/* ============================================================
   DeepSeek V4 介绍页 · style.css
   Taste Skill (tasteskill.dev) — DESIGN_VARIANCE 8 / MOTION 6 / DENSITY 4
   Zinc neutral base · single desaturated accent · no emoji · no neon
   ============================================================ */

:root {
  --bg: #fafafa;
  --surface: #ffffff;
  --ink: #18181b;        /* zinc-900, off-black */
  --ink-2: #3f3f46;
  --ink-3: #71717a;
  --ink-4: #a1a1aa;
  --line: #e4e4e7;
  --line-2: #d4d4d8;
  --accent: #2457e0;     /* single accent, saturation < 80% */
  --accent-deep: #1b44b8;
  --accent-soft: #e8edfb;
  --dark: #0c0c0e;       /* off-black, never #000 */
  --dark-2: #141417;
  --dark-line: #26262b;
  --ok: #0d9e6c;

  --font-display: "Outfit", "Noto Sans SC", "PingFang SC", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --container: 1180px;
  --radius: 20px;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--accent); color: #fff; }

a { color: inherit; text-decoration: none; }
img, svg { display: block; }

.mono { font-family: var(--font-mono); }
.text-link { color: var(--accent); border-bottom: 1px solid color-mix(in srgb, var(--accent) 40%, transparent); transition: border-color .3s var(--ease); }
.text-link:hover { border-color: var(--accent); }

/* ---------- Reveal system (JS adds .is-in; .js-off keeps content visible) ---------- */
.js-off [data-reveal] { opacity: 1 !important; transform: none !important; }
[data-reveal] {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .8s var(--ease) var(--d, 0ms), transform .8s var(--ease) var(--d, 0ms);
  will-change: opacity, transform;
}
[data-reveal].is-in { opacity: 1; transform: none; }

/* ============================================================
   NAV
   ============================================================ */
/* ============================================================
   NAV — deepseek.com official style: floating capsule, glass on scroll
   ============================================================ */
.ds-header-wrapper {
  position: fixed;
  top: 0; left: 0; right: 0;
  margin: 0 auto;
  z-index: 50;
  width: min(100% - 48px, 1280px);
  padding: 10px 0 0;
}
@media (min-width: 768px) { .ds-header-wrapper { width: min(100% - 144px, 1280px); } }

/* 官网同款：滚动时弹簧收缩（spring stiffness 180 / damping 28 的 CSS 近似） */
.ds-header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin: 0 auto;
  max-width: 1280px;
  padding: 8px 0;
  border-radius: 999px;
  border: 1px solid transparent;
  background: transparent;
  transition:
    max-width .55s cubic-bezier(.22, 1.15, .35, 1),
    padding .55s cubic-bezier(.22, 1.15, .35, 1),
    background-color .3s ease, border-color .3s ease, backdrop-filter .3s ease;
}
.ds-header-bar.is-scrolled {
  max-width: 980px;
  padding-left: 16px;
  padding-right: 6px;
  background: color-mix(in srgb, var(--surface) 78%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-color: var(--line);
  box-shadow: 0 10px 30px -18px rgba(24, 24, 27, 0.18);
}
@media (min-width: 1560px) {
  .ds-header-bar.is-scrolled { max-width: 1180px; }
}

.brand { display: flex; align-items: center; flex: none; color: var(--ds-brand, #152443); }
.brand svg { width: 143px; height: 23px; }
.brand svg path { fill: currentColor; }

.ds-nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  margin: 0 auto;   /* centered between logo and right group */
}
.ds-nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--ink-2);
  padding: 7px 14px;
  border-radius: 999px;
  transition: color .25s ease, background-color .25s ease;
}
.ds-nav-links a:hover { color: var(--ink); background: color-mix(in srgb, var(--line) 45%, transparent); }

