/* ============================================================
   FORGE Lab Design System
   Colors: #FFFFFF bg, #C41230 accent (CMU red), #1A1A1A text
   Fonts: Source Serif 4 (headings), Space Grotesk (body)
   ============================================================ */

:root {
    /* Light theme (default) - clean white */
    --color-bg: #FFFFFF;
    --color-bg-alt: #F8F8F8;
    --color-surface: #FFFFFF;
    --color-text: #1A1A1A;
    --color-text-secondary: #4A4A4A;
    --color-text-muted: #777777;
    --color-accent: #C41230;
    --color-accent-light: #FEF2F4;
    --color-border: #EAEAEA;
    --color-border-light: #F0F0F0;
    --nav-bg: rgba(255, 255, 255, 0.95);
    --font-serif: 'Source Serif 4', Georgia, serif;
    --font-sans: 'Space Grotesk', -apple-system, sans-serif;
    --max-width: 1020px;
}

/* Dark theme - activated by class on html element */
html.dark {
    --color-bg: #111111;
    --color-bg-alt: #1A1A1A;
    --color-surface: #1E1E1E;
    --color-text: #F0F0F0;
    --color-text-secondary: #B0B0B0;
    --color-text-muted: #707070;
    --color-accent: #E63950;
    --color-accent-light: rgba(230, 57, 80, 0.12);
    --color-border: #2A2A2A;
    --color-border-light: #333333;
    --nav-bg: rgba(17, 17, 17, 0.95);
}

/* Theme toggle button */
.theme-toggle {
    background: none;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: 6px 10px;
    cursor: pointer;
    color: var(--color-text-muted);
    font-size: 0.8rem;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 6px;
}

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

.theme-toggle svg {
    width: 14px;
    height: 14px;
}

/* Hide icons based on theme */
html:not(.dark) .theme-toggle .icon-sun { display: none; }
html.dark .theme-toggle .icon-moon { display: none; }

/* ============================================================
   BASE STYLES
   ============================================================ */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
}

::selection { background: var(--color-accent); color: white; }
a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ============================================================
   NAVIGATION
   ============================================================ */
nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 58px;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    font-family: var(--font-sans);
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: -0.01em;
}
.logo:hover { text-decoration: none; }

.logo-o {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 17px;
    height: 17px;
    margin: 0 -1px;
    vertical-align: middle;
}

.logo-o canvas {
    width: 17px;
    height: 17px;
}

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color 0.15s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text);
    text-decoration: none;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--color-text);
    margin: 4px 0;
    transition: all 0.3s;
}

.nav-mobile {
    display: none;
    position: absolute;
    top: 58px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 16px 40px;
}

.nav-mobile.open { display: block; }

.nav-mobile a {
    display: block;
    padding: 10px 0;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    border-bottom: 1px solid var(--color-border);
}

.nav-mobile a:last-child { border-bottom: none; }

/* ============================================================
   HERO
   ============================================================ */
.hero {
    padding: 115px 40px 56px;
    border-bottom: 1px solid var(--color-border);
    position: relative;
}


.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 48px;
}

.hero-inner {
    max-width: 600px;
}

.hero-wordmark {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    flex-shrink: 0;
}

.hero-wordmark-top {
    display: flex;
    align-items: center;
}

.hero-letter {
    font-family: var(--font-sans);
    font-size: 6rem;
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: -0.03em;
    line-height: 0.75;
}

.hero-wordmark-bottom {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--color-text-muted);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-top: 8px;
}

.hero-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
    width: 68px;
    height: 68px;
    margin: 0 6px;
}

.hero-grid .cell {
    background: var(--color-border);
    border-radius: 2px;
    transition: background 0.3s ease, opacity 0.3s ease;
}

.hero-grid .cell.active {
    background: var(--color-accent);
    opacity: 0.6;
}

.hero-grid .cell.current {
    background: var(--color-text);
}

html.dark .hero-grid .cell {
    background: #333;
}

html.dark .hero-grid .cell.active {
    background: #888;
    opacity: 0.8;
}

html.dark .hero-grid .cell.current {
    background: #fff;
}

@media (max-width: 768px) {
    .hero-wordmark {
        display: none;
    }
}

.hero-headline {
    font-family: var(--font-serif);
    font-size: 3.2rem;
    font-weight: 400;
    line-height: 1.2;
    letter-spacing: -0.01em;
    margin-bottom: 24px;
    color: var(--color-text);
}

.hero-headline em {
    font-style: italic;
    color: var(--color-accent);
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-top: 32px;
}

