/* ============================================================
   KINDLING · BUILDERS EDITION — shared design system
   "Warm Minimal" — 15+ tone: editorial restraint with paper warmth.
   Inspired by Synthyl's compositional discipline; warmth from Kindling.
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,300;9..144,400;9..144,500;9..144,600;9..144,700&family=Inter:wght@400;500;600;700;800&family=Caveat:wght@500;600&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  /* ---------- Paper & Ink (warm, less yellow than Kindling) ---------- */
  --paper:        #FAF6EC;   /* warm cream surface */
  --paper-deep:   #F2EBD8;   /* contrast block */
  --paper-warm:   #FFFCF4;   /* lightest, for cards */
  --paper-glass:  rgba(255,252,244,.78);
  --ink:          #1F2230;   /* deep warm charcoal — primary text */
  --ink-soft:     #4D5266;   /* secondary */
  --ink-faint:    #8A8FA3;   /* tertiary */
  --line:         rgba(31,34,48,.10);
  --line-soft:    rgba(31,34,48,.05);

  /* ---------- Trait colors (refined, less saturated than Kindling) ---------- */
  --passion:      #D9533F;   /* terracotta — refined fire */
  --passion-deep: #B23E2E;
  --passion-soft: #FAE0DA;
  --empathy:      #4A8B9E;   /* slate teal — quieter, more grown */
  --empathy-deep: #356D80;
  --empathy-soft: #DDEAEF;
  --taste:        #C68A2D;   /* burnished gold */
  --taste-deep:   #9C6A1D;
  --taste-soft:   #F5E7C4;

  /* ---------- Supporting accents ---------- */
  --leaf:         #6A8E5A;
  --leaf-deep:    #4F7142;
  --leaf-soft:    #DDE7D3;
  --berry:        #95538F;

  /* ---------- Fonts ---------- */
  --font-display: 'Fraunces', 'Cormorant Garamond', Georgia, serif;
  --font-body:    'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-hand:    'Caveat', 'Bradley Hand', cursive;
  --font-mono:    'JetBrains Mono', 'SF Mono', Menlo, monospace;

  /* ---------- Scale ---------- */
  --size-display: clamp(2.5rem, 6vw, 4.75rem);
  --size-h1:      clamp(1.875rem, 4vw, 2.875rem);
  --size-h2:      clamp(1.5rem, 2.8vw, 2rem);
  --size-h3:      clamp(1.15rem, 1.8vw, 1.35rem);
  --size-body:    1.0625rem;
  --size-lead:    1.1875rem;
  --size-small:   0.9375rem;
  --size-caption: 0.8125rem;

  /* ---------- Radii / shadows ---------- */
  --radius-sm:    8px;
  --radius:       14px;
  --radius-lg:    22px;
  --radius-pill:  999px;
  --shadow-soft:  0 6px 24px -10px rgba(31,34,48,.12);
  --shadow-lift:  0 18px 50px -22px rgba(31,34,48,.22);
  --stamp-ink:    2px 2px 0 var(--ink);

  /* ---------- Layout ---------- */
  --container:        min(1140px, 92vw);
  --container-narrow: min(720px, 92vw);
  --container-wide:   min(1320px, 94vw);
}

/* ============================================================ Base */
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:var(--font-body);
  font-size:var(--size-body);
  line-height:1.65;
  color:var(--ink);
  background:var(--paper);
  background-image:
    radial-gradient(circle at 8% 92%,rgba(74,139,158,.07) 0%,transparent 55%),
    radial-gradient(circle at 92% 8%,rgba(198,138,45,.08) 0%,transparent 55%),
    radial-gradient(circle at 50% 40%,rgba(217,83,63,.04) 0%,transparent 70%),
    radial-gradient(rgba(31,34,48,.045) 1px,transparent 1px);
  background-size:100% 100%,100% 100%,100% 100%,28px 28px;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
::selection{background:var(--taste-soft);color:var(--ink)}
::-webkit-scrollbar{width:8px;height:8px}
::-webkit-scrollbar-thumb{background:rgba(31,34,48,.15);border-radius:4px}
::-webkit-scrollbar-thumb:hover{background:rgba(31,34,48,.25)}

