:root {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --border: #e2e8f0;
    --danger: #ef4444;
    --danger-hover: #dc2626;
    --success: #22c55e;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.navbar {
    background: #1e293b;
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: #ffffff;
    font-weight: 600;
    font-size: 1.1rem;
}

.navbar-brand .logo {
    width: 32px;
    height: 32px;
    background: var(--accent);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.navbar-nav {
    display: flex;
    gap: 0.5rem;
    list-style: none;
}

.nav-link {
    color: #94a3b8;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all 0.2s;
}

.nav-link:hover, .nav-link.active {
    background: #334155;
    color: #ffffff;
}

.navbar-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-info {
    color: #94a3b8;
    font-size: 0.9rem;
}

.pc-link {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s;
}

.pc-link:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

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

.btn-primary:hover {
    background: var(--accent-hover);
}

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

.btn-secondary:hover {
    background: var(--border);
}

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

.btn-danger:hover {
    background: var(--danger-hover);
}

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

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

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.8rem;
}

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.form-control {
    width: 100%;
    padding: 0.625rem 0.875rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 0.9rem;
    transition: border-color 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--accent);
}

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%2394a3b8' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}

/* Cards */
.card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.card-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
}

.card-body {
    padding: 1.25rem;
}

/* Tables */
.table {
    width: 100%;
    border-collapse: collapse;
}

.table th, .table td {
    padding: 0.875rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.table th {
    background: var(--bg-card);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.table tr:hover {
    background: rgba(255,255,255,0.02);
}

/* Login Page */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.login-card {
    width: 100%;
    max-width: 400px;
}

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

.login-logo {
    width: 64px;
    height: 64px;
    background: var(--accent);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
}

.login-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.login-subtitle {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Page Header */
.page-header {
    padding: 1.5rem 0;
    margin-bottom: 1.5rem;
}

.page-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

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

/* Filters */
.filters {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
}

.filter-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.filter-actions {
    display: flex;
    align-items: flex-end;
    gap: 0.5rem;
    margin-left: auto;
}

/* Screenshot Grid */
.screenshot-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1rem;
}

.screenshot-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
}

.screenshot-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}

.screenshot-card.selected {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent);
}

.screenshot-checkbox {
    position: absolute;
    top: 0.5rem;
    left: 0.5rem;
    z-index: 10;
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.screenshot-image {
    width: 100%;
    aspect-ratio: 16/9;
    object-fit: cover;
    background: var(--bg-card);
}

.screenshot-info {
    padding: 0.75rem;
}

.screenshot-pc {
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.screenshot-time {
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1.5rem;
}

.pagination-info {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin: 0 1rem;
}

/* Image Viewer Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.95);
    z-index: 1000;
    display: none;
}

.modal-overlay.active {
    display: flex;
    flex-direction: column;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: rgba(0,0,0,0.8);
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.modal-info {
    display: flex;
    gap: 1.5rem;
    color: rgba(255,255,255,0.8);
    font-size: 0.9rem;
}

.modal-controls {
    display: flex;
    gap: 0.25rem;
}

.modal-body {
    flex: 1;
    display: flex;
    overflow: hidden;
}

.nav-area {
    width: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.5);
}

.nav-btn {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
    border: none;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.nav-btn:hover:not(:disabled) {
    background: rgba(255,255,255,0.2);
}

.nav-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.image-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    overflow: hidden;
}

.viewer-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    transition: transform 0.15s ease-out;
    user-select: none;
}

/* Alerts */
.alert {
    padding: 0.875rem 1rem;
    border-radius: 6px;
    margin-bottom: 1rem;
}

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

/* Password Change Page */
.password-card {
    max-width: 400px;
    margin: 0 auto;
}

.password-form .form-group {
    margin-bottom: 1rem;
}

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

.password-form input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
}

.password-form input:focus {
    outline: none;
    border-color: var(--accent);
}

.password-form small {
    display: block;
    margin-top: 0.25rem;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.password-form .btn {
    width: 100%;
    margin-top: 0.5rem;
}

.alert-success {
    background: rgba(34, 197, 94, 0.1);
    border: 1px solid var(--success);
    color: var(--success);
}

/* Utilities */
.text-muted {
    color: var(--text-muted);
}

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

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }

.d-flex { display: flex; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 1rem; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }

/* Password toggle */
.password-wrapper {
    position: relative;
}

.password-toggle {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.25rem;
}

.password-toggle:hover {
    color: var(--text-primary);
}

/* Responsive */
@media (max-width: 768px) {
    .filters {
        flex-direction: column;
    }
    
    .filter-actions {
        margin-left: 0;
        margin-top: 0.5rem;
    }
    
    .navbar-nav {
        display: none;
    }
    
    .screenshot-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}