/* ========================================
   Ink Scholar · 新水墨画廊
   Modern Ink Gallery — Eastern aesthetics
   meets contemporary academic design
   ======================================== */

/* --- Light Theme: Rice Paper --- */
:root {
    --bg: #f5f1e8;
    --bg-alt: #ede8db;
    --bg-hero: #f5f1e8;
    --text: #1a1816;
    --text-secondary: #4a4540;
    --text-muted: #8a8478;
    --accent: #c23b22;
    --accent-dim: rgba(194, 59, 34, 0.12);
    --border: #d4cbb8;
    --ink-wash: radial-gradient(ellipse at 50% 30%, rgba(26,24,22,0.04) 0%, transparent 70%);
    --paper-texture: repeating-linear-gradient(
        0deg, transparent, transparent 2px,
        rgba(26,24,22,0.008) 2px, rgba(26,24,22,0.008) 4px
    );
    --font-cn: 'Noto Serif SC', 'Songti SC', Georgia, serif;
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Source Sans 3', 'Helvetica Neue', sans-serif;
    --transition: 0.4s ease;
}
/* ---- Global Resets ---- */
* { -webkit-tap-highlight-color: transparent; }
[data-theme="dark"] { color-scheme: dark; }
[data-theme="light"] { color-scheme: light; }
::selection { background: var(--accent); color: #fff; }


/* --- Dark Theme: Aged Ink --- */
[data-theme="dark"] {
    --bg: #12110e;
    --bg-alt: #1a1816;
    --bg-hero: #12110e;
    --text: #d4c5a9;
    --text-secondary: #a89e8a;
    --text-muted: #6a6258;
    --accent: #c23b22;
    --accent-dim: rgba(194, 59, 34, 0.15);
    --border: #2e2a24;
    --ink-wash: radial-gradient(ellipse at 50% 30%, rgba(212,197,169,0.03) 0%, transparent 70%);
    --paper-texture: repeating-linear-gradient(
        0deg, transparent, transparent 2px,
        rgba(212,197,169,0.01) 2px, rgba(212,197,169,0.01) 4px
    );
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: var(--font-body);
    background: var(--bg);
    background-image: var(--paper-texture);
    color: var(--text);
    line-height: 1.8;
    transition: background var(--transition), color var(--transition);
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--accent);
    text-decoration: none;
    position: relative;
}
a:hover { text-decoration: underline; }

/* ========================================
   Scroll Content (主容器)
   ======================================== */
.scroll-content {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 4rem;
    min-height: 100vh;
    position: relative;
}

/* ========================================
   Vertical TOC (竖排目录)
   ======================================== */
.vertical-toc {
    position: fixed;
    right: 2.5rem;
    top: 50%;
    transform: translateY(-50%);
    z-index: 100;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.8rem;
}

.toc-link {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-family: var(--font-body);
    font-size: 0.8rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-muted);
    text-decoration: none;
    padding: 0.5rem 0;
    position: relative;
    transition: color var(--transition);
}

.toc-link::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 0;
    width: 2px;
    height: 0;
    background: var(--accent);
    transition: height 0.3s ease;
}

.toc-link:hover,
.toc-link.active {
    color: var(--text);
    text-decoration: none;
}

.toc-link.active::before {
    height: 100%;
}

/* ========================================
   Theme Toggle (墨点)
   ======================================== */
.theme-toggle {
    position: fixed;
    top: 2.5rem;
    right: 2.5rem;
    z-index: 100;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 2px solid var(--border);
    background: var(--bg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
}

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

.toggle-dot {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--text);
    transition: background var(--transition), transform 0.3s ease;
}

[data-theme="dark"] .toggle-dot {
    transform: scale(0.5);
}

/* ========================================
   Hero (首屏)
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.ink-wash {
    position: absolute;
    inset: 0;
    background: var(--ink-wash);
    pointer-events: none;
}

.hero-inner {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 4rem 0;
}

.hero-photo {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    overflow: hidden;
    border: 2px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-alt);
    margin: 0 auto 1.5rem;
    flex-shrink: 0;
}

.hero-photo svg {
    width: 40px;
    height: 40px;
    color: var(--text-muted);
    opacity: 0.4;
}

.hero-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* 古训横幅 Motto Banner */
.motto-banner {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    margin: 2.5rem auto 0;
    max-width: 360px;
}

.motto-line {
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--text-muted), transparent);
    opacity: 0.4;
}

.motto-text {
    font-family: var(--font-cn);
    font-size: 0.95rem;
    font-weight: 300;
    letter-spacing: 0.35em;
    color: var(--text-muted);
    white-space: nowrap;
}

.hero-motif {
    margin-top: 2.5rem;
    display: flex;
    justify-content: center;
    opacity: 0.85;
}

.hero-name {
    font-family: var(--font-cn);
    font-size: 4.5rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-bottom: 0.8rem;
    line-height: 1.15;
}

.hero-role {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-style: italic;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    font-weight: 400;
}

.hero-bio {
    max-width: 520px;
    margin: 0 auto 2rem;
}

.hero-bio p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 2;
}

.hero-bio em {
    color: var(--accent);
    font-style: normal;
    font-weight: 500;
}

/* Hero links */
.hero-links {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    font-family: var(--font-body);
    font-size: 1.05rem;
}

.hero-links a {
    font-weight: 500;
    letter-spacing: 0.02em;
}

.link-dot {
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--text-muted);
}

