/* ============================================
   Biohybrid Robotics Symposium - main.css
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;1,400;1,500&display=swap');

/* Scroll reveal: add class .scroll-reveal to any element you want to animate in on scroll */
.scroll-reveal {
    opacity: 0;
    transform: translateY(14px);
    transition: opacity 0.45s ease-out, transform 0.45s ease-out;
}
.scroll-reveal.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== CSS Variables for Theming ===== */
:root {
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    --ease: cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --transition: 0.6s var(--ease);
    color-scheme: dark;
    /* Dark theme: match landing page background everywhere (same as 2025) */
    --page-bg: #131312;
    --text-color: #bbbbbb;
    --text-muted: #777777;
    --header-bg: #131312;
    --header-logos-bg: #131312;
    --nav-bg: #131312;
    --nav-hover-bg: #2c2c2c;
    --section-alt-bg: #131312;
    --surface: #2c2c2c;
    --surface-alt: #333333;
    --border-color: #4f4f4f;
    --shadow-color: rgba(0, 0, 0, 0.6);
    
    /* Reddish-orange accent */
    --accent: #e54b3e;
    --accent-2: #ea6a5f;
    --accent-3: #c23d32;
    --on-accent: #ffffff;
    --hero-bg: #131312;
    --hero-gradient: linear-gradient(135deg, #131312 0%, #131312 100%);
    --video-bg: #131312;
    
    /* Subtle highlights */
    --highlight-bg: #2a2220;
    --highlight-border: #e54b3e;
    --highlight-text: #e8a49d;
    --info-bg: #252a2e;
    --info-border: #4f4f4f;
    --info-text: #bbbbbb;
    --notice-bg: #2a2220;
    --notice-border: #e54b3e;
    --notice-text: #e8a49d;
    --table-hover: #333333;
    
    /* Footer */
    --footer-bg: #131312;
    --footer-text: #bbbbbb;
    --footer-link: #777777;
    --footer-link-hover: #e54b3e;
    --footer-divider: #4f4f4f;
    
    /* Theme toggle */
    --toggle-bg: #2c2c2c;
    --toggle-border: #4f4f4f;
    --toggle-text: #bbbbbb;
}

[data-theme="light"] {
    color-scheme: light;
    /* Light theme: everything light except red accent */
    --page-bg: #f5f5f5;
    --text-color: #1a1a1a;
    --text-muted: #555555;
    --header-bg: #ffffff;
    --header-logos-bg: #ffffff;
    --nav-bg: #ffffff;
    --nav-hover-bg: #eeeeee;
    --section-alt-bg: #fafafa;
    --surface: #ffffff;
    --surface-alt: #f0f0f0;
    --border-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.08);
    --accent: #e54b3e;
    --accent-2: #ea6a5f;
    --accent-3: #c23d32;
    --on-accent: #ffffff;
    --hero-bg: linear-gradient(135deg, #e8e8e8 0%, #f0f0f0 100%);
    --hero-gradient: linear-gradient(135deg, #e8e8e8 0%, #f0f0f0 100%);
    --video-bg: #e8e8e8;
    --highlight-bg: #fff2f0;
    --highlight-border: #e54b3e;
    --highlight-text: #c23d32;
    --info-bg: #f5f7f9;
    --info-border: #cbd5e0;
    --info-text: #2d3748;
    --notice-bg: #fff2f0;
    --notice-border: #e54b3e;
    --notice-text: #c23d32;
    --table-hover: #fafafa;
    --footer-bg: #ebebeb;
    --footer-text: #2a2a2a;
    --footer-link: #555555;
    --footer-link-hover: #e54b3e;
    --footer-divider: #dddddd;
    --toggle-bg: #ffffff;
    --toggle-border: #dddddd;
    --toggle-text: #2a2a2a;
}

/* Light mode: hero uses same text color (var(--text-color)); only link underline differs */
[data-theme="light"] .hero .hero-info a {
    border-bottom-color: rgba(0, 0, 0, 0.2);
}

[data-theme="light"] .hero .hero-info a:hover {
    border-bottom-color: rgba(0, 0, 0, 0.35);
}

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

body {
    font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-weight: 500;
    line-height: 1.65;
    color: var(--text-color);
    background: var(--page-bg);
    transition: background var(--transition), color var(--transition);
    -webkit-font-smoothing: antialiased;
}

/* Subtle background texture (optional minimal grid) */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image:
        linear-gradient(var(--border-color) 1px, transparent 1px),
        linear-gradient(90deg, var(--border-color) 1px, transparent 1px);
    background-size: 60px 60px;
    opacity: 0.03;
    pointer-events: none;
    z-index: 0;
    transition: opacity var(--transition);
}

