/* ===================================
   AINO Lab — Shared Lab Page Styles
   Dongguk University Brand Colors
   =================================== */

:root {
    --du-orange:        #D4711B;   /* Dongguk primary orange */
    --du-orange-dark:   #B05C12;   /* hover / pressed */
    --du-orange-light:  #F5A820;   /* emblem yellow-orange */
    --du-gray:          #928D88;   /* brand neutral gray */
    --du-gray-light:    #F2EDE8;   /* tinted background */
}

/* Override accent color for lab pages */
.lab-page {
    --accent-color: var(--du-orange);
    --accent-hover: var(--du-orange-dark);
}

/* ===================================
   Navigation
   =================================== */
.lab-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: rgba(var(--bg-primary-rgb), 0.85);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: background-color var(--transition-base), border-color var(--transition-base);
}

[data-theme="dark"] .lab-nav {
    background-color: rgba(var(--bg-primary-rgb), 0.75);
}

.lab-nav-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}

.nav-brand {
    font-family: var(--font-sans);
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--du-orange);
    text-decoration: none;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    transition: color var(--transition-fast);
}

.nav-brand:hover {
    color: var(--du-orange-dark);
}

/* Dongguk logo — crops the orange (rightmost) panel from dg_logo.jpg */
.nav-dongguk-logo {
    display: inline-block;
    width: 90px;
    height: 36px;
    background-image: url('/assets/dg_logo.jpg');
    background-size: 300% auto;
    background-position: 100% center;
    background-repeat: no-repeat;
    border-radius: 4px;
    flex-shrink: 0;
    /* Light mode: multiply makes JPEG white areas blend into background */
    mix-blend-mode: multiply;
}

[data-theme="dark"] .nav-dongguk-logo {
    /* Dark mode: multiply would hide the orange, so use a white pill instead */
    mix-blend-mode: normal;
    background-color: #fff;
    padding: 1px 3px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    margin: 0;
    padding: 0;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 0.25rem 0;
    border-bottom: 2px solid transparent;
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
}

.nav-dark-toggle {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.3rem 0.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    font-size: 0.85rem;
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.nav-dark-toggle:hover {
    color: var(--accent-color);
    border-color: var(--accent-color);
}

/* Mobile nav */
.nav-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 1.2rem;
}

@media (max-width: 640px) {
    .nav-menu-toggle {
        display: block;
        margin-left: auto;
        order: 3;
    }

    .nav-dark-toggle {
        display: none;
    }

    .nav-links {
        max-height: 0;
        overflow: hidden;
        opacity: 0;
        flex-direction: column;
        gap: 0;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background-color: rgba(var(--bg-primary-rgb), 0.95);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border-bottom: 1px solid var(--border-color);
        transition: max-height 0.3s ease, opacity 0.25s ease;
    }

    .nav-links.open {
        max-height: 400px;
        opacity: 1;
    }

    .nav-links li {
        padding: 0 var(--spacing-md);
    }

    .nav-links a {
        display: block;
        padding: 0.6rem 0;
        border-bottom: none;
        border-top: 1px solid var(--border-color);
    }

    .nav-links a:hover,
    .nav-links a.active {
        color: var(--accent-color);
        background: none;
        border-bottom: none;
    }
}

/* ===================================
   Page Layout
   =================================== */
.lab-page {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.lab-main {
    flex: 1;
    max-width: 1100px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
    width: 100%;
}

/* ===================================
   Page Header (Hero) — with CSS particle pulse fallback
   =================================== */

@keyframes hero-pulse {
    0%, 100% { opacity: 0.18; transform: scale(1);   }
    50%       { opacity: 0.38; transform: scale(1.15); }
}

@keyframes hero-pulse-slow {
    0%, 100% { opacity: 0.12; transform: scale(1);   }
    50%       { opacity: 0.28; transform: scale(1.2); }
}

