:root {
    /* Warm off-white / stone palette */
    --paper:    #f7f4ef;
    --paper-2:  #ede9e2;
    --paper-3:  #e4dfd5;
    --ink:      #1a1714;
    --ink-2:    #2e2a25;
    --ink-3:    #4a4540;
    --mid:      #7a7068;
    --ghost:    #a89f94;
    --rule:     rgba(26,23,20,0.10);
    --rule-s:   rgba(26,23,20,0.06);

    /* Accent — a refined vermilion/terracotta */
    --accent:   #c24b2a;
    --accent-2: #e05c37;
    --accent-bg: rgba(194,75,42,0.07);

    --f-display: 'Playfair Display', 'Noto Serif SC', Georgia, serif;
    --f-serif:   'Noto Serif SC', Georgia, serif;
    --f-sans:    'Noto Sans SC', -apple-system, sans-serif;
    --f-mono:    'DM Mono', 'Fira Code', monospace;

    --w: 1160px;
    --p: clamp(1.5rem, 5vw, 4rem);
    --r: 3px;
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior:smooth; }

body {
    font-family: var(--f-sans);
    background: var(--paper);
    color: var(--ink);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

/* Subtle grain texture overlay */
body::before {
    content: '';
    position: fixed; inset: 0;
    pointer-events: none;
    z-index: 9999;
    opacity: 0.025;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
    background-size: 200px;
}

/* ─── NAV ─── */
nav {
    position: fixed; top:0; width:100%; z-index:200;
    background: rgba(247,244,239,0.92);
    backdrop-filter: blur(24px) saturate(1.4);
    border-bottom: 1px solid var(--rule);
}
.nav-wrap {
    max-width: var(--w); margin:0 auto;
    padding: 0 var(--p);
    height: 60px;
    display: flex; align-items: center; justify-content: space-between;
}
.logo {
    font-family: var(--f-serif);
    font-size: 1.05rem; font-weight: 600;
    color: var(--ink); text-decoration: none;
    letter-spacing: .04em;
    display: flex; align-items: center; gap: 10px;
}
.logo-dot {
    width: 7px; height: 7px; border-radius: 50%;
    background: var(--accent); flex-shrink: 0;
}
.nav-links { display:flex; list-style:none; }
.nav-links a {
    display:block; padding:0 0.85rem;
    line-height: 60px; font-size:.83rem; font-weight:300;
    color: var(--mid); text-decoration:none; transition:color .2s;
    letter-spacing: .02em;
}
.nav-links a:hover { color: var(--ink); }

/* ─── HERO ─── */
.hero {
    padding: 148px var(--p) 100px;
    max-width: var(--w); margin:0 auto;
    position: relative;
}

/* Large decorative char */
.hero::after {
    content: '問';
    position: absolute;
    right: calc(var(--p) - 20px);
    top: 120px;
    font-family: var(--f-serif);
    font-size: 22vw;
    font-weight: 600;
    color: var(--ink);
    opacity: 0.025;
    line-height: 1;
    pointer-events: none;
    user-select: none;
}

.hero-eyebrow {
    font-family: var(--f-mono);
    font-size: .72rem; font-weight: 400;
    color: var(--accent); letter-spacing: .18em;
    text-transform: uppercase;
    margin-bottom: 2.2rem;
    display: flex; align-items: center; gap: 12px;
}
.hero-eyebrow::after {
    content: '';
    width: 40px; height: 1px;
    background: var(--accent);
    display: inline-block;
}

.hero-h1 {
    font-family: var(--f-display);
    font-size: clamp(3rem, 6.5vw, 5.6rem);
    font-weight: 400;
    line-height: 1.1;
    letter-spacing: -.02em;
    color: var(--ink);
    margin-bottom: 2rem;
    max-width: 760px;
}
.hero-h1 em {
    font-style: italic;
    color: var(--accent);
}
.hero-h1 .break { display: block; }

.hero-sub {
    font-size: 1.02rem; font-weight: 300;
    color: var(--mid); line-height: 1.85;
    max-width: 500px; margin-bottom: 2.4rem;
    font-family: var(--f-serif);
}
.hero-vision {
    font-family: var(--f-serif);
    font-size: .92rem; font-weight: 300;
    font-style: italic;
    color: var(--ghost); letter-spacing: .03em;
    margin-bottom: 2.8rem;
    display: flex; align-items: center; gap: 12px;
}
.hero-vision::before {
    content: '';
    width: 28px; height: 1px;
    background: var(--ghost);
}

