/* =====================================================================
   Lignin 格致 · 统一设计系统  v3.0
   风格：学术简约 · 克制高级
   ===================================================================== */

:root {
    --blue:        #0072B2;
    --blue-dark:   #005A8F;
    --blue-soft:   #eaf3fa;
    --orange:      #C75300;
    --orange-soft: #fbeee4;

    --ink-900: #16202e;
    --ink-700: #344155;
    --ink-500: #64748b;
    --ink-400: #94a3b8;

    --paper:   #ffffff;
    --bg:      #f7f9fb;
    --bg-tint: #f1f5f9;
    --line:    #e6ebf1;
    --line-strong: #d6dee8;

    --shadow-xs: 0 1px 2px rgba(16,24,40,.05);
    --shadow-sm: 0 1px 2px rgba(16,24,40,.05), 0 1px 3px rgba(16,24,40,.045);
    --shadow-md: 0 10px 30px rgba(16,24,40,.07), 0 3px 8px rgba(16,24,40,.04);
    --shadow-lg: 0 22px 50px rgba(16,24,40,.11), 0 6px 14px rgba(16,24,40,.05);

    --r-sm: 8px;
    --r-md: 12px;
    --r-lg: 16px;
    --r-full: 999px;

    --font-sans:  'Inter','Noto Sans SC',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',sans-serif;
    --font-serif: 'Noto Serif SC','Source Han Serif SC','Songti SC',STSong,serif;

    --ease: cubic-bezier(.4,0,.2,1);

    --primary-blue: #0072B2;
    --primary-orange: #C75300;
    --dark-blue: #005A8F;
    --light-blue: #eaf3fa;
    --text-primary: #16202e;
    --text-secondary: #344155;
    --text-muted: #64748b;
    --bg-primary: #ffffff;
    --bg-secondary: #f7f9fb;
    --bg-tertiary: #f1f5f9;
    --border-radius: 16px;
    --border-radius-lg: 16px;
    --border-radius-xl: 20px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 15px; }

body {
    font-family: var(--font-sans);
    background: linear-gradient(180deg, #fbfcfe 0%, var(--bg) 30%);
    background-attachment: fixed;
    color: var(--ink-700);
    line-height: 1.68;
    font-size: 1rem;
    margin: 0;
    padding: 0;
    font-weight: 400;
    letter-spacing: -0.004em;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
    font-family: var(--font-serif);
    color: var(--ink-900);
    font-weight: 700;
    letter-spacing: 0.01em;
    line-height: 1.4;
}

a { text-decoration: none; }
::selection { background: rgba(0,114,178,.16); color: var(--ink-900); }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-tint); }
::-webkit-scrollbar-thumb {
    background: #c3cedb;
    border-radius: var(--r-full);
    border: 2px solid var(--bg-tint);
}
::-webkit-scrollbar-thumb:hover { background: var(--blue); }

/* ===== 导航栏 ===== */
.header {
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border-bottom: 1px solid var(--line);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: box-shadow .3s var(--ease), background .3s var(--ease);
}
.header.scrolled {
    box-shadow: var(--shadow-sm);
    background: rgba(255,255,255,.94);
}

.site-brand {
    display: inline-flex;
    align-items: baseline;
    gap: .55rem;
    font-family: var(--font-serif);
    font-weight: 700;
    font-size: 1.4rem;
    letter-spacing: .02em;
    line-height: 1;
}
.site-brand .brand-cof  { color: var(--orange); }
.site-brand .brand-zyme { color: var(--blue); }
.site-brand .brand-cn {
    font-size: .95rem;
    color: var(--ink-500);
    letter-spacing: .18em;
    font-weight: 500;
    padding-left: .55rem;
    border-left: 1px solid var(--line-strong);
}

.nav { display: flex; align-items: center; gap: .25rem; flex-wrap: wrap; }
.nav-link {
    color: var(--ink-500);
    font-family: var(--font-sans);
    font-weight: 500;
    font-size: .96rem;
    letter-spacing: .01em;
    padding: .5rem .85rem;
    border-radius: var(--r-sm);
    position: relative;
    transition: color .25s var(--ease), background .25s var(--ease);
}
.nav-link::after {
    content: '';
    position: absolute;
    left: .85rem; right: .85rem; bottom: .28rem;
    height: 2px;
    background: var(--blue);
    border-radius: 2px;
    transform: scaleX(0);
    transform-origin: center;
    transition: transform .28s var(--ease);
}
.nav-link:hover { color: var(--ink-900); }
.nav-link:hover::after { transform: scaleX(.6); }
.nav-link.active { color: var(--blue); font-weight: 600; }
.nav-link.active::after { transform: scaleX(1); }
.nav-link .lang-flag { margin-right: .35rem; opacity: .8; }