@keyframes hero-drift {
    0%   { transform: translateY(0)   translateX(0); }
    33%  { transform: translateY(-8px) translateX(5px); }
    66%  { transform: translateY(5px)  translateX(-4px); }
    100% { transform: translateY(0)   translateX(0); }
}

.lab-hero {
    position: relative;
    overflow: hidden;
    background:
        linear-gradient(135deg, rgba(212, 113, 27, 0.82) 0%, rgba(176, 92, 18, 0.88) 100%),
        url('/assets/title_aino.png') center / cover no-repeat;
    color: #fff;
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
}

/* Particle orbs via pseudo-elements */
.lab-hero::before,
.lab-hero::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    pointer-events: none;
}

.lab-hero::before {
    width: 340px;
    height: 340px;
    background: radial-gradient(circle, rgba(255,255,255,0.22) 0%, transparent 70%);
    top: -80px;
    left: -80px;
    animation: hero-pulse 6s ease-in-out infinite, hero-drift 12s ease-in-out infinite;
}

.lab-hero::after {
    width: 240px;
    height: 240px;
    background: radial-gradient(circle, rgba(255,200,100,0.18) 0%, transparent 70%);
    bottom: -60px;
    right: -40px;
    animation: hero-pulse-slow 8s ease-in-out infinite 2s, hero-drift 15s ease-in-out infinite reverse;
}

.lab-hero-inner {
    position: relative;
    z-index: 1;
}

.lab-hero h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    font-family: var(--font-sans);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
}

.lab-hero p {
    font-size: 1rem;
    opacity: 0.9;
    max-width: 640px;
    margin: 0 auto;
}

.page-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.page-header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-primary);
    font-family: var(--font-sans);
}

.page-header p {
    margin-top: var(--spacing-xs);
    color: var(--text-secondary);
}

/* ===================================
   Section
   =================================== */
.lab-section {
    margin-bottom: var(--spacing-xl);
}

.lab-section-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-xs);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lab-section-title i {
    color: var(--accent-color);
    font-size: 1rem;
}

/* ===================================
   Cards
   =================================== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.card {
    background: rgba(var(--bg-secondary-rgb), 0.7);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-hard);
    transition:
        box-shadow var(--transition-base),
        transform 0.4s var(--spring-bounce),
        border-color var(--transition-base),
        background var(--transition-base);
}

.card:hover {
    box-shadow: var(--shadow-hard-hover), 0 8px 20px rgba(0, 0, 0, 0.08);
    transform: translateY(-4px) scale(1.01);
    border-color: var(--du-orange);
}

[data-theme="dark"] .card {
    background: rgba(var(--bg-secondary-rgb), 0.6);
    border-color: rgba(255, 255, 255, 0.06);
}

[data-theme="dark"] .card:hover {
    border-color: var(--du-orange);
}

.card-icon {
    font-size: 1.5rem;
    color: var(--accent-color);
    margin-bottom: var(--spacing-sm);
}

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

.card-body {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===================================
   Tags / Keywords
   =================================== */
.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    margin-top: var(--spacing-xs);
}

.tag {
    font-size: 0.75rem;
    background: var(--bg-accent);
    color: var(--text-secondary);
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

/* ===================================
   News List
   =================================== */
.news-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.news-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--border-color);
    align-items: flex-start;
}

.news-item:last-child {
    border-bottom: none;
}

.news-date {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent-color);
    white-space: nowrap;
    min-width: 70px;
    padding-top: 0.1rem;
}

.news-content {
    font-size: 0.9rem;
    color: var(--text-primary);
    line-height: 1.6;
}

/* ===================================
   Member Cards
   =================================== */
.member-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

.member-card {
    background: rgba(var(--bg-secondary-rgb), 0.7);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    text-align: center;
    box-shadow: var(--shadow-hard);
    transition:
        box-shadow var(--transition-base),
        transform 0.4s var(--spring-bounce),
        border-color var(--transition-base);
}

