, 55%);
    --warning-bg: hsla(38, 92%, 55%, 0.1);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-xs: 0.7rem;
    --font-size-sm: 0.8rem;
    --font-size-base: 0.9rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.15rem;
    --font-size-xl: 1.35rem;
    --font-size-2xl: 1.75rem;
    --font-size-3xl: 2.25rem;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 0.75rem;
    --space-lg: 1rem;
    --space-xl: 1.5rem;
    --space-2xl: 2rem;
    --space-3xl: 3rem;

    /* Borders & Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.4);
    --shadow-glow-accent: 0 0 20px var(--accent-glow);
    --shadow-glow-free: 0 0 15px var(--free-glow);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Layout */
    --container-max: 640px;
    --header-height: 56px;
    --bottom-nav-height: 64px;
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
}

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

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

body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100dvh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Subtle gradient background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(ellipse at 20% 0%, hsla(200, 80%, 45%, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 100%, hsla(152, 60%, 40%, 0.05) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
    color: inherit;
}

input, select {
    font-family: inherit;
    color: inherit;
}

/* --- Layout --- */
.app-container {
    position: relative;
    z-index: 1;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    padding-bottom: calc(var(--bottom-nav-height) + var(--safe-area-bottom) + var(--space-lg));
}

/* --- Header --- */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(15, 17, 22, 0.85);
    backdrop-filter: blur(20px) saturate(1.2);
    -webkit-backdrop-filter: blur(20px) saturate(1.2);
    border-bottom: 1px solid var(--border-glass);
    padding: var(--space-md) var(--space-lg);
    max-width: var(--container-max);
    margin: 0 auto;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-md);
}

.header-title {
    font-size: var(--font-size-lg);
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), hsl(170, 70%, 55%));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.header-subtitle {
    font-size: var(--font-size-xs);
    color: var(--text-tertiary);
    font-weight: 400;
}

.header-back {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    color: var(--accent);
    font-size: var(--font-size-sm);
    font-weight: 500;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
}

.header-back:hover {
    background: var(--bg-glass);
    text-decoration: none;
}

/* --- Search Bar --- */
.search-container {
    position: relative;
    margin: var(--space-lg) 0 var(--space-md);
}

.search-input {
    width: 100%;
    padding: var(--space-md) var(--space-lg);
    padding-left: 2.75rem;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
    color: var(--text-primary);
    outline: none;
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
}

.search-input::placeholder {
    color: var(--text-tertiary);
}

.search-input:focus {
    border-color: var(--accent);
    box-shadow: var(--shadow-glow-accent);
    background: rgba(255, 255, 255, 0.08);
}

.search-icon {
    position: absolute;
    left: var(--space-lg);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-tertiary);
    font-size: var(--font-size-md);
    pointer-events: none;
}

/* --- Filter Chips --- */
.filter-bar {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    padding: var(--space-xs) 0 var(--space-md);
}

.filter-chip {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    white-space: nowrap;
    transition: all var(--transition-fast);
    cursor: pointer;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

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

.filter-chip.active {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
    font-weight: 500;
}

.filter-chip.active:hover {
    background: hsl(200, 85%, 50%);
}

.filter-dropdown {
    position: relative;
}

.filter-dropdown-menu {
    position: absolute;
    top: calc(100% + var(--space-xs));
    left: 0;
    min-width: 200px;
    max-height: 250px;
    overflow-y: auto;
    background: var(--bg-secondary);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    padding: var(--space-xs);
    box-shadow: var(--shadow-lg);
    z-index: 50;
    backdrop-filter: blur(20px);
    display: none;
}

.filter-dropdown-menu.open {
    display: block;
    animation: slideDown var(--transition-base) forwards;
}

.filter-dropdown-item {
    display: block;
    width: 100%;
    text-align: left;
    padding: var(--space-sm) var(--space-md);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.filter-dropdown-item:hover {
    background: var(--bg-glass);
    color: var(--text-primary);
}

.filter-dropdown-item.selected {
    color: var(--accent);
    font-weight: 500;
}

/* --- Stats Bar --- */
.stats-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-sm) 0;
    margin-bottom: var(--space-md);
}

.stats-count {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.stats-count strong {
    color: var(--free);
    font-weight: 600;
}

.stats-refresh {
    font-size: var(--font-size-xs);
    color: var(--text-tertiary);
}

/* --- Room Cards --- */
.room-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.room-card {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    overflow: hidden;
    -webkit-tap-highlight-color: transparent;
}

.room-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, transparent 60%, rgba(255,255,255,0.02));
    pointer-events: none;
}

.room-card:hover {
    background: var(--bg-card-hover);
    border-color: rgba(255, 255, 255, 0.12);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.room-card:active {
    transform: scale(0.99);
}

