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

:root {
    /* Base conference colors */
    --primary-color: #0f2538;
    --primary-dark: #0a1a28;
    --secondary-color: #1a3a5c;
    --accent-color: #2d4a6b;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #ffffff;
    --bg-light: #f8f9fa;
    --border-color: #e0e0e0;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --error-color: #dc3545;
    --max-width: 1200px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --border-radius: 4px;
    --shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
.site-header {
    background: var(--bg-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-top {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-md) 0;
}

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

.conference-title a.title-link {
    color: inherit;
    text-decoration: none;
}

.conference-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0;
}

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

/* Header buttons - need to stand out on dark background */
.header-top .btn-primary {
    background: white;
    color: var(--primary-color);
}

.header-top .btn-primary:hover,
.header-top .btn-primary:focus {
    background: #f0f0f0;
    color: var(--primary-color);
    outline: none;
    box-shadow: var(--shadow);
}

.header-top .btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.header-top .btn-secondary:hover,
.header-top .btn-secondary:focus {
    background: white;
    color: var(--primary-color);
    outline: none;
}

/* Navigation */
.main-nav {
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
}

.nav-menu {
    list-style: none;
    display: flex;
    align-items: center;
    margin: 0;
    padding: 0;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: block;
    padding: var(--spacing-md) var(--spacing-sm);
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border-bottom: 3px solid transparent;
}

.nav-link:hover,
.nav-link:focus {
    color: var(--primary-color);
    background-color: var(--bg-light);
    border-bottom-color: var(--primary-color);
    outline: none;
}

.nav-link.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Dropdown Menu */
.has-dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 200px;
    box-shadow: var(--shadow-md);
    list-style: none;
    padding: var(--spacing-xs) 0;
    margin: 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    z-index: 100;
    border-radius: var(--border-radius);
}

.has-dropdown:hover .dropdown-menu,
.has-dropdown:focus-within .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

/* Desktop: prevent active class from showing dropdown (only use hover) */
@media (min-width: 769px) {
    .has-dropdown.active .dropdown-menu {
        opacity: 0;
        visibility: hidden;
        transform: translateY(-10px);
    }
    
    .has-dropdown.active:hover .dropdown-menu,
    .has-dropdown.active:focus-within .dropdown-menu {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }
}

.dropdown-menu li {
    margin: 0;
}

.dropdown-menu a {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-color);
    text-decoration: none;
    transition: var(--transition);
}

.dropdown-menu a:hover,
.dropdown-menu a:focus {
    background-color: var(--bg-light);
    color: var(--primary-color);
    outline: none;
}

.dropdown-menu a.active {
    background-color: var(--bg-light);
    color: var(--primary-color);
    font-weight: 600;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    margin-left: auto;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    transition: var(--transition);
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* Main Content */
main#app {
    min-height: calc(100vh - 300px);
    padding: var(--spacing-xl) 0;
}

/* Hero Section */
.hero {
    background: #0f2538;
    color: white;
    padding: var(--spacing-xl) 0;
    margin-bottom: var(--spacing-xl);
}

.hero-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero-text h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.hero-main-title {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    word-break: keep-all;
    white-space: nowrap;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    opacity: 0.9;
    margin-bottom: var(--spacing-lg);
    color: #4EC3C7;
}

.hero-title-highlight {
    color: #4EC3C7;
}

.hero-text p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.95;
}

.hero-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.hero-info-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    font-size: 1.1rem;
}

.hero-info-label {
    font-weight: 600;
    opacity: 0.9;
    min-width: 60px;
}

.hero-info-value {
    opacity: 0.95;
    flex: 1;
}

.hero-actions {
    margin-top: var(--spacing-lg);
}

.hero-illustration {
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.85;
}

.hero-poster-image {
    max-width: 100%;
    max-height: 400px;
    width: auto;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    display: block;
    object-fit: contain;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.poster-clickable:hover {
    transform: scale(1.02);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* Poster Modal */
.poster-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s ease;
}

.poster-modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(4px);
}

.poster-modal-content {
    position: relative;
    max-width: 90%;
    max-height: 90%;
    z-index: 10001;
    animation: scaleIn 0.3s ease;
}

