/* ============================================
   DRUCKMANN LAB — Design System
   ============================================ */

/* Elegant font combination */
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;1,9..40,400&family=DM+Serif+Display:ital@0;1&family=IBM+Plex+Mono:wght@400;500&display=swap');

/* --- CSS Variables --- */
:root {
    /* Colors */
    --color-bg: #fdfbf9;
    --color-bg-alt: #f7f4f1;
    --color-bg-warm: #f3eeea;
    --color-surface: #ffffff;
    
    --color-text: #1a1715;
    --color-text-secondary: #5c5552;
    --color-text-muted: #9c9490;
    --color-text-faint: #c4bfba;
    
    --color-accent: #8b2942;
    --color-accent-light: #fdf2f4;
    --color-accent-dark: #6b1d32;
    
    --color-border: #e8e4e0;
    --color-border-light: #f0ece8;
    
    /* Typography - Elegant combination */
    --font-serif: 'DM Serif Display', 'Georgia', serif;
    --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'IBM Plex Mono', 'Consolas', monospace;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 5rem;
    --space-3xl: 7rem;
    
    /* Layout */
    --max-width: 1200px;
    --content-width: 900px;
    --nav-height: 64px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.08);
}

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

html {
    font-size: 18px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.7;
    min-height: 100vh;
}

::selection {
    background: var(--color-accent);
    color: white;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: 500;
    line-height: 1.3;
    letter-spacing: -0.02em;
}

h1 { font-size: 3rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: 1.5em;
}

p:last-child {
    margin-bottom: 0;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-dark);
}

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

/* --- Layout --- */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.container--narrow {
    max-width: var(--content-width);
}

/* --- Navigation --- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(253, 251, 249, 0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--color-border-light);
    z-index: 1000;
    transition: box-shadow var(--transition-base);
}

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

.nav__inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav__logo {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: 0.01em;
    position: relative;
    padding: 0.25rem 0;
    transition: color 0.3s ease;
}

.nav__logo::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-accent), var(--color-accent-dark, #6b3d35));
    transition: width 0.3s ease;
}

.nav__logo::after {
    content: '';
    position: absolute;
    top: 50%;
    left: -12px;
    width: 6px;
    height: 6px;
    background: var(--color-accent);
    border-radius: 50%;
    transform: translateY(-50%) scale(0);
    transition: transform 0.3s ease;
}

.nav__logo:hover {
    color: var(--color-accent);
}

.nav__logo:hover::before {
    width: 100%;
}

.nav__logo:hover::after {
    transform: translateY(-50%) scale(1);
}

.nav__links {
    display: flex;
    gap: var(--space-lg);
    list-style: none;
}

.nav__link {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    padding: var(--space-sm) 0;
    position: relative;
    transition: color var(--transition-fast);
}

.nav__link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition-base);
}

.nav__link:hover,
.nav__link.active {
    color: var(--color-text);
}

.nav__link.active::after,
.nav__link:hover::after {
    width: 100%;
}

/* Mobile nav toggle - styles are in each HTML file */
.nav__toggle {
    display: none;
}

/* --- Hero Section --- */
.hero {
    padding-top: calc(var(--nav-height) + var(--space-2xl));
    padding-bottom: var(--space-2xl);
    position: relative;
    overflow: hidden;
}

.hero__bg {
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    pointer-events: none;
    opacity: 0.6;
}

.hero__content {
    position: relative;
    z-index: 1;
    max-width: 720px;
}

.hero__eyebrow {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.hero__eyebrow::before {
    content: '';
    width: 32px;
    height: 1px;
    background: var(--color-accent);
}

.hero__title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    margin-bottom: var(--space-lg);
    color: var(--color-text);
}

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

.hero__description {
    font-size: 1.2rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    max-width: 600px;
}

/* --- Section --- */
.section {
    padding: var(--space-xl) 0;
}

.section--alt {
    background: var(--color-bg-alt);
}

.section__header {
    margin-bottom: var(--space-lg);
}

.section__eyebrow {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-sm);
    text-align: center;
}

.section__title {
    font-size: 2rem;
    color: var(--color-text);
    text-align: center;
}

.section__intro {
    margin-top: var(--space-md);
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    max-width: none;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

/* --- Cards --- */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: 12px;
    padding: var(--space-lg);
    transition: all var(--transition-base);
}

