/* ============================================================
   TOKENS
   ============================================================ */
:root{
  --paper: #F1ECE0;
  --paper-alt: #E7E0D0;
  --ink: #232220;
  --ink-soft: #5B5750;
  --charcoal: #1B1A18;
  --charcoal-text: #EDE8DA;
  --pencil-blue: #3E5C7A;
  --eraser-pink: #C2766E;
  --hb: #cfcabb;

  --font-display: "Space Grotesk", "Helvetica Neue", Arial, sans-serif;
  --font-body: "Source Serif 4", Georgia, "Times New Roman", serif;
  --font-hand: "Caveat", cursive;

  --container: 1140px;
  --container-narrow: 700px;
  --radius: 4px;
}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *{animation-duration:0.001ms !important; animation-iteration-count:1 !important; transition-duration:0.001ms !important;}
}

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}

img,svg{display:block;max-width:100%;}
a{color:inherit;text-decoration:none;}
ul,ol{margin:0;padding:0;}
h1,h2,h3{font-family:var(--font-display);font-weight:700;margin:0 0 0.5em;letter-spacing:-0.01em;}
p{margin:0 0 1.1em;}
.container{max-width:var(--container);margin:0 auto;padding:0 28px;}
.container.narrow{max-width:var(--container-narrow);}

.skip-link{
  position:absolute;left:-999px;top:auto;
  background:var(--charcoal);color:var(--charcoal-text);
  padding:10px 16px;border-radius:var(--radius);z-index:999;
}
.skip-link:focus{left:16px;top:16px;}

:focus-visible{outline:2.5px solid var(--pencil-blue);outline-offset:3px;border-radius:2px;}

/* ============================================================
   SCROLL PROGRESS — the page draws its own line as you read
   ============================================================ */
.progress-track{
  position:fixed;top:0;left:0;width:100%;height:4px;
  background:rgba(35,34,32,0.08);
  z-index:1000;
}
.progress-fill{
  height:100%;width:0%;
  background:var(--pencil-blue);
  transition:width 60ms linear;
}
.progress-pencil{
  position:fixed;top:-3px;left:0;
  color:var(--pencil-blue);
  transform:translateX(0) rotate(35deg);
  transition:left 60ms linear;
  pointer-events:none;
  z-index:1001;
  filter:drop-shadow(0 1px 1px rgba(0,0,0,0.25));
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header{
  position:sticky;top:0;z-index:900;
  background:rgba(241,236,224,0.88);
  backdrop-filter:blur(8px);
  border-bottom:1px solid rgba(35,34,32,0.1);
}
.header-inner{
  max-width:var(--container);margin:0 auto;padding:14px 28px;
  display:flex;align-items:center;gap:28px;
}
.brand{
  display:flex;align-items:center;gap:9px;
  font-family:var(--font-display);font-weight:600;font-size:1.08rem;
  margin-right:auto;
}
.main-nav{display:flex;gap:26px;font-family:var(--font-display);font-size:0.92rem;font-weight:500;}
.main-nav a{opacity:0.78;transition:opacity 0.15s;}
.main-nav a:hover{opacity:1;}
.nav-cta{
  font-family:var(--font-display);font-weight:600;font-size:0.88rem;
  background:var(--ink);color:var(--paper);
  padding:9px 16px;border-radius:30px;
  white-space:nowrap;
  transition:background 0.15s;
}
.nav-cta:hover{background:var(--pencil-blue);}
.nav-toggle{
  display:none;background:none;border:none;cursor:pointer;
  width:34px;height:30px;padding:0;flex-direction:column;justify-content:space-between;
}
.nav-toggle span{display:block;height:2px;background:var(--ink);border-radius:2px;}
.mobile-nav{display:none;flex-direction:column;padding:6px 28px 18px;gap:14px;font-family:var(--font-display);font-weight:500;}
.mobile-nav .nav-cta{display:inline-block;width:fit-content;}