.member-card:hover {
    box-shadow: var(--shadow-hard-hover), 0 6px 16px rgba(0, 0, 0, 0.08);
    transform: translateY(-3px);
    border-color: var(--du-orange);
}

.member-avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: var(--bg-accent);
    margin: 0 auto var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--text-muted);
    overflow: hidden;
}

.member-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.member-name {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 0.2rem;
}

.member-title {
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-bottom: 0.15rem;
}

.member-affiliation {
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-bottom: 0.15rem;
}

.member-email {
    display: block;
    font-size: 0.78rem;
    color: var(--text-muted);
    text-decoration: none;
    margin-bottom: 0.1rem;
    word-break: break-all;
}

.member-email:hover {
    color: var(--accent-color);
    text-decoration: underline;
}

.member-link {
    display: inline-block;
    margin-top: var(--spacing-xs);
    font-size: 0.8rem;
    color: var(--accent-color);
    text-decoration: none;
}

.member-link:hover {
    text-decoration: underline;
}

/* ===================================
   Recruitment Box
   =================================== */
.recruitment-box {
    background: rgba(var(--bg-secondary-rgb), 0.7);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--du-orange);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-hard);
    transition: box-shadow var(--transition-base), transform 0.4s var(--spring-bounce);
}

.recruitment-box:hover {
    box-shadow: var(--shadow-hard-hover);
    transform: translateY(-2px);
}

.recruitment-box h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.recruitment-box p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-xs);
}

.recruitment-box a {
    color: var(--accent-color);
    text-decoration: none;
}

.recruitment-box a:hover {
    text-decoration: underline;
}

/* ===================================
   Contact Info
   =================================== */
.contact-block {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.contact-row {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.contact-row i {
    color: var(--accent-color);
    width: 16px;
    text-align: center;
}

.contact-row a {
    color: var(--accent-color);
    text-decoration: none;
}

.contact-row a:hover {
    text-decoration: underline;
}

/* ===================================
   Publication List (Lab page)
   =================================== */
.pub-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.pub-item {
    padding: var(--spacing-sm);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    line-height: 1.6;
    color: var(--text-primary);
}

.pub-item .pub-authors {
    color: var(--text-secondary);
    margin-bottom: 0.2rem;
}

.pub-item .pub-title {
    font-weight: 500;
}

.pub-item .pub-venue {
    color: var(--accent-color);
    font-style: italic;
}

.pub-item .pub-year {
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* ===================================
   Publication Filter Bar
   =================================== */
.pub-filter-bar {
    display: flex;
    flex-direction: column;
    gap: 0.55rem;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: var(--spacing-md);
}

.pub-filter-group {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    flex-wrap: wrap;
}

.pub-filter-label {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    min-width: 4.5rem;
    flex-shrink: 0;
}

/* Type toggle */
.pub-type-toggle {
    display: flex;
    gap: 0.3rem;
    flex-wrap: wrap;
}

.pub-type-btn {
    padding: 0.22em 0.75em;
    font-size: 0.82rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--bg-primary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s, transform 0.25s var(--spring-bounce);
}

.pub-type-btn:hover {
    border-color: var(--du-orange);
    color: var(--du-orange);
    transform: scale(1.05);
}

.pub-type-btn.active {
    background: var(--du-orange);
    border-color: var(--du-orange);
    color: #fff;
    font-weight: 600;
}

/* Year / Member chips */
.pub-filter-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.3rem;
}

.pub-chip {
    padding: 0.2em 0.65em;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--bg-primary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s, transform 0.25s var(--spring-bounce);
}

.pub-chip:hover {
    border-color: var(--du-orange);
    color: var(--du-orange);
    transform: scale(1.05);
}

.pub-chip.active {
    background: var(--du-orange);
    border-color: var(--du-orange);
    color: #fff;
    font-weight: 600;
}

