/* ============================================================
   KernelSeq V3.0 — Scientific Infrastructure Design System
   ============================================================ */

/* ---------- Reset ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ---------- Design Tokens ---------- */
:root {
  --bg: #05070D;
  --bg-elevated: #0A0F1A;
  --bg-surface: #0E1520;
  --line: rgba(148, 163, 184, 0.10);
  --line-strong: rgba(148, 163, 184, 0.18);
  --text: #E2E8F0;
  --text-secondary: #94A3B8;
  --text-muted: #4B5A70;
  --accent: #00D4FF;
  --accent-dim: rgba(0, 212, 255, 0.12);
  --accent-faint: rgba(0, 212, 255, 0.04);

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI',
          'HarmonyOS Sans SC', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --mono: 'SF Mono', 'Roboto Mono', 'Menlo', monospace;

  --space-section: 120px;
  --space-section-sm: 80px;
  --radius: 4px;
  --radius-lg: 8px;

  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Base ---------- */
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--line-strong); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ---------- Container ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ---------- Grid Background ---------- */
.grid-bg {
  position: relative;
}
.grid-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 30%, transparent 80%);
  pointer-events: none;
  z-index: 0;
}

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(5, 7, 13, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--line);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text);
  font-weight: 600;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

/* Logo 文字整体 —— 保证 Kernel 与 Seq 无间隙 */
.logo .brand-text {
  display: inline;
  letter-spacing: -0.01em;
}

/* Logo 中的 “Seq” 颜色 —— 只改颜色 */
.logo .seq-text {
  color: #00D4FF;
}

.logo-mark {
  display: flex;
  align-items: center;
  gap: 3px;
}
.logo-mark .k {
  font-weight: 700;
  color: var(--text);
  font-size: 1.25rem;
  line-height: 1;
}
.logo-mark .seq {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: 2px;
}
.logo-mark .seq i {
  display: block;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--accent);
}
.logo-mark .seq .bar {
  width: 8px;
  height: 1px;
  background: var(--accent);
  opacity: 0.5;
}

.logo .cn {
  font-weight: 300;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-left: 2px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 450;
  letter-spacing: 0.01em;
  transition: var(--transition);
  position: relative;
}
.nav-links a:hover {
  color: var(--text);
}
.nav-links a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: var(--transition);
}
.nav-links a:hover::after {
  width: 100%;
}

.nav-cta {
  color: var(--accent) !important;
  border: 1px solid var(--line-strong);
  padding: 7px 18px;
  border-radius: var(--radius);
  transition: var(--transition);
}
.nav-cta:hover {
  border-color: var(--accent);
  background: var(--accent-faint);
}
.nav-cta::after { display: none !important; }

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--text);
  border-radius: 1px;
  transition: var(--transition);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  padding: 160px 0 120px;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 80px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 28px;
}
.hero-eyebrow .line {
  width: 32px;
  height: 1px;
  background: var(--accent);
  opacity: 0.4;
}

.hero h1 {
  font-size: clamp(2.4rem, 4vw, 3.4rem);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.03em;
  color: #fff;
}

.hero h1 .cn {
  display: block;
  font-size: 0.5em;
  font-weight: 300;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
  margin-top: 6px;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 520px;
  margin-top: 24px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 40px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--accent);
  color: var(--bg);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 13px 28px;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
}
.btn-primary:hover {
  background: #4DE0FF;
  box-shadow: 0 0 32px rgba(0, 212, 255, 0.15);
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: transparent;
  color: var(--text);
  font-weight: 500;
  font-size: 0.9rem;
  padding: 13px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--line-strong);
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
}
.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* Hero Visual */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.seq-canvas {
  width: 100%;
  max-width: 420px;
  aspect-ratio: 1;
  position: relative;
}