/* ===== Archive disclaimer banner – fixed overlay at top when viewing archive ===== */
.archive-banner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 9999;
    background: var(--surface);
    color: var(--text-color);
    border-bottom: 2px solid var(--accent);
    text-align: center;
    padding: 12px 16px;
    font-size: 0.9rem;
    font-weight: 600;
    width: 100%;
    box-sizing: border-box;
    display: block !important;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
}
[data-theme="light"] .archive-banner {
    background: #e8e8e8;
    color: #333;
    border-bottom-color: var(--accent);
}
body:has(.archive-banner) {
    padding-top: 48px;
}

/* ===== Header & Navigation ===== */
.header {
    background: var(--header-bg);
    border-bottom: 1px solid var(--border-color);
    position: relative;
    z-index: 100;
    transition: background-color var(--transition), border-color var(--transition);
}

/* Nav overlay: drops down from top when peek is clicked (menu in place, no scroll) */
.nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1002;
    background: var(--header-bg);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 8px 24px var(--shadow-color);
    transform: translateY(-100%);
    visibility: hidden;
    transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
    max-height: 85vh;
    overflow-y: auto;
}
.nav-overlay.is-open {
    transform: translateY(0);
    visibility: visible;
    transition: transform 0.25s var(--ease), visibility 0s, background var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.nav-overlay.is-open.is-closing {
    transform: translateY(-100%);
    transition: transform 0.65s var(--ease), background var(--transition), border-color var(--transition), box-shadow var(--transition);
}
body:has(.archive-banner) .nav-overlay {
    top: 48px;
}
.nav-overlay .header-placeholder-spacer {
    display: none;
}

/* Peek button: fixed at top when header has scrolled away; click opens menu overlay */
.nav-peek {
    position: fixed;
    top: 0;
    left: 50%;
    transform: translateX(-50%) translateY(-100%);
    z-index: 1001;
    width: 48px;
    height: 28px;
    padding: 0;
    border: none;
    border-bottom-left-radius: 8px;
    border-bottom-right-radius: 8px;
    background: var(--header-bg);
    border-bottom: 1px solid var(--border-color);
    border-left: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
    color: var(--text-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    box-shadow: 0 4px 12px var(--shadow-color);
    transition: background var(--transition), border-color var(--transition), color var(--transition), box-shadow var(--transition);
}
.nav-peek.is-visible {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transition: transform 0.25s var(--ease), opacity 0.25s var(--ease), visibility 0s, background var(--transition), border-color var(--transition), color var(--transition), box-shadow var(--transition);
}
.nav-peek.is-visible.is-hiding {
    transform: translateX(-50%) translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.65s var(--ease), opacity 0.65s var(--ease), background var(--transition), border-color var(--transition), color var(--transition), box-shadow var(--transition);
}
.nav-peek:hover {
    background: var(--nav-hover-bg);
}
.nav-peek:focus {
    outline: none;
}
.nav-peek:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}
body:has(.archive-banner) .nav-peek {
    top: 48px;
}
.nav-peek[aria-expanded="true"] svg {
    transform: rotate(180deg);
}
.nav-peek svg {
    transition: transform 0.4s var(--ease);
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent);
    opacity: 0.6;
}

.header-logos {
    display: none;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.nav-logo-group {
    display: flex;
    align-items: center;
    gap: 24px;
    flex-shrink: 0;
    order: 1;
}

.nav-logo-group img {
    height: 32px;
    object-fit: contain;
    opacity: 0.9;
}

/* Dark mode: ETH logo white instead of black, alpha unchanged */
[data-theme="dark"] img[src*="eth_logo"] {
    filter: brightness(0) invert(1);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
    order: 3;
}

.nav-year {
    display: flex;
    align-items: center;
    gap: 6px;
}
.nav-year-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    white-space: nowrap;
    transition: color var(--transition);
}
.year-select {
    font-size: 0.8rem;
    padding: 4px 8px;
    background: var(--nav-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-color);
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition), color var(--transition);
}
.year-select:hover,
.year-select:focus {
    border-color: var(--text-muted);
    outline: none;
}

.nav-burger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 10px;
    border: 1px solid var(--toggle-border);
    background: var(--toggle-bg);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition);
}

.nav-burger span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--toggle-text);
    border-radius: 1px;
    transition: transform var(--transition), opacity var(--transition);
}

