/* ===========================================================
   简务 · 设计令牌
   颜色：暖米纸张 + 墨黑 + 橙红批注笔
   字体：霞鹜文楷屏幕版（学者手书） + JetBrains Mono
   =========================================================== */

:root {
  /* 月白宣纸 · 深墨蓝 · 朱砂批注 */
  --bg: #f4f6f9;            /* 月白 — 微冷的白，不泛黄 */
  --bg-warm: #eaeef4;       /* 微深一档，sub-section 底 */
  --bg-deep: #d8dee7;       /* hover / divider */
  --ink: #0d1729;           /* 深墨蓝 — 带蓝调的墨色，比纯黑更有深度 */
  --ink-soft: #1f2a44;
  --ink-mid: #4b5670;
  --ink-mute: #828b9f;
  --accent: #cf2a1f;        /* 朱砂红 — 中国传统印章 / 朱批 */
  --accent-soft: #f4d4d0;
  --accent-deep: #8e1c14;
  --rule: rgba(13, 23, 41, 0.13);
  --rule-soft: rgba(13, 23, 41, 0.06);

  --font-display: "LXGW WenKai Screen", "Noto Serif SC", "Songti SC", "STSong", serif;
  --font-body: "LXGW WenKai Screen", "Noto Serif SC", "PingFang SC", "Hiragino Sans GB", serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Menlo", "Consolas", monospace;

  --content-max: 1280px;
  --gutter: clamp(20px, 4vw, 56px);
}

[data-theme="dark"] {
  /* 深空墨夜 · 暖宣白 · 朱砂 */
  --bg: #0a0f1a;            /* 深空墨夜 */
  --bg-warm: #12182a;
  --bg-deep: #1a2138;
  --ink: #ecefed;
  --ink-soft: #c9cdd6;
  --ink-mid: #8e93a3;
  --ink-mute: #5a5f72;
  --accent: #ff4f3f;
  --accent-soft: #3d1612;
  --accent-deep: #ff7263;
  --rule: rgba(236, 239, 237, 0.16);
  --rule-soft: rgba(236, 239, 237, 0.08);
}

/* ===========================================================
   Reset & base
   =========================================================== */

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

html { -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.7;
  font-feature-settings: "palt";
  letter-spacing: 0.01em;
  position: relative;
  overflow-x: hidden;
}

/* Subtle paper grain on background */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    radial-gradient(circle at 25% 30%, rgba(13,23,41,0.022) 0, transparent 60%),
    radial-gradient(circle at 75% 70%, rgba(13,23,41,0.018) 0, transparent 60%);
  background-size: 220px 220px, 180px 180px;
  z-index: 1;
}

main, header, footer { position: relative; z-index: 2; }

a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; background: none; border: none; color: inherit; }
img, svg { display: block; max-width: 100%; }

/* ===========================================================
   Container + section frame
   =========================================================== */

.container {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

section {
  position: relative;
  padding: clamp(72px, 10vw, 140px) 0;
}

.section-rule {
  height: 1px;
  background: var(--rule);
  margin: 0 var(--gutter);
}

/* Section header — number + kicker + serif title */
.section-head {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: clamp(20px, 4vw, 56px);
  align-items: baseline;
  margin-bottom: clamp(48px, 6vw, 88px);
}

.section-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ink-mute);
  padding-top: 14px;
  border-top: 1px solid var(--ink);
  display: inline-block;
  min-width: 60px;
}

.section-kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
  display: block;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(32px, 4.4vw, 56px);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--ink);
  max-width: 16ch;
  text-wrap: balance;
}

.section-sub {
  margin-top: 20px;
  font-size: 17px;
  line-height: 1.75;
  color: var(--ink-mid);
  max-width: 52ch;
  text-wrap: pretty;
}

/* ===========================================================
   Nav
   =========================================================== */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--rule-soft);
}

.nav-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 18px var(--gutter);
  display: flex;
  align-items: center;
  gap: 48px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.brand-mark {
  width: 22px;
  height: 22px;
  display: inline-block;
  position: relative;
  top: 4px;
}

.brand-mark svg { width: 100%; height: 100%; }

.brand-mark svg path {
  fill: none;
  stroke: var(--ink);
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.brand-mark svg .accent { stroke: var(--accent); }

.brand-domain {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ink-mute);
  padding-left: 12px;
  margin-left: 12px;
  border-left: 1px solid var(--rule);
}