.header-right { display: flex; align-items: center; gap: 10px; flex: none; }

.ds-btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: 1px solid var(--line-2);
  background: transparent;
  color: var(--ink-2);
  border-radius: 999px;
  cursor: pointer;
  transition: border-color .25s ease, color .25s ease, background-color .25s ease;
}
.ds-btn-ghost:hover { border-color: var(--ink); color: var(--ink); }
.ds-btn-solid {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: #fff;
  border-radius: 999px;
  cursor: pointer;
  transition: background .25s ease, border-color .25s ease,
              transform .25s ease, box-shadow .25s ease;
}
.ds-btn-solid:hover {
  background: #000;
  border-color: #000;
  box-shadow: 0 8px 20px -10px rgba(24, 24, 27, 0.45);
  transform: translateY(-1px);
}
.ds-btn-solid:active { transform: scale(0.97); }
.ds-btn-s { padding: 6px 14px; }
.ds-btn-nav { font-size: 15px; }

.ds-locale-toggle {
  display: flex;
  align-items: center;
  height: 32px;
  padding: 3px;
  border-radius: 999px;
  border: 1px solid var(--line-2);
}
.ds-locale-toggle-item {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: 0 12px;
  border: none;
  border-radius: 999px;
  background: transparent;
  font-size: 12px;
  font-weight: 500;
  font-family: var(--font-body);
  color: var(--ink-3);
  cursor: pointer;
  transition: color .2s ease, background-color .2s ease, box-shadow .2s ease;
}
.ds-locale-toggle-item.is-active {
  background: var(--surface);
  color: var(--ink);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px; height: 40px;
  border: none;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
}

/* mobile full-screen menu */
.ds-mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 9990;
  background: var(--bg);
  display: flex;
  flex-direction: column;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease;
}
.ds-mobile-menu.is-open { opacity: 1; pointer-events: auto; }
.ds-mobile-menu-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
}
.ds-mobile-menu-header .brand svg { width: 120px; height: 19px; }
.menu-close {
  display: flex; align-items: center; justify-content: center;
  width: 40px; height: 40px;
  border: none; background: transparent;
  color: var(--ink); cursor: pointer;
}
.ds-mobile-menu-body {
  flex: 1;
  overflow-y: auto;
  padding: 8px 20px;
  display: flex;
  flex-direction: column;
}
.ds-mobile-menu-item {
  display: flex;
  align-items: center;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  font-size: 18px;
  font-weight: 500;
  color: var(--ink);
}
.ds-mobile-menu-item:hover { color: var(--accent); }

@media (max-width: 900px) {
  .ds-nav-links { display: none; }
  .ds-header-wrapper { width: min(100% - 32px, 1140px); padding-top: 8px; }
  .ds-header-bar { padding: 6px 12px; }
  .header-right .ds-btn-nav,
  .ds-locale-toggle { display: none; }   /* 同官网：移动端只保留汉堡 */
  .menu-toggle { display: flex; }
  .brand svg { width: 118px; height: 19px; }
}

/* ============================================================
   HERO — split screen, left-aligned, asymmetric
   ============================================================ */
.hero {
  min-height: 100dvh;   /* never h-screen */
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  /* official gradient base layer */
  background: linear-gradient(180deg, #9cc1e7 0%, rgba(250, 250, 250, 0) 100%);
}
/* fx layers: both canvases masked to the top band, like deepseek.com */
.hero-fx {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  mask: linear-gradient(#000000fc 0%, #000000e8 8.98%, transparent 100%);
  -webkit-mask: linear-gradient(#000000fc 0%, #000000e8 8.98%, transparent 100%);
}
.hero-fx canvas {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
}
.hero-fx-flow { z-index: 0; }
.hero-fx-grid { z-index: 5; display: none; }
@media (min-width: 768px) { .hero-fx-grid { display: block; } }
.hero-inner {
  position: relative;
  z-index: 10;
  max-width: var(--container);
  margin: 0 auto;
  padding: 96px 24px 88px;
  width: 100%;
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: clamp(40px, 6vw, 88px);
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0 0 22px;
}
.status-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--ok);
  box-shadow: 0 0 0 0 color-mix(in srgb, var(--ok) 45%, transparent);
  animation: breathe 2.6s var(--ease) infinite;
  flex: none;
}
@keyframes breathe {
  0%, 100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--ok) 45%, transparent); }
  50% { box-shadow: 0 0 0 6px transparent; }
}

