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

:root {
    --color-bg: #fafaf9;
    --color-surface: #ffffff;
    --color-text: #1c1917;
    --color-text-secondary: #57534e;
    --color-accent: #b45309;
    --color-accent-light: #fef3c7;
    --color-border: #e7e5e4;
    --color-border-light: #f5f5f4;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
    --max-width: 860px;
    --nav-height: 60px;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-height) + 20px);
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #92400e;
    text-decoration: underline;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navigation ===== */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(250, 250, 249, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: box-shadow 0.3s;
}

#navbar.scrolled {
    box-shadow: 0 1px 8px rgba(0,0,0,0.06);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-name {
    font-family: var(--font-serif);
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--color-text);
    text-decoration: none;
}

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

.nav-links {
    list-style: none;
    display: flex;
    gap: 24px;
}

.nav-links a {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    transition: color 0.2s;
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 5px;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text);
    transition: transform 0.3s;
}

/* ===== Hero Section ===== */
#hero {
    padding-top: calc(var(--nav-height) + 60px);
    padding-bottom: 60px;
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: flex-start;
    gap: 48px;
}

.hero-text {
    flex: 1;
}

.hero-text h1 {
    font-family: var(--font-serif);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    margin-bottom: 2px;
}

.hero-affiliation {
    font-size: 1.05rem;
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: 20px;
}

.hero-description {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 12px;
    line-height: 1.75;
}

.hero-description strong {
    color: var(--color-text);
    font-weight: 600;
}

.hero-links {
    display: flex;
    gap: 10px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 8px 18px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text);
    background: var(--color-surface);
    transition: all 0.2s;
    text-decoration: none;
}

.btn:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
    text-decoration: none;
    background: var(--color-accent-light);
}

.hero-photo {
    flex-shrink: 0;
}

.profile-photo {
    width: 320px;
    height: 360px;
    border-radius: 12px;
    object-fit: cover;
    object-position: center top;
    border: 1px solid var(--color-border);
}

/* ===== Sections ===== */
section {
    padding: 56px 0;
}

section:nth-child(even) {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border-light);
    border-bottom: 1px solid var(--color-border-light);
}

h2 {
    font-family: var(--font-serif);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 24px;
    color: var(--color-text);
    letter-spacing: -0.01em;
}

h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-top: 28px;
    margin-bottom: 12px;
    color: var(--color-text);
}

.section-intro {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 24px;
    line-height: 1.75;
}

/* ===== About ===== */
.about-content p {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
    line-height: 1.75;
}

.research-interests {
    list-style: disc;
    padding-left: 24px;
    margin-bottom: 20px;
}

.research-interests li {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
    line-height: 1.65;
}

.awards-list {
    list-style: none;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px 24px;
}

.awards-list li {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
}

.awards-list li::before {
    content: "\2022";
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: 700;
}

/* ===== Papers ===== */
.papers-category {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    color: var(--color-text);
    border-bottom: 2px solid var(--color-accent);
    padding-bottom: 6px;
    margin-bottom: 20px;
    margin-top: 32px;
}

.papers-category:first-of-type {
    margin-top: 8px;
}

.paper {
    margin-bottom: 24px;
    padding: 16px 20px;
    background: var(--color-bg);
    border-radius: 8px;
    border: 1px solid var(--color-border-light);
    transition: border-color 0.2s;
}

.paper:hover {
    border-color: var(--color-border);
}

.paper-title {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--color-text);
    margin-bottom: 4px;
    line-height: 1.5;
}

.paper-authors {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.paper-venue {
    font-size: 0.825rem;
    color: var(--color-accent);
    font-style: italic;
    margin-bottom: 6px;
}

.paper-description {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: 6px;
}

.paper-note {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    font-style: italic;
    margin-bottom: 4px;
}

.paper-links {
    display: flex;
    gap: 12px;
}

.paper-links a {
    font-size: 0.825rem;
    font-weight: 600;
    color: var(--color-accent);
}

/* ===== Teaching ===== */
.teaching-entry {
    margin-bottom: 20px;
}

.teaching-role {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--color-text);
}

.teaching-location, .teaching-period {
    font-size: 0.85rem;
    color: var(--color-accent);
    font-style: italic;
    margin-bottom: 6px;
}

.teaching-subtitle {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    font-style: italic;
    margin-bottom: 12px;
    margin-top: -8px;
}