.poster-modal-image {
    max-width: 100%;
    max-height: 90vh;
    width: auto;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
    display: block;
    object-fit: contain;
}

.poster-modal-close {
    position: absolute;
    top: -40px;
    right: 0;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 2rem;
    line-height: 1;
    cursor: pointer;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    z-index: 10002;
}

.poster-modal-close:hover,
.poster-modal-close:focus {
    background: white;
    transform: scale(1.1);
    outline: 2px solid white;
    outline-offset: 2px;
}

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

@keyframes scaleIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

/* Hero section buttons - need to stand out on dark background */
.hero .btn-primary {
    background: white;
    color: var(--primary-color);
}

.hero .btn-primary:hover,
.hero .btn-primary:focus {
    background: #f0f0f0;
    color: var(--primary-color);
    outline: none;
    box-shadow: var(--shadow);
}

.hero .btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.hero .btn-secondary:hover,
.hero .btn-secondary:focus {
    background: white;
    color: var(--primary-color);
    outline: none;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    font-size: 1rem;
}

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

.btn-primary:hover,
.btn-primary:focus {
    background: var(--primary-dark);
    color: white;
    outline: none;
    box-shadow: var(--shadow);
}

.btn-secondary {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover,
.btn-secondary:focus {
    background: var(--primary-color);
    color: white;
    outline: none;
}

/* Cards */
.card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

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

.card-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    color: var(--primary-color);
}

/* Badge */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    background: var(--bg-light);
    color: var(--text-color);
}

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

.badge-success {
    background: var(--success-color);
    color: white;
}

.badge-warning {
    background: var(--warning-color);
    color: var(--text-color);
}

/* Table */
.table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-md) 0;
    background: white;
    box-shadow: var(--shadow);
    border-radius: var(--border-radius);
    overflow: hidden;
}

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

.table th,
.table td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table tbody tr:hover {
    background: var(--bg-light);
}

.table tbody tr:last-child td {
    border-bottom: none;
}

.table-responsive {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.lab-layout-container {
    margin: var(--spacing-md) 0;
    text-align: center;
}

.lab-layout-image {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.table td[style*="text-align: center"] {
    text-align: center;
}

.table .open-hour-cell {
    text-align: center;
    font-weight: bold;
    color: var(--success-color);
}

/* Open Lab 테이블 전체 폰트 크기 조정 */
.table-openlab {
    font-size: 0.65rem;
}

/* Open Lab 테이블의 Open Hours 열 너비 조정 */
.table-openlab thead tr:first-child th:nth-child(n+4):nth-child(-n+11),
.table-openlab thead tr:nth-child(2) th,
.table-openlab tbody td:nth-child(n+4):nth-child(-n+11) {
    width: 50px;
    min-width: 50px;
    max-width: 50px;
    padding: 0.12rem var(--spacing-xs);
    text-align: center;
}

/* Open Hours 하위 헤더 폰트 사이즈 조정 */
.table-openlab thead tr:nth-child(2) th {
    font-size: 0.6rem;
}

/* Open Lab 테이블 세로 테두리 및 패딩 조정 */
.table-openlab th,
.table-openlab td {
    border-right: 1px solid var(--border-color);
    padding: 0.12rem var(--spacing-sm);
}

.table-openlab th:last-child,
.table-openlab td:last-child {
    border-right: none;
}

/* 오픈랩 전공 분야 색상 (Professor 셀 좌측 보더) */
.table-openlab tbody tr.openlab-field td:first-child { border-left: 3px solid transparent; }
.table-openlab tbody tr.openlab-field-dynamics td:first-child { border-left-color: #2563eb; }
.table-openlab tbody tr.openlab-field-fluid td:first-child { border-left-color: #0d9488; }
.table-openlab tbody tr.openlab-field-thermal td:first-child { border-left-color: #dc2626; }
.table-openlab tbody tr.openlab-field-mechanics td:first-child { border-left-color: #ca8a04; }
.table-openlab tbody tr.openlab-field-nanobio td:first-child { border-left-color: #9333ea; }
.table-openlab tbody tr.openlab-field-design td:first-child { border-left-color: #059669; }