.nav-burger:hover {
    background: var(--nav-hover-bg);
}

.nav-links {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 4px;
    flex: 1;
    justify-content: center;
    order: 2;
}

nav a.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    padding: 10px 16px;
    font-size: 0.95rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    border-radius: var(--radius-sm);
    position: relative;
    transition: color var(--transition), background var(--transition);
}

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

nav a.nav-link.active {
    color: var(--accent);
}

nav a.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 16px;
    right: 16px;
    height: 2px;
    background: var(--accent);
    border-radius: var(--radius-full);
}

.theme-toggle {
    margin-left: 0;
    padding: 8px;
    border: 1px solid var(--toggle-border);
    background: var(--toggle-bg);
    color: var(--toggle-text);
    border-radius: var(--radius-full);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.theme-toggle .theme-toggle-icon {
    display: inline-flex;
    line-height: 0;
}

.theme-toggle .theme-toggle-icon svg {
    display: block;
    vertical-align: middle;
}

.theme-toggle:hover {
    background: var(--nav-hover-bg);
    border-color: var(--text-muted);
}

/* ===== Hero Section ===== */
.hero {
    background: var(--hero-bg, var(--hero-gradient));
    color: var(--text-color);
    padding: 60px 24px 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
    transition: background var(--transition), color var(--transition);
}

/* Landing page: hero and linktree use same background so they match */
body.page-index .hero {
    background: var(--video-bg) !important;
}

body.page-index {
    position: relative;
}

/* Wavy curves on left/right (landing). Scroll with page; above content but below header/footer. */
.cursor-bars {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 5;
    min-height: 100vh;
}
.cursor-curve {
    position: absolute;
    top: 0;
    left: 0;
    right: auto;
    bottom: 0;
    width: 80px;
    height: 100%;
    display: block;
    pointer-events: none;
    color: #2a2a2a;
    opacity: 0.9;
}
.cursor-curve-path {
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-width: 3;
}
.cursor-curve--left { left: 0; }
.cursor-curve--right { left: auto; right: 0; }
[data-theme="light"] .cursor-curve {
    color: #555;
    opacity: 0.7;
}
@media (min-width: 1024px) {
    [data-theme="light"] .cursor-curve-path {
        stroke-width: 2;
    }
}

@media (max-width: 1023px) {
    .cursor-curve {
        width: 16px;
    }
    .cursor-curve-path {
        stroke-width: 5;
    }
}

body:has(.cursor-bars) {
    position: relative;
}
/* Sticky footer on subpages: footer at bottom of viewport when content is short */
body:has(.cursor-bars):not(.page-index) {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}
body:has(.cursor-bars):not(.page-index) footer {
    margin-top: auto;
}
body:has(.cursor-bars) footer {
    position: relative;
    z-index: 100;
}

/* Decorative brush stroke (top-left, desktop reference) */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 180px;
    height: 3px;
    background: linear-gradient(90deg, rgba(255, 255, 255, 0.12) 0%, rgba(255, 255, 255, 0.04) 70%, transparent 100%);
    border-radius: 0 0 3px 0;
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 48px;
    height: 3px;
    background: var(--accent);
    border-radius: var(--radius-full);
}

.hero-inner {
    max-width: 1400px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero .hero-label {
    font-size: 0.75rem;
    font-weight: 300;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--text-color);
    margin-bottom: 12px;
}

.hero h1 {
    font-size: clamp(2.5rem, 6.5vw, 4rem);
    font-weight: 300;
    letter-spacing: 0.12em;
    margin-bottom: 28px;
    line-height: 1.15;
    color: var(--text-color);
}

.hero-info {
    font-size: 0.9rem;
    font-weight: 300;
    color: var(--text-color);
    margin-bottom: 6px;
    letter-spacing: 0.06em;
}

.hero-info a {
    color: var(--text-color);
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    transition: border-color var(--transition), color var(--transition), opacity var(--transition);
}

.hero-info a:hover {
    color: var(--text-color);
    opacity: 0.85;
    border-bottom-color: rgba(255, 255, 255, 0.4);
}

/* Collapsible event details */
.hero-details {
    margin-top: 20px;
}

.hero-details-summary {
    font-size: 0.85rem;
    font-weight: 300;
    letter-spacing: 0.08em;
    color: var(--text-color);
    cursor: pointer;
    list-style: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 0;
    transition: opacity var(--transition);
}

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

.hero-details-summary::before {
    content: '';
    display: inline-block;
    width: 0;
    height: 0;
    border-left: 5px solid currentColor;
    border-top: 4px solid transparent;
    border-bottom: 4px solid transparent;
    margin-right: 4px;
    opacity: 0.7;
    transition: transform var(--transition);
}