.hero-actions { display:flex; align-items:center; gap:28px; }
.btn-primary {
    padding: 13px 34px;
    background: var(--ink); color: var(--paper);
    font-size:.88rem; font-weight:400;
    text-decoration:none; border-radius: var(--r);
    transition: all .25s; display:inline-block;
    font-family: var(--f-sans);
    letter-spacing: .04em;
}
.btn-primary:hover {
    background: var(--ink-2);
    box-shadow: 0 8px 32px rgba(26,23,20,0.2);
    transform: translateY(-1px);
}
.hero-link {
    font-size:.86rem; font-weight:300; color: var(--mid);
    text-decoration:none; transition:color .2s;
    display: flex; align-items: center; gap: 6px;
}
.hero-link:hover { color: var(--ink); }
.hero-link::after { content: '→'; }

.hero-stats {
    display: flex; gap: 60px; flex-wrap:wrap;
    margin-top: 80px;
    padding-top: 44px;
    border-top: 1px solid var(--rule);
}
.hstat-val {
    font-family: var(--f-display);
    font-size: 2.4rem; font-weight: 400;
    color: var(--ink); line-height: 1;
    letter-spacing: -.02em;
    margin-bottom: 6px;
}
.hstat-val span { color: var(--accent); }
.hstat-lbl { font-size:.78rem; font-weight:300; color: var(--ghost); font-family: var(--f-mono); }

/* ─── DIVIDER ─── */
.full-rule {
    width: 100%;
    border: none;
    border-top: 1px solid var(--rule);
}

/* ─── SECTION COMMONS ─── */
.section {
    padding: 110px var(--p);
    max-width: var(--w); margin: 0 auto;
}
.kicker {
    display: flex; align-items: center; gap: 10px;
    font-family: var(--f-mono);
    font-size: .72rem; font-weight: 400;
    color: var(--accent); letter-spacing: .14em;
    text-transform: uppercase; margin-bottom: 1.4rem;
}
.kicker::before {
    content: '';
    width: 20px; height: 1px;
    background: var(--accent);
    flex-shrink: 0;
}
.sec-h2 {
    font-family: var(--f-display);
    font-size: clamp(1.9rem, 3.8vw, 3.2rem);
    font-weight: 400; letter-spacing:-.02em;
    line-height:1.12; color: var(--ink);
}
.sec-lead {
    font-size:.97rem; font-weight:300;
    color: var(--mid); max-width:480px;
    line-height:1.85; margin-top:1.2rem;
    font-family: var(--f-serif);
}

/* ─── MODELS ─── */
.models-bg {
    background: var(--ink);
    color: #e8e2d8;
}
.models-bg .kicker { color: #c87b5f; }
.models-bg .kicker::before { background: #c87b5f; }
.models-bg .sec-h2 { color: #f0ebe3; }
.models-bg .sec-lead { color: #8a8077; }

.models-head {
    display:grid;
    grid-template-columns: 1fr 1fr;
    gap:80px; align-items:end;
    margin-bottom: 80px;
}

/* Featured model */
.model-feature {
    display:grid; grid-template-columns:1fr 1fr; gap:80px;
    padding-bottom: 64px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    align-items:start; margin-bottom:60px;
}
.model-feature-badge {
    display: inline-flex; align-items: center; gap: 6px;
    font-family: var(--f-mono); font-size:.68rem; font-weight:400;
    color: #c87b5f; letter-spacing:.12em;
    text-transform:uppercase; margin-bottom:1.2rem;
}
.badge-dot { width:5px; height:5px; border-radius:50%; background: #c87b5f; }
.model-feature-name {
    font-family: var(--f-display);
    font-size: clamp(1.9rem, 3.2vw, 2.8rem);
    font-weight:400; letter-spacing:-.02em; color:#f0ebe3;
    line-height:1.1; margin-bottom:1.3rem;
}
.model-feature-desc {
    font-size:.92rem; font-weight:300; color:#8a8077;
    line-height:1.85; margin-bottom:2rem;
    font-family: var(--f-serif);
}
.model-feature-tags { display:flex; flex-wrap:wrap; gap:8px; }
.mtag {
    font-family: var(--f-mono);
    font-size:.7rem; font-weight:300;
    color: #6a6058;
    border: 1px solid rgba(255,255,255,0.1);
    padding:4px 12px; border-radius: 2px;
    letter-spacing: .04em;
}
.model-feature-right { padding-top:8px; }
.model-feature-right p {
    font-size:.9rem; font-weight:300; color:#8a8077;
    line-height:1.85; font-family: var(--f-serif);
}