.seq-canvas svg {
  width: 100%;
  height: 100%;
  overflow: visible;
}

.seq-canvas .node { fill: var(--accent); opacity: 0.9; }
.seq-canvas .node-muted { fill: var(--text-muted); opacity: 0.4; }
.seq-canvas .link { stroke: var(--accent); stroke-width: 1; fill: none; opacity: 0.3; }
.seq-canvas .link-dash { stroke: var(--line-strong); stroke-width: 1; stroke-dasharray: 3 4; fill: none; }
.seq-canvas .label {
  fill: var(--text-secondary);
  font-family: var(--font);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.seq-canvas .core { fill: none; stroke: var(--accent); stroke-width: 1.2; opacity: 0.6; }
.seq-canvas .core-pulse { animation: core-pulse 3s ease-in-out infinite; }
@keyframes core-pulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 0.8; }
}
.seq-canvas .travel { animation: travel 4s cubic-bezier(0.4, 0, 0.2, 1) infinite; }
@keyframes travel {
  0% { transform: translate(0, 0); opacity: 0; }
  10% { opacity: 1; }
  90% { opacity: 1; }
  100% { transform: translate(0, 200px); opacity: 0; }
}

/* ============================================================
   SECTION SHARED
   ============================================================ */
.section { padding: var(--space-section) 0; position: relative; }
.section-sm { padding: var(--space-section-sm) 0; }

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 20px;
}
.section-label .num { color: var(--accent); font-family: var(--mono); font-size: 0.68rem; }

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.025em;
  color: #fff;
}

.section-sub {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin-top: 16px;
  line-height: 1.7;
}

.divider { width: 100%; height: 1px; background: var(--line); }

/* ============================================================
   PROBLEM
   ============================================================ */
.problem-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  margin-top: 56px;
}

.problem-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 40px;
  background: var(--bg-surface);
}

.problem-list { display: flex; flex-direction: column; gap: 0; }

.problem-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.95rem;
}
.problem-item:last-child { border-bottom: none; }
.problem-item .tag { font-family: var(--mono); font-size: 0.75rem; color: var(--text-muted); }

.problem-drift {
  margin-top: 24px;
  padding: 24px;
  border: 1px solid rgba(255, 107, 107, 0.2);
  border-radius: var(--radius);
  background: rgba(255, 107, 107, 0.03);
  text-align: center;
}
.problem-drift .label {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.problem-drift .value {
  font-size: 1.3rem;
  font-weight: 600;
  color: #FF6B6B;
  margin-top: 4px;
}

/* ============================================================
   DRV INTRO
   ============================================================ */
.drv-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  margin-top: 56px;
}

.drv-flow {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.drv-step {
  width: 100%;
  max-width: 360px;
  padding: 16px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-align: center;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-surface);
  transition: var(--transition);
}
.drv-step:hover { border-color: var(--line-strong); }
.drv-step.active {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-faint);
}
.drv-arrow { color: var(--text-muted); font-size: 0.7rem; line-height: 1; }

.drv-formula {
  background: var(--bg-surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 36px 40px;
}
.drv-formula .label {
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 16px;
}
.drv-formula .equation {
  font-family: var(--mono);
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 2;
}
.drv-formula .equation strong { color: #fff; font-weight: 600; }
.drv-formula .equation .hl { color: var(--accent); }
.drv-formula .note {
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ============================================================
   HOW IT WORKS (新增)
   ============================================================ */
.how-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px;
}

.how-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  background: var(--bg-surface);
  transition: var(--transition);
}
.how-card:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.how-card .step-num {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  margin-bottom: 20px;
}

.how-card .step-vis {
  margin: 20px 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
}

.how-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 10px;
}

.how-card .step-flow {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.9;
}
.how-card .step-flow .hl { color: var(--accent); }
.how-card .step-flow .dim { color: var(--text-muted); }