.hero-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(56px, 9vw, 108px);
  line-height: 0.98;
  letter-spacing: -0.03em;
}
.hero-v4 {
  position: relative;
  isolation: isolate;   /* keep highlight below text, above background */
  color: var(--accent);
}
.hero-v4::after {
  content: "";
  position: absolute;
  left: 2px; right: 2px; bottom: 6px;
  height: 10px;
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  z-index: -1;
}
.hero-sub {
  margin: 26px 0 0;
  font-size: clamp(20px, 2.6vw, 27px);
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.hero-desc {
  margin: 18px 0 0;
  max-width: 54ch;
  color: var(--ink-3);
  font-size: 16.5px;
  line-height: 1.85;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 36px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 500;
  padding: 14px 26px;
  border-radius: 12px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .35s var(--ease), border-color .35s var(--ease),
              color .35s var(--ease), transform .35s var(--ease), box-shadow .35s var(--ease);
}
.btn svg { width: 15px; height: 15px; }
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: var(--ink);
  color: #fff;
  box-shadow: 0 14px 30px -14px color-mix(in srgb, var(--ink) 55%, transparent);
}
.btn-primary:hover { background: #000; transform: translateY(-2px); }
.btn-primary:hover svg { transform: translateX(3px); }
.btn-primary svg { transition: transform .35s var(--ease); }

.btn-ghost { border-color: var(--line-2); color: var(--ink-2); background: transparent; }
.btn-ghost:hover { border-color: var(--ink); color: var(--ink); }
/* secondary hero button: subtle arrow shift only */
.btn-arrow svg { transition: transform .35s var(--ease); }
.btn-arrow:hover svg { transform: translateX(3px); }

/* Black button — perpetual shine sweep on hover */
.btn-black {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: #fff;
  box-shadow: 0 14px 30px -14px rgba(24, 24, 27, 0.5);
}
.btn-black::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: linear-gradient(115deg,
    rgba(255, 255, 255, 0) 32%,
    rgba(255, 255, 255, 0.16) 50%,
    rgba(255, 255, 255, 0) 68%);
  transform: translateX(-135%) skewX(-18deg);
  pointer-events: none;
  animation: btn-shine 2.6s var(--ease) infinite;
  animation-play-state: paused;
}
.btn-black:hover { background: #000; transform: translateY(-2px); box-shadow: 0 20px 40px -16px rgba(24, 24, 27, 0.6); }
.btn-black:hover::before { animation-play-state: running; }
.btn-black svg { transition: transform .35s var(--ease); }
.btn-black:hover svg { transform: translateX(4px); }
@keyframes btn-shine {
  0% { transform: translateX(-135%) skewX(-18deg); }
  55%, 100% { transform: translateX(135%) skewX(-18deg); }
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
}
.hero-meta li {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-3);
}
.hero-meta li::before { content: "// "; color: var(--accent); }

/* ---------- Terminal panel ---------- */
.hero-panel { position: relative; }
.hero-panel::before {
  content: "";
  position: absolute;
  inset: -18px;
  border-radius: calc(var(--radius) + 12px);
  border: 1px dashed var(--line-2);
  pointer-events: none;
}
.terminal {
  background: var(--dark);
  border: 1px solid var(--dark-line);
  border-radius: var(--radius);
  box-shadow: 0 40px 80px -32px rgba(12, 12, 14, 0.45);
  overflow: hidden;
}
.terminal-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 13px 16px;
  border-bottom: 1px solid var(--dark-line);
  background: var(--dark-2);
}
.dot { width: 11px; height: 11px; border-radius: 50%; }
.dot-r { background: #f87171; }
.dot-y { background: #fbbf24; }
.dot-g { background: #34d399; }
.terminal-title {
  margin-left: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-4);
}
.terminal-body { padding: 22px 22px 18px; }
.term-line {
  display: flex;
  align-items: baseline;
  min-height: 26px;
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: #d4d4d8;
  margin: 0 0 20px;
}
.term-prompt { color: var(--accent); margin-right: 10px; font-weight: 600; }
.typewriter { white-space: pre; }
.caret {
  width: 8px; height: 16px;
  margin-left: 3px;
  background: var(--accent);
  animation: blink 1.1s steps(2, start) infinite;
  flex: none;
  align-self: center;
}
@keyframes blink { 50% { opacity: 0; } }

