:root{
  --paper: #f1ead7;
  --paper-2: #e8dec2;
  --paper-edge: #d9caa2;
  --ink: #22281b;
  --ink-soft: #4a5138;
  --ink-faint: #6b7259;
  --line: rgba(34,40,27,0.28);
  --line-soft: rgba(34,40,27,0.14);
  --red: #b5432c;
  --gold: #b8862f;
  --moss: #4c6b3a;

  --frog-base: #5c7a3f;
  --frog-belly: #d9cf9c;
  --frog-spot: #23291b;
  --frog-ink: #20281c;

  font-size: 17px;
}

*, *::before, *::after{ box-sizing: border-box; }

html{ scroll-behavior: smooth; }

body{
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Source Serif 4", "Iowan Old Style", Georgia, "Times New Roman", serif;
  line-height: 1.55;
  position: relative;
  -webkit-font-smoothing: antialiased;
}

/* paper grain overlay */
body::before{
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 999;
  opacity: 0.5;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='matrix' values='0 0 0 0 0.13  0 0 0 0 0.15  0 0 0 0 0.1  0 0 0 0.05 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

h1, h2, h3, .display{
  font-family: "Fraunces", "Iowan Old Style", Georgia, serif;
  font-optical-sizing: auto;
  color: var(--ink);
  letter-spacing: -0.01em;
  margin: 0;
}

.mono{
  font-family: "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, monospace;
}

a{ color: var(--red); text-decoration-thickness: 1.5px; text-underline-offset: 2px; }

::selection{ background: #d8c98a; color: var(--ink); }

.wrap{
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 28px;
}

/* ---------------- nav ---------------- */
.topnav{
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(241,234,215,0.92);
  backdrop-filter: blur(3px);
  border-bottom: 1.5px solid var(--line);
}
.topnav .wrap{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  height: 62px;
}
.brand{
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-family: "Fraunces", serif;
  font-weight: 600;
  font-size: 1.05rem;
  white-space: nowrap;
}
.brand .no{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.62rem;
  color: var(--ink-faint);
  border: 1px solid var(--line);
  padding: 2px 5px;
  border-radius: 3px;
}
.navlinks{
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}
.navlinks::-webkit-scrollbar{ display: none; }
.navlinks a{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--ink-soft);
  text-decoration: none;
  padding: 7px 11px;
  border-radius: 3px;
  white-space: nowrap;
  transition: background .15s, color .15s;
}
.navlinks a:hover{ background: var(--paper-2); color: var(--ink); }

/* ---------------- hero ---------------- */
.hero{
  padding: 64px 0 40px;
  border-bottom: 1.5px solid var(--line);
  position: relative;
}
.hero .wrap{
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 40px;
  align-items: center;
}
.eyebrow{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--red);
  margin: 0 0 14px;
}
.hero h1{
  font-size: clamp(2.6rem, 5.4vw, 4.4rem);
  font-weight: 600;
  line-height: 0.98;
}
.hero h1 em{
  font-style: italic;
  color: var(--moss);
}
.hero-sub{
  margin-top: 20px;
  font-size: 1.12rem;
  color: var(--ink-soft);
  max-width: 46ch;
}
.hero-figure{
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}
.hero-figure svg{ width: 100%; max-width: 320px; height: auto; filter: drop-shadow(0 6px 10px rgba(30,30,10,0.18)); }
.figcap{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.7rem;
  color: var(--ink-faint);
  text-align: center;
}

/* ---------------- generic section chrome ---------------- */
section{ padding: 68px 0; border-bottom: 1.5px solid var(--line); }
section:last-of-type{ border-bottom: none; }

.section-head{
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}
.section-num{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.78rem;
  color: var(--red);
}
.section-head h2{
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  font-weight: 600;
}
.section-dek{
  max-width: 62ch;
  color: var(--ink-soft);
  margin: 18px 0 40px;
  font-size: 1.05rem;
}

.essay{
  max-width: 68ch;
  font-size: 1.08rem;
}
.essay p + p{ margin-top: 1em; }
.essay .drop::first-letter{
  font-family: "Fraunces", serif;
  font-size: 3.4em;
  float: left;
  line-height: 0.8;
  padding: 0.05em 0.08em 0 0;
  color: var(--red);
}

/* ---------------- specimen cards (palette grid) ---------------- */
.grid{
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 22px;
}
.card{
  background: var(--paper-2);
  border: 1.5px solid var(--line);
  padding: 20px 20px 22px;
  position: relative;
  clip-path: polygon(0 6px, 6px 0, calc(100% - 4px) 0, 100% 6px, 100% calc(100% - 6px), calc(100% - 6px) 100%, 4px 100%, 0 calc(100% - 4px));
  transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover{ transform: translateY(-3px); box-shadow: 0 10px 18px -10px rgba(30,25,10,0.35); }
.card .pin{
  position: absolute;
  top: 10px; right: 12px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 1px 2px rgba(0,0,0,.3);
}
.spec-no{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.65rem;
  color: var(--ink-faint);
  letter-spacing: 0.06em;
}
.card-figure{
  display: flex;
  justify-content: center;
  margin: 6px 0 10px;
}
.card-figure svg{ width: 108px; height: 108px; }
.card h3{
  font-size: 1.18rem;
  font-weight: 600;
  margin-top: 2px;
}
.card .latin{
  font-style: italic;
  color: var(--ink-faint);
  font-size: 0.85rem;
  display: block;
  margin-top: 1px;
}
.tag-row{
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin: 10px 0 12px;
}
.tag{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 3px 7px;
  border: 1px solid var(--line);
  border-radius: 2px;
  color: var(--ink-soft);
}
.tag.mech{ border-color: var(--red); color: var(--red); }
.card p{
  font-size: 0.94rem;
  color: var(--ink-soft);
  margin: 0;
}
.card .locale{
  margin-top: 12px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  color: var(--ink-faint);
  border-top: 1px dashed var(--line);
  padding-top: 8px;
}