/* Step 1 visual: Event → Runtime → State */
.how-vis-1 { display: flex; align-items: center; gap: 8px; }
.how-vis-1 .box {
  width: 28px; height: 28px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-size: 0.6rem;
  color: var(--text-secondary);
}
.how-vis-1 .box.hl { border-color: var(--accent); color: var(--accent); }
.how-vis-1 .arw { color: var(--text-muted); font-size: 0.7rem; }

/* Step 2 visual: Trace → Ω* */
.how-vis-2 { display: flex; align-items: center; gap: 10px; width: 100%; }
.how-vis-2 .trace {
  display: flex; flex-direction: column; gap: 3px; flex: 1;
}
.how-vis-2 .trace i {
  display: block; height: 2px; background: var(--text-muted); opacity: 0.3;
  border-radius: 1px;
}
.how-vis-2 .trace i:nth-child(1) { width: 100%; }
.how-vis-2 .trace i:nth-child(2) { width: 80%; }
.how-vis-2 .trace i:nth-child(3) { width: 90%; }
.how-vis-2 .omega {
  width: 32px; height: 32px;
  border: 1px solid var(--accent);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-size: 0.7rem;
  color: var(--accent);
  flex-shrink: 0;
}

/* Step 3 visual: Reference vs Runtime */
.how-vis-3 { display: flex; flex-direction: column; gap: 8px; width: 100%; }
.how-vis-3 .row {
  display: flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 0.6rem; color: var(--text-muted);
}
.how-vis-3 .bar {
  height: 2px; border-radius: 1px; flex: 1;
}
.how-vis-3 .bar.ref { background: var(--accent); opacity: 0.4; }
.how-vis-3 .bar.run { background: var(--accent); }

/* ============================================================
   ARCHITECTURE
   ============================================================ */
.arch-wrap {
  margin-top: 56px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-surface);
}

.arch-layer {
  display: grid;
  grid-template-columns: 200px 1fr;
  align-items: center;
  border-bottom: 1px solid var(--line);
  transition: var(--transition);
  cursor: default;
}
.arch-layer:last-child { border-bottom: none; }
.arch-layer:hover { background: var(--accent-faint); }

.arch-layer .name {
  padding: 24px 32px;
  font-weight: 600;
  font-size: 0.92rem;
  border-right: 1px solid var(--line);
  color: var(--text);
}
.arch-layer .desc {
  padding: 24px 32px;
  color: var(--text-secondary);
  font-family: var(--mono);
  font-size: 0.82rem;
}

.arch-layer.accent .name { color: var(--accent); }
.arch-layer.accent { background: var(--accent-faint); }

/* ============================================================
   CORE TECHNOLOGY
   ============================================================ */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 56px;
}

.tech-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  background: var(--bg-surface);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.tech-card:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.tech-card .idx {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.05em;
}

.tech-card .vis {
  margin: 24px 0;
  height: 48px;
  display: flex;
  align-items: center;
}

.vis-seq { display: flex; align-items: center; gap: 6px; }
.vis-seq .n { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); opacity: 0.9; }
.vis-seq .n.muted { background: var(--text-muted); opacity: 0.4; }
.vis-seq .l { width: 20px; height: 1px; background: var(--line-strong); }

.vis-compare { display: flex; flex-direction: column; gap: 6px; width: 100%; }
.vis-compare .row { display: flex; align-items: center; gap: 8px; }
.vis-compare .bar { height: 2px; border-radius: 1px; flex: 1; }
.vis-compare .bar.ref { background: var(--accent); opacity: 0.4; }
.vis-compare .bar.run { background: var(--accent); }

.vis-compress { display: flex; align-items: center; gap: 8px; width: 100%; }
.vis-compress .big { display: flex; gap: 2px; }
.vis-compress .big i { display: block; width: 3px; height: 12px; background: var(--text-muted); opacity: 0.3; }
.vis-compress .arrow { color: var(--text-muted); font-size: 0.7rem; }
.vis-compress .small { width: 8px; height: 8px; border: 1px solid var(--accent); border-radius: 50%; }