/* 오픈랩 전공 그룹 헤더 행 */
.table-openlab tbody tr.openlab-group-header td {
    font-weight: 700;
    padding: 0.4rem var(--spacing-sm);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-light);
}
.table-openlab tbody tr.openlab-group-dynamics td { background: rgba(37, 99, 235, 0.12); border-left: 3px solid #2563eb; }
.table-openlab tbody tr.openlab-group-fluid td { background: rgba(13, 148, 136, 0.12); border-left: 3px solid #0d9488; }
.table-openlab tbody tr.openlab-group-thermal td { background: rgba(220, 38, 38, 0.12); border-left: 3px solid #dc2626; }
.table-openlab tbody tr.openlab-group-mechanics td { background: rgba(202, 138, 4, 0.12); border-left: 3px solid #ca8a04; }
.table-openlab tbody tr.openlab-group-nanobio td { background: rgba(147, 51, 234, 0.12); border-left: 3px solid #9333ea; }
.table-openlab tbody tr.openlab-group-design td { background: rgba(5, 150, 105, 0.12); border-left: 3px solid #059669; }
.table-openlab tbody tr.openlab-group-other td { background: rgba(0, 0, 0, 0.04); border-left: 3px solid #64748b; }

/* 오픈랩 전공 범례 */
.openlab-legend { display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem 1rem; margin-bottom: 1rem; font-size: 0.875rem; }
.openlab-legend-title { font-weight: 600; margin-right: 0.25rem; }
.openlab-legend-swatch { display: inline-block; width: 12px; height: 12px; border-radius: 2px; margin-right: 0.25rem; vertical-align: middle; }

/* 포스터 링크 스타일 */
.poster-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
    padding: 4px;
    border-radius: var(--border-radius);
}

.poster-link:hover {
    color: var(--secondary-color);
    background-color: var(--bg-light);
}

.poster-link svg {
    display: block;
}

/* 홈페이지 링크 스타일 */
.homepage-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
    padding: 2px 4px;
    margin-left: 6px;
    border-radius: var(--border-radius);
    vertical-align: middle;
}

.homepage-link:hover {
    color: var(--secondary-color);
    background-color: var(--bg-light);
}

.homepage-link svg {
    display: block;
}

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

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

/* Page Content */
.page-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 3px solid var(--primary-color);
}

.page-title {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.page-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
}

.content-section {
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: 1.75rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-xs);
    border-bottom: 2px solid var(--border-color);
    display: block;
    width: 100%;
}

/* Speaker Card */
#speakers-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.speaker-card {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.speaker-photo {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 700;
    overflow: hidden;
    flex-shrink: 0;
}

.speaker-photo-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
    flex-shrink: 0;
}

.speaker-info h3 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
    line-height: 1.3;
}

.speaker-name-en {
    display: block;
    font-size: 0.75em;
    font-weight: 400;
    color: var(--text-light);
    margin-top: 0.2em;
}

.speaker-affiliation {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-sm);
}

.speaker-bio {
    margin-bottom: var(--spacing-sm);
}

/* Speaker bio detail (details/summary) */
.speaker-bio-detail {
    margin-top: 0.25rem;
    font-size: 0.8rem;
    color: var(--text-light);
}

.speaker-bio-summary {
    cursor: pointer;
    color: var(--primary-color);
    font-weight: 500;
    outline: none;
}

.speaker-bio-summary::-webkit-details-marker {
    display: none;
}


.talk-title {
    font-weight: 600;
    color: var(--primary-color);
    margin-top: var(--spacing-sm);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
}

/* Schedule */
.schedule-tabs {
    margin-bottom: var(--spacing-lg);
}

.schedule-tab-list {
    display: flex;
    gap: var(--spacing-sm);
    border-bottom: 2px solid var(--border-color);
    margin-bottom: var(--spacing-md);
}

.schedule-tab {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: transparent;
    border: none;
    border-bottom: 3px solid transparent;
    color: var(--text-color);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: -2px;
}

