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

:root {
    --bg-primary: #020617;
    --bg-secondary: #0f172a;
    --bg-tile: #1e293b;
    --bg-tile-hover: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --nav-active: #3b82f6;
    --tile-radius: 16px;
    --transition-fast: 150ms ease;
}

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    padding: 16px 24px;
    text-align: center;
    background: var(--bg-secondary);
    flex-shrink: 0;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

/* Main Content */
main {
    flex: 1;
    padding: 16px;
    overflow-y: auto;
    display: flex;
    align-items: flex-start;
}

.page {
    display: none;
    width: 100%;
}

.page.active {
    display: block;
}

/* Grid Layout */
.grid {
    display: grid;
    gap: 12px;
    max-width: 800px;
    margin: 0 auto;
}

/* Responsive Grid */
@media (max-width: 600px) {
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 601px) and (max-width: 900px) {
    .grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 901px) {
    .grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Tile Button */
.tile {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 24px 16px;
    background: var(--bg-tile);
    border: none;
    border-radius: var(--tile-radius);
    cursor: pointer;
    transition: transform var(--transition-fast), background var(--transition-fast);
    aspect-ratio: 1;
    min-height: 100px;
}

.tile i {
    font-size: 2rem;
    color: var(--text-primary);
}

.tile span {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

/* Desktop Hover */
@media (hover: hover) {
    .tile:hover {
        background: var(--bg-tile-hover);
        transform: translateY(-2px);
    }
}

/* Active/Click State */
.tile:active {
    transform: scale(0.95);
    background: var(--bg-tile-hover);
}

/* Navigation */
nav {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 12px 16px;
    background: var(--bg-secondary);
    flex-shrink: 0;
}

.nav-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 12px 32px;
    background: transparent;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-btn i {
    font-size: 1.25rem;
}

.nav-btn span {
    font-size: 0.75rem;
    font-weight: 500;
}

@media (hover: hover) {
    .nav-btn:hover {
        background: var(--bg-tile);
    }
}

.nav-btn:active {
    background: var(--bg-tile);
}

.nav-btn.active {
    color: var(--nav-active);
    background: var(--bg-tile);
}

/* Ensure nav buttons stay above 48px touch target */
@media (max-width: 600px) {
    .nav-btn {
        padding: 12px 24px;
    }
    
    .tile {
        padding: 20px 12px;
        min-height: 90px;
    }
    
    .tile i {
        font-size: 1.75rem;
    }
}

/* Media page 2x2 grid */
.media-grid {
    grid-template-columns: repeat(2, 1fr) !important;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: #1e293b;
    color: #f1f5f9;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    opacity: 0;
    transition: opacity 0.3s ease, transform 0.3s ease;
    z-index: 1000;
    pointer-events: none;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}