.nav-links {
  display: flex;
  gap: 30px;
  list-style: none;
  margin-left: auto;
}

.nav-links a {
  font-size: 14.5px;
  color: var(--ink-soft);
  transition: color .2s ease;
  position: relative;
}

.nav-links a:hover { color: var(--accent); }

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--ink);
  color: var(--bg);
  font-size: 14px;
  border-radius: 2px;
  transition: transform .2s ease, background .2s ease;
}

.nav-cta:hover {
  background: var(--accent);
  transform: translate(-1px, -1px);
}

.nav-cta::after {
  content: "→";
  font-family: var(--font-mono);
}

/* ===========================================================
   Hero
   =========================================================== */

.hero {
  padding-top: clamp(56px, 7vw, 110px);
  padding-bottom: clamp(72px, 10vw, 140px);
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(32px, 5vw, 72px);
  align-items: center;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ink-mid);
  padding: 7px 14px 7px 10px;
  border: 1px solid var(--rule);
  border-radius: 100px;
  margin-bottom: 32px;
}

.hero-eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 0 3px color-mix(in oklab, var(--accent) 22%, transparent);
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(44px, 6.4vw, 92px);
  line-height: 1.05;
  letter-spacing: -0.025em;
  color: var(--ink);
  text-wrap: balance;
}

.hero-title .accent-word {
  color: var(--accent);
  position: relative;
  display: inline-block;
}

.hero-title .accent-word::after {
  content: "";
  position: absolute;
  left: -4%;
  right: -4%;
  bottom: 6%;
  height: 16px;
  background: var(--accent-soft);
  z-index: -1;
  transform: skewX(-6deg) rotate(-1deg);
  opacity: 0.7;
}

.hero-sub {
  margin-top: 28px;
  font-size: 19px;
  line-height: 1.75;
  color: var(--ink-mid);
  max-width: 30ch;
  text-wrap: pretty;
}

.hero-meta {
  margin-top: 28px;
  display: flex;
  gap: 22px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-mute);
}

.hero-meta span::before {
  content: "·";
  margin-right: 8px;
  color: var(--accent);
}

.hero-cta {
  margin-top: 44px;
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 24px;
  background: var(--ink);
  color: var(--bg);
  font-size: 15.5px;
  font-family: var(--font-body);
  border-radius: 2px;
  transition: all .2s ease;
  position: relative;
}

.btn-primary::after {
  content: "→";
  font-family: var(--font-mono);
  transition: transform .25s ease;
}

.btn-primary:hover {
  background: var(--accent);
  transform: translate(-2px, -2px);
  box-shadow: 4px 4px 0 var(--ink);
}

.btn-primary:hover::after { transform: translateX(4px); }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 8px;
  font-size: 15.5px;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--ink);
  transition: color .2s, border-color .2s;
}

.btn-ghost:hover { color: var(--accent); border-bottom-color: var(--accent); }

.btn-ghost::after { content: "→"; font-family: var(--font-mono); }

/* Hero schematic frame */

.hero-schematic {
  position: relative;
  aspect-ratio: 5 / 4.4;
  width: 100%;
}

.schematic-frame {
  position: absolute;
  inset: 0;
  border: 1px dashed var(--rule);
  border-radius: 4px;
}

.schematic-frame::before, .schematic-frame::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
  border: 1px solid var(--ink);
}

.schematic-frame::before {
  top: -5px;
  left: -5px;
  border-right: none;
  border-bottom: none;
}

.schematic-frame::after {
  bottom: -5px;
  right: -5px;
  border-left: none;
  border-top: none;
}

.schematic-corner {
  position: absolute;
  width: 10px;
  height: 10px;
  border: 1px solid var(--ink);
}

.schematic-corner.tr { top: -5px; right: -5px; border-left: none; border-bottom: none; }
.schematic-corner.bl { bottom: -5px; left: -5px; border-right: none; border-top: none; }

.schematic-label {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: var(--ink-mute);
  background: var(--bg);
  padding: 0 8px;
}

.schematic-label.tl { top: -7px; left: 16px; }
.schematic-label.br { bottom: -7px; right: 16px; }

#hero-svg {
  width: 100%;
  height: 100%;
  display: block;
}

/* Draw-on animation primitives */
.draw-path {
  stroke-dasharray: var(--len, 1000);
  stroke-dashoffset: var(--len, 1000);
  transition: stroke-dashoffset 1.2s cubic-bezier(.6,.05,.2,1);
}