/* Model rows */
.model-row {
    display:grid; grid-template-columns:220px 1fr 200px;
    gap:0;
    border-top:1px solid rgba(255,255,255,0.07);
    align-items:start;
    padding: 36px 0;
    transition: background .3s;
}
.model-row:last-child { border-bottom:1px solid rgba(255,255,255,0.07); }
.model-row:hover { background: rgba(255,255,255,0.02); }
.mr-name {
    font-family: var(--f-serif);
    font-size:1.08rem; font-weight:500;
    color:#e8e2d8; letter-spacing:.01em;
    padding-right:24px; padding-top:2px;
}
.mr-desc {
    font-size:.86rem; font-weight:300; color:#7a7068;
    line-height:1.8; padding-right:40px;
    font-family: var(--f-serif);
}
.mr-tags { display:flex; flex-direction:column; gap:6px; align-items:flex-start; }
.mr-tag {
    font-family: var(--f-mono);
    font-size:.68rem; font-weight:300; color:#5a5048;
    display:flex; align-items:center; gap:8px;
    letter-spacing: .04em;
}
.mr-tag::before { content:''; width:12px; height:1px; background:#c87b5f; flex-shrink:0; }
.mr-link {
    color:#c87b5f; text-decoration:none;
    font-family: var(--f-mono);
    font-size:.72rem; font-weight:400;
    margin-top:10px; display:inline-block;
    letter-spacing: .04em;
    transition: opacity .2s;
}
.mr-link:hover { opacity: 0.7; }

/* ─── API ─── */
.api-inner {
    display:grid; grid-template-columns:1fr 1fr;
    gap:100px; align-items:center;
}
.api-code-block {
    background: var(--ink-2);
    border:1px solid rgba(255,255,255,0.08);
    border-radius:6px; overflow:hidden;
    box-shadow: 0 24px 60px rgba(26,23,20,0.12);
}
.code-top {
    padding:14px 20px;
    border-bottom:1px solid rgba(255,255,255,0.06);
    display:flex; align-items:center; gap:8px;
    background: rgba(255,255,255,0.02);
}
.code-dot { width:9px; height:9px; border-radius:50%; }
.code-filename {
    font-family: var(--f-mono);
    font-size:.72rem; font-weight:400; color:#5a5048;
    margin-left:4px;
}
pre {
    padding:28px 24px;
    font-family: var(--f-mono);
    font-size:.77rem; line-height:1.75;
    color:#9a9088; overflow-x:auto;
}
.c-comment { color:#4a4038; font-style: italic; }
.c-key     { color:#c0a882; }
.c-str     { color:#8faa86; }
.c-num     { color:#c8946c; }
.c-func    { color:#a8b8c8; }

.api-points { display:flex; flex-direction:column; gap:0; margin-top:44px; }
.api-point {
    display:grid; grid-template-columns:28px 1fr;
    gap:18px; padding:24px 0;
    border-top:1px solid var(--rule);
}
.api-point:last-child { border-bottom:1px solid var(--rule); }
.ap-num {
    font-family: var(--f-mono);
    font-size:.68rem; color: var(--ghost); padding-top:3px; font-weight:300;
}
.ap-body h4 { font-size:.92rem; font-weight:500; color: var(--ink); margin-bottom:5px; }
.ap-body p {
    font-size:.84rem; font-weight:300; color: var(--mid); line-height:1.7;
    font-family: var(--f-serif);
}

/* ─── RESEARCH ─── */
.research-bg { background: var(--paper-2); }
.research-inner {
    display:grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap:80px; align-items:center;
}
.research-img {
    width:100%; display:block;
    border-radius:4px;
    border:1px solid var(--rule);
    box-shadow: 0 16px 48px rgba(26,23,20,0.1);
}
.research-feat { display:flex; flex-direction:column; gap:0; margin-top:40px; }
.rfeat {
    display:grid; grid-template-columns:28px 1fr;
    gap:18px; padding:24px 0;
    border-top:1px solid var(--rule);
}
.rfeat:last-child { border-bottom:1px solid var(--rule); }
.rfeat-num {
    font-family: var(--f-mono);
    font-size:.68rem; color: var(--ghost); padding-top:3px;
}
.rfeat-body h4 { font-size:.92rem; font-weight:500; color: var(--ink); margin-bottom:5px; }
.rfeat-body p {
    font-size:.84rem; font-weight:300; color: var(--mid); line-height:1.7;
    font-family: var(--f-serif);
}