.room-card.free {
    border-left: 3px solid var(--free);
}

.room-card.occupied {
    border-left: 3px solid var(--occupied);
}

.room-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-md);
    margin-bottom: var(--space-sm);
}

.room-card-name {
    font-size: var(--font-size-lg);
    font-weight: 600;
    letter-spacing: -0.01em;
}

.room-card-status {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: 3px var(--space-sm);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    white-space: nowrap;
    flex-shrink: 0;
}

.room-card-status.free {
    background: var(--free-bg);
    color: var(--free);
}

.room-card-status.occupied {
    background: var(--occupied-bg);
    color: var(--occupied);
}

.status-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: currentColor;
}

.status-dot.free {
    animation: pulse-free 2s ease-in-out infinite;
}

@keyframes pulse-free {
    0%, 100% { box-shadow: 0 0 0 0 var(--free-glow); }
    50% { box-shadow: 0 0 0 6px transparent; }
}

.room-card-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
}

.room-meta-tag {
    display: inline-flex;
    align-items: center;
    gap: 3px;
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
}

.room-meta-tag .icon {
    font-size: var(--font-size-sm);
    opacity: 0.6;
}

.room-card-type {
    display: inline-block;
    padding: 2px var(--space-sm);
    background: var(--bg-glass);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
    font-weight: 500;
}

.room-card-type.cip {
    background: hsla(270, 60%, 55%, 0.15);
    color: hsl(270, 60%, 70%);
}

.room-card-status-detail {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-top: var(--space-xs);
}

.room-card-status-detail strong {
    color: var(--text-primary);
    font-weight: 500;
}

/* --- Timetable View --- */
.timetable-container {
    margin-top: var(--space-lg);
}

.timetable-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-lg);
}

.timetable-title {
    font-size: var(--font-size-md);
    font-weight: 600;
    color: var(--text-secondary);
}

.timetable-date {
    font-size: var(--font-size-sm);
    color: var(--text-tertiary);
}

.timetable-timeline {
    position: relative;
    padding-left: 3.5rem;
}

.timetable-hour-marker {
    position: relative;
    height: 60px;
    border-top: 1px solid var(--border-subtle);
}

.timetable-hour-label {
    position: absolute;
    left: -3.5rem;
    top: -0.5em;
    font-size: var(--font-size-xs);
    color: var(--text-tertiary);
    font-variant-numeric: tabular-nums;
    width: 2.75rem;
    text-align: right;
}

.timetable-period {
    position: absolute;
    left: 0;
    right: 0;
    background: var(--occupied-bg);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-left: 3px solid var(--occupied);
    border-radius: var(--radius-sm);
    padding: var(--space-sm) var(--space-md);
    overflow: hidden;
    z-index: 2;
    transition: all var(--transition-fast);
}

.timetable-period:hover {
    background: rgba(255, 80, 80, 0.15);
}

.timetable-period.cancelled {
    opacity: 0.4;
    border-left-color: var(--text-tertiary);
    background: var(--bg-glass);
    text-decoration: line-through;
}

.timetable-period-subject {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.timetable-period-info {
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
}

.timetable-now-line {
    position: absolute;
    left: -0.5rem;
    right: 0;
    height: 2px;
    background: var(--accent);
    z-index: 10;
    box-shadow: 0 0 8px var(--accent-glow);
}

.timetable-now-line::before {
    content: '';
    position: absolute;
    left: -4px;
    top: -3px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
}

.timetable-now-label {
    position: absolute;
    left: -3.5rem;
    top: -0.5em;
    font-size: var(--font-size-xs);
    color: var(--accent);
    font-weight: 600;
    width: 2.75rem;
    text-align: right;
    z-index: 11;
}

/* Free slot indicators */
.timetable-free-slot {
    position: absolute;
    left: 0;
    right: 0;
    background: var(--free-bg);
    border: 1px dashed rgba(52, 211, 153, 0.2);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1;
}

.timetable-free-label {
    font-size: var(--font-size-xs);
    color: var(--free);
    font-weight: 500;
    opacity: 0.7;
}

/* --- Room Detail Card --- */
.room-detail {
    margin-top: var(--space-lg);
}

.room-detail-card {
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    backdrop-filter: blur(10px);
}

.room-detail-name {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: var(--space-xs);
    letter-spacing: -0.02em;
}

.room-detail-long-name {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.room-detail-badges {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
}

.room-detail-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.room-detail-badge .icon {
    font-size: var(--font-size-md);
    opacity: 0.7;
}

.room-detail-status {
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    font-weight: 500;
}

.room-detail-status.free {
    background: var(--free-bg);
    border: 1px solid rgba(52, 211, 153, 0.2);
    color: var(--free);
}

