/* ============================================================
   Seno — Zen Editorial Premium
   Palette: #FFFFFF / #111111 / #E5E5E5 hairlines
   Mathematical ink: #0B1325 · Blueprint faint: #E6ECF5
   ============================================================ */

@font-face {
  font-family: "InterVariable";
  src: url("../assets/fonts/InterVariable.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

:root {
  --bg: #FFFFFF;
  --ink: #111111;
  --ink-quiet: rgba(17, 17, 17, 0.46);
  --hairline: #E5E5E5;
  --math: #2B3E50;
  --blueprint: #E6ECF5;
  --col: 680px;
  --rail: 170px; /* reserved for the sine rail on desktop */
}

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

html {
  overflow-x: clip;
}

body {
  position: relative;
  background: var(--bg);
  color: var(--ink);
  font-family: "InterVariable", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-optical-sizing: auto;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
}

::selection { background: var(--blueprint); color: var(--math); }

/* ---------- Sine rail layer ---------- */

.wave-layer {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

#wave-svg { display: block; }

.wave-axis {
  stroke: var(--blueprint);
  stroke-width: 1;
}

.wave-passive {
  fill: none;
  stroke: var(--blueprint);
  stroke-width: 1.25;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.wave-active {
  fill: none;
  stroke: var(--math);
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.wave-dot { fill: var(--math); }

.wave-dot-halo {
  fill: none;
  stroke: var(--math);
  stroke-width: 1;
  opacity: 0.18;
}

/* ---------- Chrome ---------- */

.site-head {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  padding: 2rem clamp(1.5rem, 5vw, 4rem);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--math);
  text-decoration: none;
}

.brand-name {
  font-size: 1.05rem;
  font-weight: 560;
  letter-spacing: -0.01em;
}

.site-foot {
  position: relative;
  z-index: 2;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-top: 1px solid var(--hairline);
  margin: 0 clamp(1.5rem, 5vw, 4rem);
  padding: 1.75rem 0 2.25rem;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--ink-quiet);
}

.foot-math {
  font-feature-settings: "tnum";
  color: var(--math);
  opacity: 0.55;
}

/* ---------- Layout primitives ---------- */

main { position: relative; z-index: 1; }

.section {
  padding: clamp(7rem, 18vh, 12rem) clamp(1.5rem, 5vw, 4rem);
}

.col {
  max-width: var(--col);
  margin: 0 auto;
}

.rule-top {
  position: relative;
}

.rule-top::before {
  content: "";
  position: absolute;
  top: 0;
  left: clamp(1.5rem, 5vw, 4rem);
  right: clamp(1.5rem, 5vw, 4rem);
  height: 1px;
  background: var(--hairline);
}

.rule-top-thin {
  border-top: 1px solid var(--hairline);
  margin-top: clamp(4rem, 9vh, 6.5rem);
  padding-top: clamp(4rem, 9vh, 6.5rem);
}

.eyebrow {
  font-size: 0.6875rem;
  font-weight: 520;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-quiet);
  margin-bottom: clamp(2.5rem, 6vh, 4rem);
}

/* ---------- 1 · Hero ---------- */

.hero {
  min-height: calc(100vh - 6rem);
  display: flex;
  align-items: center;
}

.wordmark {
  font-size: clamp(4.5rem, 12vw, 9rem);
  font-weight: 560;
  letter-spacing: -0.035em;
  line-height: 0.95;
  color: var(--ink);
}

.value {
  margin-top: clamp(2.5rem, 6vh, 4rem);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 420;
  letter-spacing: -0.015em;
  line-height: 1.3;
  max-width: 26ch;
}

.sub {
  margin-top: 1.5rem;
  font-size: 1.0625rem;
  color: var(--ink-quiet);
  max-width: 52ch;
}

.scroll-cue {
  margin-top: clamp(4rem, 10vh, 7rem);
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-quiet);
}

/* ---------- 2 · Narrative ---------- */

.lede {
  font-size: clamp(1.375rem, 2.6vw, 1.875rem);
  font-weight: 400;
  letter-spacing: -0.012em;
  line-height: 1.5;
}

.lede + .lede {
  margin-top: clamp(2rem, 5vh, 3.25rem);
}

.lede em {
  font-style: normal;
  font-weight: 600;
  color: var(--math);
}

/* ---------- 3 · Engagements ---------- */

.engagement-label {
  font-size: 0.6875rem;
  font-weight: 520;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-quiet);
  margin-bottom: 1.5rem;
}

.engagement-headline {
  font-size: clamp(1.875rem, 3.8vw, 2.75rem);
  font-weight: 620;
  letter-spacing: -0.022em;
  line-height: 1.12;
  color: var(--math);
  font-feature-settings: "tnum";
}

.engagement-kicker {
  margin-top: 0.875rem;
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.015em;
  color: var(--ink-quiet);
}

.engagement-body {
  margin-top: 2.25rem;
  font-size: 1.0625rem;
  line-height: 1.75;
  max-width: 62ch;
}

/* ---------- 4 · Terminal / CTA ---------- */

.terminal {
  display: flex;
  justify-content: center;
  padding-bottom: clamp(9rem, 22vh, 15rem);
}

.terminal-panel {
  width: min(560px, 100%);
  border: 1px solid var(--hairline);
  padding: clamp(2.75rem, 6vw, 4rem) clamp(1.75rem, 5vw, 3.5rem);
  text-align: center;
  background: var(--bg);
}

.terminal-prompt {
  font-size: 0.75rem;
  font-weight: 520;
  letter-spacing: 0.14em;
  color: var(--math);
  opacity: 0.5;
  font-feature-settings: "tnum";
}

.terminal-heading {
  margin-top: 2rem;
  font-size: clamp(1.5rem, 3vw, 1.9375rem);
  font-weight: 560;
  letter-spacing: -0.018em;
}

.terminal-sub {
  margin-top: 0.875rem;
  font-size: 0.9375rem;
  color: var(--ink-quiet);
}

.cta-button {
  display: inline-block;
  margin-top: 2.75rem;
  padding: 1.05rem 2.5rem;
  border: 1px solid var(--ink);
  color: var(--ink);
  text-decoration: none;
  font-size: 0.8125rem;
  font-weight: 540;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  transition: background-color 0.35s ease, color 0.35s ease, border-color 0.35s ease;
}

.cta-button:hover,
.cta-button:focus-visible {
  background: var(--math);
  border-color: var(--math);
  color: #FFFFFF;
}

.cta-button:focus-visible,
.terminal-mail a:focus-visible,
.brand:focus-visible {
  outline: 2px solid var(--math);
  outline-offset: 3px;
}

.terminal-mail {
  margin-top: 2rem;
  font-size: 0.875rem;
  color: var(--ink-quiet);
}

.terminal-mail a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--hairline);
  transition: border-color 0.3s ease;
}

.terminal-mail a:hover { border-color: var(--math); }

/* ---------- Mobile ---------- */

@media (max-width: 767px) {
  .wave-layer { opacity: 0.5; }
  .wordmark { font-size: clamp(3.75rem, 19vw, 5.5rem); }
  .site-foot { flex-direction: column; gap: 0.5rem; }
}

/* ---------- Motion preferences ---------- */

@media (prefers-reduced-motion: reduce) {
  .cta-button { transition: none; }
}