.vis-chip {
  width: 40px;
  height: 40px;
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: 0.6rem;
  color: var(--accent);
}

.tech-card h3 { font-size: 0.98rem; font-weight: 600; color: #fff; margin-bottom: 8px; }
.tech-card p { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.6; }

/* ============================================================
   MATH FOUNDATION
   ============================================================ */
.math-section {
  background: var(--bg);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.math-inner { text-align: center; padding: 80px 0; }

.math-equation {
  font-family: var(--mono);
  font-size: clamp(1.4rem, 3vw, 2.2rem);
  color: var(--text);
  letter-spacing: 0.02em;
  margin: 40px 0 20px;
}
.math-equation .op { color: var(--text-muted); margin: 0 8px; font-size: 0.8em; }
.math-equation .sub { font-size: 0.6em; vertical-align: sub; }
.math-equation .hl { color: var(--accent); }

.math-caption {
  font-size: 0.85rem;
  color: var(--text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ============================================================
   PLATFORM
   ============================================================ */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px;
}

.platform-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--bg-surface);
  overflow: hidden;
  transition: var(--transition);
}
.platform-card:hover { border-color: var(--line-strong); }

.platform-card .visual {
  height: 160px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background: var(--bg-elevated);
}

.platform-card .body { padding: 28px 28px 32px; }
.platform-card h3 { font-size: 1.05rem; font-weight: 600; color: #fff; margin-bottom: 6px; }
.platform-card .tagline { font-size: 0.82rem; color: var(--text-muted); margin-bottom: 16px; }

.platform-card .capabilities { display: flex; flex-wrap: wrap; gap: 6px; }
.platform-card .capabilities span {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--text-secondary);
  border: 1px solid var(--line);
  padding: 3px 10px;
  border-radius: var(--radius);
}

.pv-runtime { display: flex; flex-direction: column; gap: 4px; align-items: center; }
.pv-runtime .row { display: flex; align-items: center; gap: 6px; }
.pv-runtime .dot { width: 5px; height: 5px; border-radius: 50%; background: var(--accent); }
.pv-runtime .line { width: 32px; height: 1px; background: var(--line-strong); }

.pv-sdk {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
  line-height: 1.9;
  text-align: left;
  padding: 0 32px;
}
.pv-sdk .kw { color: var(--accent); }
.pv-sdk .fn { color: #7B61FF; }
.pv-sdk .dim { color: var(--text-muted); }

.pv-studio { width: 80%; border: 1px solid var(--line-strong); border-radius: var(--radius); overflow: hidden; }
.pv-studio .bar {
  height: 16px;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 0 8px;
}
.pv-studio .bar i { width: 5px; height: 5px; border-radius: 50%; background: var(--line-strong); }
.pv-studio .content { padding: 12px; display: flex; gap: 8px; }
.pv-studio .content .col { height: 40px; border: 1px solid var(--line); border-radius: 2px; }
.pv-studio .content .col:nth-child(1) { width: 20%; }
.pv-studio .content .col:nth-child(2) { width: 55%; border-color: rgba(0,212,255,0.2); }
.pv-studio .content .col:nth-child(3) { width: 25%; }

/* ============================================================
   AUTOMOTIVE
   ============================================================ */
.auto-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  margin-top: 56px;
}

.auto-flow {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 40px;
  background: var(--bg-surface);
}

.auto-flow-item { display: flex; align-items: center; gap: 16px; padding: 14px 0; }
.auto-flow-item .marker {
  width: 8px;
  height: 8px;
  border: 1px solid var(--accent);
  border-radius: 50%;
  flex-shrink: 0;
}
.auto-flow-item .marker.filled { background: var(--accent); }
.auto-flow-item .text { font-size: 0.88rem; color: var(--text-secondary); font-family: var(--mono); }
.auto-flow-item .arrow { color: var(--text-muted); font-size: 0.7rem; padding-left: 3px; }