.term-specs { margin: 0; }
.spec-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 11px 0;
  border-top: 1px solid var(--dark-line);
}
.spec-row dt {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-4);
}
.spec-row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  color: #e4e4e7;
}
.term-foot {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--dark-line);
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-4);
}

/* ============================================================
   STATS BAND — 1px separators, no cards
   ============================================================ */
.stats {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.stats-grid {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}
.stat {
  padding: 44px 28px 46px;
  border-left: 1px solid var(--line);
}
.stat:first-child { border-left: none; }
.stat-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(34px, 4.2vw, 48px);
  font-weight: 600;
  letter-spacing: -0.03em;
  color: var(--ink);
  line-height: 1;
}
.stat-unit { font-size: 0.55em; color: var(--accent); margin-left: 4px; font-weight: 500; }
.stat-word { font-size: clamp(34px, 4.2vw, 48px); color: var(--accent); }
.stat-label { margin: 12px 0 0; font-size: 13.5px; color: var(--ink-3); }

/* ============================================================
   SECTIONS
   ============================================================ */
.section { padding: clamp(80px, 10vw, 130px) 24px; }
.section-head { max-width: var(--container); margin: 0 auto 64px; }
.section-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(30px, 4.4vw, 46px);
  line-height: 1.12;
  letter-spacing: -0.02em;
}
.section-desc {
  margin: 18px 0 0;
  max-width: 62ch;
  color: var(--ink-3);
  font-size: 16px;
  line-height: 1.85;
}

/* ============================================================
   MODELS — asymmetric 2fr/1fr, no 3-card row
   ============================================================ */
#models { border-top: 1px solid var(--line); }
.models-grid {
  max-width: var(--container);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 22px;
}
.model-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  padding: 40px 38px;
  transition: border-color .4s var(--ease), box-shadow .4s var(--ease);
  transform-style: preserve-3d;
}
.model-card:hover {
  border-color: var(--line-2);
  box-shadow: 0 32px 64px -28px rgba(24, 24, 27, 0.14);
}
.model-card-flash { background: color-mix(in srgb, var(--surface) 60%, var(--accent-soft) 40%); }

.model-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; }
.model-name {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(18px, 2vw, 22px);
  font-weight: 600;
  letter-spacing: -0.01em;
}
.model-tag { margin: 6px 0 0; font-size: 13.5px; color: var(--ink-3); }

.badge {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #fff;
  background: var(--accent);
  border-radius: 999px;
  padding: 6px 12px;
  flex: none;
}
.badge-ghost { color: var(--accent); background: var(--accent-soft); }

.model-specs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin: 30px 0;
  padding: 24px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.model-specs div { display: flex; flex-direction: column; }
.model-specs span {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.model-specs small { font-size: 12.5px; color: var(--ink-3); margin-top: 4px; }

.model-points { list-style: none; margin: 0; padding: 0; }
.model-points li {
  position: relative;
  padding: 7px 0 7px 26px;
  font-size: 14.5px;
  color: var(--ink-2);
}
.model-points li::before {
  content: "";
  position: absolute;
  left: 4px; top: 16px;
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--accent);
}

