/* ============================================================
   Abhishek Sonawane — AI Systems Portfolio (plain HTML/CSS/JS)
   ============================================================ */

/* ───────── 1. DESIGN TOKENS ───────── */
:root {
  /* surfaces */
  --bg:              #0a0b0d;
  --bg-soft:         #0d0f12;
  --panel:           #101216;
  --panel-2:         #14171c;
  --card:            #16191e;
  --hairline:        rgba(255, 255, 255, 0.06);
  --hairline-strong: rgba(255, 255, 255, 0.10);
  --hairline-bright: rgba(255, 255, 255, 0.16);

  /* text ramp */
  --fg:   #e8eaed;
  --fg-2: #c4c8ce;
  --fg-3: #8d939c;
  --fg-4: #5b6068;
  --fg-5: #3d4047;

  /* accents */
  --accent:      #5ee39a;
  --accent-dim:  rgba(94, 227, 154, 0.14);
  --accent-edge: rgba(94, 227, 154, 0.32);
  --amber:       #f5b454;
  --amber-dim:   rgba(245, 180, 84, 0.12);
  --blue:        #7aa2ff;
  --blue-dim:    rgba(122, 162, 255, 0.12);
  --rose:        #f07a82;

  /* type */
  --font-sans: "Geist", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono: "Geist Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  /* layout */
  --maxw:   1240px;
  --pad:    clamp(20px, 4vw, 56px);
  --radius:    10px;
  --radius-lg: 14px;
}

/* ───────── 2. GLOBAL ───────── */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--fg);
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-size: 15px;
  line-height: 1.55;
  letter-spacing: -0.005em;
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; }
::selection { background: rgba(94, 227, 154, 0.22); color: var(--fg); }

.mono { font-family: var(--font-mono); }

/* Ambient atmospheric gradients (kept on infra/blue regardless of theme) */
body::before {
  content: "";
  position: fixed; inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    radial-gradient(1200px 600px at 75% -10%, rgba(94, 227, 154, 0.05), transparent 60%),
    radial-gradient(900px  500px at  0% 30%, rgba(122, 162, 255, 0.03), transparent 60%);
}

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding-left: var(--pad);
  padding-right: var(--pad);
  position: relative;
  z-index: 1;
}

.section {
  padding: 96px 0;
  border-top: 1px solid var(--hairline);
  position: relative;
}
.section:first-of-type { border-top: none; }

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 32px;
  margin-bottom: 48px;
}
.section-head h2 {
  font-size: clamp(28px, 3.4vw, 40px);
  letter-spacing: -0.02em;
  margin: 12px 0 0;
  font-weight: 500;
  max-width: 720px;
}
.section-head p {
  color: var(--fg-3);
  max-width: 380px;
  margin: 0;
  font-size: 14px;
}

/* ───────── 3. ATOMS ───────── */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-3);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.eyebrow::before {
  content: "";
  width: 6px; height: 6px;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 0 3px var(--accent-dim);
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border-radius: 999px;
  border: 1px solid var(--hairline-strong);
  background: rgba(255, 255, 255, 0.02);
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-2);
  letter-spacing: 0.02em;
}
.pill.live {
  color: var(--accent);
  border-color: var(--accent-edge);
  background: var(--accent-dim);
}
.pill .dot { width: 6px; height: 6px; border-radius: 50%; background: currentColor; }
.pill.live .dot { animation: pulse 1.6s ease-in-out infinite; }

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 var(--accent-edge); opacity: 1; }
  50%      { box-shadow: 0 0 0 5px rgba(94, 227, 154, 0); opacity: .7; }
}

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: -0.005em;
  border: 1px solid var(--hairline-strong);
  background: var(--panel);
  color: var(--fg);
  cursor: pointer;
  transition: background .15s ease, border-color .15s ease, transform .15s ease;
}
.btn:hover { background: var(--panel-2); border-color: var(--hairline-bright); }
.btn.primary {
  background: var(--accent);
  color: #052012;
  border-color: var(--accent);
}
.btn.primary:hover { background: #74ecaa; }
.btn .arrow { transition: transform .2s ease; }
.btn:hover .arrow { transform: translateX(2px); }