.auto-apps { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 32px; }
.auto-apps span {
  font-size: 0.78rem;
  color: var(--text-secondary);
  border: 1px solid var(--line);
  padding: 5px 14px;
  border-radius: var(--radius);
}

/* ============================================================
   TIMELINE
   ============================================================ */
.timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  margin-top: 56px;
  border-top: 1px solid var(--line);
}

.timeline-item {
  padding: 32px 24px;
  border-right: 1px solid var(--line);
  position: relative;
}
.timeline-item:last-child { border-right: none; }
.timeline-item .year { font-family: var(--mono); font-size: 0.75rem; color: var(--accent); letter-spacing: 0.05em; }
.timeline-item .label { font-size: 1rem; font-weight: 600; color: #fff; margin-top: 8px; }
.timeline-item .desc { font-size: 0.82rem; color: var(--text-muted); margin-top: 4px; }
.timeline-item::before {
  content: '';
  position: absolute;
  top: -4px;
  left: 24px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--line-strong);
}
.timeline-item.active::before { background: var(--accent); border-color: var(--accent); }

/* ============================================================
   RESEARCH
   ============================================================ */
.research-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  margin-top: 56px;
}

.research-paper {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 36px;
  background: var(--bg-surface);
  border-left: 3px solid var(--accent);
}
.research-paper .type {
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
}
.research-paper .title { font-size: 1.05rem; font-weight: 600; color: #fff; margin: 12px 0; line-height: 1.5; }
.research-paper .abstract { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.7; }
.research-paper .topics {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}
.research-paper .topics span {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  border: 1px solid var(--line);
  padding: 3px 10px;
  border-radius: var(--radius);
}

.research-topics { display: flex; flex-direction: column; gap: 0; }
.research-topic {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  cursor: default;
  transition: var(--transition);
}
.research-topic:hover { padding-left: 8px; }
.research-topic:last-child { border-bottom: none; }
.research-topic .name { font-size: 0.95rem; font-weight: 500; color: var(--text); }
.research-topic .idx { font-family: var(--mono); font-size: 0.72rem; color: var(--text-muted); }

.research-categories {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  font-size: 0.85rem;
  color: var(--text-muted);
}
.research-categories span {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.research-categories span::before {
  content: '';
  display: block;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--accent);
}

/* ============================================================
   VISION
   ============================================================ */
.vision-layers {
  margin-top: 56px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.vision-layer {
  display: grid;
  grid-template-columns: 140px 1fr;
  align-items: center;
  border-bottom: 1px solid var(--line);
  transition: var(--transition);
}
.vision-layer:last-child { border-bottom: none; }
.vision-layer:hover { background: var(--accent-faint); }

.vision-layer .era {
  padding: 28px 32px;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  border-right: 1px solid var(--line);
}
.vision-layer .content { padding: 28px 32px; }
.vision-layer .layer-name { font-size: 1.05rem; font-weight: 600; color: var(--text); }
.vision-layer .layer-desc { font-size: 0.85rem; color: var(--text-muted); margin-top: 2px; }

.vision-layer.highlight { background: var(--accent-faint); }
.vision-layer.highlight .era { color: var(--accent); }
.vision-layer.highlight .layer-name { color: var(--accent); }

/* ============================================================
   CONTACT
   ============================================================ */
.contact-section {
  border-top: 1px solid var(--line);
  padding: 100px 0;
}

.contact-inner { text-align: center; max-width: 720px; margin: 0 auto; }

.contact-inner h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.15;
  color: #fff;
}

.contact-inner .sub { color: var(--text-secondary); margin-top: 16px; font-size: 1.05rem; }

.contact-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-top: 40px;
}

/* ============================================================
   BRAND STATEMENT
   ============================================================ */
.brand-statement {
  padding: 64px 0;
  border-top: 1px solid var(--line);
  text-align: center;
}
.brand-statement .en { font-size: 1rem; color: var(--text-secondary); max-width: 640px; margin: 0 auto; line-height: 1.7; }
.brand-statement .cn { font-size: 0.95rem; color: var(--accent); margin-top: 12px; }