.schedule-tab:hover {
    color: var(--primary-color);
}

.schedule-tab.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    font-weight: 600;
}

.schedule-day {
    margin-bottom: var(--spacing-xl);
    display: none;
}

.schedule-day.active {
    display: block;
}

.day-header {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-md);
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    font-size: 1.25rem;
    font-weight: 600;
}

.session-card {
    border: 1px solid var(--border-color);
    border-top: none;
    padding: var(--spacing-md);
    background: white;
}

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

.session-time {
    font-weight: 600;
    color: var(--primary-color);
}

.session-title {
    font-weight: 600;
    font-size: 1.1rem;
}

.session-room {
    color: var(--text-light);
    font-size: 0.9rem;
}

.schedule-image-container {
    width: 100%;
    text-align: center;
    margin: var(--spacing-lg) 0;
}

.schedule-image {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.schedule-table-wrapper {
    overflow: visible;
}

.schedule-table {
    width: 100%;
    border: 1px solid var(--border-color);
    border-top: none;
    background: white;
    min-width: 720px;
}

.schedule-table-header,
.schedule-row {
    display: grid;
    /* 기본 2컬럼(Time + 1세션) 레이아웃 */
    grid-template-columns: 110px 1fr;
    font-size: 0.9rem;
    text-align: center;
}

.schedule-row {
    align-items: stretch;
    min-height: 60px;
    height: 60px;
}

.schedule-table-header {
    background: var(--bg-light);
    font-weight: 600;
}

.schedule-col {
    padding: 0.5rem;
    border-top: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
}

.schedule-col:last-child {
    border-right: none;
}

.schedule-row:nth-child(even) {
    background: #fafafa;
}

.schedule-col-session {
    vertical-align: top;
}

.session-title {
    font-weight: 600;
    margin-bottom: 2px;
    line-height: 1.2;
    font-size: 0.85rem;
}

.session-meta {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-top: 1px;
    line-height: 1.2;
}

/* Shared (common) events spanning both sessions */
.schedule-row-shared {
    grid-template-columns: 110px 1fr;
    align-items: stretch;
}

.schedule-col-shared {
    grid-column: 2 / -1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 0.4rem 0.5rem;
}

.shared-title {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 1px;
    line-height: 1.2;
}

.shared-meta {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-top: 1px;
    line-height: 1.2;
}

.shared-location {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-top: 1px;
    line-height: 1.2;
}

@media (max-width: 900px) {
    .schedule-table {
        min-width: 600px;
    }
}

/* Footer */
.site-footer {
    background: var(--bg-light);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-section h3 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
    font-size: 1.1rem;
}

.footer-section p {
    margin-bottom: var(--spacing-xs);
    color: var(--text-light);
}

.footer-section a {
    color: var(--primary-color);
    text-decoration: none;
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }

    .nav-menu {
        display: none;
        flex-direction: column;
        width: 100%;
        position: absolute;
        top: 100%;
        left: 0;
        background: white;
        box-shadow: var(--shadow-md);
        padding: var(--spacing-sm) 0;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-item {
        width: 100%;
    }

    .nav-link {
        padding: var(--spacing-xs) var(--spacing-md);
        font-size: 0.9rem;
    }

    .main-nav {
        padding: var(--spacing-xs) 0;
    }

    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background: var(--bg-light);
        margin-left: var(--spacing-md);
        display: none;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.2s ease-out;
    }

    .has-dropdown.active .dropdown-menu {
        display: block;
        max-height: 500px;
        overflow: visible;
        opacity: 1;
        visibility: visible;
    }

    .header-top {
        padding: var(--spacing-xs) 0;
    }

    .header-content {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
    }

    .conference-title {
        font-size: 1.1rem;
        line-height: 1.3;
    }

    .header-actions {
        width: 100%;
        flex-direction: row;
        gap: var(--spacing-xs);
        margin-top: var(--spacing-xs);
    }

    .header-actions .btn {
        width: auto;
        flex: 1;
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.85rem;
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .hero-main-title {
        font-size: 1.75rem;
        white-space: normal;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .hero-info-item {
        font-size: 1rem;
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .hero-info-label {
        min-width: auto;
    }

