/* ==========================================================================
   White Silence Design System — CSS Variables
   ========================================================================== */
:root {
    --bg-body: #F5F6F9;
    --bg-surface: #FFFFFF;
    --bg-elevated: #EDF0F4;
    --bg-input: #FFFFFF;
    --bg-hover: rgba(107, 123, 152, 0.10);
    --bg-active: rgba(107, 123, 152, 0.15);
    --text-primary: #2C3345;
    --text-secondary: #536178;
    --text-muted: #7B8BA0;
    --accent: #6B7B98;
    --accent-hover: #5A6A85;
    --accent-glow: rgba(107, 123, 152, 0.15);
    --border: rgba(44, 51, 69, 0.14);
    --border-subtle: rgba(44, 51, 69, 0.08);
    --success: #6B987E;
    --danger: #986B6B;
    --warning: #98906B;
    --radius: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --shadow-card: 0 0 0 1px rgba(44, 51, 69, 0.05), 0 2px 8px rgba(44, 51, 69, 0.06);
    --shadow-hover: 0 8px 24px rgba(44, 51, 69, 0.12);
    --transition: 150ms ease;
    --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", "SFMono-Regular", Menlo, Consolas, monospace;
}

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

html {
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-stack);
    color: var(--text-primary);
    background: var(--bg-body);
    line-height: 1.6;
    min-height: 100vh;
}

body.modal-active {
    overflow: hidden;
}

/* ==========================================================================
   Navigation — Sticky with Frosted Glass
   ========================================================================== */
.top-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(245, 246, 249, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 600;
    font-size: 15px;
    letter-spacing: -0.01em;
}

.nav-brand i {
    font-size: 22px;
    color: var(--accent);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: var(--radius);
    font-size: 14px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: background var(--transition), color var(--transition);
}

.nav-links a:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.nav-links a.active {
    background: var(--bg-active);
    color: var(--text-primary);
}

.nav-links a i {
    font-size: 17px;
}

/* --- Mobile Navigation --- */

.nav-hamburger {
    display: none;
    padding: 6px 8px;
    font-size: 22px;
    color: var(--text-secondary);
    border-radius: var(--radius);
    border: none;
    background: none;
    cursor: pointer;
    transition: background var(--transition), color var(--transition);
}

.nav-hamburger:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.nav-hamburger.active {
    background: var(--bg-active);
    color: var(--text-primary);
}

.nav-mobile-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(245, 246, 249, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 8px 16px;
    box-shadow: 0 4px 16px rgba(44, 51, 69, 0.08);
}

.nav-mobile-menu.active {
    display: block;
}

.nav-mobile-menu a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    border-radius: var(--radius);
    font-size: 15px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: background var(--transition), color var(--transition);
}

.nav-mobile-menu a:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.nav-mobile-menu a.active {
    background: var(--bg-active);
    color: var(--text-primary);
}

.nav-mobile-menu a i {
    font-size: 20px;
}

.d-none {
    display: none !important;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

#user-info {
    font-size: 13px;
    color: var(--text-secondary);
}

.user-info {
    font-size: 13px;
    color: var(--text-secondary);
}

.logout-btn {
    font-size: 13px;
    color: var(--text-secondary);
    padding: 6px 12px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: transparent;
    cursor: pointer;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-family: var(--font-stack);
}

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

/* ==========================================================================
   Main Content
   ========================================================================== */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 32px 24px 48px;
}

/* Legacy search container (for backward compatibility) */
.search-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 32px 24px 48px;
}

/* ==========================================================================
   Search Section
   ========================================================================== */
.search-section {
    margin-bottom: 32px;
}

.search-title {
    font-size: 24px;
    font-weight: 300;
    color: var(--text-primary);
    letter-spacing: -0.02em;
    margin-bottom: 20px;
}

.search-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 32px;
}

.search-header .logo {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 15px;
}

.search-header .logo svg {
    color: var(--accent);
}

.search-header .logo h2 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.search-form {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: flex-start;
}

.search-input-group {
    position: relative;
    flex: 1;
    min-width: 280px;
}

.search-input-group .search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 18px;
    color: var(--text-muted);
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: 12px 16px 12px 44px;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-input);
    outline: none;
    font-family: var(--font-stack);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.search-input::placeholder {
    color: var(--text-muted);
}

.search-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow), 0 0 20px rgba(107, 123, 152, 0.08);
}

.topk-input-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.topk-label {
    font-size: 13px;
    color: var(--text-secondary);
    white-space: nowrap;
}

.topk-input {
    width: 80px;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-input);
    outline: none;
    text-align: center;
    font-family: var(--font-stack);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.topk-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.search-actions {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 12px 20px;
    font-size: 13px;
    font-weight: 500;
    font-family: var(--font-stack);
    line-height: 1.5;
    border-radius: var(--radius);
    border: 1px solid transparent;
    cursor: pointer;
    transition: background var(--transition), color var(--transition), border-color var(--transition), opacity var(--transition), transform var(--transition);
    text-decoration: none;
    white-space: nowrap;
    background: transparent;
}