/* ─── CAMPUS ─── */
.campus-bg { background: var(--paper); }
.campus-card {
    position: relative;
    margin-top: 56px;
    background: var(--ink);
    border-radius: 8px;
    padding: 72px 80px;
    display: grid;
    grid-template-columns: 1fr 280px;
    gap: 80px;
    align-items: center;
    overflow: hidden;
}
.campus-card::before {
    content: '';
    position: absolute;
    bottom: -60px; right: -60px;
    width: 280px; height: 280px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(194,75,42,0.15) 0%, transparent 70%);
    pointer-events: none;
}
.campus-info { position: relative; z-index: 1; }
.campus-info .kicker { color: #c87b5f; }
.campus-info .kicker::before { background: #c87b5f; }
.campus-info h3 {
    font-family: var(--f-display);
    font-size: 2rem; font-weight: 400;
    color: #f0ebe3; margin-bottom: 20px; line-height: 1.2;
}
.campus-info p {
    font-size: .95rem; color: #7a7068;
    line-height: 1.85; margin-bottom: 36px;
    font-family: var(--f-serif);
    max-width: 460px;
}
.btn-campus {
    display: inline-block;
    padding: 12px 32px;
    background: var(--accent); color: #fff;
    font-size:.87rem; font-weight:400;
    text-decoration:none; border-radius: var(--r);
    transition: all .25s;
    letter-spacing: .04em;
}
.btn-campus:hover {
    background: var(--accent-2);
    box-shadow: 0 8px 28px rgba(194,75,42,0.35);
    transform: translateY(-1px);
}
.campus-promo {
    position: relative; z-index: 1;
    text-align: center;
    border-left: 1px solid rgba(255,255,255,0.08);
    padding-left: 60px;
}
.cp-val {
    font-family: var(--f-display);
    font-size: 5rem; font-weight: 400;
    color: #f0ebe3; line-height: 1;
    letter-spacing: -0.04em;
}
.cp-val span { font-size: 1.6rem; color: #c87b5f; vertical-align: super; }
.cp-lbl {
    margin-top: 12px;
    font-family: var(--f-mono);
    font-size: .72rem; color: #5a5048;
    text-transform: uppercase; letter-spacing: .12em;
}

/* ─── SOLUTIONS ─── */
.sol-rows { margin-top:64px; }
.sol-row {
    display:grid; grid-template-columns:200px 1fr 1fr;
    padding:40px 0;
    border-top:1px solid var(--rule);
    transition: background .2s;
}
.sol-row:last-child { border-bottom:1px solid var(--rule); }
.sol-row:hover { background: rgba(26,23,20,0.02); }
.sol-topic {
    font-family: var(--f-serif); font-size:1.02rem; font-weight:500;
    color: var(--ink); padding-right:20px; padding-top:2px; line-height:1.4;
}
.sol-topic small {
    display:block; font-family: var(--f-mono); font-size:.68rem; font-weight:300;
    color: var(--ghost); margin-bottom:7px; letter-spacing:.08em;
}
.sol-pain {
    font-size:.87rem; font-weight:300; color: var(--mid);
    line-height:1.8; padding-right:40px;
    font-family: var(--f-serif);
}
.sol-power {
    font-size:.87rem; font-weight:400; color: var(--ink-2);
    line-height:1.8;
    border-left:2px solid var(--accent); padding-left:24px;
    font-family: var(--f-serif);
}

/* ─── RESPONSIBILITY ─── */
.resp-bg { background: var(--paper-2); }
.mission-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    margin-top: 60px;
    border-top: 1px solid var(--rule);
    border-left: 1px solid var(--rule);
}
.mission-item {
    padding: 40px;
    border-right: 1px solid var(--rule);
    border-bottom: 1px solid var(--rule);
    transition: background .25s;
}
.mission-item:hover { background: rgba(26,23,20,0.025); }
.mission-num {
    font-family: var(--f-mono);
    font-size: .68rem; color: var(--ghost); margin-bottom: 16px; display: block;
    letter-spacing: .08em;
}
.mission-item h4 {
    font-family: var(--f-serif); font-size: 1.08rem; font-weight: 500;
    margin-bottom: 14px; color: var(--ink);
}
.mission-item p {
    font-size: .87rem; color: var(--mid); line-height: 1.8;
    font-family: var(--f-serif);
}