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

/* ============================================================ Container */
.container{width:var(--container);margin-inline:auto}
.container-narrow{width:var(--container-narrow);margin-inline:auto}
.container-wide{width:var(--container-wide);margin-inline:auto}

/* ============================================================ Top nav */
.nav{
  position:sticky;top:0;z-index:50;
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
  background:rgba(250,246,236,.78);
  border-bottom:1px solid var(--line);
}
.nav-inner{
  width:var(--container-wide);
  margin-inline:auto;
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 0;
}
.brand{
  display:flex;align-items:center;gap:10px;
  font-family:var(--font-display);
  font-weight:600;font-size:1.15rem;
  letter-spacing:-.01em;
  color:var(--ink);
}
.brand .mark{
  width:30px;height:30px;border-radius:8px;
  background:linear-gradient(135deg,var(--passion) 0%,var(--taste) 100%);
  position:relative;
  box-shadow:inset 0 0 0 2px rgba(255,252,244,.7);
}
.brand .mark::after{
  content:"+";position:absolute;inset:0;
  display:flex;align-items:center;justify-content:center;
  color:#fff;font-weight:800;font-size:14px;line-height:1;
}
.brand .edition{
  font-family:var(--font-body);
  font-size:11px;font-weight:600;letter-spacing:.18em;
  text-transform:uppercase;color:var(--ink-soft);
  padding:3px 8px;border:1px solid var(--line);border-radius:999px;
  margin-left:6px;
}
.nav-links{display:flex;gap:28px;align-items:center}
.nav-links a{
  font-size:.93rem;font-weight:500;color:var(--ink-soft);
  transition:color .15s;
}
.nav-links a:hover,.nav-links a.active{color:var(--ink)}
.nav-links a.cta{
  padding:8px 16px;border-radius:999px;
  background:var(--ink);color:var(--paper-warm);font-weight:600;
}
.nav-links a.cta:hover{background:var(--passion-deep);color:#fff}
@media(max-width:720px){
  .nav-links a:not(.cta):not(.always){display:none}
}

/* ============================================================ Type */
h1,h2,h3,h4{font-family:var(--font-display);color:var(--ink);letter-spacing:-.015em;line-height:1.15}
h1{font-size:var(--size-h1);font-weight:600;margin:0 0 .5em}
h2{font-size:var(--size-h2);font-weight:600;margin:1.4em 0 .55em}
h3{font-size:var(--size-h3);font-weight:600;margin:1.4em 0 .4em}
p{margin:0 0 1em}
em{font-style:italic;color:var(--passion-deep)}
strong{font-weight:700;color:var(--ink)}

.eyebrow{
  display:inline-block;font-family:var(--font-body);
  font-size:.72rem;font-weight:700;letter-spacing:.2em;
  text-transform:uppercase;color:var(--ink-soft);
  margin-bottom:1rem;
}
.lead{font-size:var(--size-lead);line-height:1.7;color:var(--ink)}
.hand{font-family:var(--font-hand);color:var(--ink-soft);font-size:1.4em;letter-spacing:.01em}
.kicker{
  display:inline-block;padding:4px 12px;border-radius:999px;
  background:var(--paper-warm);border:1px solid var(--line);
  font-size:.75rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;
  color:var(--ink-soft);
}
.kicker.passion{color:var(--passion-deep);border-color:var(--passion-soft);background:rgba(250,224,218,.5)}
.kicker.empathy{color:var(--empathy-deep);border-color:var(--empathy-soft);background:rgba(221,234,239,.5)}
.kicker.taste{color:var(--taste-deep);border-color:var(--taste-soft);background:rgba(245,231,196,.5)}
.kicker.leaf{color:var(--leaf-deep);border-color:var(--leaf-soft);background:rgba(221,231,211,.5)}

.divider{width:60px;height:1px;background:var(--ink);opacity:.18;margin:36px auto;border:0}