.chip {
  padding: 4px 9px;
  border-radius: 5px;
  background: var(--panel-2);
  border: 1px solid var(--hairline-strong);
  color: var(--fg-2);
  font-size: 11.5px;
  font-family: var(--font-mono);
}
.chip-sm {
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--hairline);
  color: var(--fg-3);
  font-size: 10.5px;
  font-family: var(--font-mono);
}

/* ───────── 4. NAV ───────── */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: rgba(10, 11, 13, 0.72);
  border-bottom: 1px solid var(--hairline);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px var(--pad);
  max-width: var(--maxw);
  margin: 0 auto;
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: -0.005em;
}
.nb-mark {
  width: 22px; height: 22px;
  border-radius: 6px;
  background: var(--panel-2);
  border: 1px solid var(--hairline-strong);
  display: grid; place-items: center;
  color: var(--accent);
  font-weight: 600;
  position: relative;
}
.nb-mark::after {
  content: ""; position: absolute; inset: -2px;
  border-radius: 8px;
  border: 1px solid var(--accent-edge);
  opacity: 0.4;
  animation: pulse-ring 2.4s ease-in-out infinite;
}
@keyframes pulse-ring {
  0%, 100% { opacity: 0.35; transform: scale(1); }
  50%      { opacity: 0.05; transform: scale(1.18); }
}
.nb-name { color: var(--fg); font-weight: 500; }
.nb-role { color: var(--fg-3); }

.nav-links { display: flex; gap: 26px; font-size: 13px; }
.nav-links a {
  color: var(--fg-3);
  transition: color .15s ease;
  font-family: var(--font-mono);
  font-size: 12px;
}
.nav-links a:hover { color: var(--fg); }
.nav-right { display: flex; gap: 8px; align-items: center; }

@media (max-width: 820px) { .nav-links { display: none; } }

/* ───────── 4.1 THEME SWITCH ───────── */
.theme-switch { position: relative; }
.theme-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 10px 6px 8px;
  border-radius: 7px;
  background: var(--panel);
  border: 1px solid var(--hairline-strong);
  color: var(--fg-2);
  cursor: pointer;
  font-size: 12px;
  transition: background .15s ease, border-color .15s ease;
}
.theme-btn:hover { background: var(--panel-2); border-color: var(--hairline-bright); color: var(--fg); }
.theme-btn-label { font-size: 11.5px; letter-spacing: 0.02em; color: var(--fg-3); }
.theme-btn:hover .theme-btn-label { color: var(--fg-2); }
.theme-swatch {
  width: 14px; height: 14px;
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.45), 0 0 0 2px rgba(255,255,255,0.04);
  transition: transform .2s ease, box-shadow .2s ease;
}
.theme-btn:hover .theme-swatch { transform: scale(1.05); }
.theme-chev { color: var(--fg-4); transition: transform .2s ease; }
.theme-chev.open { transform: rotate(180deg); }

.theme-pop {
  position: absolute;
  top: calc(100% + 8px); right: 0;
  width: 280px;
  background: var(--panel);
  border: 1px solid var(--hairline-strong);
  border-radius: 10px;
  box-shadow: 0 14px 40px rgba(0,0,0,0.6), 0 2px 8px rgba(0,0,0,0.4);
  overflow: hidden;
  z-index: 60;
  animation: theme-pop-in 0.18s ease-out;
}
@keyframes theme-pop-in {
  from { opacity: 0; transform: translateY(-4px) scale(0.98); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}
.theme-pop-head, .theme-pop-foot {
  padding: 10px 14px;
  font-size: 10.5px;
  color: var(--fg-4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: var(--bg-soft);
}
.theme-pop-head { border-bottom: 1px solid var(--hairline); }
.theme-pop-foot { border-top: 1px solid var(--hairline); font-size: 10px; }
.theme-pop-list { display: flex; flex-direction: column; padding: 4px; }
.theme-opt {
  display: grid;
  grid-template-columns: 22px 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 10px;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 7px;
  cursor: pointer;
  text-align: left;
  color: var(--fg);
  transition: background .12s ease, border-color .12s ease;
  font-family: var(--font-sans);
}
.theme-opt:hover { background: var(--panel-2); }
.theme-opt.active { background: var(--panel-2); border-color: var(--hairline-strong); }
.theme-opt-swatch {
  width: 22px; height: 22px;
  border-radius: 50%;
  display: grid; place-items: center;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.5), 0 0 0 2px rgba(255,255,255,0.06);
}
.theme-opt-text { display: flex; flex-direction: column; gap: 1px; }
.theme-opt-name { font-size: 13px; color: var(--fg); letter-spacing: -0.005em; }
.theme-opt-sub  { font-size: 10px; color: var(--fg-4); letter-spacing: 0.04em; }
.theme-opt-hex  { font-size: 10.5px; color: var(--fg-4); letter-spacing: 0.02em; }
.theme-opt.active .theme-opt-hex { color: var(--accent); }

