/* =========================================================
   Algebra — brand system (v2, matched to real guidelines)

   Primary type:    Helvetica Neue (fallback stack)
   Secondary type:  IBM Plex Mono
   Palette:         chartreuse · teal · rust · off-white · ink
                    + electric-blue accent (complementary, tech-forward)
   No rounded-corner cards. No serif. No Claude-beige.
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500&display=swap');

:root {
  /* Neutrals — clean, not beige */
  --paper:    #FAFAF8;   /* warm near-white canvas */
  --paper-2:  #E7E7E3;   /* slightly darker for alt blocks */
  --paper-3:  #FFFFFF;   /* pure white for contrast panels */
  --ink:      #0E0E0C;   /* near-black */
  --ink-2:    #26261F;
  --ink-soft: #6E6E66;

  /* Brand colors — taken from current site + brand sheet */
  --chartreuse:   #DDE55C;    /* signature */
  --chartreuse-2: #C6CE44;
  --teal:         #5D9384;    /* muted teal block */
  --teal-2:       #457260;
  --rust:         #9F5B3D;    /* terracotta block */
  --rust-2:       #7E4528;

  /* Complementary accent — electric blue (tech-forward, high contrast to chartreuse) */
  --blue:         #1d1d1d;
  --blue-2:       #4a1fa8;
  --blue-soft:    #d4c2f7;

  --rule:        rgba(14,14,12,0.14);
  --rule-strong: rgba(14,14,12,0.28);
  --rule-ink:    rgba(242,242,240,0.14);

  /* Type stack — Helvetica Neue primary, Plex Mono secondary */
  --font-sans: 'Helvetica Neue', Helvetica, Arial, 'Inter', sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  --gutter: clamp(20px, 3.2vw, 48px);
  --page-max: 1440px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* =====================  Layout  ===================== */

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

/* =====================  Nav (thin, technical)  ===================== */

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px var(--gutter);
  max-width: var(--page-max);
  margin: 0 auto;
  position: relative;
  z-index: 10;
  border-bottom: 1px solid var(--rule);
}
.nav__logo {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: -0.03em;
}
.nav__links {
  display: flex;
  gap: 28px;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.nav__links a { opacity: 0.7; transition: opacity .15s; }
.nav__links a:hover { opacity: 1; }
.nav__cta {
  background: var(--chartreuse);
  color: var(--ink);
  padding: 8px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border: 1px solid var(--ink);
  transition: background .15s;
}
.nav__cta:hover { background: var(--ink); color: var(--chartreuse); }

/* Mobile nav: hamburger + slide-down drawer */
.nav__burger {
  display: none;
  background: transparent;
  border: 1px solid var(--ink);
  width: 40px;
  height: 40px;
  padding: 0;
  cursor: pointer;
  position: relative;
}
.nav__burger span {
  display: block;
  position: absolute;
  left: 10px;
  right: 10px;
  height: 1.5px;
  background: var(--ink);
  transition: transform .25s ease, opacity .2s ease, top .25s ease;
}
.nav__burger span:nth-child(1) { top: 14px; }
.nav__burger span:nth-child(2) { top: 19px; }
.nav__burger span:nth-child(3) { top: 24px; }
.nav.is-open .nav__burger span:nth-child(1) { top: 19px; transform: rotate(45deg); }
.nav.is-open .nav__burger span:nth-child(2) { opacity: 0; }
.nav.is-open .nav__burger span:nth-child(3) { top: 19px; transform: rotate(-45deg); }

@media (max-width: 760px) {
  .nav { padding: 14px var(--gutter); flex-wrap: wrap; row-gap: 0; }
  .nav__burger { display: block; }
  .nav__links {
    order: 3;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
    margin-top: 14px;
    padding-top: 14px;
    border-top: 1px solid var(--rule);
  }
  .nav.is-open .nav__links { display: flex; }
  .nav__links a {
    padding: 14px 0;
    border-bottom: 1px solid var(--rule);
    opacity: 1;
    font-size: 13px;
  }
  .nav__links a:last-child { border-bottom: 0; }
  .nav__cta {
    align-self: flex-start;
    margin-top: 10px;
    padding: 10px 16px;
  }
}

