/* ============================================================
   MANIFOLD 流形 — Black / White / Futurist
   ============================================================ */

:root {
  --bg: #050505;
  --bg-soft: #0b0b0b;
  --ink: #f2f2f2;
  --ink-dim: #9a9a9a;
  --ink-faint: #4a4a4a;
  --line: rgba(255, 255, 255, 0.14);
  --line-strong: rgba(255, 255, 255, 0.35);
  --mono: "SF Mono", "JetBrains Mono", "IBM Plex Mono", Menlo, Consolas, monospace;
  --sans: "Helvetica Neue", "Roboto", "PingFang SC", "MiSans", "HarmonyOS Sans SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --serif: "Songti SC", "Noto Serif SC", "SimSun", serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  overflow-x: hidden;
  cursor: none;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--ink); color: var(--bg); }

a { color: inherit; text-decoration: none; }

/* ---------- noise overlay ---------- */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9990;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='120' height='120' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
}

/* ---------- custom cursor ---------- */
.cursor-dot, .cursor-ring {
  position: fixed;
  top: 0; left: 0;
  pointer-events: none;
  z-index: 9999;
  border-radius: 50%;
  transform: translate(-50%, -50%);
}
.cursor-dot { width: 6px; height: 6px; background: var(--ink); }
.cursor-ring {
  width: 34px; height: 34px;
  border: 1px solid var(--line-strong);
  transition: width .25s ease, height .25s ease, border-color .25s ease, opacity .25s;
}
.cursor-ring.is-hover { width: 56px; height: 56px; border-color: var(--ink); }
.cursor-label {
  position: fixed;
  z-index: 9999;
  pointer-events: none;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .15em;
  color: var(--bg);
  background: var(--ink);
  padding: 3px 8px;
  transform: translate(14px, 14px);
  opacity: 0;
  transition: opacity .2s;
  white-space: nowrap;
}
.cursor-label.show { opacity: 1; }
@media (hover: none) {
  body { cursor: auto; }
  .cursor-dot, .cursor-ring, .cursor-label { display: none; }
}

/* ---------- background canvas ---------- */
#manifold-canvas {
  position: fixed;
  inset: 0;
  z-index: 0;
  opacity: 0.9;
}

/* ---------- grid frame lines ---------- */
.frame-line {
  position: fixed;
  z-index: 1;
  background: var(--line);
  pointer-events: none;
}
.frame-line.v { top: 0; bottom: 0; width: 1px; }
.frame-line.h { left: 0; right: 0; height: 1px; }

/* ---------- nav ---------- */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 22px 4vw;
  mix-blend-mode: difference;
}
.nav-logo {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .35em;
  display: flex;
  align-items: center;
  gap: 12px;
}
.nav-logo .dot { width: 8px; height: 8px; border: 1px solid var(--ink); border-radius: 50%; }
.nav-links { display: flex; gap: 34px; font-family: var(--mono); font-size: 11px; letter-spacing: .2em; }
.nav-links a { position: relative; padding: 4px 0; color: var(--ink-dim); transition: color .3s; }
.nav-links a:hover { color: var(--ink); }
.nav-links a::before { content: "/"; position: absolute; left: -12px; opacity: 0; transition: opacity .3s; }
.nav-links a:hover::before { opacity: 1; }
@media (max-width: 760px) { .nav-links { display: none; } }

/* ---------- 语言切换 ---------- */
.lang-btn {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 120;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--ink);
  background: rgba(5, 5, 5, .6);
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 10px 20px;
  cursor: pointer;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: border-color .3s, background .3s;
}
.lang-btn:hover { border-color: var(--ink); background: rgba(255, 255, 255, .08); }

