/* ==========================================
   API-571 損傷機制篩選系統 - 樣式表
   ========================================== */

/* CSS Variables */
:root {
    /* Colors - Light Theme */
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-primary-light: #dbeafe;
    --color-secondary: #64748b;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;

    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-card: #ffffff;
    --bg-hover: #e2e8f0;

    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --text-inverse: #ffffff;

    /* Border Colors */
    --border-color: #e2e8f0;
    --border-color-dark: #cbd5e1;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

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

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;

    /* Layout */
    --header-height: 64px;
    --filter-width: 320px;
    --filter-width-mobile: 100%;
}

/* Dark Theme */
[data-theme="dark"] {
    --color-primary: #3b82f6;
    --color-primary-hover: #60a5fa;
    --color-primary-light: #1e3a5f;

    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    --bg-hover: #334155;

    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;

    --border-color: #334155;
    --border-color-dark: #475569;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans TC', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    min-height: 100vh;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 600;
    line-height: 1.3;
}

h1 {
    font-size: 1.5rem;
}

h2 {
    font-size: 1.25rem;
}

h3 {
    font-size: 1.125rem;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: linear-gradient(135deg, var(--color-primary) 0%, #1e40af 100%);
    color: var(--text-inverse);
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-container {
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-icon {
    font-size: 1.75rem;
}

.logo h1 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

/* Search Bar */
.search-container {
    position: relative;
    width: 300px;
}

#global-search {
    width: 100%;
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 9999px;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: all 0.2s;
}

#global-search:focus {
    outline: none;
    border-color: var(--color-primary);
    /* Changed from --primary-color to --color-primary */
    box-shadow: 0 0 0 2px var(--color-primary-light);
    /* Changed from --primary-light to --color-primary-light */
}

.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    border: none;
    background: rgba(255, 255, 255, 0.15);
    color: var(--text-inverse);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: background var(--transition-fast);
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.25);
}

/* Main Layout */
.main-content {
    display: flex;
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
}

/* Filter Panel */
.filter-panel {
    width: var(--filter-width);
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    padding: var(--spacing-lg);
    overflow-y: auto;
    height: calc(100vh - var(--header-height));
    position: sticky;
    top: var(--header-height);
}

.filter-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.filter-header h2 {
    font-size: 1.125rem;
}

/* Filter Sections */
.filter-section {
    margin-bottom: var(--spacing-md);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.filter-toggle {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: background var(--transition-fast);
}

.filter-toggle:hover {
    background: var(--bg-hover);
}

.filter-toggle.active .toggle-icon {
    transform: rotate(180deg);
}

.toggle-icon {
    transition: transform var(--transition-fast);
    font-size: 0.75rem;
}

.filter-content {
    padding: var(--spacing-md);
    background: var(--bg-primary);
    max-height: 300px;
    overflow-y: auto;
    transition: max-height var(--transition-normal), padding var(--transition-normal);
}

.filter-content.collapsed {
    max-height: 0;
    padding-top: 0;
    padding-bottom: 0;
    overflow: hidden;
}

.filter-search {
    margin-bottom: var(--spacing-sm);
}

.filter-search input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    background: var(--bg-secondary);
    color: var(--text-primary);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.filter-search input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

.filter-options {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

/* Filter Option Items */
.filter-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.filter-option:hover {
    background: var(--bg-hover);
}

.filter-option input[type="checkbox"],
.filter-option input[type="radio"] {
    width: 16px;
    height: 16px;
    accent-color: var(--color-primary);
    cursor: pointer;
}

.filter-option-label {
    flex: 1;
    font-size: 0.875rem;
    color: var(--text-primary);
}

.filter-option-count {
    font-size: 0.75rem;
    color: var(--text-muted);
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
}

.temperature-semantics-guide {
    margin-bottom: var(--spacing-sm);
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    font-size: 0.75rem;
    line-height: 1.4;
}

.filter-option-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
    flex: 1;
}

.filter-option-label-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.filter-option-meaning {
    color: var(--text-muted);
    font-size: 0.75rem;
    line-height: 1.35;
}