/* ───────── 5. HERO ───────── */
.hero { padding: 64px 0 32px; position: relative; overflow: hidden; }
.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 56px;
  align-items: center;
  min-height: 70vh;
}
.hero-left { display: flex; flex-direction: column; gap: 22px; }
.hero-h1 {
  font-size: clamp(36px, 4.8vw, 64px);
  line-height: 1.04;
  letter-spacing: -0.028em;
  margin: 12px 0 0;
  font-weight: 500;
  max-width: 14ch;
  text-wrap: balance;
}
.hero-h1 em { font-style: normal; color: var(--accent); }
.hero-sub {
  color: var(--fg-3);
  font-size: 16px;
  line-height: 1.6;
  max-width: 52ch;
  margin: 0;
}
.hero-ctas { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.hero-strip {
  display: flex; flex-wrap: wrap; gap: 28px;
  padding-top: 24px; margin-top: 16px;
  border-top: 1px solid var(--hairline);
}
.hs-item { display: flex; flex-direction: column; gap: 2px; font-size: 13px; }
.hs-k { font-size: 10.5px; color: var(--fg-4); letter-spacing: 0.08em; text-transform: uppercase; }
.hs-v { color: var(--fg-2); }
.hero-right { display: flex; flex-direction: column; gap: 16px; }

@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
}

/* ───────── 5.1 WORKFLOW GRAPH ───────── */
.wfg {
  background: var(--panel);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  padding: 16px;
  position: relative;
  overflow: hidden;
}
.wfg::before {
  content: "";
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent-edge), transparent);
  opacity: 0.6;
}
.wfg-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 8px; }
.wfg-meta { font-size: 11px; color: var(--fg-4); }
.wfg-svg { width: 100%; height: auto; display: block; }
.wfg-foot {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 8px;
  padding-top: 12px;
  border-top: 1px solid var(--hairline);
}
.wfg-foot-item { display: flex; flex-direction: column; gap: 2px; }
.wfg-k { font-size: 10px; color: var(--fg-4); letter-spacing: 0.08em; text-transform: uppercase; }
.wfg-v { font-size: 13px; color: var(--fg-2); }

/* nodes (default = idle) */
.node-rect    { fill: #16191e; stroke: rgba(255,255,255,0.10); transition: fill .4s, stroke .4s; }
.node-dot     { fill: rgba(255,255,255,0.30); transition: fill .4s; }
.node-label   { fill: #e8eaed; font-family: var(--font-sans); font-size: 11.5px; font-weight: 500; }
.node-sub     { fill: #8d939c; font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.04em; }
.node-status  { fill: #5b6068; font-family: var(--font-mono); font-size: 9px; transition: fill .4s; }

.wfg-node.active .node-rect { fill: var(--accent-dim); stroke: var(--accent); }
.wfg-node.active .node-dot  { fill: var(--accent); }
.wfg-node.active .node-status { fill: var(--accent); }