/* ---------- hero ---------- */
main { position: relative; z-index: 2; }

.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0 4vw;
  position: relative;
}
.hero-meta {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .3em;
  color: var(--ink-dim);
  display: flex;
  gap: 40px;
  margin-bottom: 3vh;
  flex-wrap: wrap;
}
.hero-title {
  font-size: clamp(64px, 14vw, 220px);
  line-height: .92;
  font-weight: 700;
  letter-spacing: -.02em;
  text-transform: uppercase;
}
.hero-title .stroke {
  color: transparent;
  -webkit-text-stroke: 1.5px var(--ink);
}
/* 描边字禁用合成粗体：移动端字体缺真 700 时，faux bold 会把描边画成错位重影 */
.hero-title .stroke, .sec-title .stroke, .foot-title .stroke, .p-glyph {
  font-synthesis: none;
  font-synthesis-weight: none;
}
/* 触屏设备兼平：部分国产浏览器内核不认 font-synthesis，中文无真粗体仍会重影，
   直接用常规字重描边（只看轮廓，不需要加粗），并把描边加粗一档补视觉量 */
@media (hover: none) {
  .hero-title .stroke, .sec-title .stroke, .foot-title .stroke, .p-glyph { font-weight: 400; }
  .hero-title .stroke { -webkit-text-stroke-width: 2px; }
  .sec-title .stroke, .foot-title .stroke { -webkit-text-stroke-width: 1.5px; }
}
.hero-title-row { display: flex; align-items: baseline; gap: 3vw; flex-wrap: wrap; }
.hero-cn {
  font-family: var(--serif);
  font-size: clamp(28px, 4vw, 64px);
  letter-spacing: .5em;
  color: var(--ink-dim);
  font-weight: 400;
}
/* 英文模式：SEMANTIC SKELETON 比「语义骨架」长得多，
   收紧字距缩小字号并禁止换行，保证留在「流形」右侧同一行 */
html[lang="en"] .hero-cn {
  font-size: clamp(18px, 2.6vw, 42px);
  letter-spacing: .2em;
  white-space: nowrap;
}
.hero-sub {
  margin-top: 5vh;
  max-width: 640px;
  font-size: clamp(15px, 1.4vw, 19px);
  line-height: 1.9;
  color: var(--ink-dim);
}
.hero-sub strong { color: var(--ink); font-weight: 600; }
.hero-coord {
  position: absolute;
  bottom: 34px;
  left: 4vw;
  right: 4vw;
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .25em;
  color: var(--ink-faint);
}
.hero-scroll {
  position: absolute;
  bottom: 90px;
  right: 4vw;
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .4em;
  color: var(--ink-dim);
  animation: floatY 2.4s ease-in-out infinite;
}
@keyframes floatY { 0%,100% { transform: translateY(0); } 50% { transform: translateY(10px); } }

/* ---------- marquee ---------- */
.marquee {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
  padding: 16px 0;
  background: rgba(5,5,5,.6);
  backdrop-filter: blur(4px);
}
.marquee-track {
  display: flex;
  width: max-content;
  animation: marquee 28s linear infinite;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .3em;
  color: var(--ink-dim);
  white-space: nowrap;
}
@keyframes marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }
.marquee-track span { padding: 0 34px; }
.marquee-track b { color: var(--ink); font-weight: 400; }

/* ---------- section shell ---------- */
section { position: relative; padding: 14vh 4vw; }
.sec-head { display: flex; align-items: flex-end; justify-content: space-between; margin-bottom: 8vh; gap: 20px; flex-wrap: wrap; }
.sec-index { font-family: var(--mono); font-size: 12px; letter-spacing: .3em; color: var(--ink-dim); }
.sec-title { font-size: clamp(38px, 6vw, 92px); font-weight: 700; letter-spacing: -.02em; line-height: 1.05; text-transform: uppercase; }
.sec-title .stroke { color: transparent; -webkit-text-stroke: 1px var(--ink); }
.sec-note { font-family: var(--mono); font-size: 11px; letter-spacing: .2em; color: var(--ink-faint); text-align: right; max-width: 300px; line-height: 2; }