.temperature-badge {
    font-size: 0.65rem;
    line-height: 1;
    padding: 3px 6px;
    border-radius: 999px;
    border: 1px solid transparent;
    white-space: nowrap;
}

.semantics-window {
    background: rgba(59, 130, 246, 0.12);
    color: #1d4ed8;
    border-color: rgba(59, 130, 246, 0.25);
}

.semantics-threshold {
    background: rgba(245, 158, 11, 0.12);
    color: #b45309;
    border-color: rgba(245, 158, 11, 0.3);
}

.semantics-rate {
    background: rgba(239, 68, 68, 0.12);
    color: #b91c1c;
    border-color: rgba(239, 68, 68, 0.25);
}

.semantics-overlap {
    background: rgba(139, 92, 246, 0.12);
    color: #6d28d9;
    border-color: rgba(139, 92, 246, 0.25);
}

[data-theme="dark"] .semantics-window {
    color: #93c5fd;
}

[data-theme="dark"] .semantics-threshold {
    color: #fcd34d;
}

[data-theme="dark"] .semantics-rate {
    color: #fca5a5;
}

[data-theme="dark"] .semantics-overlap {
    color: #c4b5fd;
}

/* Category Header in Filter */
.filter-category {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: var(--spacing-sm) var(--spacing-sm) var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.filter-category:first-child {
    margin-top: 0;
}

/* Results Panel */
.results-panel {
    flex: 1;
    padding: var(--spacing-lg);
    overflow-y: auto;
}

.results-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.results-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

#results-count {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.sort-select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.875rem;
    cursor: pointer;
}

/* Active Filters */
.active-filters {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.active-filters:empty {
    display: none;
}

.filter-tag {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-radius: var(--radius-md);
    font-size: 0.8125rem;
    font-weight: 500;
}

.filter-tag-remove {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    color: var(--color-primary);
    padding: 0;
    line-height: 1;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

.filter-tag-remove:hover {
    opacity: 1;
}

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

/* Result Card */
.result-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
}

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

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

.card-id {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-primary);
    background: var(--color-primary-light);
    padding: 2px 8px;
    border-radius: var(--radius-sm);
}

.card-type-badge {
    font-size: 0.6875rem;
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    font-weight: 500;
}

.card-type-badge.corrosion {
    background: #fef3c7;
    color: #92400e;
}

.card-type-badge.cracking {
    background: #fee2e2;
    color: #991b1b;
}

.card-type-badge.embrittlement {
    background: #e0e7ff;
    color: #3730a3;
}

.card-type-badge.mechanical {
    background: #d1fae5;
    color: #065f46;
}

.card-type-badge.metallurgical {
    background: #f3e8ff;
    color: #6b21a8;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.card-title-en {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-md);
}

.card-description {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin-bottom: var(--spacing-md);
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.card-tag {
    font-size: 0.6875rem;
    padding: 2px 6px;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
}

.card-footer {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
}

.btn-view-detail {
    font-size: 0.8125rem;
    color: var(--color-primary);
    background: none;
    border: none;
    cursor: pointer;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.btn-view-detail:hover {
    text-decoration: underline;
}

/* No Results */
.no-results {
    text-align: center;
    padding: var(--spacing-xl) * 2;
    color: var(--text-secondary);
}

.no-results.hidden {
    display: none;
}

.no-results-icon {
    font-size: 4rem;
    display: block;
    margin-bottom: var(--spacing-lg);
}

.no-results p {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
}

/* Buttons */
.btn-primary {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-primary);
    color: var(--text-inverse);
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition-fast);
}

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

.btn-secondary {
    padding: var(--spacing-xs) var(--spacing-md);
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

/* Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    opacity: 1;
    transition: opacity var(--transition-normal);
}

.modal-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    max-width: 700px;
    width: 100%;
    max-height: 85vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
    transform: scale(1);
    transition: transform var(--transition-normal);
}

.modal-overlay.hidden .modal {
    transform: scale(0.95);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-tertiary);
}