    .hero-illustration {
        height: auto;
        max-height: 250px;
        margin-top: var(--spacing-md);
    }

    .hero-poster-image {
        max-height: 250px;
    }

    .poster-modal-content {
        max-width: 95%;
        max-height: 85%;
    }

    .poster-modal-close {
        top: -35px;
        width: 35px;
        height: 35px;
        font-size: 1.5rem;
    }

    .poster-modal-image {
        max-height: 85vh;
    }

    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

    .table {
        font-size: 0.9rem;
    }

    .table th,
    .table td {
        padding: var(--spacing-xs);
    }

    .speaker-card {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* Accessibility */
*:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

button:focus,
a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

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

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

/* Padding utilities */
.pl-0 { padding-left: 0; }
.pl-1 { padding-left: 0.5rem; }
.pl-2 { padding-left: 1rem; }
.pl-3 { padding-left: 1.5rem; }
.pl-4 { padding-left: 2rem; }
.pr-0 { padding-right: 0; }
.pr-1 { padding-right: 0.5rem; }
.pr-2 { padding-right: 1rem; }
.pt-1 { padding-top: 0.5rem; }
.pt-2 { padding-top: 1rem; }
.pt-3 { padding-top: 1.5rem; }
.pt-4 { padding-top: 2rem; }
.pb-1 { padding-bottom: 0.5rem; }
.pb-2 { padding-bottom: 1rem; }
.pb-3 { padding-bottom: 1.5rem; }
.p-0 { padding: 0; }
.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

/* Display utilities */
.overflow-x-auto { overflow-x: auto; }
.list-style-none { list-style: none; padding: 0; }
.d-flex { display: flex; }
.flex-column { flex-direction: column; }
.align-items-center { align-items: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.width-100 { width: 100%; }
.max-width-800 { max-width: 800px; margin: 0 auto; }
.max-width-900 { max-width: 900px; margin: 0 auto; }

/* Color utilities */
.text-light { color: var(--text-light); }
.text-primary { color: var(--primary-color); }
.text-warning { color: var(--warning-color); }
.bg-light { background: var(--bg-light); }

/* Font utilities */
.font-weight-600 { font-weight: 600; }
.font-size-small { font-size: 0.9rem; }
.font-size-large { font-size: 1.1rem; }
.font-size-xl { font-size: 1.2rem; }
.font-size-2xl { font-size: 2rem; }
.font-size-4xl { font-size: 4rem; }
.font-style-italic { font-style: italic; }

/* Border utilities */
.border-radius { border-radius: var(--border-radius); }
.border-top { border-top: 1px solid var(--border-color); }

/* Position utilities */
.position-relative { position: relative; }
.float-left { float: left; }
.clear-both { clear: both; }

/* Image utilities */
.img-float-left { float: left; margin-right: 2rem; margin-bottom: 1rem; }
.img-cover { object-fit: cover; }

/* Spacing utilities */
.margin-0 { margin: 0; }
.margin-auto { margin: 0 auto; }
.my-4 { margin-top: 2rem; margin-bottom: 2rem; }

/* Section title with accent bar */
.section-title-accent {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.section-title-accent::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 1.5rem;
    background: var(--primary-color);
}

/* Button large */
.btn-large {
    font-size: 1.1rem;
    padding: 1rem 2rem;
}

/* Hero text light */
.hero-text-light {
    color: rgba(255,255,255,0.9);
}

/* Image greeting */
.img-greeting {
    width: 200px;
    height: auto;
}
/* Card spacing */
.greeting-card { padding: 28px; }

/* Title */
.section-title { margin: 0 0 18px; font-weight: 700; }
.section-title .subtle { opacity: .6; font-weight: 600; }

/* Layout: 2-column */
.greeting-layout{
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 28px;
  align-items: start;
}

/* Profile */
.greeting-profile{
  position: sticky;
  top: 18px;
  align-self: start;
}

.greeting-photo{
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: 14px;
  border: 1px solid rgba(0,0,0,.08);
}

.greeting-meta{
  margin-top: 12px;
  padding: 12px 14px;
  border-radius: 12px;
  background: rgba(0,0,0,.03);
}