/* ============================================================
   FOOTER  —  与导航栏 Logo 完全一致的处理方式
   ============================================================ */
footer {
  border-top: 1px solid var(--line);
  padding: 64px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
}

/* 页脚品牌名 —— 结构与导航栏一致 */
.footer-brand .name {
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.01em;
}

/* “KernelSeq” 作为整体，内部无色差间隙 */
.footer-brand .name .brand-text {
  display: inline;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: #fff;
}

/* 只改颜色，不改粗细 */
.footer-brand .name .seq-text {
  color: #00D4FF;
}

/* “擎序” —— 与导航栏保持一致的 300 字重、次要颜色 */
.footer-brand .name .cn {
  font-weight: 300;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-left: 6px;
}

.footer-brand p { font-size: 0.85rem; color: var(--text-muted); margin-top: 12px; max-width: 320px; line-height: 1.7; }

.footer-col h4 {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 18px;
}
.footer-col a {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  text-decoration: none;
  padding: 5px 0;
  transition: var(--transition);
}
.footer-col a:hover { color: var(--accent); }

.footer-bottom {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--text-muted);
}
.footer-bottom a { color: var(--text-muted); text-decoration: none; transition: var(--transition); }
.footer-bottom a:hover { color: var(--accent); }

/* ============================================================
   RESPONSIVE — TABLET (≤1024px)
   ============================================================ */
@media (max-width: 1024px) {
  .container { padding: 0 28px; }
  .nav-links { gap: 24px; }
  .hero-grid { gap: 48px; }
  .problem-grid { gap: 48px; }
  .drv-layout { gap: 48px; }
  .auto-layout { gap: 48px; }
  .research-layout { gap: 48px; }
  .tech-grid { grid-template-columns: repeat(2, 1fr); }
  .how-grid { grid-template-columns: repeat(3, 1fr); gap: 20px; }
}

/* ============================================================
   RESPONSIVE — TABLET (≤768px) & MOBILE
   ============================================================ */
@media (max-width: 768px) {
  :root {
    --space-section: 72px;
    --space-section-sm: 56px;
  }
  .container { padding: 0 20px; }

  .hamburger { display: flex; }
  .nav-links {
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: 8px 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: var(--transition);
  }
  .nav-links.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
  .nav-links a {
    width: 100%;
    padding: 14px 32px;
    font-size: 0.95rem;
  }
  .nav-links a::after { display: none; }
  .nav-cta {
    border: none;
    padding: 14px 32px;
    border-radius: 0;
    color: var(--accent) !important;
  }

  .hero { padding: 130px 0 80px; }
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 60px;
    text-align: center;
  }
  .hero-sub { margin-left: auto; margin-right: auto; }
  .hero-actions { justify-content: center; }
  .seq-canvas { max-width: 320px; }

  .problem-grid,
  .drv-layout,
  .auto-layout,
  .research-layout {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .problem-panel { padding: 28px; }
  .drv-formula { padding: 28px; }

  .how-grid { grid-template-columns: 1fr; gap: 20px; }

  .arch-layer { grid-template-columns: 1fr; }
  .arch-layer .name {
    border-right: none;
    border-bottom: 1px solid var(--line);
    padding: 16px 24px;
  }
  .arch-layer .desc { padding: 16px 24px; }

  .platform-grid { grid-template-columns: 1fr; }

  .timeline { grid-template-columns: 1fr 1fr; }
  .timeline-item { border-bottom: 1px solid var(--line); }
  .timeline-item:nth-child(2) { border-right: none; }
  .timeline-item:nth-child(3),
  .timeline-item:nth-child(4) { border-bottom: none; }