.btn {
    display: inline-block;
    padding: 14px 28px;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: 4px;
    transition: all 0.15s ease;
}

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

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

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

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

.hero-label {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-accent);
    margin-bottom: 20px;
}

.hero h1 {
    font-family: var(--font-serif);
    font-size: 2.1rem;
    font-weight: 400;
    line-height: 1.3;
    letter-spacing: -0.01em;
    margin-bottom: 18px;
}

.hero h1 .highlight {
    color: var(--color-accent);
    font-style: italic;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    max-width: 540px;
}

.hero-links {
    display: flex;
    gap: 24px;
}

.hero-links a {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color 0.15s;
}

.hero-links a:hover { color: var(--color-accent); }

.hero-news {
    display: flex;
    align-items: center;
    gap: 8px;
    max-width: var(--max-width);
    margin: 24px auto 0;
    padding-top: 20px;
    border-top: 1px solid var(--color-border);
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color 0.15s;
}

.hero-news:hover {
    color: var(--color-text);
}

.hero-news strong {
    color: var(--color-accent);
    font-weight: 600;
}

.hero-news .news-link {
    margin-left: auto;
    color: var(--color-text-muted);
    font-size: 0.8rem;
    transition: color 0.15s;
}

.hero-news:hover .news-link {
    color: var(--color-accent);
}

/* ============================================================
   PAGE HEADER (for inner pages)
   ============================================================ */
.page-header {
    padding: 100px 40px 40px;
    border-bottom: 1px solid var(--color-border);
}

.page-header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
}

.page-header h1 {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 400;
    display: flex;
    align-items: baseline;
    gap: 14px;
}

.page-header .section-number {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-accent);
}

.page-header p {
    margin-top: 12px;
    color: var(--color-text-secondary);
    max-width: 600px;
}

/* ============================================================
   SECTIONS
   ============================================================ */
section {
    padding: 60px 40px;
}

.section-inner {
    max-width: var(--max-width);
    margin: 0 auto;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 28px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--color-border);
}

.section-title {
    font-family: var(--font-serif);
    font-size: 1.35rem;
    font-weight: 400;
    display: flex;
    align-items: baseline;
    gap: 14px;
}

.section-number {
    font-family: var(--font-sans);
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--color-accent);
    letter-spacing: 0.02em;
}

.section-link {
    font-size: 0.85rem;
    font-weight: 500;
}

/* ============================================================
   RESEARCH
   ============================================================ */
.research-section {
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.research-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: 24px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.research-card:hover {
    border-color: var(--color-text-muted);
}

.research-card-image {
    width: 100%;
    height: 140px;
    background: var(--color-bg-alt);
    border-radius: 4px;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    font-size: 0.8rem;
    overflow: hidden;
}

.research-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.research-card h3 {
    font-family: var(--font-serif);
    font-size: 1.05rem;
    font-weight: 400;
    margin-bottom: 10px;
    color: var(--color-text);
}

.research-card p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Full research card (for research page) */
.research-card-full {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: 32px;
    margin-bottom: 24px;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 32px;
}

.research-card-full:last-child {
    margin-bottom: 0;
}

.research-card-full-image {
    width: 100%;
    height: 200px;
    background: var(--color-bg-alt);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    font-size: 0.8rem;
    overflow: hidden;
}

.research-card-full-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.research-card-full h3 {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 12px;
}

.research-card-full p {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 16px;
}

.research-card-full p:last-child {
    margin-bottom: 0;
}

.research-papers {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--color-border);
}

.research-papers h4 {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-text-muted);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.research-papers ul {
    list-style: none;
}

.research-papers li {
    font-size: 0.85rem;
    margin-bottom: 6px;
}

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

.research-papers a:hover {
    color: var(--color-accent);
}

/* ============================================================
   PUBLICATIONS
   ============================================================ */
.pub-list {
    display: flex;
    flex-direction: column;
}

.pub-item {
    display: grid;
    grid-template-columns: 48px 1fr auto;
    gap: 20px;
    padding: 16px 0;
    border-bottom: 1px solid var(--color-border);
    transition: all 0.15s;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
}

.pub-item:hover {
    text-decoration: none;
    background: var(--color-bg-alt);
    margin: 0 -16px;
    padding: 16px;
    border-radius: 4px;
}

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

.pub-year {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    font-weight: 500;
}

.pub-info { flex: 1; }

.pub-title {
    font-family: var(--font-serif);
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--color-text);
    margin-bottom: 3px;
    transition: color 0.15s;
}

.pub-item:hover .pub-title { color: var(--color-accent); }

.pub-authors {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    margin-bottom: 2px;
}