.room-detail-status.occupied {
    background: var(--occupied-bg);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: var(--occupied);
}

/* --- Empty State --- */
.empty-state {
    text-align: center;
    padding: var(--space-3xl) var(--space-lg);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: var(--space-lg);
    opacity: 0.3;
}

.empty-state-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

.empty-state-text {
    font-size: var(--font-size-sm);
    color: var(--text-tertiary);
}

/* --- Loading States --- */
.skeleton {
    background: linear-gradient(
        90deg,
        var(--bg-glass) 25%,
        rgba(255, 255, 255, 0.08) 50%,
        var(--bg-glass) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s ease-in-out infinite;
    border-radius: var(--radius-md);
}

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

.skeleton-card {
    height: 100px;
    margin-bottom: var(--space-md);
    border-radius: var(--radius-lg);
}

.skeleton-line {
    height: 14px;
    margin-bottom: var(--space-sm);
    border-radius: var(--radius-sm);
}

.skeleton-line.short { width: 40%; }
.skeleton-line.medium { width: 65%; }
.skeleton-line.long { width: 85%; }

/* --- Loading Spinner --- */
.loading-spinner {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-2xl);
}

.spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--border-glass);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* --- Toggle Switch --- */
.toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) 0;
}

.toggle-label {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

/* --- Animations --- */
@keyframes slideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(16px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn var(--transition-base) forwards;
}

.slide-up {
    animation: slideUp var(--transition-slow) forwards;
}

.room-card {
    animation: slideUp var(--transition-slow) backwards;
}

.room-card:nth-child(1) { animation-delay: 0ms; }
.room-card:nth-child(2) { animation-delay: 40ms; }
.room-card:nth-child(3) { animation-delay: 80ms; }
.room-card:nth-child(4) { animation-delay: 120ms; }
.room-card:nth-child(5) { animation-delay: 160ms; }
.room-card:nth-child(6) { animation-delay: 200ms; }
.room-card:nth-child(7) { animation-delay: 240ms; }
.room-card:nth-child(8) { animation-delay: 280ms; }
.room-card:nth-child(9) { animation-delay: 320ms; }
.room-card:nth-child(10) { animation-delay: 360ms; }

/* --- Notification Toast --- */
.toast {
    position: fixed;
    bottom: calc(var(--bottom-nav-height) + var(--safe-area-bottom) + var(--space-lg));
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--bg-secondary);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-xl);
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    box-shadow: var(--shadow-lg);
    z-index: 200;
    transition: transform var(--transition-base);
    backdrop-filter: blur(20px);
}

.toast.visible {
    transform: translateX(-50%) translateY(0);
}

/* --- Bottom Navigation (for future use) --- */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: calc(var(--bottom-nav-height) + var(--safe-area-bottom));
    padding-bottom: var(--safe-area-bottom);
    background: rgba(15, 17, 22, 0.92);
    backdrop-filter: blur(20px) saturate(1.2);
    -webkit-backdrop-filter: blur(20px) saturate(1.2);
    border-top: 1px solid var(--border-glass);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xl);
    z-index: 100;
    max-width: var(--container-max);
    margin: 0 auto;
}

/* Fix bottom nav for wide screens */
@media (min-width: 641px) {
    .bottom-nav {
        left: 50%;
        transform: translateX(-50%);
        width: var(--container-max);
    }
}

.bottom-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: var(--space-sm) var(--space-lg);
    color: var(--text-tertiary);
    font-size: var(--font-size-xs);
    font-weight: 500;
    transition: color var(--transition-fast);
    -webkit-tap-highlight-color: transparent;
    min-width: 64px;
}

.bottom-nav-item:hover,
.bottom-nav-item.active {
    color: var(--accent);
    text-decoration: none;
}

.bottom-nav-item .icon {
    font-size: 1.25rem;
}

/* --- Misc Utilities --- */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.text-free { color: var(--free); }
.text-occupied { color: var(--occupied); }
.text-warning { color: var(--warning); }
.text-accent { color: var(--accent); }
.text-secondary { color: var(--text-secondary); }

/* --- Error State --- */
.error-banner {
    background: var(--occupied-bg);
    border: 1px solid rgba(239, 68, 68, 0.2);
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-lg);
    margin: var(--space-lg) 0;
    font-size: var(--font-size-sm);
    color: var(--occupied);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.error-banner .icon {
    font-size: var(--font-size-lg);
    flex-shrink: 0;
}

/* --- Responsive --- */
@media (max-width: 380px) {
    :root {
        --space-lg: 0.75rem;
    }

    .room-card-name {
        font-size: var(--font-size-md);
    }
}