  .vision-layer { grid-template-columns: 1fr; }
  .vision-layer .era {
    border-right: none;
    border-bottom: 1px solid var(--line);
    padding: 16px 24px;
  }
  .vision-layer .content { padding: 20px 24px; }

  .research-paper { padding: 28px; }

  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}

/* ============================================================
   RESPONSIVE — MOBILE (≤480px)
   ============================================================ */
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .logo { font-size: 1.05rem; }
  .logo-mark .k { font-size: 1.15rem; }
  .logo .cn { font-size: 0.85rem; }

  .tech-grid { grid-template-columns: 1fr; }
  .timeline { grid-template-columns: 1fr; }
  .timeline-item { border-right: none; border-bottom: 1px solid var(--line); }
  .timeline-item:last-child { border-bottom: none; }

  .footer-grid { grid-template-columns: 1fr; }

  .contact-actions { flex-direction: column; align-items: stretch; }
  .contact-actions .btn-primary,
  .contact-actions .btn-ghost { justify-content: center; }

  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions .btn-primary,
  .hero-actions .btn-ghost { justify-content: center; }
}

/* V4 dual-product company site */
:root{--ghost:#9D8CFF;--ghost-dim:rgba(157,140,255,.10)}
.hero{padding:156px 0 94px}.hero h1{font-size:clamp(2.4rem,4.5vw,4.1rem)}
.hero-sub{max-width:680px}.hero-grid{grid-template-columns:1fr .72fr;gap:45px}
.product-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:52px}
.product-tile{border:1px solid var(--line-strong);background:var(--bg-surface);border-radius:10px;padding:38px;position:relative;overflow:hidden}
.product-tile:before{content:"";position:absolute;top:0;left:0;right:0;height:2px;background:var(--accent)}
.product-tile.ghost:before{background:var(--ghost)}
.product-tile .eyebrow{font:600 .7rem var(--mono);letter-spacing:.12em;color:var(--accent);margin-bottom:20px}
.product-tile.ghost .eyebrow,.ghost-color{color:var(--ghost)!important}
.product-tile h3{font-size:2rem;color:#fff;line-height:1.2}
.product-tile .sub{font-size:.96rem;color:var(--text-secondary);margin:15px 0 22px;min-height:72px}
.product-tile ul{list-style:none;margin:20px 0 30px}
.product-tile li{padding:9px 0;border-bottom:1px solid var(--line);font-size:.86rem;color:var(--text-secondary)}
.product-tile li:before{content:"↗";color:var(--accent);margin-right:12px}
.product-tile.ghost li:before{color:var(--ghost)}
.product-tile a{color:var(--accent);text-decoration:none;font-size:.88rem;font-weight:600}
.product-tile.ghost a{color:var(--ghost)}
.pill{display:inline-block;border:1px solid var(--line-strong);border-radius:100px;padding:5px 12px;color:var(--text-secondary);font-size:.74rem;margin-bottom:16px}
.cap-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:42px}
.cap{padding:26px;border:1px solid var(--line);border-radius:8px;background:var(--bg-surface)}
.cap b{display:block;color:#fff;margin-bottom:10px}.cap p{font-size:.87rem;color:var(--text-secondary)}
.product-detail{display:grid;grid-template-columns:1fr 1fr;gap:55px;align-items:center;margin-top:42px}
.diagram{padding:28px;border:1px solid var(--line);border-radius:8px;background:var(--bg-surface);font: .81rem var(--mono)}
.diagram .step{padding:13px;border:1px solid var(--line-strong);border-radius:4px;text-align:center;color:var(--text-secondary)}
.diagram .step.em{border-color:var(--accent);color:var(--accent)}.diagram.ghost .step.em{border-color:var(--ghost);color:var(--ghost)}
.diagram .arr{text-align:center;color:var(--text-muted);padding:5px}
.detail-copy p{color:var(--text-secondary);margin-top:18px}.detail-copy h3{color:#fff;font-size:1.3rem;margin-top:20px}
.detail-copy .pill{margin-top:20px}
.small-note{font-size:.8rem;color:var(--text-muted);margin-top:18px}
@media(max-width:768px){.hero-grid,.product-grid,.product-detail{grid-template-columns:1fr}.cap-grid{grid-template-columns:1fr}.product-tile{padding:28px}.product-tile .sub{min-height:0}.hero{padding-top:125px}}