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

.pub-arrow {
    color: var(--color-border-light);
    font-size: 0.9rem;
    transition: transform 0.15s, color 0.15s;
    align-self: center;
}

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

/* Publication filters */
.pub-filters {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.pub-filter {
    padding: 6px 14px;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid var(--color-border);
    border-radius: 20px;
    background: transparent;
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}

.pub-filter:hover {
    border-color: var(--color-text-muted);
    color: var(--color-text);
}

.pub-filter.active {
    background: var(--color-text);
    color: var(--color-bg);
    border-color: var(--color-text);
}

/* ============================================================
   PEOPLE
   ============================================================ */
.people-section {
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
}

.people-layout {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 56px;
}

.pi-image {
    width: 100%;
    aspect-ratio: 1;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-serif);
    font-size: 1.8rem;
    color: var(--color-text-muted);
    overflow: hidden;
}

.pi-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.pi-name {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 400;
    margin-bottom: 3px;
}

.pi-role {
    font-size: 0.8rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: 12px;
}

.pi-bio {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: 14px;
}

.pi-links {
    display: flex;
    gap: 16px;
}

.pi-links a {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color 0.15s;
}

.pi-links a:hover { color: var(--color-accent); }

/* Team */
.team-section {
    margin-bottom: 32px;
}

.team-section h3 {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 400;
    margin-bottom: 16px;
}

.team-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.team-member {
    display: flex;
    align-items: center;
    gap: 14px;
}

.member-image {
    width: 52px;
    height: 52px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text-muted);
    overflow: hidden;
}

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

.member-name {
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 2px;
}

.member-role {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* Join placeholder */
.join-placeholder .placeholder-image {
    background: var(--color-bg-alt);
    border: 2px dashed var(--color-border);
    font-family: var(--font-serif);
    font-size: 1.5rem;
    color: var(--color-text-muted);
}

.join-placeholder:hover .placeholder-image {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.join-placeholder:hover .member-name,
.join-placeholder:hover .member-role {
    color: var(--color-accent);
}

/* Positions */
.positions-section h3 {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 400;
    margin-bottom: 16px;
}

.positions-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.position-card {
    padding: 18px;
    border: 1px dashed var(--color-border);
    border-radius: 6px;
    background: var(--color-surface);
    transition: all 0.15s;
}

.position-card:hover {
    border-color: var(--color-accent);
    border-style: solid;
    background: var(--color-accent-light);
}

.position-title {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 4px;
}

.position-desc {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    margin-bottom: 10px;
}

.position-status {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--color-accent);
}

.apply-info {
    padding: 18px;
    background: var(--color-surface);
    border-radius: 6px;
    border: 1px solid var(--color-border);
}

.apply-info h4 {
    font-family: var(--font-serif);
    font-size: 0.95rem;
    font-weight: 400;
    margin-bottom: 10px;
}

.apply-info p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: 12px;
}

.apply-info p:last-child { margin-bottom: 0; }

/* ============================================================
   NEWS
   ============================================================ */
.news-list {
    display: flex;
    flex-direction: column;
}

.news-item {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 24px;
    padding: 20px 0;
    border-bottom: 1px solid var(--color-border);
}

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

.news-date {
    font-size: 0.8rem;
    color: var(--color-accent);
    font-weight: 600;
}

.news-content h3 {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 400;
    margin-bottom: 6px;
}

.news-content p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ============================================================
   FOOTER
   ============================================================ */
footer {
    padding: 36px 40px;
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.footer-left {
    display: flex;
    align-items: center;
    gap: 24px;
}

.footer-logo {
    display: flex;
    align-items: center;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: -0.01em;
}

.footer-info {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color 0.15s;
}

.footer-links a:hover { color: var(--color-accent); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
    .research-grid { grid-template-columns: 1fr; }
    .research-card-full {
        grid-template-columns: 1fr;
    }
    .research-card-full-image {
        height: 180px;
    }
}

@media (max-width: 768px) {
    .nav-inner, section, footer, .page-header {
        padding-left: 24px;
        padding-right: 24px;
    }
    .nav-links { display: none; }
    .nav-toggle { display: block; }
    .hero-inner { grid-template-columns: 1fr; }
    .hero-visual { display: none; }
    .hero h1 { font-size: 1.75rem; }
    .people-layout { grid-template-columns: 1fr; }
    .positions-grid { grid-template-columns: 1fr; }
    .footer-inner { flex-direction: column; gap: 16px; }
    .footer-left { flex-direction: column; align-items: flex-start; gap: 8px; }
    .news-item { grid-template-columns: 1fr; gap: 8px; }
}