.draw-path.is-in { stroke-dashoffset: 0; }

.fade-el {
  opacity: 0;
  transition: opacity .6s ease;
}

.fade-el.is-in { opacity: 1; }

/* ===========================================================
   Logo wall
   =========================================================== */

.logos {
  padding: 56px 0 64px;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.logos-head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 32px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ink-mute);
}

.logos-head::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--ink);
}

.logos-row {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 24px 48px;
  align-items: center;
  font-family: var(--font-display);
  color: var(--ink-soft);
}

.logo-item {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 48px;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.04em;
  opacity: 0.75;
  transition: opacity .2s;
  white-space: nowrap;
}

.logo-item:hover { opacity: 1; }

.logo-item .dot { color: var(--accent); margin: 0 2px; }
.logo-item.mono { font-family: var(--font-mono); font-weight: 500; font-size: 16px; letter-spacing: 0.06em; }
.logo-item.italic { font-style: italic; font-weight: 400; font-size: 20px; }

/* ===========================================================
   Capabilities (4-up grid)
   =========================================================== */

.capabilities {
  position: relative;
}

.cap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border-top: 1px solid var(--ink);
}

.cap-card {
  padding: clamp(32px, 4vw, 56px) clamp(28px, 4vw, 48px);
  border-bottom: 1px solid var(--rule);
  border-right: 1px solid var(--rule);
  position: relative;
  transition: background .25s;
}

.cap-card:nth-child(2n) { border-right: none; }
.cap-card:nth-last-child(-n+2) { border-bottom: none; }

.cap-card:hover { background: var(--bg-warm); }

.cap-icon {
  width: 72px;
  height: 72px;
  margin-bottom: 28px;
}

.cap-icon svg {
  width: 100%;
  height: 100%;
}

.cap-icon svg path,
.cap-icon svg circle,
.cap-icon svg line,
.cap-icon svg rect {
  fill: none;
  stroke: var(--ink);
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.cap-icon svg .accent { stroke: var(--accent); }

.cap-num {
  position: absolute;
  top: clamp(28px, 4vw, 48px);
  right: clamp(28px, 4vw, 48px);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--ink-mute);
}

.cap-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 24px;
  margin-bottom: 12px;
  color: var(--ink);
}

.cap-desc {
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--ink-mid);
  max-width: 42ch;
}

.cap-tags {
  margin-top: 20px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.cap-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ink-mid);
  padding: 4px 10px;
  border: 1px solid var(--rule);
  border-radius: 100px;
}

/* ===========================================================
   Features (interactive tabs)
   =========================================================== */

.features-wrap {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: clamp(32px, 5vw, 80px);
  align-items: start;
}

.feature-tabs {
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--rule);
}

.feature-tab {
  text-align: left;
  padding: 18px 24px;
  border-left: 2px solid transparent;
  margin-left: -1px;
  color: var(--ink-mid);
  font-family: var(--font-display);
  font-size: 17px;
  display: flex;
  align-items: baseline;
  gap: 12px;
  transition: all .2s;
}

.feature-tab .num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-mute);
  letter-spacing: 0.1em;
}

.feature-tab:hover { color: var(--ink); }

.feature-tab.active {
  color: var(--ink);
  border-left-color: var(--accent);
  font-weight: 700;
}

.feature-tab.active .num { color: var(--accent); }

.feature-panel {
  background: var(--bg-warm);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: clamp(32px, 4vw, 56px);
  min-height: 460px;
  position: relative;
  overflow: hidden;
}

.feature-panel::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  height: 1px; width: 80px;
  background: var(--accent);
}

.feature-content { display: none; }
.feature-content.active { display: block; }

.feature-title {
  font-family: var(--font-display);
  font-size: clamp(24px, 2.6vw, 32px);
  font-weight: 700;
  margin-bottom: 14px;
  color: var(--ink);
}

.feature-desc {
  font-size: 16px;
  color: var(--ink-mid);
  line-height: 1.75;
  max-width: 56ch;
  margin-bottom: 32px;
}

.feature-demo {
  margin-top: 8px;
  position: relative;
}

/* Code demo box */
.code-box {
  background: var(--ink);
  color: #d2d8e3;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  padding: 22px 24px;
  border-radius: 3px;
  position: relative;
  overflow: hidden;
}