/* Product pages V4.1 */
.product-hero{padding:154px 0 88px;position:relative;overflow:hidden}
.product-hero .container{position:relative;z-index:1}
.product-hero h1{font-size:clamp(3rem,6vw,5.3rem);line-height:1.05;letter-spacing:-.045em;color:white;margin:16px 0}
.product-hero .lede{font-size:clamp(1.12rem,2vw,1.45rem);color:#e2e8f0;max-width:800px;line-height:1.6}
.product-hero .description{color:var(--text-secondary);max-width:760px;margin-top:22px;line-height:1.85}
.product-hero.ghost{background:radial-gradient(ellipse at 80% 20%,rgba(157,140,255,.14),transparent 55%)}
.product-hero.kernel{background:radial-gradient(ellipse at 80% 20%,rgba(0,212,255,.10),transparent 55%)}
.kicker{font:600 .76rem var(--mono);letter-spacing:.14em;color:var(--accent)}
.ghost .kicker,.ghost-accent{color:var(--ghost)!important}
.page-tabs{display:flex;gap:28px;flex-wrap:wrap;padding:18px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.page-tabs a{font-size:.84rem;text-decoration:none;color:var(--text-secondary)}.page-tabs a:hover{color:#fff}
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:44px}
.feature{padding:29px;border:1px solid var(--line-strong);background:var(--bg-surface);border-radius:8px}
.feature .num{font:600 .72rem var(--mono);color:var(--accent)}.ghost .feature .num{color:var(--ghost)}
.feature h3{color:#fff;margin:19px 0 12px;font-size:1.04rem}.feature p{color:var(--text-secondary);font-size:.87rem;line-height:1.8}
.split{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;margin-top:45px}
.split p,.body-copy{color:var(--text-secondary);line-height:1.9}
.flow-diagram{padding:30px;border:1px solid var(--line-strong);background:var(--bg-surface);border-radius:8px}
.flow-diagram .step{padding:14px;border:1px solid var(--line-strong);border-radius:4px;text-align:center;font: .81rem var(--mono);color:var(--text-secondary)}
.flow-diagram .step.active{border-color:var(--accent);color:var(--accent);background:var(--accent-faint)}
.ghost .flow-diagram .step.active{border-color:var(--ghost);color:var(--ghost);background:var(--ghost-dim)}
.flow-diagram .arrow{text-align:center;color:var(--text-muted);padding:6px}
.info-list{margin-top:22px;list-style:none}.info-list li{border-bottom:1px solid var(--line);padding:14px 0;color:var(--text-secondary);font-size:.9rem}
.info-list li strong{color:#fff}
.disclosure{border-left:2px solid var(--accent);background:var(--bg-surface);padding:20px 25px;margin-top:32px;color:var(--text-secondary);font-size:.84rem;line-height:1.8}
.ghost .disclosure{border-color:var(--ghost)}
.related{display:flex;justify-content:space-between;gap:24px;align-items:center;padding:30px;border:1px solid var(--line-strong);border-radius:8px;margin-top:38px}
.related a{color:var(--accent);text-decoration:none}.ghost .related a{color:var(--ghost)}
a:focus-visible,button:focus-visible{outline:2px solid var(--accent);outline-offset:4px}
section[id]{scroll-margin-top:82px}
@media(max-width:768px){.feature-grid,.split{grid-template-columns:1fr}.related{flex-direction:column;align-items:flex-start}.product-hero{padding:128px 0 70px}.page-tabs{gap:15px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation:none!important;transition:none!important}}