.models-shared {
  max-width: var(--container);
  margin: 26px auto 0;
  border: 1px dashed var(--line-2);
  border-radius: var(--radius);
  padding: 26px 34px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px 34px;
}
.shared-title { margin: 0; font-size: 13px; font-weight: 700; letter-spacing: 0.05em; color: var(--ink-3); text-transform: uppercase; }
.shared-list { list-style: none; display: flex; flex-wrap: wrap; gap: 10px 30px; margin: 0; padding: 0; }
.shared-list li { font-size: 14px; color: var(--ink-2); }
.shared-list li::before { content: "· "; color: var(--accent); font-weight: 700; }

/* ============================================================
   FEATURES — 2-col zig-zag
   ============================================================ */
.section-features { background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.feature {
  max-width: var(--container);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(40px, 7vw, 100px);
  align-items: center;
  padding: clamp(48px, 6vw, 84px) 0;
  border-top: 1px solid var(--line);
}
.feature:first-of-type { border-top: none; }
.feature-reverse .feature-copy { order: 2; }
.feature-reverse .feature-visual { order: 1; }

.feature-index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  letter-spacing: 0.08em;
  margin: 0 0 14px;
}
.feature-title { margin: 0; font-size: clamp(22px, 2.8vw, 30px); font-weight: 700; letter-spacing: -0.015em; line-height: 1.25; }
.feature-desc { margin: 16px 0 0; color: var(--ink-3); line-height: 1.9; font-size: 15.5px; max-width: 52ch; }

/* feature visuals */
.feature-visual {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  padding: 36px 32px;
  min-height: 260px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.viz-label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-4);
  margin-bottom: 12px;
}

/* DSA compression viz */
.viz-compress { width: 100%; }
.token-row {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  align-items: center;
  min-height: 26px;
}
.token-row i {
  width: var(--w);
  height: 12px;
  border-radius: 3px;
  background: color-mix(in srgb, var(--accent) 55%, var(--line));
}
.token-row-compressed i { background: var(--accent); height: 16px; border-radius: 4px; }
.viz-arrow {
  width: 100%;
  height: 22px;
  margin: 10px 0 12px;
  background:
    linear-gradient(90deg, transparent 0%, var(--line-2) 60%, var(--line-2) 100%);
  -webkit-mask: linear-gradient(90deg, transparent, #000 40%, #000 100%);
  mask: linear-gradient(90deg, transparent, #000 40%, #000 100%);
  clip-path: polygon(0 44%, 78% 44%, 78% 20%, 100% 50%, 78% 80%, 78% 56%, 0 56%);
  opacity: 0.7;
}
.viz-caption { margin: 18px 0 0; font-size: 12.5px; color: var(--ink-3); }

/* agents viz */
.viz-agents { position: relative; width: 100%; display: flex; flex-direction: column; align-items: center; gap: 16px; padding: 10px 0 26px; }
.agent-chip {
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: var(--ink-2);
  background: var(--surface);
  border: 1px solid var(--line-2);
  border-radius: 999px;
  padding: 9px 20px;
  width: min(280px, 90%);
  text-align: center;
  position: relative;
  z-index: 2;
  transition: border-color .35s var(--ease), color .35s var(--ease), transform .35s var(--ease);
}
.agent-chip:hover { border-color: var(--accent); color: var(--accent); transform: translateX(6px); }
.viz-hub {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  background: var(--dark);
  border-radius: 14px;
  padding: 16px 26px;
  z-index: 2;
}
.agent-line {
  position: absolute;
  top: 34px; bottom: 34px;
  left: 50%;
  width: 1px;
  background: var(--line-2);
  z-index: 1;
}