/* ---------- generation axis (solution) ---------- */
.gen-axis { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line); }
.gen-cell {
  padding: 48px 36px 56px;
  border-right: 1px solid var(--line);
  position: relative;
  transition: background .4s;
  min-height: 300px;
  display: flex;
  flex-direction: column;
}
.gen-cell:last-child { border-right: none; }
.gen-cell:hover { background: rgba(255,255,255,.04); }
.gen-num { font-family: var(--mono); font-size: 11px; letter-spacing: .3em; color: var(--ink-faint); }
.gen-name { font-size: clamp(24px, 2.6vw, 40px); margin: 18px 0 6px; font-weight: 700; }
.gen-tag { font-family: var(--mono); font-size: 11px; letter-spacing: .2em; color: var(--ink-dim); margin-bottom: 24px; }
.gen-desc { font-size: 14px; line-height: 1.9; color: var(--ink-dim); flex: 1; }
.gen-cell.active-gen { background: var(--ink); color: var(--bg); }
.gen-cell.active-gen .gen-desc, .gen-cell.active-gen .gen-tag, .gen-cell.active-gen .gen-num { color: rgba(0,0,0,.65); }
.gen-cell.active-gen .gen-name { color: var(--bg); }
.gen-badge {
  display: inline-block;
  margin-top: 28px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .3em;
  border: 1px solid currentColor;
  padding: 6px 14px;
  width: fit-content;
}
@media (max-width: 900px) { .gen-axis { grid-template-columns: 1fr; } .gen-cell { border-right: none; border-bottom: 1px solid var(--line); min-height: 0; } .gen-cell:last-child { border-bottom: none; } }

/* ---------- products ---------- */
.products { display: grid; grid-template-columns: repeat(2, 1fr); border: 1px solid var(--line); }
.product {
  position: relative;
  border-bottom: 1px solid var(--line);
  padding: 44px 40px 40px;
  min-height: 320px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: background .45s;
}
.product:nth-child(odd) { border-right: 1px solid var(--line); }
.product:nth-last-child(-n+2) { border-bottom: none; }
.product:hover { background: rgba(255,255,255,.05); }
.p-index {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .3em;
  color: var(--ink-faint);
  display: flex;
  justify-content: space-between;
}
.p-status { display: flex; align-items: center; gap: 8px; }
.p-status .blink { width: 6px; height: 6px; border-radius: 50%; background: var(--ink); animation: blink 1.6s infinite; }
.p-status.soon .blink { background: var(--ink-faint); animation: none; }
@keyframes blink { 0%,100% { opacity: 1; } 50% { opacity: .15; } }
.p-glyph {
  position: absolute;
  right: -10px;
  bottom: -40px;
  font-size: clamp(120px, 14vw, 220px);
  font-weight: 700;
  color: transparent;
  -webkit-text-stroke: 1px rgba(255,255,255,.12);
  line-height: 1;
  pointer-events: none;
  transition: -webkit-text-stroke .5s, transform .6s cubic-bezier(.2,.8,.2,1);
}
.product:hover .p-glyph { -webkit-text-stroke: 1px rgba(255,255,255,.4); transform: translateY(-12px); }
.p-name { font-size: clamp(30px, 3.4vw, 52px); font-weight: 700; margin: 26px 0 4px; letter-spacing: .02em; }
.p-en { font-family: var(--mono); font-size: 11px; letter-spacing: .35em; color: var(--ink-dim); text-transform: uppercase; }
.p-desc { margin-top: 22px; font-size: 14px; line-height: 1.9; color: var(--ink-dim); max-width: 420px; flex: 1; }
.p-foot { margin-top: 30px; display: flex; justify-content: space-between; align-items: center; font-family: var(--mono); font-size: 11px; letter-spacing: .2em; }
.p-arrow { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); }
.p-arrow .bar { width: 42px; height: 1px; background: var(--ink); transition: width .35s; }
.product:hover .p-arrow .bar { width: 70px; }
.p-tags { color: var(--ink-faint); font-size: 10px; }
@media (max-width: 900px) {
  .products { grid-template-columns: 1fr; }
  .product:nth-child(odd) { border-right: none; }
  .product:nth-last-child(-n+2) { border-bottom: 1px solid var(--line); }
  .product:last-child { border-bottom: none; }
}

