/* ============================================================
   THE QUITE QUANT — shared stylesheet
   Quantitative research notes, videos & book recommendations
   ============================================================ */

:root{
  --cream:      #FAF6EF;
  --paper:      #FFFFFF;
  --ink:        #221F1D;
  --stone:      #7A7268;
  --stone-soft: #B9AF9E;
  --hairline:   #E4DDD0;
  --rust:       #C8442B;
  --rust-deep:  #8E2F1C;
  --rust-tint:  #F3E3DC;

  --serif: "Fraunces", "Iowan Old Style", Georgia, serif;
  --sans:  "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono:  "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;

  --max: 1080px;
}

*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

body{
  margin: 0;
  background: var(--cream);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

.wrap{
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3{
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.15;
  margin: 0 0 0.4em;
  letter-spacing: -0.01em;
}

.eyebrow{
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--rust);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
}
.eyebrow .ridge-glyph{ width: 22px; height: 12px; flex: none; }

p{ margin: 0 0 1em; color: var(--ink); }
.muted{ color: var(--stone); }

/* ---------- header ---------- */
.site-header{
  position: sticky; top: 0; z-index: 20;
  background: rgba(250, 246, 239, 0.92);
  backdrop-filter: saturate(140%) blur(6px);
  border-bottom: 1px solid var(--hairline);
}
.site-header .wrap{
  display: flex; align-items: center; justify-content: space-between;
  padding-top: 14px; padding-bottom: 14px;
}
.brand{
  display: flex; align-items: center; gap: 10px;
  font-family: var(--serif); font-weight: 600; font-size: 1.05rem;
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.brand img{ height: 30px; width: 30px; }

.nav-links{
  display: flex; gap: 30px; align-items: center;
  font-family: var(--mono); font-size: 0.78rem;
  letter-spacing: 0.06em; text-transform: uppercase;
}
.nav-links a{
  color: var(--stone);
  padding: 6px 0;
  border-bottom: 2px solid transparent;
  transition: color .15s ease, border-color .15s ease;
}
.nav-links a:hover{ color: var(--ink); }
.nav-links a.active{ color: var(--rust); border-color: var(--rust); }

.nav-toggle{
  display: none;
  background: none; border: 1px solid var(--hairline); border-radius: 6px;
  padding: 8px 10px; cursor: pointer;
}
.nav-toggle span{ display:block; width:18px; height:2px; background:var(--ink); margin:3px 0; }

/* ---------- hero ---------- */
.hero{ padding: 72px 0 56px; }
.hero .wrap{
  display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 48px; align-items: center;
}
.hero h1{ font-size: clamp(2.1rem, 4vw, 3.1rem); }
.hero .lede{ font-size: 1.08rem; max-width: 46ch; color: var(--stone); }
.hero-ctas{ display: flex; gap: 14px; margin-top: 28px; flex-wrap: wrap; }

.btn{
  font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.06em; text-transform: uppercase;
  padding: 12px 20px; border-radius: 999px; border: 1px solid var(--ink);
  display: inline-flex; align-items: center; gap: 8px;
  transition: background .15s ease, color .15s ease, border-color .15s ease;
}
.btn.primary{ background: var(--ink); color: var(--paper); }
.btn.primary:hover{ background: var(--rust-deep); border-color: var(--rust-deep); }
.btn.ghost{ background: transparent; color: var(--ink); }
.btn.ghost:hover{ border-color: var(--rust); color: var(--rust); }

.hero-signature{ position: relative; }
.ridge-anim{ width: 100%; height: auto; }
.ridge-anim path{
  fill: none; stroke: var(--rust); stroke-width: 1.4; opacity: .55;
  vector-effect: non-scaling-stroke;
}
.ridge-anim path:nth-child(1){ opacity: .95; stroke-width: 1.8; }

@media (prefers-reduced-motion: no-preference){
  .ridge-anim .drift{ animation: drift 9s ease-in-out infinite alternate; }
  .ridge-anim .drift2{ animation: drift 12s ease-in-out infinite alternate-reverse; }
}
@keyframes drift{
  from{ transform: translateY(0px); }
  to{ transform: translateY(-6px); }
}

/* ---------- section dividers ---------- */
.ridge-divider{ width: 100%; height: 26px; margin: 6px 0 0; opacity: .5; }
.ridge-divider path{ fill:none; stroke: var(--rust); stroke-width: 1.2; }

/* ---------- preview cards (home) ---------- */
.tracks{ padding: 8px 0 72px; }
.tracks-grid{
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px;
  margin-top: 28px;
}
.track-card{
  background: var(--paper); border: 1px solid var(--hairline); border-radius: 14px;
  padding: 26px; display: flex; flex-direction: column; gap: 10px;
  transition: border-color .15s ease, transform .15s ease;
}
.track-card:hover{ border-color: var(--rust); transform: translateY(-2px); }
.track-card h3{ font-size: 1.2rem; }
.track-tag{
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--stone-soft);
}
.track-card .go{
  margin-top: auto; font-family: var(--mono); font-size: 0.76rem; color: var(--rust);
  letter-spacing: 0.05em;
}