.hero-details[open] .hero-details-summary::before {
    transform: rotate(90deg);
}

.hero-details-summary:hover {
    opacity: 0.85;
}

.hero-details-content {
    margin-top: 12px;
    padding-left: 0;
}

.hero-details-content .hero-info {
    margin-top: 0;
}

/* Index page desktop: hero + overview + footer stack and scroll (no 100vh lock). */
@media (min-width: 1024px) {
    body.page-index {
        min-height: 100vh;
        display: flex;
        flex-direction: column;
        box-sizing: border-box;
    }
    .page-index .header {
        flex-shrink: 0;
        position: relative;
        width: 100%;
        box-sizing: border-box;
    }
    .page-index .header #header-placeholder {
        width: 100%;
    }
    /* Nav uses same styles as subpages – no .page-index overrides */
    .page-index .hero {
        flex-shrink: 0;
        min-height: 0;
        overflow: hidden;
        padding: 4vh 2rem 4vh;
        text-align: left;
        box-sizing: border-box;
        display: flex;
        flex-direction: column;
    }
    .page-index .hero-inner {
        display: grid;
        grid-template-columns: 1fr 1fr;
        grid-template-rows: 1fr;
        gap: 3rem;
        align-items: stretch;
        max-width: 50vw;
        margin: 0 auto;
        height: 100%;
        min-height: 0;
        box-sizing: border-box;
    }
    .page-index .hero-content {
        min-height: 0;
        display: flex;
        flex-direction: column;
        justify-content: center;
    }
    .page-index .hero-media {
        min-height: 0;
        height: 100%;
        display: flex;
        align-items: center;
        justify-content: center;
    }
    .page-index .hero-media .video-container--hero {
        width: auto;
        height: 70vh;
        display: flex;
        align-items: center;
        justify-content: center;
    }
    .page-index .hero-content { text-align: left; }
    .page-index .hero-details .hero-details-content {
        margin-top: 1.2vh;
    }
    .page-index .hero .hero-label {
        font-size: 1.1vh;
        margin-bottom: 1.2vh;
    }
    .page-index .hero h1 {
        font-size: 3.5vh;
        margin-bottom: 1.2vh;
    }
    .page-index .hero-info {
        font-size: 1.35vh;
        margin-bottom: 0.5vh;
    }
    .page-index .hero-media .video-container--hero video {
        display: block;
        height: 70vh;
        width: auto;
        object-fit: contain;
    }
    .page-index footer {
        flex-shrink: 0;
        width: 100%;
        padding: 1.5rem 2rem 1.25rem;
        box-sizing: border-box;
    }
    .page-index .footer-content {
        gap: 2vh;
    }
    .page-index .footer-section h4 {
        margin-bottom: 0.8vh;
        font-size: 1vh;
    }
    .page-index .footer-section a {
        margin: 0.5vh 0;
        font-size: 1.25vh;
    }
    .page-index .footer-divider {
        margin-top: 1.5vh;
        padding-top: 1.2vh;
    }
    .page-index .footer-divider p {
        font-size: 1.2vh;
    }
}

/* Smaller desktop only: same vh-based fonts, just tighter horizontal layout. */
@media (min-width: 1024px) and (max-width: 1439px) {
    .page-index .hero {
        padding: 2vh 1.25rem 2vh;
    }
    .page-index .hero-inner {
        gap: 1.5vh;
        max-width: 50vw;
    }
    .page-index footer {
        padding: 1vh 1.25rem;
    }
    .page-index .footer-content {
        gap: 1.2vh;
    }
}

/* Hero: transparent container and video so transparent WebM blends with #131312 */
.hero-media .video-container--hero {
    background: transparent;
}

.hero-media .video-container--hero video {
    background: transparent;
}

@media (max-width: 1023px) {
    .hero-media {
        margin-top: 32px;
    }
    .hero-media .video-container--hero {
        max-width: 90%;
        margin-left: auto;
        margin-right: auto;
    }
    .page-index .hero {
        padding-bottom: 28px;
    }
    section.landing-overview {
        padding-top: 24px;
        padding-left: 16px;
        padding-right: 16px;
        padding-bottom: 56px;
    }
}

/* ===== Landing overview: horizontal link strips ===== */
section.landing-overview {
    padding: 80px 24px 100px;
    background: var(--video-bg) !important;
    position: relative;
    z-index: 1;
}

.landing-overview-inner {
    max-width: 640px;
    margin: 0 auto;
}

.landing-overview-title {
    text-align: center;
    margin-bottom: 56px;
    font-size: 1.75rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    color: var(--text-color);
}