/* ---------- syntax demo ---------- */
.syntax-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 6vw; align-items: center; }
@media (max-width: 900px) { .syntax-wrap { grid-template-columns: 1fr; gap: 60px; } }
.code-panel {
  border: 1px solid var(--line);
  background: var(--bg-soft);
  font-family: var(--mono);
  font-size: 13px;
  line-height: 2.2;
  padding: 36px;
  position: relative;
  overflow-x: auto;
}
.code-panel::before {
  content: "MANIFOLD / INLINE ANNOTATION";
  position: absolute;
  top: 0; left: 0;
  font-size: 9px;
  letter-spacing: .3em;
  color: var(--ink-faint);
  border-bottom: 1px solid var(--line);
  border-right: 1px solid var(--line);
  padding: 8px 14px;
}
.code-panel code { display: block; margin-top: 28px; white-space: pre-wrap; word-break: break-all; }
.anno { border-bottom: 1px solid var(--ink-dim); padding: 0 2px; position: relative; transition: background .3s, color .3s; }
.anno:hover { background: var(--ink); color: var(--bg); }
.tk { color: var(--ink-faint); }
.syntax-list { display: flex; flex-direction: column; gap: 0; border-top: 1px solid var(--line); }
.syntax-item {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 24px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}
.syntax-item .sig { font-family: var(--mono); font-size: 13px; color: var(--ink); }
.syntax-item .mean { font-size: 13px; color: var(--ink-dim); line-height: 1.8; }

/* ---------- chain ---------- */
.chain-grid { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); }
.chain-cell { padding: 36px 28px 44px; border-right: 1px solid var(--line); min-height: 220px; display: flex; flex-direction: column; gap: 14px; transition: background .4s; }
.chain-cell:last-child { border-right: none; }
.chain-cell:hover { background: rgba(255,255,255,.05); }
.chain-step { font-family: var(--mono); font-size: 11px; letter-spacing: .3em; color: var(--ink-faint); }
.chain-name { font-size: 20px; font-weight: 700; }
.chain-desc { font-size: 13px; line-height: 1.9; color: var(--ink-dim); flex: 1; }
.chain-data { font-family: var(--mono); font-size: 10px; letter-spacing: .15em; color: var(--ink-faint); }
@media (max-width: 900px) { .chain-grid { grid-template-columns: 1fr 1fr; } .chain-cell:nth-child(2n) { border-right: none; } .chain-cell { border-bottom: 1px solid var(--line); } .chain-cell:nth-last-child(-n+2) { border-bottom: none; } }
@media (max-width: 560px) { .chain-grid { grid-template-columns: 1fr; } .chain-cell { border-right: none !important; border-bottom: 1px solid var(--line) !important; } .chain-cell:last-child { border-bottom: none !important; } }

/* ---------- footer ---------- */
footer {
  border-top: 1px solid var(--line);
  padding: 10vh 4vw 5vh;
  position: relative;
  z-index: 2;
  background: var(--bg);
}
.foot-title {
  font-size: clamp(48px, 10vw, 160px);
  font-weight: 700;
  line-height: .95;
  text-transform: uppercase;
  letter-spacing: -.02em;
}
.foot-title .stroke { color: transparent; -webkit-text-stroke: 1px var(--ink); }
.foot-grid { display: flex; justify-content: space-between; margin-top: 8vh; gap: 30px; flex-wrap: wrap; font-family: var(--mono); font-size: 11px; letter-spacing: .2em; color: var(--ink-dim); line-height: 2.4; }
.foot-grid b { color: var(--ink); font-weight: 400; }

/* ---------- reveal animations ---------- */
.reveal { opacity: 0; transform: translateY(40px); transition: opacity .9s cubic-bezier(.2,.8,.2,1), transform .9s cubic-bezier(.2,.8,.2,1); }
.reveal.in { opacity: 1; transform: none; }