/* modes viz */
.viz-modes { width: 100%; display: flex; flex-direction: column; gap: 22px; }
.mode-switch {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--dark);
  border-radius: 999px;
  padding: 5px;
  width: fit-content;
  position: relative;
}
.mode-opt {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-4);
  padding: 8px 0;
  width: 96px;
  text-align: center;
  border-radius: 999px;
  cursor: pointer;
  transition: color .35s var(--ease);
  position: relative;
  z-index: 2;
  outline: none;
}
.mode-opt:focus-visible { box-shadow: inset 0 0 0 2px var(--accent); }
.mode-opt.is-active { color: #fff; }
.mode-knob {
  position: absolute;
  top: 5px; left: 5px;
  width: 96px; height: 34px;
  background: var(--accent);
  border-radius: 999px;
  z-index: 1;
  transition: transform .5s var(--ease);
}
.viz-modes .mode-switch:has(.mode-opt:nth-child(3).is-active) .mode-knob { transform: translateX(96px); }
.mode-console {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.mode-line { margin: 0; font-size: 13px; color: var(--ink-2); }
.mode-line-dim { color: var(--ink-4); font-size: 12px; }

/* context viz */
.viz-context { width: 100%; }
.ctx-bar { height: 44px; border-radius: 10px; background: var(--line); overflow: hidden; position: relative; }
.ctx-fill {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 14px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-3);
  background: color-mix(in srgb, var(--accent) 22%, var(--line));
}
.ctx-200k { width: 20%; }
.ctx-1m {
  width: 100%;
  background: var(--accent);
  color: #fff;
  animation: ctx-shimmer 3.2s linear infinite;
  background-image: linear-gradient(100deg, var(--accent) 30%, #4d7df0 50%, var(--accent) 70%);
  background-size: 220% 100%;
}
@keyframes ctx-shimmer { 0% { background-position: 130% 0; } 100% { background-position: -90% 0; } }
.ctx-bar-main { margin-top: 8px; }
.ctx-label { margin: 10px 0 0; font-size: 12px; color: var(--ink-4); }
.ctx-label:last-of-type { margin-bottom: 0; }

/* ============================================================
   BENCHMARKS — dark band, 1px rows
   ============================================================ */
.section-dark {
  background: var(--dark);
  color: #e4e4e7;
}
.section-head-dark .section-title { color: #f4f4f5; }
.section-head-dark .section-desc { color: #9b9ba3; }
.section-head-dark .eyebrow { color: #8b8b93; }

.bench-table {
  max-width: var(--container);
  margin: 0 auto;
  border-top: 1px solid var(--dark-line);
}
.bench-row {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 18px;
  padding: 20px 8px;
  border-bottom: 1px solid var(--dark-line);
  font-size: 14.5px;
  transition: background .3s var(--ease), padding-left .3s var(--ease);
}
.bench-row:not(.bench-head):hover { background: var(--dark-2); padding-left: 18px; }
.bench-head { font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; color: #8b8b93; font-family: var(--font-mono); }
.bench-row span:first-child { color: #f4f4f5; font-weight: 500; }
.bench-row .mono { font-size: 13.5px; color: #bdbdc4; }
.bench-row .ok { color: var(--ok); font-weight: 600; }
.bench-note { max-width: var(--container); margin: 22px auto 0; font-family: var(--font-mono); font-size: 12px; color: #6f6f78; }

/* ============================================================
   TIMELINE
   ============================================================ */
.timeline {
  max-width: var(--container);
  margin: 0 auto;
  list-style: none;
  padding: 0;
  position: relative;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 7px; top: 10px; bottom: 10px;
  width: 1px;
  background: var(--line-2);
}
.timeline li {
  position: relative;
  padding: 0 0 34px 46px;
}
.timeline li::before {
  content: "";
  position: absolute;
  left: 0; top: 8px;
  width: 15px; height: 15px;
  border-radius: 50%;
  background: var(--surface);
  border: 3px solid var(--accent);
  transition: background .35s var(--ease), box-shadow .35s var(--ease);
}
.timeline li:hover::before { background: var(--accent); box-shadow: 0 0 0 6px var(--accent-soft); }
.timeline time {
  font-size: 13px;
  color: var(--accent);
  font-weight: 600;
}
.timeline p { margin: 6px 0 0; color: var(--ink-2); font-size: 15px; line-height: 1.75; }
.timeline li:last-child p strong { color: var(--ink); }