.overview-links {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.overview-link {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 28px;
    padding: 18px 22px;
    background: #1e1e1e;
    border: 1px solid var(--border-color);
    margin-bottom: -1px;
    color: var(--text-color);
    text-decoration: none;
    transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.overview-link:first-child {
    border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.overview-link:last-child {
    margin-bottom: 0;
    border-radius: 0 0 var(--radius-md) var(--radius-md);
}

.overview-link:hover {
    background: #252525;
    border-color: var(--accent);
    z-index: 1;
    position: relative;
}

/* Light mode: overview link strips (lighter grey) */
[data-theme="light"] .overview-link {
    background: #eeeeee;
    border-color: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .overview-link:hover {
    background: #e5e5e5;
    border-color: var(--accent);
}

.overview-link:hover + .overview-link,
.overview-link:has(+ .overview-link:hover) {
    border-top-color: var(--border-color);
}

[data-theme="light"] .overview-link:hover + .overview-link,
[data-theme="light"] .overview-link:has(+ .overview-link:hover) {
    border-top-color: rgba(0, 0, 0, 0.08);
}

.overview-link-icon {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    transition: color var(--transition);
}
.overview-link:hover .overview-link-icon {
    color: var(--accent);
}
.overview-link-icon svg {
    display: block;
}
.overview-link-title {
    flex-shrink: 0;
    width: 140px;
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    color: var(--text-color);
}

.overview-link-desc {
    width: 100%;
    order: 1;
    font-size: 0.95rem;
    font-weight: 400;
    line-height: 1.5;
    color: var(--text-muted);
}

.overview-link-arrow {
    flex-shrink: 0;
    font-size: 1.25rem;
    color: var(--text-muted);
    transition: color var(--transition), transform var(--transition);
}

.overview-link:hover .overview-link-arrow {
    color: var(--accent);
    transform: translateX(4px);
}

/* Desktop: one line (icon, title, desc, arrow) */
@media (min-width: 641px) {
    .overview-link {
        flex-wrap: nowrap;
    }
    .overview-link-desc {
        width: auto;
        flex: 1;
        order: 0;
    }
}

/* Mobile: description BELOW (icon+title+arrow on first line, desc on second) */
@media (max-width: 640px) {
    .landing-overview-inner {
        max-width: 380px;
    }
    .overview-link {
        gap: 12px;
        padding: 18px 20px;
    }
    .overview-link-desc {
        width: 100%;
        order: 1;
        padding-right: 2rem;
    }
    .overview-link-title {
        width: auto;
        white-space: nowrap;
    }
    .overview-link-arrow {
        position: absolute;
        top: 24px;
        right: 20px;
    }
    .overview-link {
        position: relative;
    }
}

/* ===== Container & Sections ===== */
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 32px 24px;
    position: relative;
    z-index: 1;
}

section {
    padding: 80px 24px;
}

section:nth-child(even) {
    background: var(--section-alt-bg);
    transition: background var(--transition);
}

/* ===== Typography & professional labels ===== */
.section-label {
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 12px;
    display: block;
}

h2 {
    font-size: 3rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    margin-bottom: 40px;
    text-align: center;
    color: var(--text-color);
    line-height: 1.25;
}

h2 + .section-label,
.section-label + h2 {
    margin-top: 0;
}

h3 {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin: 48px 0 16px;
    color: var(--text-color);
}

h3:first-of-type {
    margin-top: 0;
}

/* Uniform body text in sections */
section .container,
section .container p,
section .container li,
section .container .info-box,
section .container .highlight-box {
    font-size: 1rem;
}

/* Lead paragraph for professional body text */
.lead {
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.85;
    color: var(--text-color);
    max-width: 68ch;
    margin-left: auto;
    margin-right: auto;
}

/* ===== Content Boxes ===== */
.highlight-box {
    background: var(--highlight-bg);
    border-left: 3px solid var(--highlight-border);
    color: var(--highlight-text);
    padding: 24px 28px;
    margin: 36px 0;
    font-size: 1rem;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-weight: 500;
}

.info-box {
    background: var(--info-bg);
    border: 1px solid var(--info-border);
    color: var(--info-text);
    padding: 24px 28px;
    margin: 24px 0;
    border-radius: var(--radius-md);
}

.info-box strong {
    display: block;
    margin-bottom: 12px;
    font-size: 1rem;
    font-weight: 600;
}

.highlight-box a,
.info-box a {
    color: inherit;
    text-decoration: none;
    border-bottom: 1px solid currentColor;
    opacity: 0.9;
}