/* ===== 英雄区 ===== */
.page-hero { text-align: center; padding: 3.25rem 1rem 2.5rem; }
.page-hero h1 {
    font-size: clamp(2rem, 4.2vw, 2.9rem);
    margin: 0 0 .55rem;
    letter-spacing: -0.022em;
    line-height: 1.18;
    background: linear-gradient(118deg, var(--blue) 0%, var(--blue) 50%, var(--orange) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: var(--ink-900);
    -webkit-text-fill-color: transparent;
}
.hero-rule {
    width: 56px; height: 3px;
    margin: 1.1rem auto 0;
    border-radius: var(--r-full);
    background: linear-gradient(90deg, var(--blue), var(--orange));
}
.hero-sub {
    font-family: var(--font-serif);
    font-size: clamp(1.25rem, 2.4vw, 1.75rem);
    font-weight: 700;
    letter-spacing: .03em;
    margin-top: 1rem;
    background: linear-gradient(100deg, var(--blue) 0%, var(--blue) 38%, var(--orange) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: var(--blue);
    -webkit-text-fill-color: transparent;
}
.hero-lead {
    max-width: 44rem;
    margin: 1.15rem auto 0;
    color: #5c6b7d;
    font-size: 1.1rem;
    font-weight: 400;
    letter-spacing: .005em;
    line-height: 1.65;
}
.hero-role {
    color: var(--ink-500);
    font-size: 1.02rem;
    font-weight: 500;
    letter-spacing: .01em;
    margin: .1rem 0 0;
}
.hero-avatar {
    width: 7rem; height: 7rem;
    margin: .25rem auto 1.2rem;
    border: 4px solid #fff;
    box-shadow: 0 8px 24px -6px rgba(16,24,40,.22);
    ring-offset: 0;
}
.hero-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: .5rem;
    margin-top: 1.15rem;
}
.eyebrow {
    display: inline-block;
    font-family: var(--font-sans);
    font-size: .8rem;
    font-weight: 600;
    letter-spacing: .22em;
    text-transform: uppercase;
    color: var(--blue);
    margin-bottom: 1rem;
}

/* ===== 卡片 ===== */
.card {
    background: var(--paper);
    border: 1px solid transparent;
    border-radius: var(--r-lg);
    box-shadow: 0 1px 2px rgba(16,24,40,.04), 0 14px 30px -14px rgba(16,24,40,.12);
    transition: transform .45s var(--ease), box-shadow .45s var(--ease);
    position: relative;
    overflow: hidden;
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 2px 6px rgba(16,24,40,.05), 0 26px 50px -18px rgba(16,24,40,.18);
}

.feature-card { text-align: center; }
.feature-card .feature-icon {
    width: 64px; height: 64px;
    margin: 0 auto 1.4rem;
    border-radius: var(--r-md);
    display: flex; align-items: center; justify-content: center;
    font-size: 1.6rem;
    color: var(--blue);
    background: var(--blue-soft);
    transition: background .35s var(--ease), color .35s var(--ease);
}
.feature-card:hover .feature-icon { background: var(--blue); color: #fff; }
.feature-card h2, .feature-card h3 { font-size: 1.3rem; margin: 0 0 .5rem; }
.feature-card p { color: var(--ink-500); margin: 0 0 1.5rem; font-size: .98rem; }

/* ===== 按钮 ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: .5rem;
    background: var(--blue);
    color: #fff;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: .95rem;
    letter-spacing: .01em;
    padding: .65rem 1.5rem;
    border-radius: var(--r-sm);
    border: none;
    cursor: pointer;
    box-shadow: var(--shadow-xs);
    transition: background .25s var(--ease), transform .25s var(--ease), box-shadow .25s var(--ease);
}
.btn:hover {
    background: var(--blue-dark);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.btn:active { transform: translateY(0); }
.btn-ghost {
    background: transparent;
    color: var(--blue);
    border: 1px solid var(--line-strong);
    box-shadow: none;
}
.btn-ghost:hover { background: var(--blue-soft); color: var(--blue-dark); }

/* ===== 研究标签 ===== */
.research-tag {
    display: inline-flex;
    align-items: center;
    background: var(--blue-soft);
    color: var(--blue);
    padding: .4rem .95rem;
    border-radius: var(--r-full);
    margin: 0 .55rem .55rem 0;
    font-family: var(--font-sans);
    font-size: .88rem;
    font-weight: 500;
    border: 1px solid rgba(0,114,178,.16);
    transition: background .25s var(--ease), color .25s var(--ease), transform .25s var(--ease);
    cursor: default;
}
.research-tag:hover { background: var(--blue); color: #fff; transform: translateY(-2px); }