.greeting-name{ font-weight: 800; }
.greeting-role, .greeting-org{ opacity: .75; margin-top: 4px; font-size: 0.95rem; line-height: 1.25; }

/* Content */
.greeting-title{ margin: 0 0 10px; font-size: 2rem; font-weight: 800; }
.greeting-lead{
  margin: 0 0 16px;
  font-size: 1.05rem;
  line-height: 1.6;
  opacity: .9;
}

/* Box to visually separate long paragraphs */
.greeting-box{
  padding: 14px 16px;
  border-radius: 14px;
  border: 1px solid rgba(0,0,0,.08);
  background: rgba(0,0,0,.02);
}

.greeting-box p{ margin: 10px 0; line-height: 1.75; }

/* Topics */
.greeting-subtitle{ margin: 18px 0 10px; font-weight: 800; }

.topic-chips{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 14px;
}
.topic-sub {
    display: block;
    margin-top: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    opacity: 0.75;
  }

.chip{
  display: inline-flex;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid rgba(0,0,0,.12);
  background: rgba(0,0,0,.02);
  font-weight: 650;
  font-size: 0.95rem;
  line-height: 1.2;
}

/* Closing */
.greeting-closing{ line-height: 1.75; margin: 12px 0 8px; }
.greeting-signoff{ margin: 0; }

/* Responsive */
@media (max-width: 900px){
  .greeting-layout{ grid-template-columns: 1fr; }
  .greeting-profile{ position: static; display: grid; grid-template-columns: 120px 1fr; gap: 14px; }
  .greeting-photo{ width: 120px; aspect-ratio: 1 / 1; border-radius: 16px; }
}
/* Iframe styles */
iframe {
    border: 1px solid var(--border-color);
}

.google-form-iframe {
    display: block;
    overflow: hidden;
}

/* Google Form iframe container - prevent double scroll */
.google-form-iframe-container {
    position: relative;
    overflow: hidden;
}

/* Organizer logos */
.organizer-logos {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    align-items: center;
    justify-content: center;
    margin-top: var(--spacing-md);
}

.organizer-logo-wrapper {
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm);
    box-sizing: border-box;
}

.organizer-logo-link {
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    height: 100%;
    width: 100%;
}

.organizer-logo {
    max-height: calc(120px - 2 * var(--spacing-sm));
    width: auto;
    height: auto;
    object-fit: contain;
    filter: grayscale(0%);
    transition: var(--transition);
}

.organizer-logo:hover {
    opacity: 0.8;
    transform: scale(1.05);
}
.section-title {
    display: flex;
    align-items: baseline;
    gap: 8px;
  }
.section-title .subtle { opacity: .6; font-weight: 600; }

/* Grid: responsive */
.logo-grid{
display: grid;
grid-template-columns: repeat(3, minmax(0, 1fr));
gap: 18px;
margin-top: 14px;
}

/* Tile: uniform logo boxes */
.logo-tile{
display: flex;
align-items: center;
justify-content: center;
min-height: 130px;
padding: 18px;
border-radius: 14px;
background: #fff;
border: 1px solid rgba(0,0,0,.08);
box-shadow: 0 6px 16px rgba(0,0,0,.06);
transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
text-decoration: none;
}

.logo-tile:hover{
transform: translateY(-2px);
box-shadow: 0 10px 22px rgba(0,0,0,.10);
border-color: rgba(0,0,0,.14);
}

/* Make all logos visually consistent */
.logo-img{
max-width: 100%;
max-height: 70px;     /* 핵심: 높이 통일 */
object-fit: contain;  /* 비율 유지 */
}

/* Tier blocks */
.tier-block{
margin-top: 20px;
padding-top: 10px;
border-top: 1px solid rgba(0,0,0,.08);
}

.tier-header{
display: flex;
align-items: center;
justify-content: space-between;
margin: 8px 0 6px;
}

.tier-title {
margin: 0;
font-weight: 800;
letter-spacing: -0.01em;
}
  
/* tier container */
.iap-tier{
  padding: 14px 0 18px;
  border-top: 1px solid rgba(0,0,0,.08);
}