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

.card__eyebrow {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-sm);
}

.card__title {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

.card__title a {
    color: inherit;
    text-decoration: none;
}

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

.card__text {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
}

/* --- Grid Layouts --- */
.grid {
    display: grid;
    gap: var(--space-lg);
}

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

@media (max-width: 900px) {
    .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
    .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
}

/* --- Publication List --- */
.pub-list {
    display: flex;
    flex-direction: column;
}

.pub-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: var(--space-lg);
    padding: var(--space-lg) 0;
    border-bottom: 1px solid var(--color-border-light);
    transition: background var(--transition-fast);
}

.pub-item:first-child {
    padding-top: 0;
}

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

.pub-item:hover {
    background: var(--color-bg-alt);
    margin: 0 calc(var(--space-md) * -1);
    padding-left: var(--space-md);
    padding-right: var(--space-md);
    border-radius: 8px;
}

.pub-item__year {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.pub-item__title {
    font-family: var(--font-serif);
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--space-xs);
    line-height: 1.5;
}

.pub-item__title a {
    color: inherit;
}

.pub-item__title a:hover {
    color: var(--color-accent);
}

.pub-item__authors {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xs);
}

.pub-item__venue {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    font-style: italic;
}

/* --- Team Grid --- */
.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: var(--space-lg);
}

.team-member {
    text-align: center;
}

.team-member__photo {
    width: 160px;
    height: 160px;
    margin: 0 auto var(--space-md);
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-bg-warm) 0%, var(--color-bg-alt) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-serif);
    font-size: 2rem;
    color: var(--color-text-muted);
    transition: transform var(--transition-base);
}

.team-member:hover .team-member__photo {
    transform: scale(1.05);
}

.team-member__name {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 500;
    margin-bottom: var(--space-xs);
}

.team-member__role {
    font-size: 0.875rem;
    color: var(--color-accent);
    margin-bottom: var(--space-xs);
}

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

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 0.75rem 1.5rem;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

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

.btn--primary:hover {
    background: var(--color-accent);
    color: white;
    transform: translateY(-1px);
}

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

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

.btn--ghost {
    background: transparent;
    color: var(--color-text-secondary);
    padding: 0.5rem 0;
}

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

.btn svg {
    width: 16px;
    height: 16px;
    transition: transform var(--transition-fast);
}

.btn:hover svg {
    transform: translateX(4px);
}

/* --- Affiliations --- */
.affiliations {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md) var(--space-lg);
    margin-top: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border-light);
}

.affiliations__item {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.affiliations__item a {
    color: var(--color-text-secondary);
    text-decoration: underline;
    text-decoration-color: var(--color-border);
    text-underline-offset: 3px;
    transition: all var(--transition-fast);
}

.affiliations__item a:hover {
    color: var(--color-accent);
    text-decoration-color: var(--color-accent);
}

/* --- Footer --- */
.footer {
    margin-top: var(--space-xl);
    padding: var(--space-lg) 0;
    border-top: 1px solid var(--color-border);
    background: var(--color-bg-alt);
}

.footer__inner {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: var(--space-xl);
}

.footer__brand {
    max-width: 320px;
}

.footer__logo {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
}

.footer__tagline {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    line-height: 1.6;
}

.footer__links {
    display: flex;
    gap: var(--space-xl);
}

.footer__column h4 {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-bottom: var(--space-md);
}

.footer__column ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer__column a {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

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

.footer__bottom {
    margin-top: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border-light);
    font-size: 0.8rem;
    color: var(--color-text-muted);
    text-align: center;
}

/* --- Page Header --- */
.page-header {
    padding-top: calc(var(--nav-height) + var(--space-xl));
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--color-border-light);
}

.page-header__title {
    font-size: 2.5rem;
    margin-bottom: var(--space-sm);
    text-align: center;
}

.page-header__description {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    max-width: none;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

/* --- Utilities --- */
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

/* --- Animations --- */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(24px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    animation: fadeInUp 0.6s ease forwards;
}

.animate-delay-1 { animation-delay: 0.1s; }
.animate-delay-2 { animation-delay: 0.2s; }
.animate-delay-3 { animation-delay: 0.3s; }

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

/* --- Tablet (max-width: 900px) --- */
@media (max-width: 900px) {
    :root {
        --space-xl: 2.5rem;
        --space-2xl: 4rem;
    }
    