/* edges */
.wfg-edge {
  fill: none;
  stroke: rgba(255,255,255,0.10);
  stroke-width: 1;
  transition: stroke .4s, stroke-width .4s;
}
.wfg-edge.active {
  stroke: var(--accent);
  stroke-width: 1.4;
}
.wfg-travel {
  fill: var(--accent);
  filter: url(#glow);
  opacity: 0;
}
.wfg-edge.active + .wfg-travel,
.wfg-travel.active { opacity: 1; }

/* ───────── 5.2 TERMINAL ───────── */
.terminal {
  background: var(--panel);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.terminal-head {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 14px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--hairline);
}
.tl-dots { display: flex; gap: 6px; }
.tl-dots span { width: 9px; height: 9px; border-radius: 50%; }
.tl-title { font-size: 11px; color: var(--fg-3); flex: 1; }
.tl-title:last-child { flex: none; }
.terminal-body {
  padding: 12px 14px;
  font-size: 11.5px;
  line-height: 1.7;
  max-height: 200px;
  overflow: hidden;
  display: flex; flex-direction: column;
}
.tl-line {
  display: grid;
  grid-template-columns: 64px 50px 1fr;
  gap: 10px;
  align-items: center;
  animation: fadeUp 0.4s ease;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}
.tl-time { color: var(--fg-4); font-size: 10.5px; }
.tl-tag {
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-align: center;
  border: 1px solid transparent;
  white-space: pre;
}
.tl-tag-g { color: var(--accent);  background: var(--accent-dim);  border-color: var(--accent-edge); }
.tl-tag-b { color: var(--blue);    background: var(--blue-dim);    border-color: rgba(122,162,255,0.32); }
.tl-tag-a { color: var(--amber);   background: var(--amber-dim);   border-color: rgba(245,180,84,0.32); }
.tl-tag-d { color: var(--fg-3);    background: rgba(255,255,255,0.03); border-color: var(--hairline-strong); }
.tl-text  { color: var(--fg-2); font-size: 11.5px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.tl-cursor { grid-template-columns: 1fr; color: var(--accent); animation: blink 1s steps(2) infinite; }
@keyframes blink { 50% { opacity: 0.2; } }

/* ───────── 6. METRICS ───────── */
.section-metrics { padding: 56px 0; }
.metrics-head {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 20px;
}
.metrics-head-meta { font-size: 11px; color: var(--fg-4); letter-spacing: 0.06em; }
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.metric-card {
  background: var(--panel);
  padding: 22px 20px;
  display: flex; flex-direction: column; gap: 8px;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity .6s ease, transform .6s ease;
  position: relative;
}
.metric-card.in { opacity: 1; transform: translateY(0); }
.metric-card:hover { background: var(--panel-2); }
.metric-v {
  font-size: clamp(22px, 2.6vw, 28px);
  color: var(--fg);
  letter-spacing: -0.01em;
  font-weight: 500;
}
.metric-label { font-size: 12.5px; color: var(--fg-2); }
.metric-sub   { font-size: 10.5px; color: var(--fg-4); letter-spacing: 0.02em; margin-top: auto; }

@media (max-width: 980px) { .metrics-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 600px) { .metrics-grid { grid-template-columns: repeat(2, 1fr); } }

/* ───────── 7. PHILOSOPHY ───────── */
.philosophy {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 64px;
  align-items: start;
}
.philosophy-side { position: sticky; top: 100px; display: flex; flex-direction: column; gap: 10px; }
.philosophy-meta { font-size: 11px; color: var(--fg-4); }
.philosophy-body { max-width: 64ch; }
.philosophy-body p { color: var(--fg-2); font-size: 16px; line-height: 1.65; margin: 0 0 18px; }
.philosophy-lede {
  font-size: 22px !important;
  line-height: 1.45 !important;
  color: var(--fg) !important;
  letter-spacing: -0.012em;
  font-weight: 400;
}
.philosophy-goal em { color: var(--accent); font-style: normal; }
.philosophy-quote {
  margin: 32px 0 0;
  padding: 24px 28px;
  background: var(--panel);
  border-left: 2px solid var(--accent);
  border-radius: 0 8px 8px 0;
  font-size: 17px;
  line-height: 1.5;
  color: var(--fg);
  letter-spacing: -0.008em;
}
.q-mark { color: var(--accent); margin-right: 6px; font-size: 24px; }