.modal-header h2 {
    font-size: 1.125rem;
    color: var(--text-primary);
}

.modal-close {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
    border: none;
    background: var(--bg-hover);
    cursor: pointer;
    font-size: 1rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--color-danger);
    color: var(--text-inverse);
}

.modal-body {
    padding: var(--spacing-lg);
    overflow-y: auto;
    flex: 1;
}

/* Modal Content Sections */
.modal-section {
    margin-bottom: var(--spacing-lg);
}

.modal-section:last-child {
    margin-bottom: 0;
}

.modal-section h3 {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.modal-section p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.modal-section ul {
    list-style: none;
    padding: 0;
}

.modal-section li {
    font-size: 0.875rem;
    color: var(--text-secondary);
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-lg);
    position: relative;
}

.modal-section li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-primary);
}

.modal-tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.modal-tag {
    font-size: 0.8125rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: var(--radius-md);
}

/* Info Modal */
.info-modal .modal-body h3 {
    margin-top: var(--spacing-lg);
}

.info-modal .modal-body h3:first-child {
    margin-top: 0;
}

.info-modal .modal-body h4 {
    font-size: 0.875rem;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.info-modal .modal-body ol,
.info-modal .modal-body ul {
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.info-modal .modal-body li {
    padding-left: 0;
}

.info-modal .modal-body li::before {
    display: none;
}

.info-footer {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
}

/* Language Toggle in Modal */
.modal-lang-toggle {
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.lang-btn {
    padding: var(--spacing-xs) var(--spacing-md);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.lang-btn:hover {
    background: var(--bg-hover);
    border-color: var(--color-primary);
}

.lang-btn.active {
    background: var(--color-primary);
    color: var(--text-inverse);
    border-color: var(--color-primary);
}

/* Bilingual Content */
.text-en {
    font-style: italic;
    color: var(--text-muted);
}

.bilingual-block {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
    padding: var(--spacing-sm);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.zh-col,
.en-col {
    padding: var(--spacing-sm);
}

.lang-label {
    display: inline-block;
    font-size: 0.6875rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    margin-bottom: var(--spacing-xs);
    padding: 2px 6px;
    background: var(--bg-hover);
    border-radius: var(--radius-sm);
}

.en-col .lang-label {
    background: var(--color-primary-light);
    color: var(--color-primary);
}

/* Related mechanism links */
.related-link {
    cursor: pointer;
    transition: background var(--transition-fast);
}

.related-link:hover {
    background: var(--color-primary-light);
    color: var(--color-primary);
}

@media (max-width: 640px) {
    .bilingual-block {
        grid-template-columns: 1fr;
    }
}

/* Loading */
.loading-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    z-index: 300;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    transition: opacity var(--transition-slow);
}

.loading-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

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

/* Responsive */
@media (max-width: 1024px) {
    .filter-panel {
        position: fixed;
        left: -100%;
        top: var(--header-height);
        width: 100%;
        max-width: 360px;
        height: calc(100vh - var(--header-height));
        z-index: 50;
        transition: left var(--transition-normal);
        box-shadow: var(--shadow-xl);
    }

    .filter-panel.open {
        left: 0;
    }

    .results-panel {
        width: 100%;
    }

    .header-container {
        padding: 0 var(--spacing-md);
    }

    .logo h1 {
        font-size: 1rem;
    }
}

@media (max-width: 640px) {
    .results-grid {
        grid-template-columns: 1fr;
    }

    .results-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .modal {
        max-height: 90vh;
        margin: var(--spacing-md);
    }
}

/* Mobile Filter Toggle */
.mobile-filter-toggle {
    display: none;
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--color-primary);
    color: var(--text-inverse);
    border: none;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    font-size: 1.5rem;
    z-index: 40;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

@media (max-width: 1024px) {
    .mobile-filter-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }
}

/* Mobile Filter Overlay */
.mobile-filter-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 45;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.mobile-filter-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* Close Filter Panel Button */
.btn-close-panel {
    display: none;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
    border: none;
    background: var(--bg-hover);
    cursor: pointer;
    font-size: 1rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.btn-close-panel:hover {
    background: var(--color-danger);
    color: var(--text-inverse);
}