/* Reset button */
.pub-filter-reset-group {
    justify-content: flex-end;
}

.pub-filter-reset {
    padding: 0.22em 0.75em;
    font-size: 0.78rem;
    font-weight: 600;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: transparent;
    color: var(--text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.3rem;
    transition: color 0.15s, border-color 0.15s;
}

.pub-filter-reset:hover {
    color: var(--text-primary);
    border-color: var(--text-secondary);
}

.pub-category-header {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: var(--spacing-lg) 0 var(--spacing-sm);
    padding-bottom: 0.4rem;
    border-bottom: 2px solid var(--border-color);
}

/* ===================================
   Project Cards (Lab page)
   =================================== */

.project-status-header {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: var(--spacing-lg) 0 var(--spacing-md);
    padding-bottom: 0.4rem;
    border-bottom: 2px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.project-status-header.ongoing-header {
    border-bottom-color: var(--du-orange);
    color: var(--du-orange-dark);
}

.project-status-header.completed-header {
    color: var(--text-secondary);
}

.project-card {
    border: 1.5px solid var(--border-color);
    border-radius: 8px;
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    background: rgba(var(--bg-secondary-rgb), 0.7);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    box-shadow: var(--shadow-hard);
    transition:
        box-shadow var(--transition-base),
        transform 0.4s var(--spring-bounce),
        border-color var(--transition-base);
}

.project-card:hover {
    box-shadow: var(--shadow-hard-hover), 0 6px 16px rgba(0,0,0,0.08);
    transform: translateY(-3px);
    border-color: var(--du-orange);
}

.project-card-header {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.project-status-badge {
    flex-shrink: 0;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    padding: 0.2em 0.6em;
    border-radius: 4px;
    margin-top: 0.15rem;
}

.project-status-badge.ongoing {
    background: var(--du-orange);
    color: #fff;
}

.project-status-badge.completed {
    background: var(--border-color);
    color: var(--text-secondary);
}

.project-titles {
    flex: 1;
}

.project-title-ko {
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-primary);
    line-height: 1.4;
}

.project-title-en {
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-top: 0.2rem;
    line-height: 1.4;
}

.project-info {
    margin-top: var(--spacing-sm);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.3rem 1.5rem;
    font-size: 0.84rem;
}

@media (max-width: 600px) {
    .project-info {
        grid-template-columns: 1fr;
    }
}

.project-info-row {
    display: flex;
    align-items: baseline;
    gap: 0.4rem;
    color: var(--text-secondary);
}

.project-info-label {
    flex-shrink: 0;
    font-weight: 600;
    color: var(--text-muted);
    min-width: 6rem;
    font-size: 0.8rem;
}

.project-info-label i {
    margin-right: 0.25rem;
    color: var(--du-orange);
    opacity: 0.75;
    width: 0.9rem;
    text-align: center;
}

.project-acknowledgment {
    margin-top: var(--spacing-sm);
    padding: 0.5rem 0.75rem;
    background: var(--bg-secondary);
    border-left: 3px solid var(--border-color);
    border-radius: 0 4px 4px 0;
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.55;
}

.ack-label {
    font-weight: 600;
    margin-right: 0.25rem;
}

.project-papers {
    margin-top: var(--spacing-sm);
    font-size: 0.84rem;
}

.project-papers-title {
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.35rem;
    font-size: 0.82rem;
}

.project-papers-title i {
    margin-right: 0.3rem;
    color: var(--du-orange);
    opacity: 0.75;
}

.project-papers-list {
    margin: 0;
    padding-left: 1.2rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.project-paper-item {
    margin-bottom: 0.3rem;
}

.project-paper-item em {
    font-style: italic;
    color: var(--accent-color);
}

.project-paper-item a {
    color: var(--accent-color);
    text-decoration: none;
}