@media (max-width: 760px){
  .main-nav{display:none;}
  .nav-cta{display:none;}
  .nav-toggle{display:flex;}
  .mobile-nav.open{display:flex;}
}

/* ============================================================
   HERO
   ============================================================ */
.hero{
  position:relative;overflow:hidden;
  padding:72px 0 0;
}
.paper-grain{
  position:absolute;inset:0;pointer-events:none;opacity:0.5;
  background-image:
    radial-gradient(rgba(35,34,32,0.045) 1px, transparent 1px);
  background-size:3px 3px;
}
.hero-inner{
  max-width:var(--container);margin:0 auto;padding:40px 28px 60px;
  display:grid;grid-template-columns:1.1fr 0.9fr;gap:40px;align-items:center;
  position:relative;z-index:1;
}
.eyebrow{
  font-family:var(--font-hand);font-size:1.35rem;color:var(--pencil-blue);
  margin-bottom:2px;
}
.hero-text h1{
  font-size:clamp(2.6rem, 6vw, 4.4rem);line-height:0.98;margin-bottom:22px;
}
.hero-sub{font-size:1.15rem;color:var(--ink-soft);max-width:46ch;}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin:22px 0 18px;}
.btn{
  font-family:var(--font-display);font-weight:600;font-size:0.95rem;
  padding:13px 26px;border-radius:30px;display:inline-block;
  transition:transform 0.15s, background 0.15s, color .15s;
  border:1.5px solid var(--ink);
}
.btn-primary{background:var(--ink);color:var(--paper);}
.btn-primary:hover{background:var(--pencil-blue);border-color:var(--pencil-blue);transform:translateY(-1px);}
.btn-ghost{background:transparent;color:var(--ink);}
.btn-ghost:hover{background:var(--ink);color:var(--paper);transform:translateY(-1px);}
.hero-meta{font-size:0.88rem;color:var(--ink-soft);font-family:var(--font-display);}

.hero-art{display:flex;justify-content:center;}
.hero-sketch{width:100%;max-width:340px;color:var(--ink);}
.hero-sketch .draw-path{fill:none;stroke:var(--ink);stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round;}
.hero-sketch .draw-path-accent{fill:none;stroke:var(--pencil-blue);stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round;}
.hero-sketch path, .hero-sketch ellipse, .hero-sketch circle{
  stroke-dasharray:100;stroke-dashoffset:100;
  animation:draw 0.7s ease forwards;
}
.hero-sketch > *:nth-child(1){animation-delay:0.1s;}
.hero-sketch > *:nth-child(2){animation-delay:0.55s;}
.hero-sketch > *:nth-child(3){animation-delay:0.9s;}
.hero-sketch > *:nth-child(4){animation-delay:1.3s;}
.hero-sketch > *:nth-child(5){animation-delay:1.45s;}
.hero-sketch > *:nth-child(6){animation-delay:1.6s;}
.hero-sketch > *:nth-child(7){animation-delay:1.75s;}
.hero-sketch > *:nth-child(8){animation-delay:1.9s;}
.hero-sketch > *:nth-child(9){animation-delay:2.05s;}
.hero-sketch > *:nth-child(10){animation-delay:2.4s;}
@keyframes draw{to{stroke-dashoffset:0;}}

@media (max-width:880px){
  .hero-inner{grid-template-columns:1fr;text-align:left;}
  .hero-art{order:-1;max-width:240px;margin:0 auto 8px;}
}

/* ============================================================
   INTRO
   ============================================================ */
.intro{padding:64px 0 10px;}
.intro h2{font-size:1.9rem;margin-bottom:0.7em;}
.intro p{font-size:1.08rem;color:var(--ink-soft);}
.intro em{color:var(--ink);font-style:italic;}

