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

:root {
    --color-bg: #faf6f1;
    --color-bg-warm: #f3ece3;
    --color-surface: #ffffff;
    --color-text: #3b2f2f;
    --color-text-secondary: #7a6b63;
    --color-accent: #b85c38;
    --color-accent-hover: #a04e2e;
    --color-accent-soft: rgba(184, 92, 56, 0.08);
    --color-gold: #c4a14a;
    --color-gold-light: rgba(196, 161, 74, 0.2);
    --color-border: #e2d8ce;
    --color-border-light: #ede6dd;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-serif: 'Crimson Pro', Georgia, serif;
    --max-width: 880px;
    --shadow-sm: 0 1px 3px rgba(59, 47, 47, 0.06);
    --shadow-md: 0 4px 16px rgba(59, 47, 47, 0.07);
    --transition: 0.25s ease;
}

html {
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.7;
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

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

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

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

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    height: 56px;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 2.5rem;
}

.nav-links a {
    color: var(--color-text-secondary);
    font-size: 0.88rem;
    font-weight: 500;
    text-decoration: none;
    letter-spacing: 0.03em;
    padding-bottom: 3px;
    transition: color var(--transition), border-color var(--transition);
    border-bottom: 2px solid transparent;
}

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

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

/* ===== Page Content ===== */
.page-content {
    flex: 1;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.content-narrow {
    max-width: 720px;
    padding-top: 2.5rem;
    padding-bottom: 4rem;
}

/* ===== Headings ===== */
h2 {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--color-text);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--color-border);
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--color-gold);
}

.content-narrow h2:first-child {
    margin-top: 0;
}

/* ===== Home Layout ===== */
.home-layout {
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: 3rem;
    padding-top: 3rem;
    padding-bottom: 4rem;
}

.photo-placeholder {
    width: 200px;
    height: 260px;
    background: linear-gradient(145deg, var(--color-bg-warm), var(--color-border-light));
    border: 1px solid var(--color-border);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-secondary);
    font-size: 0.85rem;
    font-weight: 500;
    box-shadow: var(--shadow-sm);
}

.home-sidebar img {
    width: 200px;
    height: auto;
    border-radius: 4px;
    box-shadow: var(--shadow-md);
}

.sidebar-info {
    margin-top: 1.25rem;
}

.sidebar-info h1 {
    font-family: var(--font-serif);
    font-size: 1.45rem;
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-text);
}

.sidebar-info .title {
    font-size: 0.88rem;
    color: var(--color-accent);
    margin-top: 0.35rem;
    font-weight: 500;
}

.sidebar-info .institution {
    font-size: 0.84rem;
    color: var(--color-text-secondary);
}

.sidebar-contact {
    margin-top: 1rem;
    font-size: 0.84rem;
}

/* Home main */
.home-main h2 {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--color-text);
    margin-top: 2rem;
    margin-bottom: 0.75rem;
    padding-bottom: 0.4rem;
    border-bottom: 1px solid var(--color-border);
    position: relative;
}

.home-main h2::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--color-gold);
}

.home-main h2:first-child {
    margin-top: 0;
}

.home-main p {
    font-size: 0.95rem;
    color: var(--color-text);
    margin-bottom: 0.85rem;
    line-height: 1.8;
}

.contact-block {
    font-size: 0.92rem;
    line-height: 1.7;
}

.contact-block p {
    margin-bottom: 0.5rem;
}

/* ===== Papers ===== */
.paper {
    margin-bottom: 0.75rem;
    padding: 1.1rem 1.25rem;
    background: var(--color-surface);
    border-radius: 6px;
    border: 1px solid var(--color-border-light);
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition), transform var(--transition);
}

.paper:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.paper-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.5;
}

.paper-authors {
    font-size: 0.86rem;
    color: var(--color-text-secondary);
    margin-top: 0.2rem;
}

.paper-venue {
    font-size: 0.86rem;
    color: var(--color-text-secondary);
    margin-top: 0.1rem;
}

.paper-description {
    font-size: 0.86rem;
    color: var(--color-text-secondary);
    margin-top: 0.35rem;
    line-height: 1.65;
}

.paper-links {
    margin-top: 0.4rem;
    font-size: 0.84rem;
}

.paper-links a {
    font-weight: 500;
}

.link-sep {
    color: var(--color-border);
    margin: 0 0.3rem;
}

.paper-abstract {
    margin-top: 0.5rem;
}

.paper-abstract summary {
    font-size: 0.84rem;
    color: var(--color-accent);
    cursor: pointer;
    font-weight: 500;
    list-style: none;
}

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

.paper-abstract summary::before {
    content: '[+] ';
    font-weight: 400;
}

details[open] > summary::before {
    content: '[\2212] ';
}

.paper-abstract summary:hover {
    text-decoration: underline;
}

.paper-abstract p {
    margin-top: 0.5rem;
    font-size: 0.86rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    padding: 0.75rem 1rem;
    background: var(--color-bg);
    border-left: 3px solid var(--color-gold);
    border-radius: 0 4px 4px 0;
}

/* ===== CV ===== */
.cv-download {
    margin-bottom: 1.5rem;
}

.btn {
    display: inline-block;
    padding: 0.55rem 1.4rem;
    background: var(--color-accent);
    color: #fff;
    font-size: 0.85rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: 4px;
    transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}

.btn:hover {
    background: var(--color-accent-hover);
    text-decoration: none;
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(184, 92, 56, 0.2);
}

.cv-item {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 1.5rem;
    padding: 0.7rem 0;
    align-items: start;
    font-size: 0.92rem;
    border-bottom: 1px solid var(--color-border-light);
}

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

.cv-year {
    font-size: 0.84rem;
    color: var(--color-text-secondary);
    padding-top: 0.05rem;
}

.cv-detail {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
    line-height: 1.6;
}

.cv-detail strong {
    font-weight: 600;
    font-size: 0.92rem;
}

.cv-institution {
    font-size: 0.88rem;
    color: var(--color-text-secondary);
}

.cv-note {
    font-size: 0.82rem;
    color: var(--color-text-secondary);
}

.cv-teaching-note {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-bottom: 0.5rem;
    font-style: italic;
}

/* ===== Footer ===== */
.footer {
    margin-top: auto;
    padding: 2rem 0;
    text-align: center;
    font-size: 0.78rem;
    color: var(--color-text-secondary);
    border-top: 1px solid var(--color-border-light);
}

/* ===== Responsive ===== */
@media (max-width: 700px) {
    .home-layout {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .home-sidebar {
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .photo-placeholder {
        width: 160px;
        height: 210px;
    }

    .home-main h2,
    .home-main p,
    .contact-block {
        text-align: left;
    }

    .cv-item {
        grid-template-columns: 1fr;
        gap: 0.15rem;
    }

    .container {
        padding: 0 1.25rem;
    }

    .nav-links {
        gap: 1.5rem;
    }
}