.project-paper-item a:hover {
    text-decoration: underline;
}

/* ===================================
   Footer
   =================================== */
.lab-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-md);
    text-align: center;
    font-size: 0.82rem;
    color: var(--text-muted);
}

.lab-footer a {
    color: var(--accent-color);
    text-decoration: none;
}

.lab-footer a:hover {
    text-decoration: underline;
}

/* ===================================
   Loading / Empty States
   =================================== */
.empty-msg {
    text-align: center;
    color: var(--text-muted);
    padding: var(--spacing-lg);
    font-size: 0.9rem;
}

.loading-msg {
    text-align: center;
    color: var(--text-muted);
    padding: var(--spacing-lg);
    font-size: 0;          /* hide text; spinner provides the visual */
}

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

.loading-msg::before {
    content: '';
    display: block;
    width: 32px;
    height: 32px;
    border: 3px solid var(--border-color);
    border-top-color: var(--du-orange);
    border-radius: 50%;
    animation: lab-spin 0.8s linear infinite;
    margin: 0 auto var(--spacing-xs);
}

/* ===================================
   Publication Search Input
   =================================== */
.pub-search-input {
    flex: 1;
    min-width: 180px;
    max-width: 400px;
    padding: 0.28em 0.75em;
    font-size: 0.85rem;
    font-family: var(--font-sans);
    color: var(--text-primary);
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    outline: none;
    transition: border-color 0.15s, box-shadow 0.15s;
}

.pub-search-input:focus {
    border-color: var(--du-orange);
    box-shadow: 0 0 0 2px rgba(212, 113, 27, 0.15);
}

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

/* ===================================
   Back-to-Top Button
   =================================== */
#back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--du-orange);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.25s ease, transform 0.35s var(--spring-bounce), background 0.15s;
    z-index: 500;
    pointer-events: none;
}

#back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

#back-to-top:hover {
    background: var(--du-orange-dark);
}

.mobile-dark-toggle {
    display: none;
    position: fixed;
    bottom: 5.5rem;
    right: 2rem;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1.5px solid var(--border-color);
    cursor: pointer;
    font-size: 1rem;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    z-index: 500;
    transition: background var(--transition-fast), color var(--transition-fast);
}

.mobile-dark-toggle:hover {
    background: var(--bg-accent);
}

@media (max-width: 640px) {
    .mobile-dark-toggle {
        display: flex;
    }
}

/* ===================================
   Member Default SVG Avatar
   =================================== */
.member-avatar-svg {
    width: 100%;
    height: 100%;
    display: block;
}

/* ===================================
   Publication Detail Button
   =================================== */
.pub-detail-btn {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-size: 0.75rem;
    font-family: var(--font-sans);
    padding: 0.15rem 0.5rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    transition: border-color var(--transition-fast), color var(--transition-fast), transform 0.25s var(--spring-bounce);
    vertical-align: middle;
}
.pub-detail-btn:hover {
    border-color: var(--du-orange);
    color: var(--du-orange);
    transform: scale(1.08);
}

/* ===================================
   Publication Deep Dive Dialog
   =================================== */
#pub-detail-dialog {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 0;
    background: var(--bg-primary);
    color: var(--text-primary);
    box-shadow: var(--shadow-lg);
    width: min(680px, 94vw);
    max-height: 85vh;
    overflow: hidden;
}
#pub-detail-dialog::backdrop {
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}
.pub-dialog-inner {
    display: flex;
    flex-direction: column;
    max-height: 85vh;
    overflow-y: auto;
    padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-md);
    position: relative;
}
.pub-dialog-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    width: 28px;
    height: 28px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    transition: border-color var(--transition-fast), color var(--transition-fast);
}
.pub-dialog-close:hover { border-color: var(--du-orange); color: var(--du-orange); }