/* ─── CTA ─── */
.cta-section {
    padding: 140px var(--p);
    text-align: center; position: relative;
    overflow: hidden;
}
.cta-section::before {
    content: '无';
    position: absolute;
    font-family: var(--f-serif); font-weight: 600;
    font-size: 60vw; color: var(--ink); opacity: 0.025;
    top: 50%; left: 50%;
    transform: translate(-50%, -52%);
    pointer-events: none; user-select: none;
    line-height: 1;
}
.cta-inner { max-width: 640px; margin: 0 auto; position: relative; }
.cta-vision {
    font-family: var(--f-serif); font-size:.95rem; font-style:italic;
    color: var(--ghost); margin-bottom:1.8rem; font-weight:300;
    display: flex; align-items: center; justify-content: center; gap: 14px;
}
.cta-vision::before, .cta-vision::after {
    content: ''; width: 32px; height: 1px; background: var(--ghost);
}
.cta-h2 {
    font-family: var(--f-display);
    font-size: clamp(2.2rem, 4.5vw, 3.8rem);
    font-weight: 400; letter-spacing: -.02em;
    line-height: 1.1; color: var(--ink); margin-bottom: 1.4rem;
}
.cta-h2 em { font-style: italic; color: var(--accent); }
.cta-sub {
    font-size: .97rem; font-weight: 300; color: var(--mid);
    line-height: 1.85; margin-bottom: 3rem;
    font-family: var(--f-serif);
}
.cta-note {
    margin-top: 20px; font-family: var(--f-mono);
    font-size: .7rem; font-weight: 300; color: var(--ghost);
    letter-spacing: .08em;
}

/* ─── FOOTER ─── */
footer {
    background: var(--ink);
    color: #8a8077;
    padding: 80px var(--p) 40px;
}
.foot-wrap { max-width: var(--w); margin: 0 auto; }
.foot-top {
    display:grid; grid-template-columns:2.4fr 1fr 1fr 1fr;
    gap:60px; margin-bottom:64px;
}
.foot-brand-name {
    font-family: var(--f-serif); font-size:1.05rem;
    font-weight:600; color:#e8e2d8; margin-bottom:10px;
    display: flex; align-items: center; gap: 8px;
}
.foot-tagline {
    font-family: var(--f-serif); font-style:italic;
    font-size:.87rem; font-weight:300;
    color:#5a5048; margin-bottom:18px;
}
.foot-brand p {
    font-size:.82rem; font-weight:300;
    color:#5a5048; line-height:1.85;
    font-family: var(--f-serif);
}
.foot-col h5 {
    font-family: var(--f-mono);
    font-size:.68rem; font-weight:400; color:#4a4038;
    text-transform:uppercase; letter-spacing:.1em; margin-bottom:20px;
}
.foot-col a {
    display:block; font-size:.84rem; font-weight:300;
    color:#5a5048; text-decoration:none;
    margin-bottom:12px; transition:color .2s;
    font-family: var(--f-serif);
}
.foot-col a:hover { color:#e8e2d8; }
.foot-bottom {
    padding-top:28px; border-top:1px solid rgba(255,255,255,0.06);
    display:flex; justify-content:space-between; flex-wrap:wrap; gap:8px;
    font-family: var(--f-mono);
    font-size:.68rem; font-weight:300; color:#3a3830;
}
.foot-bottom a { color:inherit; text-decoration:none; transition:color .2s; }
.foot-bottom a:hover { color:#5a5048; }

/* ─── SCROLL REVEAL ─── */
.up { opacity:0; transform:translateY(24px); transition:opacity .7s cubic-bezier(.25,.46,.45,.94), transform .7s cubic-bezier(.25,.46,.45,.94); }
.up.show { opacity:1; transform:none; }
.d1 { transition-delay:.08s; }
.d2 { transition-delay:.16s; }
.d3 { transition-delay:.24s; }
.d4 { transition-delay:.32s; }

/* ─── RESPONSIVE ─── */
@media (max-width:1024px) {
    .models-head { grid-template-columns:1fr; gap:24px; }
    .model-feature { grid-template-columns:1fr; gap:32px; }
    .api-inner { grid-template-columns:1fr; }
    .research-inner { grid-template-columns:1fr; }
    .sol-row { grid-template-columns:1fr; gap:16px; }
    .sol-power { border-left:none; border-top:2px solid var(--accent); padding-left:0; padding-top:16px; }
    .foot-top { grid-template-columns:1fr 1fr; gap:40px; }
    .model-row { grid-template-columns:1fr; gap:12px; }
    .campus-card { grid-template-columns:1fr; padding:48px 40px; gap:48px; }
    .campus-promo { border-left:none; border-top:1px solid rgba(255,255,255,0.08); padding-left:0; padding-top:40px; }
    .mission-grid { grid-template-columns:1fr; border-left:none; }
    .mission-item { border-left:1px solid var(--rule); }
}
@media (max-width:640px) {
    .nav-links { display:none; }
    .hero::after { display:none; }
    .hero-stats { gap:36px; }
    .foot-top { grid-template-columns:1fr; gap:32px; }
    .cta-section { padding:100px var(--p); }
}