@media (max-width: 1024px) {
    .btn-close-panel {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .filter-header-actions {
        display: flex;
        gap: var(--spacing-sm);
        align-items: center;
    }
}

/* Improved Mobile Filter Panel */
@media (max-width: 1024px) {
    .filter-panel.open {
        left: 0;
    }

    .mobile-filter-toggle.hide {
        transform: scale(0);
        opacity: 0;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color-dark);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}


/* ==========================================
   Image Gallery Styles
   ========================================== */
.image-gallery {
    margin-top: 1rem;
    display: grid;
    gap: 1.5rem;
    /* Increased gap */
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    /* Slightly wider cards */
}

.image-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--bg-card);
    transition: transform 0.2s, box-shadow 0.2s;
}

.image-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.image-item img {
    width: 100%;
    height: auto;
    display: block;
    border-bottom: 1px solid var(--border-color);
    background-color: #f8fafc;
    /* Placeholder bg */
}

.image-caption {
    padding: 0.75rem 1rem;
    font-size: 0.9rem;
    /* Larger font */
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    margin: 0;
    white-space: pre-wrap;
    text-align: left;
    /* Left align */
    line-height: 1.6;
    /* Better readability */
}

.image-caption strong {
    color: var(--text-primary);
    font-weight: 700;
    display: block;
    /* Make Figure ID stand out on its own line if needed, or just bold */
    margin-bottom: 0.25rem;
}

/* ==========================================
   Mobile Optimization (Added)
   ========================================== */
@media (max-width: 640px) {

    /* Header Optimization: 2-ROW LAYOUT */
    .header {
        height: auto;
        padding-bottom: var(--spacing-sm);
    }

    .header-container {
        padding: 0 var(--spacing-sm);
        flex-wrap: wrap;
        height: auto;
        min-height: var(--header-height);
        padding-top: var(--spacing-xs);
    }

    .logo {
        flex: 1;
        order: 1;
        margin-bottom: 0;
        min-width: 0;
        /* Allow logo text to shrink if needed, preventing overflow */
    }

    .header-nav {
        display: contents;
        /* Unwrap nav children to flow in header-container */
    }

    /* Search Bar: Full width on second row */
    .search-container {
        order: 3;
        width: 100%;
        margin: var(--spacing-xs) 0 0 0;
        flex: 0 0 100%;
        /* Force new line */
    }

    #global-search {
        padding: 0.5rem 1rem;
        font-size: 1rem;
        /* Prevent iOS zoom */
    }

    /* Buttons: Sit next to logo */
    .icon-btn {
        order: 2;
        width: 36px;
        height: 36px;
        margin-left: var(--spacing-xs);
        font-size: 1.1rem;
        flex-shrink: 0;
        /* Prevent buttons from being squashed */
    }

    /* Adjust main content to not be hidden behind taller fixed header */
    .main-content {
        margin-top: 110px;
        /* Approx height of 2-row header */
    }

    /* Adjust filter panel top position */
    .filter-panel {
        top: 110px;
        height: calc(100vh - 110px);
    }

    /* Modal Optimization */
    .modal {
        width: 100%;
        height: 100%;
        max-height: 100%;
        max-width: 100%;
        border-radius: 0;
        margin: 0;
        display: flex;
        flex-direction: column;
    }

    .modal-overlay {
        padding: 0;
        align-items: flex-end;
    }

    .modal-header,
    .modal-body {
        padding: var(--spacing-md);
    }

    .modal-body {
        padding-bottom: 80px;
    }

    /* Results Grid */
    .results-grid {
        gap: var(--spacing-md);
    }

    .result-card {
        padding: var(--spacing-md);
    }
}

/* Hide Title Suffix on Small Screens */
@media (max-width: 480px) {
    .header-title-suffix {
        display: none;
    }

    .logo h1 {
        font-size: 1.125rem;
    }
}