/* ============================================================
   TOC
   ============================================================ */
.toc{padding:56px 0 70px;}
.section-label{
  font-family:var(--font-display);font-weight:600;font-size:0.82rem;
  letter-spacing:0.08em;text-transform:uppercase;color:var(--pencil-blue);
  margin-bottom:8px;
}
.section-label.center{text-align:center;}
.toc h2{font-size:1.9rem;margin-bottom:30px;}
.toc-grid{
  list-style:none;display:grid;grid-template-columns:repeat(2,1fr);gap:14px;
}
.toc-grid li a{
  display:flex;align-items:center;gap:16px;
  background:var(--paper-alt);border-radius:var(--radius);
  padding:16px 18px;font-family:var(--font-display);font-weight:500;font-size:1rem;
  transition:transform 0.15s, background 0.15s;
}
.toc-grid li a:hover{background:var(--ink);color:var(--paper);transform:translateX(3px);}
.toc-num{
  font-family:var(--font-hand);font-size:1.4rem;color:var(--pencil-blue);
  min-width:34px;
}
.toc-grid li a:hover .toc-num{color:var(--charcoal-text);}
@media (max-width:680px){.toc-grid{grid-template-columns:1fr;}}

/* ============================================================
   CHAPTERS
   ============================================================ */
.chapter{
  position:relative;
  padding:80px 0;
  border-top:1px solid rgba(35,34,32,0.08);
}
.chapter--alt{background:var(--paper-alt);}
.chapter--dark{background:var(--charcoal);color:var(--charcoal-text);}
.chapter--dark .section-label{color:#9EC1E0;}

.page-tab{
  position:absolute;top:28px;right:0;
  font-family:var(--font-hand);font-weight:600;font-size:1.05rem;
  background:var(--ink);color:var(--paper);
  padding:6px 16px 6px 20px;border-radius:20px 0 0 20px;
  letter-spacing:0.02em;
}
.page-tab--dark{background:var(--charcoal-text);color:var(--charcoal);}

.chapter-grid{
  display:grid;grid-template-columns:120px 1fr;gap:48px;align-items:start;
}
.chapter-grid--reverse{grid-template-columns:1fr 120px;}
.chapter-grid--reverse .chapter-icon{order:2;}
.chapter-grid--reverse .chapter-text{order:1;}

.chapter-icon{
  width:88px;height:88px;border-radius:50%;
  background:var(--paper);border:1.5px solid var(--ink);
  display:flex;align-items:center;justify-content:center;
  color:var(--ink);
}
.chapter--alt .chapter-icon{background:var(--paper-alt);}
.chapter-icon svg{width:46px;height:46px;}
.chapter-icon--center{margin:0 auto 18px;}

.chapter-text h2{font-size:2rem;margin-bottom:0.6em;}
.chapter-text p{color:var(--ink-soft);font-size:1.06rem;max-width:62ch;}
.chapter--dark .chapter-text p, .chapter--dark p{color:#CFC9B8;}

@media (max-width:760px){
  .chapter{padding:56px 0;}
  .chapter-grid, .chapter-grid--reverse{grid-template-columns:1fr;gap:20px;}
  .chapter-grid--reverse .chapter-icon, .chapter-grid--reverse .chapter-text{order:initial;}
  .chapter-icon{width:64px;height:64px;}
  .chapter-icon svg{width:34px;height:34px;}
  .page-tab{position:static;display:inline-block;margin-bottom:18px;border-radius:20px;}
}

.check-list{list-style:none;margin-top:22px;}
.check-list li{
  position:relative;padding-left:30px;margin-bottom:13px;
  color:var(--ink-soft);font-size:1.04rem;max-width:62ch;
}
.check-list li::before{
  content:"";position:absolute;left:0;top:7px;width:14px;height:14px;
  border:1.5px solid var(--pencil-blue);border-radius:50%;
}
.check-list--dark li{color:#CFC9B8;}
.check-list--dark li::before{border-color:#9EC1E0;}

.callout{
  font-family:var(--font-hand);font-size:1.3rem;color:var(--pencil-blue);
  border-left:3px solid var(--pencil-blue);padding-left:16px;margin-top:24px;
}