/* ---------------- how colour works ---------------- */
.layers{
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 46px;
  align-items: center;
}
.layer-diagram{
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.layer-row{
  display: grid;
  grid-template-columns: 120px 1fr;
  align-items: stretch;
  gap: 14px;
}
.layer-block{
  height: 76px;
  border: 1.5px solid var(--ink);
  position: relative;
  display: flex;
  align-items: center;
  padding: 0 14px;
}
.layer-block .lname{ font-weight: 600; font-size: 0.95rem; }
.layer-block .lsub{ font-size: 0.78rem; color: var(--ink-soft); display:block; margin-top: 2px;}
.layer-xantho{ background: #e8c65b; }
.layer-irido{ background: #9fd0d6; }
.layer-melano{ background: #3a3324; color: #f1ead7; }
.layer-melano .lsub{ color: #cfc9ab; }
.layer-label{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  color: var(--ink-faint);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  text-align: right;
}
.layers .essay{ max-width: none; }

/* ---------------- morph swatch strip ---------------- */
.morphs{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 16px;
  margin-top: 34px;
}
.morph{
  border: 1.5px solid var(--line);
  background: var(--paper-2);
  padding: 14px;
  text-align: center;
}
.morph svg{ width: 70px; height: 70px; }
.morph .mname{ font-weight: 600; font-size: 0.88rem; margin-top: 6px; }
.morph .mplace{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.65rem;
  color: var(--ink-faint);
  margin-top: 2px;
}

/* ---------------- build a frog ---------------- */
.builder{
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 46px;
  align-items: start;
}
.builder-controls{
  background: var(--paper-2);
  border: 1.5px solid var(--line);
  padding: 24px;
}
.control{
  margin-bottom: 20px;
}
.control label{
  display: block;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  margin-bottom: 8px;
}
.control input[type=color]{
  width: 52px; height: 34px;
  border: 1.5px solid var(--ink);
  padding: 2px;
  background: none;
  cursor: pointer;
}
.swatch-row{ display: flex; align-items: center; gap: 12px; }
.hexval{ font-family: "IBM Plex Mono", monospace; font-size: 0.82rem; color: var(--ink-faint); }
.pattern-options{ display: flex; gap: 8px; flex-wrap: wrap; }
.pattern-options button{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  text-transform: uppercase;
  padding: 7px 12px;
  border: 1.5px solid var(--ink);
  background: var(--paper);
  cursor: pointer;
  color: var(--ink);
}
.pattern-options button.active{ background: var(--ink); color: var(--paper); }
.dice-btn{
  margin-top: 6px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 10px 16px;
  background: var(--red);
  color: var(--paper);
  border: none;
  cursor: pointer;
  transition: transform .1s;
}
.dice-btn:active{ transform: scale(0.97); }
.builder-preview{
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  border: 1.5px solid var(--line);
  background: var(--paper-2);
  padding: 34px 20px;
}
.builder-preview svg{ width: 220px; height: 220px; }
.field-id{
  font-family: "Fraunces", serif;
  font-style: italic;
  font-size: 1.3rem;
  text-align: center;
}
.field-id-sub{
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.7rem;
  color: var(--ink-faint);
  text-align: center;
}

/* ---------------- quiz ---------------- */
.quiz-grid{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 20px;
}
.flip{
  perspective: 1200px;
  height: 300px;
  cursor: pointer;
}
.flip-inner{
  position: relative;
  width: 100%; height: 100%;
  transition: transform .55s cubic-bezier(.2,.8,.2,1);
  transform-style: preserve-3d;
}
.flip.flipped .flip-inner{ transform: rotateY(180deg); }
.flip-face{
  position: absolute; inset: 0;
  backface-visibility: hidden;
  border: 1.5px solid var(--ink);
  padding: 18px;
  display: flex;
  flex-direction: column;
  background: var(--paper-2);
}
.flip-front{ align-items: center; text-align: center; justify-content: space-between; }
.flip-front svg{ width: 96px; height: 96px; margin-top: 6px; }
.flip-front h4{ font-family:"Fraunces",serif; font-size: 1.05rem; margin: 8px 0 0; }
.flip-front .latin{ font-style: italic; color: var(--ink-faint); font-size: 0.8rem; }
.flip-front .prompt{
  margin-top: auto;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  text-transform: uppercase;
  color: var(--red);
  border-top: 1px dashed var(--line);
  padding-top: 10px;
  width: 100%;
}
.flip-back{
  transform: rotateY(180deg);
  justify-content: center;
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.flip-back .verdict{
  font-family: "IBM Plex Mono", monospace;
  text-transform: uppercase;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: #e8c65b;
  margin-bottom: 8px;
}
.flip-back p{ font-size: 0.88rem; margin: 0; color: #ded6bc; }

/* ---------------- footer / sources ---------------- */
footer{ padding: 50px 0 70px; }
.sources{
  columns: 2;
  column-gap: 40px;
  font-size: 0.86rem;
  color: var(--ink-soft);
  max-width: 900px;
}
.sources li{ break-inside: avoid; margin-bottom: 12px; }
.foot-note{
  margin-top: 40px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  color: var(--ink-faint);
  border-top: 1px solid var(--line);
  padding-top: 18px;
}

@media (max-width: 860px){
  .hero .wrap{ grid-template-columns: 1fr; }
  .hero-figure{ order: -1; }
  .layers{ grid-template-columns: 1fr; }
  .builder{ grid-template-columns: 1fr; }
  .sources{ columns: 1; }
}