/* ============================================================
   CTA
   ============================================================ */
.cta {
  background: var(--surface);
  border-top: 1px solid var(--line);
  text-align: left;
}
.cta-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(32px, 5vw, 54px);
  font-weight: 700;
  letter-spacing: -0.025em;
  max-width: var(--container);
  margin-left: auto; margin-right: auto;
}
.cta-desc {
  max-width: var(--container);
  margin: 14px auto 44px;
  color: var(--ink-3);
  font-size: 16.5px;
}
.cta-links {
  max-width: var(--container);
  margin: 0 auto;
  border-top: 1px solid var(--line);
}
.cta-link {
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: 22px;
  padding: 26px 6px;
  border-bottom: 1px solid var(--line);
  transition: padding-left .35s var(--ease), background .35s var(--ease);
}
.cta-link:hover { padding-left: 22px; background: color-mix(in srgb, var(--accent) 3%, transparent); }
.cta-link-label { font-size: 18px; font-weight: 600; letter-spacing: -0.01em; }
.cta-link .mono { font-size: 13.5px; color: var(--ink-3); }
.cta-link svg { width: 18px; height: 18px; color: var(--ink-3); transition: transform .35s var(--ease), color .35s var(--ease); }
.cta-link:hover svg { transform: translate(4px, -4px); color: var(--accent); }

/* ============================================================
   CURSOR RING — deepseek.com style: difference-blend lens
   ============================================================ */
.ds-cursor-ring {
  position: fixed;
  top: 0; left: 0;
  pointer-events: none;
  z-index: 9999;
  will-change: transform, opacity;
  border-radius: 50%;
  opacity: 0;
  width: 0; height: 0;
  mix-blend-mode: difference;
  transition: width .3s cubic-bezier(.16, 1, .3, 1), height .3s cubic-bezier(.16, 1, .3, 1),
              margin .3s cubic-bezier(.16, 1, .3, 1), background-color .3s ease,
              border-color .3s ease, opacity .3s ease;
}
.ds-cursor-ring.is-blend {
  width: 64px; height: 64px;
  margin-left: -32px; margin-top: -32px;
  border-color: transparent;
  background: var(--ds-cursor-blend-color, #fff);
  mix-blend-mode: difference;
}
@media (hover: none), (pointer: coarse) {
  .ds-cursor-ring { display: none; }
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer { background: var(--dark); color: #8b8b93; }
.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 44px 24px 48px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 40px;
  justify-content: space-between;
  align-items: baseline;
}
.footer p { margin: 0; font-size: 13px; }
.footer a { color: #c7c7cd; border-bottom: 1px solid #3f3f46; transition: color .3s var(--ease), border-color .3s var(--ease); }
.footer a:hover { color: #fff; border-color: var(--accent); }
.footer-meta { font-size: 12px !important; color: #5d5d66 !important; }

/* ============================================================
   RESPONSIVE — strict single-column under 900px
   ============================================================ */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; padding-top: 72px; }
  .hero-panel { max-width: 520px; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .stat:nth-child(3) { border-left: none; }
  .stat { padding: 30px 22px; }
  .models-grid { grid-template-columns: 1fr; }
  .feature { grid-template-columns: 1fr; gap: 34px; }
  .feature-reverse .feature-copy { order: 1; }
  .feature-reverse .feature-visual { order: 2; }
  .bench-row { grid-template-columns: 1.2fr 1fr 1fr; }
  .bench-row span:last-child { display: none; }
  .nav-links { display: none; }
}

@media (max-width: 560px) {
  .stats-grid { grid-template-columns: 1fr; }
  .stat, .stat:nth-child(3) { border-left: none; border-top: 1px solid var(--line); }
  .stat:first-child { border-top: none; }
  .model-card { padding: 30px 24px; }
  .models-shared { padding: 22px 22px; }
  .feature-visual { padding: 26px 20px; min-height: 220px; }
  .cta-link { grid-template-columns: 1fr auto; }
  .cta-link .mono { display: none; }
  .hero::before { display: none; }
}

/* ============================================================
   REDUCED MOTION — respect the user
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
}