/* Modern Premium Design System */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Utilities */
.hidden {
    display: none !important;
}

.flex {
    display: flex;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.justify-center {
    justify-content: center;
}

.gap-2 {
    gap: 0.5rem;
}

.gap-4 {
    gap: 1rem;
}

.p-4 {
    padding: 1rem;
}

.p-6 {
    padding: 1.5rem;
}

.text-sm {
    font-size: 0.875rem;
}

.font-medium {
    font-weight: 500;
}

.text-gray {
    color: var(--text-secondary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid transparent;
    font-size: 0.77rem;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.btn-outline {
    background-color: white;
    border-color: var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    background-color: #f1f5f9;
}

.btn-danger {
    background-color: #fee2e2;
    color: var(--danger-color);
}

.btn-danger:hover {
    background-color: #fecaca;
}

/* Inputs */
.input {
    width: 100%;
    padding: 0.625rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    transition: border-color 0.2s;
}

.input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Login Page */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.login-card {
    background: white;
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.login-subtitle {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

/* Main Layout */
.app-container {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

.sidebar {
    width: 260px;
    background-color: white;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 1.02rem;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-menu {
    padding: 1rem;
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 0.25rem;
}

.nav-item:hover,
.nav-item.active {
    background-color: #eff6ff;
    color: var(--primary-color);
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-color);
    overflow: hidden;
}

.top-bar {
    height: 64px;
    background-color: white;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.5rem;
}

.file-area {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
}

.file-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1.5rem;
}

.file-card {
    background: white;
    border-radius: var(--radius-md);
    padding: 1rem;
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    position: relative;
}

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

.file-icon {
    font-size: 3rem;
    margin-bottom: 0.75rem;
    color: #94a3b8;
}

.file-icon.folder {
    color: #fbbf24;
}

.file-name {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-all;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.file-meta {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

/* Breadcrumb */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.breadcrumb-item {
    cursor: pointer;
}

.breadcrumb-item:hover {
    color: var(--primary-color);
}

.breadcrumb-separator {
    color: #cbd5e1;
}

/* Loading */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 50;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid #e2e8f0;
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    z-index: 100;
    animation: slideUp 0.3s ease-out;
}

.toast.success {
    border-left: 4px solid var(--success-color);
}

.toast.error {
    border-left: 4px solid var(--danger-color);
}

@keyframes slideUp {
    from {
        transform: translateY(100%);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* File Card Checkbox */
.file-checkbox {
    position: absolute;
    top: 8px;
    left: 8px;
    z-index: 10;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.2s;
    color: var(--text-secondary);
}

.file-card:hover .file-checkbox,
.file-card.selected .file-checkbox {
    opacity: 1;
}

.file-card.selected {
    background-color: #eef2ff;
    border-color: var(--primary-color);
}

.file-card.selected .file-checkbox {
    color: var(--primary-color);
}

/* Batch Bar */
.batch-bar {
    background: #fff;
    border-bottom: 1px solid var(--border-color);
    padding: 0.75rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Loading Spinner for Scroll */
#scrollLoading {
    padding: 20px;
    text-align: center;
    color: var(--text-secondary);
}