/* ============================================================
   PRODUCT DETAIL PAGES
   ============================================================ */
.detail-hero { min-height: 72vh; display: flex; flex-direction: column; justify-content: flex-end; padding: 0 4vw 8vh; position: relative; }
.detail-hero .p-glyph.big {
  position: absolute;
  right: 2vw;
  top: 8vh;
  font-size: clamp(200px, 30vw, 480px);
  -webkit-text-stroke: 1px rgba(255,255,255,.08);
}
.back-link {
  position: fixed;
  top: 22px; left: 4vw;
  z-index: 101;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .3em;
  mix-blend-mode: difference;
  display: flex; align-items: center; gap: 10px;
}
.back-link .bar { width: 34px; height: 1px; background: var(--ink); transition: width .3s; }
.back-link:hover .bar { width: 54px; }
.detail-meta { font-family: var(--mono); font-size: 11px; letter-spacing: .3em; color: var(--ink-dim); display: flex; gap: 34px; flex-wrap: wrap; margin-bottom: 3vh; }
.detail-title { font-size: clamp(56px, 11vw, 180px); font-weight: 700; line-height: .95; letter-spacing: -.02em; }
.detail-title-en { font-family: var(--mono); font-size: clamp(11px, 1.2vw, 14px); letter-spacing: .5em; color: var(--ink-dim); margin-top: 2vh; text-transform: uppercase; }
.detail-lead { max-width: 680px; margin-top: 5vh; font-size: clamp(15px, 1.5vw, 20px); line-height: 2; color: var(--ink-dim); }
.detail-lead strong { color: var(--ink); font-weight: 600; }

.spec-grid { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line); }
.spec-cell { padding: 40px; border-bottom: 1px solid var(--line); }
.spec-cell:nth-child(odd) { border-right: 1px solid var(--line); }
.spec-cell:nth-last-child(-n+2) { border-bottom: none; }
.spec-cell h3 { font-family: var(--mono); font-size: 11px; letter-spacing: .3em; color: var(--ink-faint); margin-bottom: 22px; font-weight: 400; }
.spec-cell p, .spec-cell li { font-size: 14px; line-height: 2; color: var(--ink-dim); }
.spec-cell ul { list-style: none; }
.spec-cell li { padding-left: 18px; position: relative; }
.spec-cell li::before { content: "—"; position: absolute; left: 0; color: var(--ink-faint); }
.spec-cell code { font-family: var(--mono); font-size: 12px; color: var(--ink); }
@media (max-width: 900px) { .spec-grid { grid-template-columns: 1fr; } .spec-cell { border-right: none !important; border-bottom: 1px solid var(--line) !important; } .spec-cell:last-child { border-bottom: none !important; } }

.demo-panel {
  border: 1px solid var(--line);
  background: var(--bg-soft);
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 2.1;
  padding: 40px;
  overflow-x: auto;
  white-space: pre;
  color: var(--ink-dim);
}
.demo-panel .hl { color: var(--ink); }

.next-products { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line); }
.next-item { padding: 34px 30px; border-right: 1px solid var(--line); transition: background .35s; display: block; }
.next-item:last-child { border-right: none; }
.next-item:hover { background: rgba(255,255,255,.06); }
.next-item .ni-idx { font-family: var(--mono); font-size: 10px; letter-spacing: .3em; color: var(--ink-faint); }
.next-item .ni-name { font-size: 22px; font-weight: 700; margin-top: 12px; }
.next-item .ni-en { font-family: var(--mono); font-size: 10px; letter-spacing: .25em; color: var(--ink-dim); margin-top: 4px; text-transform: uppercase; }
@media (max-width: 760px) { .next-products { grid-template-columns: 1fr; } .next-item { border-right: none; border-bottom: 1px solid var(--line); } .next-item:last-child { border-bottom: none; } }