.highlight-box a:hover,
.info-box a:hover {
    opacity: 1;
}

.closed-notice {
    background: var(--notice-bg);
    border: 1px solid var(--notice-border);
    color: var(--notice-text);
    padding: 16px 24px;
    border-radius: var(--radius-md);
    margin: 24px 0;
    text-align: center;
    font-weight: 500;
    font-size: 1rem;
}

/* ===== Speaker Cards ===== */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
    margin: 48px 0;
}

.speaker-card {
    text-align: center;
    background: var(--surface);
    padding: 0;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
    display: flex;
    flex-direction: column;
    min-height: 420px;
}

.speaker-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
    border-color: var(--surface-alt);
}

@media (max-width: 768px) {
    .speaker-card {
        width: 280px;
        max-width: 100%;
        margin-left: auto;
        margin-right: auto;
    }
    .speaker-card:hover {
        transform: none;
        box-shadow: none;
        border-color: var(--border-color);
    }
    .speaker-card.card-in-center {
        transform: translateY(-4px);
        box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
        border-color: var(--surface-alt);
    }
}

.speaker-card img {
    width: 100%;
    height: 240px;
    object-fit: cover;
    margin-bottom: 0;
    flex-shrink: 0;
}

.speaker-card .speaker-name {
    padding: 20px 20px 4px;
}

.speaker-card .speaker-affiliation {
    padding: 0 20px 20px;
    margin-top: auto;
}

.speaker-name {
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 4px;
    letter-spacing: 0.01em;
}

.speaker-name a {
    color: var(--text-color);
    text-decoration: none;
    transition: color var(--transition);
}

.speaker-name a:hover {
    color: var(--accent);
}

.speaker-affiliation {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 400;
}

/* ===== Tables (Program Schedule) ===== */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 32px 0;
    background: var(--surface);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

table th {
    background: var(--surface);
    color: var(--text-color);
    padding: 18px 24px;
    text-align: left;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    border-bottom: 1px solid var(--border-color);
}

table td {
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.9rem;
    letter-spacing: 0.01em;
}

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

table tr:hover td {
    background: var(--table-hover);
}

.schedule-day {
    background: var(--surface-alt);
    color: var(--text-color);
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    border-bottom: 2px solid var(--accent);
}

.session-header {
    background: var(--surface-alt);
    color: var(--text-color);
    font-weight: 600;
    font-size: 0.9rem;
    letter-spacing: 0.02em;
    border-left: 3px solid var(--accent);
    padding: 14px 24px;
}

/* ===== Buttons ===== */
.register-btn {
    display: inline-block;
    background: var(--accent);
    color: var(--on-accent);
    padding: 14px 32px;
    text-decoration: none;
    border-radius: var(--radius-full);
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    margin: 20px 0;
    transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}

.register-btn:hover {
    background: var(--accent-2);
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(229, 75, 62, 0.35);
}

.register-btn.closed {
    background: var(--accent-3);
    cursor: not-allowed;
    transform: none;
}

/* ===== Organizer Cards ===== */
.organizers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
    margin: 48px 0;
}

.organizer-card {
    text-align: center;
    background: var(--surface);
    padding: 0;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
    display: flex;
    flex-direction: column;
    min-height: 420px;
}

.organizer-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
    border-color: var(--surface-alt);
}

@media (max-width: 768px) {
    .organizer-card:hover {
        transform: none;
        box-shadow: none;
        border-color: var(--border-color);
    }
    .organizer-card.card-in-center {
        transform: translateY(-4px);
        box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
        border-color: var(--surface-alt);
    }
}

.organizer-card img {
    width: 100%;
    height: 280px;
    object-fit: cover;
    margin-bottom: 0;
}

.organizer-card .organizer-name {
    padding: 20px 20px 0;
}

.organizer-card .organizer-title {
    padding: 8px 20px 0;
}

.organizer-card .organizer-email {
    display: block;
    padding: 8px 20px 20px;
    margin-top: auto;
}

.organizer-name {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 4px;
    letter-spacing: 0.01em;
}

.organizer-title {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 12px;
}

.organizer-email {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color var(--transition);
}