/* Global overflow safety */
html, body { overflow-x: hidden; }

/* =====================  Typography primitives  ===================== */

/* Eyebrow / mono label */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
  font-weight: 400;
}
.eyebrow--ink { color: rgba(242,242,240,0.7); }

/* Hairline meta (smaller mono) */
.meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

/* Display — Helvetica bold, tight, ALL sans */
.display {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: clamp(48px, 6.8vw, 104px);
  line-height: 0.96;
  letter-spacing: -0.035em;
  margin: 0;
}
.h1 {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: clamp(36px, 4.6vw, 64px);
  line-height: 1.02;
  letter-spacing: -0.025em;
  margin: 0;
}
.h2 {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: clamp(28px, 3.2vw, 44px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0;
}
.h3 {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 22px;
  line-height: 1.2;
  margin: 0;
  letter-spacing: -0.01em;
}

.lede {
  font-family: var(--font-sans);
  font-size: 18px;
  line-height: 1.4;
  color: var(--ink-2);
  max-width: 560px;
  margin: 0;
  font-weight: 400;
}

.body  { font-size: 15px; line-height: 1.55; color: var(--ink-2); }
.small { font-size: 13px; line-height: 1.5; color: var(--ink-soft); }
.mono  { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.02em; }

/* =====================  Blocks — SQUARE, no radius  ===================== */

.block {
  padding: clamp(32px, 4.2vw, 64px);
  position: relative;
}
.block--paper     { background: var(--paper); color: var(--ink); }
.block--white     { background: var(--paper-3); color: var(--ink); border: 1px solid var(--rule); }
.block--ink       { background: var(--ink); color: var(--paper); }
.block--chartreuse{ background: var(--chartreuse); color: var(--ink); }
.block--rust      { background: var(--rust); color: var(--paper); }
.block--teal      { background: var(--teal); color: var(--paper); }
.block--blue      { background: var(--blue); color: var(--paper); }

/* =====================  Buttons  ===================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border: 1px solid var(--ink);
  background: var(--chartreuse);
  color: var(--ink);
  cursor: pointer;
  transition: background .15s, color .15s;
}
.btn:hover { background: var(--ink); color: var(--chartreuse); }
.btn--chartreuse { background: var(--chartreuse); color: var(--ink); }
.btn--chartreuse:hover { background: var(--ink); color: var(--chartreuse); }
.btn--blue { background: var(--blue); color: #fff; border-color: var(--blue); }
.btn--blue:hover { background: transparent; color: var(--blue); }
.btn--ghost { background: transparent; color: inherit; border-color: currentColor; opacity: 0.75; }
.btn--ghost:hover { opacity: 1; background: transparent; color: inherit; }
.btn .arrow { display: inline-block; transition: transform .2s ease; }
.btn:hover .arrow { transform: translateX(3px); }


/* =====================  Utilities  ===================== */

.hr {
  border: 0;
  height: 1px;
  background: var(--rule);
  margin: 56px 0;
}
.hr--ink { background: var(--rule-ink); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px;
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  opacity: 0.8;
}

.dot { width: 6px; height: 6px; background: currentColor; display: inline-block; }

/* Reveal — opt-in so content never invisible by default */
html.js-reveal-enabled [data-reveal] { opacity: 0; transform: translateY(10px); transition: opacity .5s ease, transform .5s ease; }
html.js-reveal-enabled [data-reveal].is-in { opacity: 1; transform: translateY(0); }

/* Marquee/ticker (for logo & section transitions) */
.ticker {
  overflow: hidden;
  white-space: nowrap;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 14px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
  display: flex;
  gap: 48px;
}