.code-box-head {
  display: flex;
  gap: 6px;
  margin-bottom: 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.code-box-head .dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: rgba(255,255,255,0.18);
}

.code-box-head .label {
  margin-left: 14px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.4);
}

.code-line { display: block; min-height: 1.7em; }
.tok-kw { color: #ff6b5b; }
.tok-fn { color: #f0c674; }
.tok-str { color: #94c79a; }
.tok-com { color: rgba(255,255,255,0.36); font-style: italic; }
.tok-num { color: #e9a777; }
.cursor {
  display: inline-block;
  width: 8px;
  height: 1.1em;
  background: #ff6b5b;
  vertical-align: -2px;
  animation: blink 1s steps(2) infinite;
}

@keyframes blink { 50% { opacity: 0; } }

/* ===========================================================
   Architecture diagram (large)
   =========================================================== */

.arch {
  background: var(--bg-warm);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.arch-canvas {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  margin-top: 48px;
  background: var(--bg);
  border: 1px solid var(--rule);
  border-radius: 4px;
  overflow: hidden;
}

#arch-svg { width: 100%; height: 100%; display: block; }

.arch-legend {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-mid);
}

.arch-legend-item { display: flex; align-items: center; gap: 8px; }

.arch-legend-item .swatch {
  width: 18px;
  height: 2px;
  background: var(--ink);
}

.arch-legend-item.accent .swatch { background: var(--accent); }
.arch-legend-item.dashed .swatch {
  background: transparent;
  border-top: 1.5px dashed var(--ink);
  height: 0;
}

/* ===========================================================
   Metrics
   =========================================================== */

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}

.metric {
  padding: 48px 32px;
  border-right: 1px solid var(--rule);
  position: relative;
}

.metric:last-child { border-right: none; }

.metric-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-bottom: 14px;
}

.metric-num {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: clamp(40px, 5vw, 64px);
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.02em;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.metric-num .suffix {
  font-size: 0.45em;
  color: var(--accent);
  font-weight: 400;
}

.metric-desc {
  margin-top: 18px;
  font-size: 14px;
  color: var(--ink-mid);
  line-height: 1.65;
  max-width: 22ch;
}

.metric-annotation {
  position: absolute;
  bottom: 14px;
  right: 18px;
  font-family: var(--font-display);
  font-size: 13px;
  color: var(--accent);
  transform: rotate(-3deg);
  opacity: 0.75;
}

/* ===========================================================
   Values (team)
   =========================================================== */

.values-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.value-card {
  position: relative;
  padding: 36px 32px 32px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--bg);
  transition: all .25s;
}

.value-card:hover {
  border-color: var(--ink);
  transform: translate(-3px, -3px);
  box-shadow: 6px 6px 0 var(--ink);
}

.value-num {
  position: absolute;
  top: -1px;
  left: 24px;
  background: var(--bg);
  padding: 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--accent);
  transform: translateY(-50%);
}

.value-glyph {
  width: 56px;
  height: 56px;
  margin-bottom: 24px;
}

.value-glyph svg { width: 100%; height: 100%; }

.value-glyph svg path,
.value-glyph svg circle,
.value-glyph svg line {
  fill: none;
  stroke: var(--ink);
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.value-glyph svg .accent { stroke: var(--accent); }

.value-title {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 12px;
}

.value-desc {
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-mid);
}

/* ===========================================================
   CTA
   =========================================================== */

.cta {
  padding: clamp(72px, 9vw, 140px) 0;
  position: relative;
}

.cta-inner {
  position: relative;
  background: var(--ink);
  color: var(--bg);
  padding: clamp(48px, 7vw, 96px) clamp(32px, 6vw, 88px);
  border-radius: 4px;
  overflow: hidden;
}

.cta-inner::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: var(--accent);
}

.cta-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: clamp(32px, 5vw, 80px);
  align-items: end;
}

.cta-title {
  font-family: var(--font-display);
  font-size: clamp(36px, 5vw, 64px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.cta-title .marker {
  color: var(--accent);
  position: relative;
}

.cta-sub {
  font-size: 17px;
  line-height: 1.75;
  color: rgba(244, 246, 249, 0.62);
  margin-top: 22px;
  max-width: 36ch;
}

.cta-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.cta-input {
  background: transparent;
  border: 1px solid rgba(244, 246, 249, 0.22);
  color: var(--bg);
  font-family: var(--font-body);
  font-size: 15px;
  padding: 14px 16px;
  border-radius: 2px;
  transition: border-color .2s;
  outline: none;
}