.tier-head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  margin: 6px 0 12px;
}

.tier-badge {
    font-size: 0.85rem;
    padding: 5px 12px;
    border-radius: 999px;
    background: transparent;
    font-weight: 600;
}
  

/* logo tiles baseline */
.logo-tile{
  border: 1px solid rgba(0,0,0,.10);
  border-radius: 14px;
  background: #fff;
  box-shadow: 0 6px 14px rgba(0,0,0,.06);
  transition: transform .15s ease, box-shadow .15s ease;
}

/* Diamond: slightly larger + stronger emphasis */
.tier-diamond .logo-tile{
  min-height: 140px;
  border: 1px solid rgba(0,0,0,.16);
  box-shadow: 0 10px 22px rgba(0,0,0,.10);
}

/* Gold: default (can keep as-is) */
.tier-gold .logo-tile{
  min-height: 130px;
}

/* Silver: lighter */
.tier-silver .logo-tile{
  min-height: 120px;
  border: 1px solid rgba(0,0,0,.08);
  box-shadow: 0 4px 10px rgba(0,0,0,.05);
}
/* Diamond */
.tier-diamond .tier-title {
    color: #1a1f2b; /* deep navy / charcoal */
  }
  .tier-diamond .tier-badge {
    color: #1a1f2b;
    border: 1px solid rgba(26, 31, 43, 0.35);
  }
  
  /* Gold */
  .tier-gold .tier-title {
    color: #4b5563; /* neutral gray */
  }
  .tier-gold .tier-badge {
    color: #4b5563;
    border: 1px solid rgba(75, 85, 99, 0.35);
  }
  
  /* Silver */
  .tier-silver .tier-title {
    color: #9ca3af; /* light gray */
  }
  .tier-silver .tier-badge {
    color: #9ca3af;
    border: 1px solid rgba(156, 163, 175, 0.45);
  }
/* Optional: header strip effect without “color” */
.tier-diamond{ border-top-width: 2px; }
.tier-gold{ border-top-width: 1.5px; }
.tier-silver{ border-top-width: 1px; }

/* Responsive: tablet */
@media (max-width: 900px){
.logo-grid{ grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* Responsive: mobile */
@media (max-width: 520px){
.logo-grid{ grid-template-columns: 1fr; }
.logo-tile{ min-height: 110px; }
.logo-img{ max-height: 60px; }
}
/* 임시로 abstract 버튼 숨김 */
.hide-abstract {
    display: none !important;
}

/* Committee Member Cards */
.committee-grid {
    display: grid;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.committee-grid-single {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    max-width: 300px;
}

.committee-grid-double {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    max-width: 600px;
}

.committee-grid-triple {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    max-width: 900px;
}

.committee-grid-multiple {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

@media (max-width: 1200px) {
    .committee-grid-multiple {
        grid-template-columns: repeat(2, 1fr);
    }
}

.committee-member-card {
    display: flex;
    flex-direction: row;
    align-items: center;
    text-align: left;
    padding: var(--spacing-md);
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
    gap: var(--spacing-md);
}

.committee-member-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    transform: translateY(-2px);
}

.committee-member-photo {
    width: 120px;
    height: 150px;
    min-width: 120px;
    border-radius: 8px;
    background: white;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: 700;
    overflow: hidden;
    flex-shrink: 0;
}

.committee-member-photo img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: center;
}

.committee-member-initial {
    display: block;
}

.committee-member-info {
    display: flex;
    flex-direction: column;
    justify-content: center;
    flex: 1;
}

.committee-member-name {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: var(--spacing-xs);
    line-height: 1.4;
}

.committee-member-affiliation {
    font-size: 0.95rem;
    color: var(--text-light);
    line-height: 1.4;
}

@media (max-width: 768px) {
    .committee-grid-single,
    .committee-grid-double,
    .committee-grid-triple {
        max-width: 100%;
    }
    
    .committee-grid-multiple {
        grid-template-columns: 1fr;
    }
    
    .committee-member-photo {
        width: 100px;
        height: 125px;
        font-size: 2rem;
    }
}