.pub-dialog-title {
    font-size: 1.1rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: 0.6rem;
    padding-right: 2rem;
}
.pub-dialog-authors {
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-bottom: 0.3rem;
}
.pub-dialog-venue {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: 0.75rem;
}
.pub-dialog-doi {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    font-size: 0.85rem;
    color: var(--du-orange);
    text-decoration: none;
    margin-bottom: 1rem;
}
.pub-dialog-doi:hover { text-decoration: underline; }

.pub-dialog-section-label {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    margin: 0.75rem 0 0.4rem;
}
.pub-dialog-abstract {
    font-size: 0.88rem;
    line-height: 1.7;
    color: var(--text-secondary);
}
.pub-dialog-bibtex-wrap {
    position: relative;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.75rem;
}
.pub-dialog-bibtex {
    font-family: 'Fira Mono', 'Courier New', monospace;
    font-size: 0.78rem;
    color: var(--text-primary);
    white-space: pre-wrap;
    word-break: break-all;
    margin: 0;
}
.pub-bibtex-copy {
    margin-top: 0.6rem;
    background: var(--du-orange);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.35rem 0.8rem;
    font-size: 0.8rem;
    font-family: var(--font-sans);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    transition: background var(--transition-fast);
}
.pub-bibtex-copy:hover { background: var(--du-orange-dark); }

/* ===================================
   Skeleton Screens
   =================================== */
@keyframes shimmer {
    0%   { background-position: -600px 0; }
    100% { background-position:  600px 0; }
}

.skeleton {
    background: linear-gradient(
        90deg,
        var(--bg-accent) 25%,
        var(--border-color) 50%,
        var(--bg-accent) 75%
    );
    background-size: 1200px 100%;
    animation: shimmer 1.6s infinite linear;
    border-radius: var(--radius-sm);
}

/* News skeleton */
.skeleton-news-item {
    display: flex;
    gap: 0.75rem;
    align-items: flex-start;
    margin-bottom: 0.75rem;
}
.skeleton-news-date { width: 70px; height: 16px; flex-shrink: 0; }
.skeleton-news-text { flex: 1; height: 16px; }

/* Card skeleton (research / member) */
.skeleton-card {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}
.skeleton-card-icon { width: 36px; height: 36px; border-radius: 50%; }
.skeleton-card-title { width: 60%; height: 18px; }
.skeleton-card-line  { height: 13px; }
.skeleton-card-line.short { width: 45%; }

/* Publication skeleton */
.skeleton-pub-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.25rem;
}
.skeleton-pub-num  { width: 30px; height: 30px; flex-shrink: 0; border-radius: 50%; }
.skeleton-pub-body { flex: 1; display: flex; flex-direction: column; gap: 0.5rem; }
.skeleton-pub-title   { height: 18px; }
.skeleton-pub-authors { height: 14px; width: 75%; }
.skeleton-pub-venue   { height: 13px; width: 55%; }

/* ===================================
   Empty States
   =================================== */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
    color: var(--text-muted);
}
.empty-state-icon {
    font-size: 2.5rem;
    opacity: 0.4;
}
.empty-state-message {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
}
.empty-state-hint {
    font-size: 0.85rem;
}

/* ===================================
   News — title + content layout
   =================================== */

/* Home page: title-only link */
.news-title-link {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    line-height: 1.5;
    margin-top: 0.25rem;
    transition: color var(--transition-fast);
}

.news-title-link:hover {
    color: var(--du-orange);
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* News page: full item with title + content (block layout, overrides flex from .news-item) */
.news-item-full {
    display: block;          /* override .news-item flex */
    padding: var(--spacing-md);
    border-left: 3px solid var(--border-color);
    border-bottom: none;     /* override .news-item border-bottom */
    margin-bottom: var(--spacing-md);
    scroll-margin-top: 80px; /* offset for sticky nav */
    transition: border-color var(--transition-base), background var(--transition-base);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.news-item-full:last-child {
    margin-bottom: 0;
}