@media (max-width: 820px) {
  .philosophy { grid-template-columns: 1fr; gap: 24px; }
  .philosophy-side { position: static; }
}

/* ───────── 8. FEATURED SYSTEMS ───────── */
.sys-case {
  padding: 56px 0;
  border-top: 1px dashed var(--hairline);
}
.sys-case:first-of-type { border-top: none; padding-top: 0; }
.sys-head {
  display: flex; justify-content: space-between; align-items: flex-start;
  gap: 24px;
  margin-bottom: 32px;
}
.sys-head-left { display: flex; flex-direction: column; gap: 6px; }
.sys-idx { font-size: 11px; color: var(--fg-4); letter-spacing: 0.08em; }
.sys-title {
  font-size: clamp(28px, 3.4vw, 38px);
  letter-spacing: -0.02em;
  margin: 0; font-weight: 500;
}
.sys-subtitle {
  margin: 4px 0 0; color: var(--fg-3);
  font-size: 15px;
  max-width: 60ch;
}
.sys-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 48px;
  margin-bottom: 32px;
}
.sys-body { display: flex; flex-direction: column; gap: 24px; }
.sys-desc { font-size: 16px; line-height: 1.6; color: var(--fg-2); margin: 0; max-width: 64ch; }
.sys-block { display: flex; flex-direction: column; gap: 10px; }
.sys-block-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-4);
}
.sys-block p { margin: 0; color: var(--fg-2); font-size: 14.5px; line-height: 1.6; }
.sys-ul { margin: 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 8px; }
.sys-ul li {
  position: relative; padding-left: 18px;
  color: var(--fg-2); font-size: 14.5px; line-height: 1.55;
}
.sys-ul li::before {
  content: ""; position: absolute; left: 0; top: 9px;
  width: 8px; height: 1px; background: var(--accent);
}

.tradeoff-tbl {
  display: flex; flex-direction: column;
  border: 1px solid var(--hairline);
  border-radius: 8px;
  overflow: hidden;
}
.tradeoff-row {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 16px;
  padding: 14px 16px;
  border-top: 1px solid var(--hairline);
  background: var(--panel);
}
.tradeoff-row:first-child { border-top: none; }
.tradeoff-row:hover { background: var(--panel-2); }
.tradeoff-choice { color: var(--accent); font-size: 13px; font-weight: 500; }
.tradeoff-why    { font-size: 13.5px; color: var(--fg-2); line-height: 1.55; }

.sys-foot { display: flex; gap: 8px; margin-top: 8px; }

.sys-aside {
  display: flex; flex-direction: column; gap: 20px;
  position: sticky; top: 100px; align-self: start;
}
.sys-metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
  border-radius: 10px;
  overflow: hidden;
}
.sys-metric {
  background: var(--panel);
  padding: 16px 14px;
  display: flex; flex-direction: column; gap: 4px;
}
.sys-metric-v { font-size: 18px; color: var(--fg); letter-spacing: -0.01em; }
.sys-metric-k { font-size: 10.5px; color: var(--fg-4); letter-spacing: 0.04em; }
.sys-stack { display: flex; flex-direction: column; gap: 10px; }
.sys-stack-chips { display: flex; flex-wrap: wrap; gap: 6px; }

.sys-diagram {
  background: var(--panel);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.sys-diagram-head {
  display: flex; justify-content: space-between;
  padding: 10px 16px;
  border-bottom: 1px solid var(--hairline);
  background: var(--bg-soft);
  font-size: 11.5px;
  color: var(--fg-3);
}
.arch-svg {
  width: 100%; height: auto; display: block;
  background: var(--panel);
}

@media (max-width: 980px) {
  .sys-grid { grid-template-columns: 1fr; gap: 32px; }
  .sys-aside { position: static; }
  .sys-metrics { grid-template-columns: repeat(3, 1fr); }
  .tradeoff-row { grid-template-columns: 1fr; gap: 4px; }
}