.btn:hover {
    opacity: 0.9;
}

.btn:active {
    transform: scale(0.98);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

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

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

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

.btn-sm {
    padding: 10px 16px;
    font-size: 12px;
}

/* ==========================================================================
   Results Section
   ========================================================================== */
.results-section {
    margin-top: 8px;
}

.results-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-subtle);
    flex-wrap: wrap;
    gap: 12px;
}

.results-header h3 {
    font-size: 18px;
    font-weight: 500;
    margin: 0;
    color: var(--text-primary);
}

.results-count {
    font-size: 15px;
    color: var(--text-primary);
    font-weight: 500;
}

.results-count span {
    color: var(--text-muted);
}

/* ==========================================================================
   Results Grid
   ========================================================================== */
.results-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

/* ==========================================================================
   Result Card
   ========================================================================== */
.result-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-card);
    transition: transform var(--transition), box-shadow var(--transition);
    display: flex;
    flex-direction: column;
    cursor: pointer;
}

.result-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.card-image-wrapper {
    position: relative;
    height: 200px;
    overflow: hidden;
    background: var(--bg-elevated);
}

.card-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: opacity var(--transition);
}

.result-card:hover .card-image {
    opacity: 0.9;
}

/* Skeleton shimmer for images pending lazy load */
.card-image[data-src] {
    opacity: 0;
    background: linear-gradient(
        110deg,
        var(--bg-elevated) 30%,
        rgba(255, 255, 255, 0.5) 50%,
        var(--bg-elevated) 70%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s ease-in-out infinite;
}

/* Fade-in animation when image finishes loading */
.card-image.loaded {
    opacity: 1;
    animation: fadeInImage 0.4s ease forwards;
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

@keyframes fadeInImage {
    from { opacity: 0; }
    to { opacity: 1; }
}

.rank-badge {
    position: absolute;
    top: 12px;
    left: 12px;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.95);
    border-radius: var(--radius);
    font-size: 13px;
    font-weight: 700;
    color: var(--accent);
    box-shadow: 0 2px 8px rgba(44, 51, 69, 0.1);
    backdrop-filter: blur(8px);
}

.card-body {
    padding: 16px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.card-description {
    font-size: 14px;
    color: var(--text-primary);
    line-height: 1.5;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.card-meta {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.meta-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.similarity-score {
    font-size: 15px;
    font-weight: 700;
    color: var(--accent);
}

.gen-time {
    font-size: 12px;
    color: var(--text-muted);
}

.uuid {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    background: var(--bg-elevated);
    padding: 3px 8px;
    border-radius: 4px;
}

.card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 10px;
    border-top: 1px solid var(--border-subtle);
}

.download-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-surface);
    color: var(--text-muted);
    cursor: pointer;
    font-size: 18px;
    transition: all var(--transition);
}

.download-btn:hover {
    background: var(--bg-hover);
    color: var(--accent);
    border-color: var(--accent);
}

/* ==========================================================================
   Loading States
   ========================================================================== */
.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 16px;
}

.loading-spinner-small {
    width: 16px;
    height: 16px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    display: inline-block;
    margin-right: 8px;
    vertical-align: middle;
}

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

/* ==========================================================================
   Infinite Scroll Sentinel
   ========================================================================== */
.sentinel {
    height: 20px;
    margin: 20px 0;
}

/* ==========================================================================
   End Message
   ========================================================================== */
.end-message {
    text-align: center;
    padding: 24px;
    color: var(--text-muted);
    font-size: 14px;
}

/* ==========================================================================
   Custom Image Viewer Modal
   ========================================================================== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.85);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition), visibility var(--transition);
}

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

.modal-container {
    max-width: 1200px;
    width: 95vw;
    max-height: 90vh;
    background: var(--bg-surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: row;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
    transform: scale(0.95);
    transition: transform var(--transition);
}

.modal-overlay.active .modal-container {
    transform: scale(1);
}

.modal-image-area {
    flex: 1;
    min-height: 400px;
    max-height: 80vh;
    background: #1a1a2e;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.modal-image-area img {
    max-height: 70vh;
    max-width: 100%;
    object-fit: contain;
}

.modal-nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.5);
    border: none;
    color: #fff;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition), opacity var(--transition);
    z-index: 10;
}

.modal-nav-btn:hover {
    background: rgba(0, 0, 0, 0.7);
}

.modal-nav-btn.prev {
    left: 20px;
}

.modal-nav-btn.next {
    right: 20px;
}

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

.modal-metadata-area {
    width: 350px;
    max-height: 80vh;
    overflow-y: auto;
    padding: 24px;
    background: var(--bg-surface);
    border-left: 1px solid var(--border);
    position: relative;
}

.modal-metadata-area h5 {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 18px;
    font-weight: 600;
}