.news-item-full .news-date {
    display: block;
    margin-bottom: 0.3rem;
}

.news-title {
    display: block;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0 0 0.6rem;
    line-height: 1.5;
}

.news-item-full .news-content {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.75;
    margin: 0;
}

/* Anchor highlight — when navigated to via #news-N */
.news-highlight {
    border-left-color: var(--du-orange);
    background: rgba(212, 113, 27, 0.06);
}

[data-theme="dark"] .news-highlight {
    background: rgba(212, 113, 27, 0.1);
}

/* CSS :target fallback (works even without JS) */
.news-item-full:target {
    border-left-color: var(--du-orange);
    background: rgba(212, 113, 27, 0.06);
}

[data-theme="dark"] .news-item-full:target {
    background: rgba(212, 113, 27, 0.1);
}

/* ===================================
   PI Availability Calendar
   =================================== */
.calendar-wrapper {
    position: relative;
    width: 100%;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1.5px solid var(--border-color);
    box-shadow: var(--shadow-hard);
}

.calendar-iframe {
    display: block;
    width: 100%;
    height: 480px;
    border: none;
    background: #fff;
}

/* Dark mode: Google Calendar iframe는 자체 배경이 흰색이므로
   wrapper에 약한 오버레이로 시각적 구분 */
[data-theme="dark"] .calendar-wrapper {
    border-color: var(--border-color);
    box-shadow: var(--shadow-hard);
}

[data-theme="dark"] .calendar-wrapper::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: var(--radius-md);
    pointer-events: none;
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.06);
}

@media (max-width: 640px) {
    .calendar-iframe {
        height: 380px;
    }
}

/* ===================================
   Scroll Reveal Animation
   =================================== */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s var(--spring-snappy);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

.reveal.delay-1 { transition-delay: 0.08s; }
.reveal.delay-2 { transition-delay: 0.16s; }
.reveal.delay-3 { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
    .reveal {
        opacity: 1;
        transform: none;
        transition: none;
    }
    .card,
    .member-card,
    .project-card,
    .recruitment-box {
        transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
    }
    .card:hover,
    .member-card:hover,
    .project-card:hover,
    .recruitment-box:hover {
        transform: none;
    }
    .pub-type-btn,
    .pub-chip,
    .pub-detail-btn {
        transition: background 0.15s, color 0.15s, border-color 0.15s;
    }
    .pub-type-btn:hover,
    .pub-chip:hover,
    .pub-detail-btn:hover {
        transform: none;
    }
}

@media print {
    .reveal {
        opacity: 1;
        transform: none;
    }
}

/* ===================================
   Bento Grid — Home Page Layout
   =================================== */
.bento-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

/* First card spans 2 columns — featured / hero card */
.bento-grid .card:first-child {
    grid-column: span 2;
}

/* News bento: featured left (2fr), stack right (1fr) */
.bento-news-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-md);
    align-items: start;
}

.bento-news-featured {
    background: rgba(var(--bg-secondary-rgb), 0.7);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    border: 1.5px solid var(--du-orange);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-hard);
    transition: box-shadow var(--transition-base), transform 0.4s var(--spring-bounce);
}

.bento-news-featured:hover {
    box-shadow: var(--shadow-hard-hover);
    transform: translateY(-2px);
}

.bento-news-featured .news-date {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--du-orange);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.bento-news-featured .news-content {
    margin-top: 0.5rem;
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--text-primary);
}

.bento-news-stack {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

/* Tablet: 2-column bento */
@media (max-width: 900px) {
    .member-grid {
        grid-template-columns: 1fr;
    }
    .bento-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .bento-grid .card:first-child {
        grid-column: span 2;
    }
    .bento-news-grid {
        grid-template-columns: 1fr;
    }
}

/* Mobile: single column */
@media (max-width: 600px) {
    .bento-grid {
        grid-template-columns: 1fr;
    }
    .bento-grid .card:first-child {
        grid-column: span 1;
    }
}