.teaching-entry p, #teaching > .container > p {
    font-size: 0.925rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 12px;
}

.teaching-table-wrapper {
    overflow-x: auto;
    margin: 16px 0 20px;
}

.teaching-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.teaching-table th {
    text-align: left;
    padding: 10px 12px;
    background: var(--color-bg);
    border-bottom: 2px solid var(--color-border);
    font-weight: 600;
    color: var(--color-text);
    font-size: 0.825rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.teaching-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--color-border-light);
    color: var(--color-text-secondary);
}

.teaching-table tr:hover td {
    background: var(--color-accent-light);
}

/* ===== Competitions ===== */
.competitions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
}

.competition-card {
    padding: 20px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.competition-card:hover {
    border-color: var(--color-accent);
    box-shadow: 0 2px 12px rgba(180, 83, 9, 0.06);
}

.competition-card h3 {
    margin-top: 0;
    font-size: 1rem;
    margin-bottom: 4px;
}

.competition-card h3 a {
    color: var(--color-text);
}

.competition-card h3 a:hover {
    color: var(--color-accent);
}

.competition-role {
    font-size: 0.825rem;
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: 8px;
}

.competition-card p {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ===== Course Notes ===== */
.notes-placeholder {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    font-style: italic;
    margin-bottom: 24px;
}

.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 12px;
}

.note-card {
    padding: 16px 18px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: border-color 0.2s;
}

.note-card:hover {
    border-color: var(--color-accent);
}

.note-code {
    font-weight: 700;
    font-size: 0.9rem;
    color: var(--color-accent);
    margin-bottom: 2px;
}

.note-title {
    font-size: 0.85rem;
    color: var(--color-text);
    margin-bottom: 8px;
    line-height: 1.4;
}

.note-link {
    font-size: 0.8rem;
    font-weight: 600;
}

.note-link.coming-soon {
    color: var(--color-text-secondary);
    font-style: italic;
    font-weight: 400;
}

/* ===== Projects ===== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.project-card {
    padding: 20px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: border-color 0.2s;
}

.project-card:hover {
    border-color: var(--color-accent);
}

.project-card h3 {
    margin-top: 0;
    font-size: 1rem;
    margin-bottom: 2px;
}

.project-date {
    font-size: 0.8rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: 8px;
}

.project-card p {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.project-card code {
    background: var(--color-accent-light);
    padding: 1px 5px;
    border-radius: 3px;
    font-size: 0.85em;
}

.project-links {
    margin-top: 10px;
}

.project-links a {
    font-size: 0.825rem;
    font-weight: 600;
    color: var(--color-accent);
}

/* ===== Blog ===== */
.blog-placeholder {
    padding: 40px;
    text-align: center;
    background: var(--color-surface);
    border: 1px dashed var(--color-border);
    border-radius: 8px;
    color: var(--color-text-secondary);
    font-size: 0.925rem;
}

.blog-grid {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.blog-loading {
    color: var(--color-text-secondary);
    font-size: 0.925rem;
}

.blog-card {
    display: block;
    padding: 20px 24px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    text-decoration: none;
    color: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.blog-card:hover {
    border-color: var(--color-accent);
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.blog-card-date {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.blog-card-title {
    font-family: 'Source Serif 4', Georgia, serif;
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 6px;
}

.blog-card-excerpt {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
    margin-bottom: 8px;
}

.blog-card-read {
    font-size: 0.85rem;
    color: var(--color-accent);
    font-weight: 500;
}

/* ===== Footer ===== */
footer {
    padding: 32px 0;
    border-top: 1px solid var(--color-border);
    background: var(--color-surface);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-content p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

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

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .hero-container {
        flex-direction: column-reverse;
        gap: 24px;
        align-items: center;
        text-align: center;
    }

    .hero-text h1 {
        font-size: 2rem;
    }

    .hero-links {
        justify-content: center;
    }

    .profile-photo {
        width: 260px;
        height: 290px;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--color-bg);
        border-bottom: 1px solid var(--color-border);
        flex-direction: column;
        padding: 16px 24px;
        gap: 12px;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .awards-list {
        grid-template-columns: 1fr;
    }

    .competitions-grid,
    .notes-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }

    h2 {
        font-size: 1.5rem;
    }

    section {
        padding: 40px 0;
    }
}

@media (max-width: 480px) {
    .hero-text h1 {
        font-size: 1.7rem;
    }

    .container {
        padding: 0 16px;
    }
}