/* ───────── 9. DECISIONS ───────── */
.decisions-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.decision-card {
  background: var(--panel);
  padding: 28px;
  display: flex; flex-direction: column; gap: 14px;
  transition: background .15s ease;
}
.decision-card:hover { background: var(--panel-2); }
.decision-head { display: flex; align-items: center; justify-content: space-between; }
.decision-idx { color: var(--fg-4); font-size: 11px; letter-spacing: 0.08em; }
.decision-q {
  font-size: 19px; font-weight: 500; line-height: 1.35;
  margin: 0; color: var(--fg); letter-spacing: -0.015em;
}
.decision-points {
  list-style: none; padding: 0; margin: 0;
  display: flex; flex-direction: column; gap: 10px;
}
.decision-points li { display: flex; gap: 10px; font-size: 14px; line-height: 1.55; color: var(--fg-2); }
.decision-bullet { color: var(--accent); font-family: var(--font-mono); font-size: 13px; flex-shrink: 0; }

@media (max-width: 820px) { .decisions-grid { grid-template-columns: 1fr; } }

/* ───────── 10. FAILURES ───────── */
.failures-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.failure-card {
  background: var(--panel);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex; flex-direction: column; gap: 12px;
  position: relative;
}
.failure-card::before {
  content: "";
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--amber), transparent);
  opacity: 0.5;
}
.failure-head  { font-size: 11px; color: var(--amber); letter-spacing: 0.08em; }
.failure-title { font-size: 16px; font-weight: 500; margin: 0; letter-spacing: -0.012em; }
.failure-body  { font-size: 13.5px; color: var(--fg-2); line-height: 1.6; margin: 0; }

@media (max-width: 820px) { .failures-grid { grid-template-columns: 1fr; } }

/* ───────── 11. TIMELINE ───────── */
.timeline { position: relative; padding-left: 8px; }
.timeline-line {
  position: absolute;
  left: 92px;
  top: 0; bottom: 0;
  width: 1px;
  background: var(--hairline);
}
.tl-row {
  display: grid;
  grid-template-columns: 80px 24px 1fr;
  gap: 16px;
  padding: 14px 0;
  align-items: center;
}
.tl-year { font-size: 13px; color: var(--fg-3); text-align: right; }
.tl-dot-wrap { display: grid; place-items: center; width: 24px; height: 24px; }
.tl-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--bg), 0 0 0 5px var(--hairline-strong);
  position: relative; z-index: 2;
}
.tl-row:hover .tl-dot { box-shadow: 0 0 0 4px var(--bg), 0 0 0 5px var(--accent); }
.tl-content { display: flex; flex-direction: column; gap: 2px; }
.tl-t { font-size: 15px; color: var(--fg); letter-spacing: -0.01em; }
.tl-d { font-size: 13px; color: var(--fg-3); }

/* ───────── 12. STACK ───────── */
.stack-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.stack-card {
  background: var(--panel);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex; flex-direction: column; gap: 16px;
}
.stack-head { display: flex; gap: 14px; align-items: flex-start; }
.stack-idx {
  width: 34px; height: 34px;
  border-radius: 7px;
  background: var(--accent-dim);
  border: 1px solid var(--accent-edge);
  color: var(--accent);
  display: grid; place-items: center;
  font-size: 12px; flex-shrink: 0;
}
.stack-layer { font-size: 16px; color: var(--fg); letter-spacing: -0.01em; }
.stack-note  { font-size: 11px; color: var(--fg-4); letter-spacing: 0.06em; margin-top: 2px; }
.stack-chips { display: flex; flex-wrap: wrap; gap: 6px; }