.organizer-email:hover {
    color: var(--accent-2);
}

@media (max-width: 767px) {
    .organizers-grid {
        grid-template-columns: 1fr;
        gap: 20px;
        margin: 32px 0;
    }
    .organizer-card {
        width: 260px;
        max-width: 100%;
        min-height: 380px;
        margin-left: auto;
        margin-right: auto;
        display: flex;
        flex-direction: column;
    }
    .organizer-card img {
        height: 200px;
        flex-shrink: 0;
    }
    .organizer-card .organizer-name,
    .organizer-card .organizer-title,
    .organizer-card .organizer-email {
        padding-left: 16px;
        padding-right: 16px;
    }
    .organizer-card .organizer-name {
        padding-top: 14px;
        font-size: 1rem;
    }
    .organizer-card .organizer-title {
        font-size: 0.85rem;
    }
    .organizer-card .organizer-email {
        padding-bottom: 14px;
        font-size: 0.85rem;
        margin-top: auto;
    }
}

/* ===== Sponsors ===== */
.sponsors-grid {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 48px;
    flex-wrap: wrap;
    margin: 48px 0;
    padding: 32px 0;
}

.sponsors-grid img {
    max-height: 56px;
    object-fit: contain;
    opacity: 0.85;
    filter: grayscale(0.2);
    transition: opacity var(--transition);
}

.sponsors-grid img:hover {
    opacity: 1;
    filter: grayscale(0);
}

/* Sponsor logos: half size and tighter on viewports ≤1024px (tablet + mobile) */
@media (max-width: 1024px) {
    .sponsors-grid {
        gap: 12px;
        margin: 24px 0;
        padding: 20px 0;
    }

    .sponsors-grid img {
        max-height: 28px !important;
        height: 28px !important;
        width: auto;
        object-fit: contain;
    }
}

.sponsor-levels {
    background: var(--surface);
    padding: 32px 36px;
    border-radius: var(--radius-md);
    margin: 32px 0;
    border: 1px solid var(--border-color);
}

.sponsor-level {
    margin-bottom: 28px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
}

.sponsor-level:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.sponsor-level h4 {
    color: var(--text-color);
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.sponsor-level ul {
    margin-left: 20px;
}

.sponsor-level li {
    margin: 6px 0;
    font-size: 0.95rem;
    color: var(--text-muted);
}

/* ===== Footer ===== */
footer {
    background: var(--footer-bg);
    color: var(--footer-text);
    padding: 48px 24px 32px 96px;
    text-align: center;
    border-top: 1px solid var(--footer-divider);
    position: relative;
    z-index: 1;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
}

/* Same horizontal centering as .container: max-width 960px, margin auto, padding 24px */
.footer-content {
    max-width: 960px;
    margin-left: auto;
    margin-right: auto;
    padding-left: 24px;
    padding-right: 24px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 40px;
    text-align: center;
    box-sizing: border-box;
}

.footer-section {
    text-align: left;
}

.footer-section h4 {
    margin-bottom: 16px;
    color: var(--footer-text);
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    opacity: 0.75;
}

.footer-section a {
    color: var(--footer-link);
    text-decoration: none;
    display: block;
    margin: 10px 0;
    font-size: 0.9rem;
    transition: color var(--transition);
}

.footer-section a:hover {
    color: var(--footer-link-hover);
}

/* Partners: third column, logos stacked vertically on desktop */
.footer-partner-logos {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    margin-top: 0;
}
.footer-partner-logos img {
    height: 20px;
    width: auto;
    object-fit: contain;
    opacity: 0.85;
}
.footer-partner-logos img:hover {
    opacity: 1;
}

/* Mobile: About us + Social shifted; Partners and disclaimer unshifted (full width, centered) */
@media (max-width: 767px) {
    .footer-content {
        padding-left: 20px;
        padding-right: 20px;
        grid-template-columns: 1fr 1fr;
        gap: 28px 24px;
    }
    .footer-section--partners {
        grid-column: 1 / -1;
        text-align: center;
        margin-left: -96px;
        margin-right: -24px;
        width: calc(100% + 120px);
        padding-left: 20px;
        padding-right: 20px;
        box-sizing: border-box;
    }
    .footer-section--partners .footer-partner-logos {
        flex-direction: row;
        justify-content: center;
        align-items: center;
        flex-wrap: wrap;
        gap: 12px;
        margin-top: 0;
    }
    .footer-section--partners .footer-partner-logos img {
        height: 18px;
    }
    .footer-divider {
        max-width: none;
        margin-left: -96px;
        margin-right: -24px;
        width: calc(100% + 120px);
        margin-top: 24px;
        padding: 20px 20px 24px;
        text-align: center;
        box-sizing: border-box;
    }
}