/* pencil grades */
.pencil-row{display:flex;gap:10px;margin:26px 0 30px;flex-wrap:wrap;}
.pencil-swatch{
  flex:1;min-width:110px;
  background:var(--tone);
  border-radius:var(--radius);
  padding:16px 14px;
  display:flex;flex-direction:column;gap:4px;
}
.pencil-label{font-family:var(--font-display);font-weight:700;font-size:1.15rem;color:#fff;text-shadow:0 1px 2px rgba(0,0,0,0.35);}
.pencil-use{font-size:0.82rem;color:rgba(255,255,255,0.92);text-shadow:0 1px 2px rgba(0,0,0,0.3);}
.pencil-swatch--light .pencil-label, .pencil-swatch--light .pencil-use{color:var(--ink);text-shadow:none;}
.pencil-swatch--light .pencil-use{color:var(--ink-soft);}

.supply-list{list-style:none;margin-top:6px;}
.supply-list li{
  margin-bottom:14px;color:var(--ink-soft);font-size:1.02rem;max-width:62ch;
  padding-left:18px;border-left:2px solid var(--paper-alt);
}
.chapter--alt .supply-list li{border-left-color:var(--paper);}
.supply-list strong{color:var(--ink);font-family:var(--font-display);font-weight:600;font-size:0.97rem;}

/* shading value scale + textures */
.value-scale{
  height:34px;border-radius:var(--radius);margin:24px 0 8px;
  background:linear-gradient(to right, #fff, #1c1a17);
  border:1px solid rgba(35,34,32,0.15);
}
.scale-labels{display:flex;justify-content:space-between;font-family:var(--font-display);font-size:0.8rem;color:var(--ink-soft);margin-bottom:28px;}

.texture-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:24px;}
.texture-card{display:flex;flex-direction:column;align-items:center;gap:8px;font-family:var(--font-display);font-size:0.82rem;color:var(--ink-soft);}
.texture{width:100%;aspect-ratio:1;border-radius:var(--radius);border:1px solid rgba(35,34,32,0.15);background:#fff;}
.texture--hatch{background-image:repeating-linear-gradient(115deg, var(--ink) 0 1.5px, transparent 1.5px 7px);}
.texture--cross{background-image:
  repeating-linear-gradient(115deg, var(--ink) 0 1.5px, transparent 1.5px 7px),
  repeating-linear-gradient(25deg, var(--ink) 0 1.5px, transparent 1.5px 7px);}
.texture--blend{background:radial-gradient(circle at 30% 30%, transparent 0%, rgba(35,34,32,0.75) 100%);}
.texture--stipple{background-image:radial-gradient(var(--ink) 1.1px, transparent 1.2px); background-size:7px 7px;}
@media (max-width:600px){.texture-grid{grid-template-columns:repeat(2,1fr);}}

/* portrait diagram */
.face-diagram-wrap{display:flex;flex-direction:column;align-items:center;gap:22px;margin:8px 0 36px;}
.face-diagram{width:100%;max-width:300px;color:var(--ink);overflow:visible;}
.diagram-tag{font-family:var(--font-display);font-size:11px;font-weight:700;fill:#fff;text-anchor:middle;dominant-baseline:middle;}
.diagram-legend{
  list-style:none;display:grid;grid-template-columns:1fr 1fr;gap:10px 28px;
  max-width:560px;width:100%;
}
.diagram-legend li{font-size:0.94rem;color:var(--ink-soft);display:flex;gap:10px;align-items:flex-start;}
.legend-tag{
  flex-shrink:0;width:20px;height:20px;border-radius:50%;background:var(--pencil-blue);color:#fff;
  font-family:var(--font-display);font-size:0.72rem;font-weight:700;
  display:flex;align-items:center;justify-content:center;margin-top:1px;
}
@media (max-width:600px){.diagram-legend{grid-template-columns:1fr;}}