.modal-metadata-area .metadata-section {
    margin-bottom: 16px;
}

.modal-metadata-area .metadata-label-tilt {
    font-size: 12px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 4px;
    display: block;
}

.modal-metadata-area .metadata-value {
    color: var(--text-primary);
    font-size: 14px;
    line-height: 1.5;
}

.modal-metadata-area a {
    color: var(--accent);
    text-decoration: none;
    word-break: break-all;
}

.modal-metadata-area a:hover {
    text-decoration: underline;
}

.modal-close-btn {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    border-radius: var(--radius);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
    z-index: 10;
}

.modal-close-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-color: var(--accent);
}

.modal-keyboard-hint {
    position: absolute;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0, 0, 0, 0.6);
    color: rgba(255, 255, 255, 0.8);
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 12px;
    pointer-events: none;
}

/* ==========================================================================
   Admin-only utility
   ========================================================================== */
.admin-only {
    display: none;
}

body.is-admin .admin-only {
    display: inline-flex;
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */
.text-center {
    text-align: center;
}

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

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

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

.me-3 {
    margin-right: 12px;
}

.small {
    font-size: 13px;
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 768px) {
    .nav-inner {
        padding: 0 16px;
    }

    .nav-hamburger {
        display: block;
    }

    .nav-links {
        display: none;
    }

    .nav-left {
        gap: 16px;
    }

    .top-nav {
        position: relative;
    }

    #user-info,
    .user-info {
        display: none;
    }

    .main-content,
    .search-container {
        padding: 20px 16px 32px;
    }

    .search-title {
        font-size: 20px;
    }

    .search-form {
        flex-direction: column;
    }

    .search-input-group {
        min-width: 100%;
    }

    .topk-input-group {
        width: 100%;
        justify-content: flex-start;
    }

    .search-actions {
        width: 100%;
    }

    .search-actions .btn {
        flex: 1;
    }

    .results-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

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

    .card-image-wrapper {
        height: 180px;
    }

    /* Modal responsive - stack vertically */
    .modal-container {
        flex-direction: column;
        width: 100vw;
        height: 100vh;
        max-height: 100vh;
        border-radius: 0;
    }

    .modal-image-area {
        flex: 1;
        min-height: 50vh;
        max-height: 60vh;
    }

    .modal-image-area img {
        max-height: 55vh;
    }

    .modal-metadata-area {
        width: 100%;
        max-height: 40vh;
        border-left: none;
        border-top: 1px solid var(--border);
    }

    .modal-nav-btn {
        width: 40px;
        height: 40px;
    }

    .modal-nav-btn.prev {
        left: 10px;
    }

    .modal-nav-btn.next {
        right: 10px;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .results-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ==========================================================================
   Legacy Compatibility (for smooth transition)
   ========================================================================== */
.card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-card);
}

.card-body {
    padding: 16px;
}

.card-img-top {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.h-100 {
    height: 100%;
}

.border-0 {
    border: none;
}

.shadow-sm {
    box-shadow: var(--shadow-card);
}

.position-relative {
    position: relative;
}

.position-absolute {
    position: absolute;
}

.top-0 {
    top: 0;
}

.start-0 {
    left: 0;
}

.m-2 {
    margin: 8px;
}

.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 4px 8px;
    font-size: 12px;
    font-weight: 600;
    border-radius: var(--radius);
    background: var(--accent);
    color: #fff;
}

.bg-dark {
    background: var(--bg-elevated);
    color: var(--text-primary);
}

.d-flex {
    display: flex;
}

.d-inline-flex {
    display: inline-flex;
}

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

.align-items-start {
    align-items: flex-start;
}

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

.mb-2 {
    margin-bottom: 8px;
}

.mb-0 {
    margin-bottom: 0;
}

.text-truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.row {
    display: flex;
    flex-wrap: wrap;
    margin: -8px;
}

.row > * {
    padding: 8px;
}

.col-6 {
    width: 50%;
}

.col-12 {
    width: 100%;
}

.col-lg-8 {
    flex: 1;
}

.col-lg-4 {
    width: 350px;
}

.g-2 {
    gap: 8px;
}

.w-100 {
    width: 100%;
}

.py-3 {
    padding-top: 12px;
    padding-bottom: 12px;
}

.py-4 {
    padding-top: 16px;
    padding-bottom: 16px;
}

.py-5 {
    padding-top: 20px;
    padding-bottom: 20px;
}

.mt-2 {
    margin-top: 8px;
}

.mt-4 {
    margin-top: 16px;
}

.ms-2 {
    margin-left: 8px;
}

.overflow-auto {
    overflow: auto;
}

.p-0 {
    padding: 0;
}

.p-4 {
    padding: 16px;
}

.container-fluid {
    width: 100%;
}

.fw-bold {
    font-weight: 700;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.form-control {
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-input);
    outline: none;
    font-family: var(--font-stack);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.form-control:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}