/* ========================================
   Ink Brush Divider (水墨分隔线)
   ======================================== */
.ink-divider {
    height: 1px;
    margin: 5rem auto;
    position: relative;
    background: transparent;
}

.ink-divider::before {
    content: '';
    position: absolute;
    top: 0;
    left: 5%;
    width: 90%;
    height: 2px;
    background: linear-gradient(
        90deg,
        transparent 0%,
        var(--border) 15%,
        var(--text-muted) 40%,
        var(--text) 50%,
        var(--text-muted) 60%,
        var(--border) 85%,
        transparent 100%
    );
    opacity: 0.3;
    border-radius: 1px;
}

.ink-divider::after {
    content: '';
    position: absolute;
    top: -3px;
    left: 50%;
    transform: translateX(-50%);
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
    opacity: 0.6;
}

/* ========================================
   Section Grid Layout (左标签 + 右内容)
   ======================================== */
section {
    padding: 1rem 0;
}

.section-grid {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 3rem;
    align-items: start;
}

.section-side {
    position: sticky;
    top: 3rem;
    padding-top: 0.3rem;
}

.section-heading {
    font-family: var(--font-cn);
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    margin-bottom: 0.6rem;
    line-height: 1.3;
}

.section-label-cn {
    display: block;
    font-family: var(--font-cn);
    font-size: 0.85rem;
    color: var(--text-muted);
    letter-spacing: 0.2em;
}

/* ========================================
   Publications (论文发表)
   ======================================== */
.bib-list {
    list-style: none;
    padding-left: 0;
    counter-reset: bib-counter;
}

.bib-entry {
    margin-bottom: 2rem;
    padding: 1.2rem 1.5rem;
    font-size: 1.05rem;
    line-height: 1.9;
    color: var(--text-secondary);
    border-left: 3px solid var(--accent-dim);
    background: var(--bg-alt);
    transition: border-color 0.3s ease, background 0.3s ease;
}

.bib-entry:hover {
    border-left-color: var(--accent);
}

.bib-title {
    color: var(--text);
    font-family: var(--font-display);
    font-weight: 500;
}

.bib-venue em {
    font-family: var(--font-display);
}

.bib-links {
    font-size: 0.95rem;
    font-family: var(--font-body);
}

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

/* ========================================
   Experience Timeline (墨点时间线)
   ======================================== */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 5px;
    top: 10px;
    bottom: 10px;
    width: 1px;
    background: linear-gradient(180deg, var(--accent), var(--border));
}

.timeline-item {
    position: relative;
    margin-bottom: 2.2rem;
}

.timeline-item:last-child { margin-bottom: 0; }

.timeline-dot {
    position: absolute;
    left: -2rem;
    top: 8px;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid var(--bg);
    z-index: 1;
}

.timeline-content h3 {
    font-family: var(--font-cn);
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.15rem;
}

.timeline-content p {
    font-size: 1.05rem;
    color: var(--text-secondary);
}

.timeline-period {
    font-family: var(--font-display);
    font-size: 0.9rem;
    color: var(--text-muted);
    font-style: italic;
}

/* ========================================
   Projects (研究项目)
   ======================================== */
.project-entry {
    margin-bottom: 1.8rem;
    padding-bottom: 1.8rem;
    border-bottom: 1px solid var(--border);
}

.project-entry:last-child { border-bottom: none; padding-bottom: 0; }

.project-entry h3 {
    font-family: var(--font-cn);
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.4rem;
}

.project-entry p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ========================================
   Contact (联系方式)
   ======================================== */
.contact-line {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-family: var(--font-display);
    font-style: italic;
}

/* ========================================
   Footer (页脚)
   ======================================== */
.scroll-footer {
    margin-top: 5rem;
    padding: 3rem 0;
    text-align: center;
    border-top: 1px solid var(--border);
}

.scroll-footer p {
    font-size: 0.85rem;
    color: var(--text-muted);
    letter-spacing: 0.08em;
    font-family: var(--font-body);
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 1100px) {
    .vertical-toc { display: none; }
}

@media (max-width: 768px) {
    .scroll-content { padding: 0 1.5rem; }
    .section-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    .section-side {
        position: static;
        display: flex;
        align-items: baseline;
        gap: 1rem;
    }
    .section-label-cn { display: inline; }
    .hero-name { font-size: 3rem; }
    .hero { min-height: 85vh; }
    .ink-divider { margin: 3rem auto; }
    .theme-toggle { top: 1.2rem; right: 1.2rem; }
}

@media (max-width: 375px) {
    .hero { padding: 3rem 1rem; min-height: 80vh; }
    .hero-name { font-size: 2.5rem; }
    .hero-role { font-size: 0.8rem; }
    .section-grid { gap: 0.8rem; }
    .bib-entry { font-size: 0.85rem; }
    .timeline-content h3 { font-size: 0.95rem; }
    .contact-line { font-size: 0.9rem; }
}

/* ========================================
   Reduced Motion
   ======================================== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        transition-duration: 0.01ms !important;
    }
}

/* ---- Focus Styles ---- */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

/* ---- Skip Link ---- */
.skip-link { position: absolute; top: -40px; left: 0; background: var(--accent); color: #fff; padding: 8px 16px; z-index: 9999; font-size: 0.875rem; transition: top 0.2s; }
.skip-link:focus { top: 0; }