.cta-input:focus { border-color: var(--accent); }

.cta-input::placeholder { color: rgba(244, 246, 249, 0.4); }

.cta-submit {
  background: var(--accent);
  color: var(--bg);
  padding: 16px 20px;
  font-size: 15px;
  font-family: var(--font-body);
  border-radius: 2px;
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  transition: all .2s;
}

.cta-submit:hover { background: var(--bg); color: var(--ink); }

.cta-submit::after { content: "→"; font-family: var(--font-mono); }

.cta-foot {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: rgba(244, 246, 249, 0.4);
}

/* ===========================================================
   Footer
   =========================================================== */

.footer {
  padding: 64px 0 32px;
  border-top: 1px solid var(--rule);
  font-size: 14px;
  color: var(--ink-mid);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(4, 1fr);
  gap: 48px;
  margin-bottom: 56px;
}

.footer h5 {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-bottom: 18px;
  font-weight: 500;
}

.footer ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.footer a { transition: color .15s; }
.footer a:hover { color: var(--accent); }

.footer-brand-desc {
  margin-top: 14px;
  max-width: 32ch;
  color: var(--ink-mid);
  font-size: 14px;
  line-height: 1.7;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  padding-top: 28px;
  border-top: 1px solid var(--rule);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--ink-mute);
}

/* ===========================================================
   Hand-drawn schematic styling (rough.js paths)
   =========================================================== */

.rough-stroke {
  fill: none;
  stroke: var(--ink);
  stroke-width: 1.3;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.rough-stroke.accent { stroke: var(--accent); }
.rough-stroke.thin { stroke-width: 1; }
.rough-stroke.thick { stroke-width: 1.6; }

.schematic-text {
  font-family: var(--font-display);
  font-size: 14px;
  fill: var(--ink);
}

.schematic-text.mono {
  font-family: var(--font-mono);
  font-size: 11px;
  fill: var(--ink-mid);
  letter-spacing: 0.08em;
}

.schematic-text.hand {
  font-family: var(--font-display);
  fill: var(--accent);
  font-size: 14px;
}

.schematic-text.label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  fill: var(--ink);
}

/* ===========================================================
   Responsive
   =========================================================== */

@media (max-width: 900px) {
  .nav-links { display: none; }
  .hero-grid { grid-template-columns: 1fr; }
  .hero-schematic { aspect-ratio: 5 / 4; }
  .cap-grid { grid-template-columns: 1fr; }
  .cap-card { border-right: none !important; }
  .features-wrap { grid-template-columns: 1fr; }
  .metrics-grid { grid-template-columns: repeat(2, 1fr); }
  .metric:nth-child(2n) { border-right: none; }
  .values-grid { grid-template-columns: 1fr; }
  .cta-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .logos-row { grid-template-columns: repeat(3, 1fr); }
  .section-head { grid-template-columns: 1fr; gap: 24px; }
}

/* ===========================================================
   Tweaks panel — minimal
   =========================================================== */

.tweaks-panel {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 100;
  background: var(--bg);
  border: 1px solid var(--ink);
  border-radius: 4px;
  padding: 20px;
  width: 260px;
  box-shadow: 6px 6px 0 var(--ink);
  font-family: var(--font-body);
  display: none;
}

.tweaks-panel.is-open { display: block; }

.tweaks-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--rule);
}

.tweaks-title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
}

.tweaks-close {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink-mid);
  padding: 4px;
}

.tweak-row { margin-bottom: 16px; }

.tweak-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--ink-mid);
  margin-bottom: 8px;
  display: block;
}

.tweak-swatches { display: flex; gap: 8px; }

.tweak-swatch {
  width: 28px; height: 28px;
  border: 1px solid var(--rule);
  border-radius: 2px;
  cursor: pointer;
  transition: transform .15s;
}

.tweak-swatch:hover { transform: scale(1.1); }
.tweak-swatch.is-active { border: 2px solid var(--ink); }

.tweak-segments { display: flex; border: 1px solid var(--rule); border-radius: 2px; overflow: hidden; }
.tweak-segments button {
  flex: 1;
  padding: 8px 10px;
  font-size: 12px;
  color: var(--ink-mid);
  background: transparent;
  transition: all .15s;
}

.tweak-segments button.is-active { background: var(--ink); color: var(--bg); }