/* mistakes table */
.center{text-align:center;}
.narrow-text{max-width:520px;margin-left:auto;margin-right:auto;color:var(--ink-soft);}
.mistake-table{display:flex;flex-direction:column;gap:14px;margin-top:34px;}
.mistake-row{
  display:grid;grid-template-columns:auto 1fr auto auto 1fr;align-items:center;gap:14px;
  background:var(--paper);border-radius:var(--radius);padding:16px 20px;
  border:1px solid rgba(35,34,32,0.08);
}
.mistake-row p{margin:0;font-size:0.98rem;color:var(--ink-soft);}
.mistake-tag{
  font-family:var(--font-display);font-weight:600;font-size:0.75rem;
  letter-spacing:0.04em;text-transform:uppercase;
  padding:5px 10px;border-radius:20px;white-space:nowrap;
}
.mistake-tag--avoid{background:rgba(194,118,110,0.18);color:var(--eraser-pink);}
.mistake-tag--try{background:rgba(62,92,122,0.14);color:var(--pencil-blue);}
.mistake-arrow{color:var(--ink-soft);font-size:1.1rem;}
@media (max-width:780px){
  .mistake-row{grid-template-columns:1fr;gap:8px;text-align:left;}
  .mistake-arrow{display:none;}
}

/* ============================================================
   CHALLENGE
   ============================================================ */
.challenge-intro{font-size:1.1rem;max-width:62ch;}
.challenge-grid-wrap{margin-top:38px;}
.challenge-grid-head{
  display:flex;justify-content:space-between;align-items:baseline;
  font-family:var(--font-display);font-weight:600;margin-bottom:14px;
  color:var(--charcoal-text);
}
#challengeCount{font-family:var(--font-hand);font-size:1.2rem;color:#9EC1E0;}
.day-grid{
  display:grid;grid-template-columns:repeat(10,1fr);gap:9px;
}
.day-grid button{
  aspect-ratio:1;border-radius:6px;
  border:1.5px solid rgba(237,232,218,0.35);
  background:transparent;color:var(--charcoal-text);
  font-family:var(--font-display);font-size:0.85rem;font-weight:600;
  cursor:pointer;transition:background 0.15s, transform 0.1s, border-color .15s;
}
.day-grid button:hover{border-color:#9EC1E0;transform:translateY(-2px);}
.day-grid button.done{background:var(--pencil-blue);border-color:var(--pencil-blue);}
.challenge-note{font-size:0.88rem;color:#A9A395;margin-top:16px;}
.reset-link{
  background:none;border:none;color:#9EC1E0;text-decoration:underline;
  cursor:pointer;font-family:var(--font-body);font-size:0.88rem;padding:0;
}
@media (max-width:680px){.day-grid{grid-template-columns:repeat(6,1fr);}}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer{background:var(--ink);color:var(--paper);padding:60px 0 0;}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:36px;padding-bottom:40px;}
.footer-brand p{color:rgba(241,236,224,0.65);font-size:0.95rem;margin-top:14px;max-width:36ch;}
.brand--footer{color:var(--paper);}
.footer-heading{font-family:var(--font-display);font-weight:600;font-size:0.82rem;text-transform:uppercase;letter-spacing:0.06em;color:rgba(241,236,224,0.5);margin-bottom:14px;}
.footer-links{display:flex;flex-direction:column;}
.footer-links a{display:block;padding:6px 0;color:rgba(241,236,224,0.78);font-family:var(--font-display);font-size:0.95rem;transition:color 0.15s;}
.footer-links a:hover{color:var(--paper);}
.footer-bottom{
  border-top:1px solid rgba(241,236,224,0.12);
  padding:20px 0 26px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px;
  font-size:0.85rem;color:rgba(241,236,224,0.55);
}
.back-top{font-family:var(--font-display);font-weight:500;color:rgba(241,236,224,0.78);}
.back-top:hover{color:var(--paper);}
@media (max-width:760px){.footer-grid{grid-template-columns:1fr;gap:28px;}}

/* reveal on scroll */
.reveal{opacity:0;transform:translateY(16px);transition:opacity 0.6s ease, transform 0.6s ease;}
.reveal.in-view{opacity:1;transform:translateY(0);}