/* ===== 论文 / 项目 / 专利 条目 ===== */
.publication-item {
    border-left: 3px solid var(--blue);
    background: var(--bg);
    padding: .8rem 1.15rem;
    margin-bottom: .85rem;
    border-radius: 0 var(--r-sm) var(--r-sm) 0;
    transition: border-color .25s var(--ease), background .25s var(--ease), box-shadow .25s var(--ease), transform .25s var(--ease);
}
.publication-item:hover { border-left-color: var(--orange); background: var(--blue-soft); box-shadow: var(--shadow-xs); transform: translateX(2px); }
.publication-item .pub-title { font-family: var(--font-sans); font-weight: 600; color: var(--ink-900); }
.publication-item .pub-meta  { font-size: .88rem; color: var(--ink-500); margin-top: .15rem; }
.publication-item .pub-note  { font-size: .9rem; color: var(--ink-700); margin-top: .25rem; }

/* ===== 章节标题 / 排版辅助 ===== */
.section-title {
    font-size: 1.5rem;
    color: var(--ink-900);
    margin: 0 0 1.1rem;
    padding-bottom: .55rem;
    position: relative;
}
.section-title::after {
    content: '';
    position: absolute;
    left: 0; bottom: 0;
    width: 44px; height: 3px;
    border-radius: 2px;
    background: var(--orange);
}
.subhead {
    font-family: var(--font-sans);
    font-weight: 600;
    color: var(--orange);
    border-bottom: 1px solid var(--line);
    padding-bottom: .5rem;
    margin-bottom: 1rem;
}
.info-panel {
    background: var(--bg);
    border: 1px solid var(--line);
    border-left: 4px solid var(--blue);
    border-radius: var(--r-md);
    padding: 1.25rem 1.4rem;
}
.info-panel.accent-green { border-left-color: #2e9e6b; }
.info-panel h4 { font-family: var(--font-sans); font-size: 1.02rem; margin: 0 0 .6rem; color: var(--ink-900); }

.gradient-bg {
    background: linear-gradient(135deg, var(--blue-soft), #f3f8fc);
    border: 1px solid var(--line);
    border-radius: var(--r-md);
}

.avatar {
    border-radius: var(--r-full);
    object-fit: cover;
    background: var(--bg-tint);
    border: 3px solid #fff;
    box-shadow: var(--shadow-sm);
}

.figure-frame {
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    padding: 1rem;
    box-shadow: var(--shadow-xs);
}

/* ===== 紧凑排版（全站统一微调） ===== */
.card.p-8 { padding: 1.6rem 1.75rem; }
.card.p-9 { padding: 1.75rem 1.9rem; }
.card.p-5 { padding: 1.1rem; }
main.py-12 { padding-top: 2rem; padding-bottom: 1.5rem; }
.card.mb-10 { margin-bottom: 1.85rem; }
@media (min-width: 768px) {
    .page-hero { padding-top: 2.75rem; padding-bottom: 2.25rem; }
}

/* ===== 页脚 ===== */
.site-footer {
    background: #0e1a28;
    color: #cdd7e3;
    padding: 2.5rem 1rem 2rem;
    margin-top: 3rem;
    text-align: center;
    position: relative;
}
.site-footer::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,.18), transparent);
}
.site-footer .footer-brand { font-family: var(--font-serif); font-size: 1.5rem; font-weight: 700; letter-spacing: .03em; }
.site-footer .footer-brand .brand-cof  { color: #f08a3c; }
.site-footer .footer-brand .brand-zyme { color: #57aede; }
.site-footer .footer-tag { font-size: .82rem; letter-spacing: .25em; color: #7d8da0; margin-top: .5rem; }
.site-footer .footer-copy { color: #aab6c4; font-size: .92rem; margin-top: 1.4rem; }
.site-footer .footer-fine { color: #7d8da0; font-size: .82rem; margin-top: .35rem; }
.site-footer .footer-fine a { color: #9fb3c8; text-decoration: underline; transition: color .2s; }
.site-footer .footer-fine a:hover { color: #57aede; }
.site-footer .footer-divider { width: 60px; height: 1px; background: rgba(255,255,255,.16); margin: 1.6rem auto 0; }

/* ===== 进场动画 ===== */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(18px); }
    to   { opacity: 1; transform: translateY(0); }
}
.reveal { opacity: 0; animation: fadeInUp .7s var(--ease) forwards; }

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: .01ms !important;
        transition-duration: .01ms !important;
        scroll-behavior: auto !important;
    }
    .reveal { opacity: 1; }
}

/* ===== 响应式 ===== */
@media (max-width: 860px) {
    .nav { gap: 0; }
    .nav-link { padding: .45rem .6rem; font-size: .9rem; }
    .site-brand { font-size: 1.2rem; }
    .site-brand .brand-cn { display: none; }
}
@media (max-width: 640px) {
    .page-hero { padding: 2.5rem .75rem 2rem; }
    html { font-size: 15.5px; }
}