@media (max-width: 820px) { .stack-grid { grid-template-columns: 1fr; } }

/* ───────── 13. PROOF ───────── */
.proof-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.proof-card {
  background: var(--panel);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  padding: 22px;
  display: flex; flex-direction: column; gap: 14px;
  transition: background .15s ease, border-color .15s ease, transform .15s ease;
  cursor: pointer;
}
.proof-card:hover {
  background: var(--panel-2);
  border-color: var(--hairline-bright);
  transform: translateY(-1px);
}
.proof-head { display: flex; align-items: center; gap: 10px; }
.proof-name { font-size: 14px; color: var(--fg); font-weight: 500; }
.proof-desc { font-size: 13.5px; color: var(--fg-2); line-height: 1.55; margin: 0; }
.proof-meta { display: flex; justify-content: space-between; align-items: center; }
.proof-lang { display: inline-flex; align-items: center; gap: 6px; font-size: 11.5px; color: var(--fg-3); }
.lang-dot   { width: 8px; height: 8px; border-radius: 50%; background: var(--blue); }
.proof-tags { display: flex; gap: 6px; flex-wrap: wrap; }

@media (max-width: 820px) { .proof-grid { grid-template-columns: 1fr; } }

/* ───────── 14. FAST PATH ───────── */
.section-fastpath {
  background: linear-gradient(180deg, transparent, rgba(94,227,154,0.025) 50%, transparent);
}
.fp-grid {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 56px;
  align-items: start;
}
.fp-side { display: flex; flex-direction: column; gap: 14px; position: sticky; top: 100px; }
.fp-h {
  font-size: clamp(24px, 2.6vw, 32px);
  font-weight: 500; letter-spacing: -0.018em;
  margin: 8px 0 0; line-height: 1.2;
}
.fp-p { color: var(--fg-3); margin: 0; font-size: 14.5px; max-width: 38ch; }
.fp-p em { color: var(--fg); font-style: normal; }
.fp-list {
  display: flex; flex-direction: column;
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.fp-row {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  padding: 18px 22px;
  background: var(--panel);
  border-top: 1px solid var(--hairline);
  transition: background .15s ease;
}
.fp-row:first-child { border-top: none; }
.fp-row:hover { background: var(--panel-2); }
.fp-idx { color: var(--accent); font-size: 12px; }
.fp-k { font-size: 15px; color: var(--fg); letter-spacing: -0.012em; }
.fp-v { font-size: 13.5px; color: var(--fg-3); line-height: 1.5; margin-top: 4px; }

@media (max-width: 820px) {
  .fp-grid { grid-template-columns: 1fr; gap: 24px; }
  .fp-side { position: static; }
}

/* ───────── 15. CONTACT + FOOTER ───────── */
.section-contact { padding-bottom: 56px; }
.contact { display: flex; flex-direction: column; gap: 40px; }
.contact-head { max-width: 56ch; }
.contact-h {
  font-size: clamp(32px, 4vw, 48px);
  letter-spacing: -0.022em;
  font-weight: 500;
  margin: 12px 0 16px;
  line-height: 1.05;
}
.contact-h em { font-style: normal; color: var(--accent); }
.contact-p { color: var(--fg-3); font-size: 16px; margin: 0; line-height: 1.55; }

.contact-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.contact-card {
  background: var(--panel);
  padding: 22px;
  display: flex; flex-direction: column; gap: 6px;
  position: relative;
  transition: background .15s ease;
}
.contact-card:hover { background: var(--panel-2); }
.cc-k { font-size: 11px; color: var(--fg-4); letter-spacing: 0.08em; }
.cc-v { font-size: 14px; color: var(--fg); letter-spacing: -0.005em; }
.cc-arrow {
  position: absolute; top: 22px; right: 22px;
  color: var(--fg-4); font-family: var(--font-mono); font-size: 14px;
  transition: transform .15s ease, color .15s ease;
}
.contact-card:hover .cc-arrow { color: var(--accent); transform: translate(2px, -2px); }

.footer {
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 12px;
  padding-top: 24px; margin-top: 8px;
  border-top: 1px solid var(--hairline);
  font-size: 11.5px;
  color: var(--fg-4);
}
.footer-l, .footer-r { display: flex; align-items: center; gap: 12px; }
.footer-sep { color: var(--fg-5); }

@media (max-width: 820px) { .contact-grid { grid-template-columns: repeat(2, 1fr); } }