:root {
    --primary-color: #007aff;
    --bg-color: #f5f5f7;
    --card-bg: rgba(255, 255, 255, 0.7);
    --sidebar-bg: rgba(255, 255, 255, 0.5);
    --text-color: #1d1d1f;
    --text-secondary: #86868b;
    --border-radius: 18px;
    --glass-blur: 20px;
    --glass-border: 1px solid rgba(255, 255, 255, 0.3);
    --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.1);
}

[data-theme="dark"] {
    --bg-color: #1c1c1e;
    --card-bg: rgba(28, 28, 30, 0.7);
    --sidebar-bg: rgba(28, 28, 30, 0.5);
    --text-color: #f5f5f7;
    --text-secondary: #a1a1a6;
    --glass-border: 1px solid rgba(255, 255, 255, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    transition: background-color 0.3s ease;
}

.glass {
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border-radius: var(--border-radius);
    border: var(--glass-border);
    box-shadow: var(--shadow);
}

/* Auth Pages */
.auth-container {
    width: 100%;
    max-width: 400px;
    margin: auto;
    padding: 40px;
    animation: slideUp 0.6s ease-out;
}

.auth-header {
    text-align: center;
    margin-bottom: 30px;
}

.auth-header h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 10px;
}

.auth-header p {
    color: var(--text-secondary);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border-radius: 12px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    background: rgba(255, 255, 255, 0.8);
    font-size: 16px;
    transition: all 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.btn {
    width: 100%;
    padding: 14px;
    border-radius: 12px;
    border: none;
    background: var(--primary-color);
    color: white;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, opacity 0.2s;
}

.btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.btn:active {
    transform: translateY(0);
}

.auth-footer {
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
    color: var(--text-secondary);
}

.auth-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

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

/* Drag and Drop */
.grid-view.drag-over {
    border: 2px dashed var(--primary-color);
    background: rgba(0, 122, 255, 0.05);
    border-radius: 16px;
}

.grid-view.drag-over::after {
    content: 'Drop files to upload';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 20px;
    font-weight: 600;
    color: var(--primary-color);
    pointer-events: none;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 16px;
    flex: 1;
}

#menu-toggle {
    display: flex !important; /* Force visible on desktop too */
}

/* Sidebar Toggle State */
.sidebar.collapsed {
    width: 0;
    margin: 0;
    padding: 0;
    overflow: hidden;
    opacity: 0;
    pointer-events: none;
}

/* Mobile Enhancements */
@media (max-width: 480px) {
    body {
        padding: 0;
        margin: 0;
        overflow: hidden; /* Prevent body scroll, use container scroll */
    }
    
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100vh;
        z-index: 1000;
        margin: 0;
        border-radius: 0 24px 24px 0;
        box-shadow: 20px 0 50px rgba(0,0,0,0.1);
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }
    
    .sidebar.active {
        transform: translateX(0);
        width: 280px;
        opacity: 1;
        pointer-events: auto;
    }
    
    main {
        padding: 16px !important;
        height: calc(100vh - 80px); /* Fit screen */
        overflow-y: auto;
    }
    
    .header {
        margin: 10px 10px 0 10px;
        padding: 0 16px;
        border-radius: 16px;
    }
    
    .header-search {
        display: none; /* Hide search on mobile header to save space */
    }
    
    .stats-grid {
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }
    
    .stat-card {
        padding: 16px;
        gap: 12px;
    }
    
    .stat-icon {
        width: 40px;
        height: 40px;
        font-size: 18px;
    }
    
    .stat-info p {
        font-size: 16px;
    }
    
    .dashboard-content {
        grid-template-columns: 1fr;
    }
    
    .files-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
    }
    
    .recent-file-item {
        border-radius: 12px;
    }
    
    .grid-view {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr)) !important;
        gap: 12px !important;
    }
    
    .file-card {
        padding: 12px !important;
    }
    
    .file-name {
        font-size: 12px !important;
    }

    .auth-container {
        padding: 20px;
    }
}