/* Desktop: disclaimer full width and centered (unshifted like mobile) */
@media (min-width: 768px) {
    .footer-divider {
        max-width: none;
        margin-left: -96px;
        margin-right: -24px;
        width: calc(100% + 120px);
        padding-left: 24px;
        padding-right: 24px;
        text-align: center;
        margin-top: 48px;
        padding-top: 24px;
        box-sizing: border-box;
    }
}
.footer-divider {
    border-top: 1px solid var(--footer-divider);
}

.footer-divider p {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: 0.02em;
}

/* ===== Video Container (transparent – for transparent WebM, no visible border) ===== */
section:has(.video-container) {
    background: var(--video-bg);
}

.video-container {
    width: 90%;
    max-width: 900px;
    margin: 40px auto;
    overflow: visible;
    background: transparent;
}

.video-container video {
    width: 100%;
    display: block;
    vertical-align: middle;
    background: transparent;
}

video {
    background: transparent;
}

/* ===== Contact Info ===== */
.contact-info {
    text-align: center;
    font-size: 1.2em;
    margin: 30px 0;
}

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

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

/* ===== Archive Page Styles ===== */
.archive-list {
    list-style: none;
    padding: 0;
    margin: 48px 0;
}

.archive-list li {
    margin: 16px 0;
    padding: 24px 28px;
    background: var(--surface);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: border-color var(--transition), box-shadow var(--transition);
}

.archive-list li:hover {
    border-color: var(--surface-alt);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.archive-list a {
    color: var(--accent);
    text-decoration: none;
    font-size: 1.05rem;
    font-weight: 600;
    transition: color var(--transition);
}

.archive-list a:hover {
    color: var(--accent-2);
}

/* ===== Quick links grid (homepage) ===== */
.quick-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin: 48px 0;
}

.quick-links .register-btn {
    margin: 0;
    text-align: center;
}

/* =============================================================================
   MOBILE STYLES – Burger dropdown menu (no vertical stacking of nav items)
   Breakpoint: 768px
   ============================================================================= */
@media (max-width: 768px) {
    /* Layout & spacing */
    section {
        padding: 56px 20px;
    }

    .container {
        padding: 24px 20px;
    }

    .video-container {
        width: 100%;
        max-width: 100%;
    }

    body::before {
        opacity: 0.02;
        background-size: 80px 80px;
    }

    /* ----- Mobile header: burger (left) + logos + theme (right) ----- */
    nav {
        flex-wrap: nowrap;
        padding: 12px 20px;
        gap: 16px;
        align-items: center;
    }

    .nav-burger {
        display: flex;
        order: -1;
        flex-shrink: 0;
    }

    .nav-logo-group {
        flex: 0 1 auto;
        gap: 12px;
    }

    .nav-logo-group img {
        height: 19px !important;
        max-height: 19px !important;
    }

    .nav-right {
        margin-left: auto;
    }

    /* Burger icon → X when menu open */
    .header.menu-open .nav-burger span:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }
    .header.menu-open .nav-burger span:nth-child(2) {
        opacity: 0;
    }
    .header.menu-open .nav-burger span:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }

    /* ----- Dropdown menu: compact width, frosted, left-aligned below burger ----- */
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 20px;
        right: auto;
        width: max-content;
        max-width: min(200px, calc(100vw - 40px));
        min-width: 0;
        transform: none;
        flex-direction: column;
        margin: 8px 0 0;
        padding: 6px 6px 8px;
        gap: 2px;
        background: rgba(28, 28, 28, 0.65);
        -webkit-backdrop-filter: blur(12px);
        backdrop-filter: blur(12px);
        border: 1px solid rgba(255, 255, 255, 0.08);
        border-radius: var(--radius-md);
        box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
        z-index: 999;
    }

    [data-theme="light"] .nav-links {
        background: rgba(255, 255, 255, 0.7);
        border-color: rgba(0, 0, 0, 0.06);
        box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    }

    .header.menu-open .nav-links {
        display: flex;
    }

    /* When nav is in peek overlay, burger toggle targets overlay; let dropdown extend out (no scrollbar) */
    .nav-overlay.burger-open {
        overflow: visible;
    }
    .nav-overlay.burger-open .nav-burger span:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }
    .nav-overlay.burger-open .nav-burger span:nth-child(2) {
        opacity: 0;
    }
    .nav-overlay.burger-open .nav-burger span:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }
    .nav-overlay.burger-open .nav-links {
        display: flex;
    }

    nav a.nav-link {
        display: block;
        padding: 6px 8px;
        font-size: 0.85rem;
        text-align: center;
        border-radius: var(--radius-sm);
    }

    nav a.nav-link.active::after {
        left: 8px;
        right: 8px;
    }

    .header {
        position: relative;
    }

}