    .grid--3, .grid--4 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    /* Mobile Navigation */
    .nav__toggle {
        display: flex !important;
        flex-direction: column;
        justify-content: center;
        gap: 5px;
        width: 44px;
        height: 44px;
        background: none;
        border: none;
        cursor: pointer;
        padding: 10px;
        margin-right: -10px;
        z-index: 1001;
    }
    
    .nav__toggle span {
        display: block;
        width: 22px;
        height: 2px;
        background: var(--color-text);
        border-radius: 1px;
        transition: 0.3s ease;
    }
    
    .nav__toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav__toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav__toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .nav__links {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--color-bg);
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        transform: translateX(100%);
        transition: transform 0.3s ease;
        z-index: 999;
        padding: 0;
    }
    
    .nav__links.active {
        transform: translateX(0);
    }
    
    .nav__links li {
        width: 100%;
        background: var(--color-bg);
    }
    
    .nav__link {
        display: block;
        padding: 1.25rem 1.5rem;
        font-size: 1.1rem;
        border-bottom: 1px solid var(--color-border);
        background: var(--color-bg);
    }
    
    .nav__link:hover,
    .nav__link.active {
        background: var(--color-bg-alt);
    }
    
    .nav__link::after {
        display: none;
    }
}

/* --- Mobile (max-width: 768px) --- */
@media (max-width: 768px) {
    html {
        font-size: 16px;
    }
    
    :root {
        --space-lg: 1.5rem;
        --space-xl: 2.5rem;
        --space-2xl: 4rem;
        --nav-height: 60px;
    }
    
    body {
        line-height: 1.65;
    }
    
    .container {
        padding: 0 1.25rem;
    }
    
    /* Logo - hide left dot on mobile */
    .nav__logo::after {
        display: none;
    }
    
    /* Typography scaling */
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    
    /* Section - Mobile */
    .section {
        padding: var(--space-xl) 0;
    }
    
    .section__header {
        margin-bottom: var(--space-lg);
    }
    
    .section__title {
        font-size: 1.5rem;
    }
    
    .section__intro {
        font-size: 1rem;
    }
    
    /* Grids - Mobile */
    .grid--2, .grid--3, .grid--4 {
        grid-template-columns: 1fr;
    }
    
    /* Cards - Mobile */
    .card {
        padding: var(--space-md);
    }
    
    /* Publications - Mobile */
    .pub-item {
        grid-template-columns: 1fr;
        gap: var(--space-xs);
        padding: var(--space-md) 0;
    }
    
    .pub-item__year {
        font-size: 0.8rem;
    }
    
    .pub-item__title {
        font-size: 1rem;
    }
    
    .pub-item:hover {
        margin: 0;
        padding-left: 0;
        padding-right: 0;
        background: transparent;
    }
    
    /* Team - Mobile */
    .team-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-md);
    }
    
    .team-member__photo {
        width: 90px;
        height: 90px;
    }
    
    .team-member__name {
        font-size: 0.95rem;
    }
    
    .team-member__role {
        font-size: 0.8rem;
    }
    
    /* Buttons - Mobile */
    .btn--primary {
        justify-content: center;
        padding: 0.875rem 1.25rem;
    }
    
    .btn--ghost {
        width: auto;
    }
    
    /* Footer - Mobile */
    .footer {
        margin-top: var(--space-xl);
        padding: var(--space-lg) 0;
    }
    
    .footer__inner {
        flex-direction: column;
        gap: var(--space-lg);
    }
    
    .footer__brand {
        max-width: 100%;
    }
    
    .footer__links {
        flex-wrap: wrap;
        gap: var(--space-lg);
    }
    
    .footer__bottom {
        margin-top: var(--space-lg);
        padding-top: var(--space-md);
    }
    
    /* Page Header - Mobile */
    .page-header {
        padding-top: calc(var(--nav-height) + var(--space-lg));
        padding-bottom: var(--space-lg);
    }
    
    .page-header__title {
        font-size: 1.75rem;
    }
    
    .page-header__description {
        font-size: 1rem;
    }
}

/* --- Small Mobile (max-width: 480px) --- */
@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .hero__title {
        font-size: 1.625rem;
    }
    
    .section__title {
        font-size: 1.375rem;
    }
    
    .team-grid {
        gap: var(--space-md);
    }
    
    .team-member__photo {
        width: 80px;
        height: 80px;
    }
}