/* ---------- page header (inner pages) ---------- */
.page-head{ padding: 56px 0 28px; border-bottom: 1px solid var(--hairline); }
.page-head h1{ font-size: clamp(1.8rem, 3.4vw, 2.5rem); }
.page-head .lede{ color: var(--stone); max-width: 62ch; }

/* ---------- article list ---------- */
.article-list{ padding: 36px 0 80px; }
.article-row{
  display: grid; grid-template-columns: 140px 1fr; gap: 26px;
  padding: 30px 0; border-bottom: 1px solid var(--hairline);
}
.article-row:first-child{ padding-top: 6px; }
.article-date{
  font-family: var(--mono); font-size: 0.78rem; color: var(--stone); letter-spacing: 0.04em;
  padding-top: 6px;
}
.article-body h2{ font-size: 1.4rem; margin-bottom: 8px; }
.article-body h2 a:hover{ color: var(--rust); }
.article-excerpt{ color: var(--stone); max-width: 68ch; }
.tag-row{ display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.tag{
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--rust); background: var(--rust-tint); padding: 4px 10px; border-radius: 999px;
}
.read-more{
  font-family: var(--mono); font-size: 0.78rem; color: var(--ink); letter-spacing: 0.04em;
  display: inline-block; margin-top: 14px; border-bottom: 1px solid var(--ink);
}
.read-more:hover{ color: var(--rust); border-color: var(--rust); }

/* ---------- videos ---------- */
.video-grid{
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px;
  padding: 36px 0 80px;
}
.video-card{ display: flex; flex-direction: column; gap: 12px; }
.video-frame{
  position: relative; width: 100%; padding-top: 56.25%;
  background: var(--ink); border-radius: 10px; overflow: hidden;
  border: 1px solid var(--hairline);
}
.video-frame iframe{
  position: absolute; inset: 0; width: 100%; height: 100%; border: 0;
}
.video-card h3{ font-size: 1.15rem; }
.video-meta{
  font-family: var(--mono); font-size: 0.72rem; color: var(--stone-soft);
  text-transform: uppercase; letter-spacing: 0.08em;
}

/* ---------- books ---------- */
.book-list{ padding: 36px 0 80px; display: flex; flex-direction: column; gap: 0; }
.book-row{
  display: grid; grid-template-columns: 96px 1fr; gap: 24px;
  padding: 28px 0; border-bottom: 1px solid var(--hairline); align-items: start;
}
.book-row:first-child{ padding-top: 6px; }
.book-spine{
  width: 96px; height: 140px; border-radius: 4px;
  background: linear-gradient(160deg, var(--rust) 0%, var(--rust-deep) 100%);
  position: relative; overflow: hidden;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--rust-deep);
}
.book-spine svg{ width: 60%; opacity: .8; }
.book-title{ font-size: 1.15rem; margin-bottom: 2px; }
.book-author{
  font-family: var(--mono); font-size: 0.76rem; color: var(--stone); letter-spacing: 0.03em;
  margin-bottom: 10px; display: block;
}
.book-why{ color: var(--ink); max-width: 64ch; }
.book-link{
  font-family: var(--mono); font-size: 0.74rem; color: var(--rust); letter-spacing: 0.04em;
  display: inline-block; margin-top: 10px;
}
.book-link:hover{ text-decoration: underline; }

/* ---------- footer ---------- */
.site-footer{
  border-top: 1px solid var(--hairline); padding: 40px 0;
}
.site-footer .wrap{
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px;
}
.footer-brand{ display: flex; align-items: center; gap: 10px; }
.footer-brand img{ height: 22px; width: 22px; }
.footer-note{ font-family: var(--mono); font-size: 0.72rem; color: var(--stone-soft); letter-spacing: 0.03em; }
.footer-links{ display: flex; gap: 20px; font-family: var(--mono); font-size: 0.74rem; color: var(--stone); }
.footer-links a:hover{ color: var(--rust); }

/* ---------- responsive ---------- */
@media (max-width: 860px){
  .hero .wrap{ grid-template-columns: 1fr; }
  .hero-signature{ order: -1; max-width: 260px; }
  .tracks-grid{ grid-template-columns: 1fr; }
  .video-grid{ grid-template-columns: 1fr; }
  .nav-links{
    position: absolute; top: 100%; left: 0; right: 0;
    background: var(--cream); border-bottom: 1px solid var(--hairline);
    flex-direction: column; align-items: flex-start; gap: 4px;
    padding: 12px 24px 20px; display: none;
  }
  .nav-links.open{ display: flex; }
  .nav-toggle{ display: block; }
  .article-row, .book-row{ grid-template-columns: 1fr; }
  .article-date{ padding-top: 0; }
  .book-spine{ width: 72px; height: 104px; }
}