* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --bg-1: #1a1a1a;
    --bg-2: #2d2d2d;
    --panel: #242424;
    --text: #c0c0c0;
    --text-strong: #ffffff;
    --accent: #ff6600;
    --rule: rgba(255, 255, 255, 0.08);
}

html { scroll-behavior: smooth; scroll-padding-top: 4.5rem; }

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: linear-gradient(135deg, var(--bg-1) 0%, var(--bg-2) 100%);
    min-height: 100vh;
}

a {
    color: var(--accent);
    text-decoration: none;
    font-weight: bold;
}

a:hover { text-decoration: underline; }

section {
    padding: 4rem 1.5rem;
    border-bottom: 1px solid var(--rule);
}

.wrap {
    max-width: 960px;
    margin: 0 auto;
}

/* Navbar */
.nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(36, 36, 36, 0.92);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--rule);
}

.nav-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0.9rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
}

.nav-brand {
    color: var(--text-strong);
    font-weight: bold;
    font-size: 1.1rem;
    letter-spacing: 0.12em;
}

.nav-brand:hover { text-decoration: none; color: var(--accent); }

.nav-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    align-items: center;
}

.nav-links a {
    color: var(--text);
    font-weight: bold;
    font-size: 0.95rem;
}

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

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

/* Hero (home) */
.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 5rem 1.5rem;
}

.hero-inner {
    max-width: 1100px;
    width: 100%;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 3.5rem;
    align-items: center;
}

.hero .eyebrow {
    color: var(--accent);
    font-size: 0.9rem;
    letter-spacing: 0.2em;
    font-weight: bold;
    margin-bottom: 1rem;
}

.hero h1 {
    font-size: 3rem;
    color: var(--text-strong);
    line-height: 1.15;
    margin-bottom: 1.5rem;
}

.hero p {
    font-size: 1.15rem;
    margin-bottom: 0.75rem;
}

.hero-image {
    width: 100%;
    max-width: 380px;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    border-radius: 6px;
    justify-self: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.buttons {
    margin-top: 2.5rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--accent);
    border-radius: 4px;
    color: var(--accent);
    font-weight: bold;
    transition: background 0.2s, color 0.2s;
}

.btn:hover {
    background: var(--accent);
    color: #1a1a1a;
    text-decoration: none;
}

.btn-primary {
    background: var(--accent);
    color: #1a1a1a;
}

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

/* Section headings */
h2.section-title {
    font-size: 2rem;
    color: var(--text-strong);
    margin-bottom: 0.75rem;
}

.section-lede {
    font-size: 1.1rem;
    max-width: 720px;
    margin-bottom: 2.5rem;
}

/* Card grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.card {
    background: var(--panel);
    border: 1px solid var(--rule);
    border-radius: 6px;
    padding: 1.5rem;
}

.card h3 {
    color: var(--text-strong);
    font-size: 1.15rem;
    margin-bottom: 0.75rem;
}

.card p {
    font-size: 1rem;
}

/* About */
.about p {
    font-size: 1.1rem;
    max-width: 720px;
}

/* Contact */
.contact {
    text-align: center;
}

.contact p {
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto 2rem;
}

/* Research listing page */
.page-hero {
    padding: 4.5rem 1.5rem 3.5rem;
    border-bottom: 1px solid var(--rule);
}

.page-hero .eyebrow {
    color: var(--accent);
    font-size: 0.9rem;
    letter-spacing: 0.2em;
    font-weight: bold;
    margin-bottom: 1rem;
}

.page-hero h1 {
    font-size: 2.6rem;
    color: var(--text-strong);
    line-height: 1.15;
    margin-bottom: 1.25rem;
}

.page-hero p {
    font-size: 1.15rem;
    max-width: 720px;
}

.papers {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 2rem;
}

.paper {
    background: var(--panel);
    border: 1px solid var(--rule);
    border-radius: 6px;
    padding: 1.75rem;
    transition: border-color 0.2s;
}

.paper:hover { border-color: rgba(255, 102, 0, 0.5); }

.paper h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.paper h3 a { color: var(--text-strong); }
.paper h3 a:hover { color: var(--accent); text-decoration: none; }

.paper-meta {
    font-size: 0.85rem;
    color: #8f8f8f;
    letter-spacing: 0.03em;
    margin-bottom: 0.9rem;
}

.paper-abstract {
    font-size: 1rem;
    max-width: 760px;
    margin-bottom: 1rem;
}

.paper-more {
    font-size: 0.95rem;
}

/* Individual paper article */
.article {
    max-width: 760px;
    margin: 0 auto;
    padding: 3.5rem 1.5rem 4rem;
    line-height: 1.7;
}

.back-link {
    display: inline-block;
    font-size: 0.9rem;
    margin-bottom: 2rem;
}

.article h1 {
    font-size: 2.4rem;
    color: var(--text-strong);
    line-height: 1.2;
    margin-bottom: 0.85rem;
}

.article-meta {
    font-size: 0.9rem;
    color: #8f8f8f;
    letter-spacing: 0.03em;
    margin-bottom: 2.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--rule);
}

.abstract {
    background: var(--panel);
    border: 1px solid var(--rule);
    border-radius: 6px;
    padding: 1.5rem;
    margin-bottom: 2.5rem;
}

.abstract h2 {
    font-size: 0.85rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

/* Supporting materials download */
.materials {
    background: var(--panel);
    border: 1px solid var(--rule);
    border-radius: 6px;
    padding: 1.5rem;
    margin-bottom: 2.5rem;
}

.materials h2 {
    font-size: 0.85rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

.materials p {
    font-size: 1rem;
    margin-bottom: 1.1rem;
}

.materials .file-meta {
    font-size: 0.85rem;
    color: #8f8f8f;
    margin-top: 0.9rem;
    margin-bottom: 0;
}

.article h2 {
    font-size: 1.5rem;
    color: var(--text-strong);
    margin: 2.5rem 0 0.75rem;
}

.article p {
    font-size: 1.05rem;
    margin-bottom: 1.25rem;
}

.article ul {
    margin: 0 0 1.25rem 1.25rem;
    font-size: 1.05rem;
}

.article li { margin-bottom: 0.5rem; }

/* Footer */
footer {
    padding: 2rem 1.5rem;
    text-align: center;
    font-size: 0.9rem;
    color: #888;
}

.article + footer { border-top: 1px solid var(--rule); }

@media (max-width: 800px) {
    .hero-inner {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    .buttons { justify-content: center; }
    .hero-image { order: -1; max-width: 260px; }
}

@media (max-width: 600px) {
    .hero h1 { font-size: 2rem; }
    .page-hero h1 { font-size: 1.9rem; }
    .article h1 { font-size: 1.8rem; }
    h2.section-title { font-size: 1.6rem; }
    section { padding: 3rem 1.5rem; }
    .nav-inner { justify-content: center; text-align: center; }
    .nav-links { gap: 1rem 1.25rem; justify-content: center; }
}