/* ============================================================ Cards / panels */
.panel{
  background:var(--paper-glass);
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter:blur(12px);
  border:1px solid var(--line);
  border-radius:var(--radius-lg);
  padding:38px 44px;
  box-shadow:var(--shadow-soft);
}
@media(max-width:720px){.panel{padding:28px 22px}}

.card{
  background:var(--paper-warm);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:26px 28px;
  transition:transform .2s ease,box-shadow .2s ease,border-color .2s ease;
}
.card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lift);border-color:rgba(31,34,48,.18)}

.tile{
  display:block;background:var(--paper-warm);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:28px;color:inherit;text-decoration:none;
  position:relative;overflow:hidden;
  transition:transform .2s,box-shadow .2s,border-color .2s;
}
.tile::before{
  content:"";position:absolute;left:0;top:0;bottom:0;width:3px;
  background:var(--accent,var(--ink));opacity:0;transition:opacity .2s;
}
.tile:hover{transform:translateY(-3px);box-shadow:var(--shadow-lift);border-color:rgba(31,34,48,.18)}
.tile:hover::before{opacity:1}
.tile .num{font-family:var(--font-mono);font-size:.78rem;color:var(--ink-faint);letter-spacing:.1em;font-weight:600}
.tile h3{margin:.4em 0 .25em;font-size:1.3rem}
.tile p{font-size:.95rem;color:var(--ink-soft);margin:0 0 .8em}
.tile .open{
  display:inline-flex;align-items:center;gap:.4em;
  font-size:.85rem;font-weight:600;color:var(--ink);
}
.tile .open::after{content:"→";transition:transform .2s}
.tile:hover .open::after{transform:translateX(4px)}

/* ============================================================ Buttons */
.btn,a.btn{
  display:inline-flex;align-items:center;gap:.55em;
  padding:13px 24px;border-radius:999px;
  background:var(--ink);color:var(--paper-warm);
  font-weight:600;font-size:.95rem;
  border:1px solid var(--ink);
  text-decoration:none;cursor:pointer;
  transition:transform .15s,box-shadow .15s,background .15s;
}
.btn:hover{transform:translateY(-1px);box-shadow:var(--shadow-soft);background:var(--passion-deep);border-color:var(--passion-deep)}
.btn-ghost{
  display:inline-flex;align-items:center;gap:.55em;
  padding:11px 22px;border-radius:999px;
  background:var(--paper-warm);color:var(--ink);
  font-weight:600;font-size:.95rem;
  border:1px solid var(--line);
  text-decoration:none;
  transition:transform .15s,box-shadow .15s,border-color .15s;
}
.btn-ghost:hover{transform:translateY(-1px);box-shadow:var(--shadow-soft);border-color:rgba(31,34,48,.25)}

/* ============================================================ Code blocks */
pre,code{font-family:var(--font-mono);font-size:.88rem}
:not(pre)>code{
  padding:.12em .42em;border-radius:6px;
  background:rgba(198,138,45,.12);
  color:var(--taste-deep);
  font-weight:500;font-size:.9em;
  border:1px solid rgba(198,138,45,.18);
}
pre{
  background:#1B1E2A;color:#E8EAF0;
  padding:18px 20px;border-radius:12px;
  overflow-x:auto;line-height:1.7;
  border:1px solid rgba(255,255,255,.06);
  position:relative;margin:18px 0;
  font-size:.86rem;
}
pre code{background:none;color:inherit;border:0;padding:0;font-size:inherit}
pre .com{color:#7A8090;font-style:italic}
pre .key{color:#E8B547}
pre .str{color:#A6CD81}
pre .num{color:#D9866A}
pre .fun{color:#7CB6D9}
.code-head{
  display:flex;align-items:center;justify-content:space-between;
  background:rgba(255,255,255,.05);
  margin:18px 0 -18px 0;
  padding:9px 16px;border-radius:12px 12px 0 0;
  border:1px solid rgba(255,255,255,.06);border-bottom:0;
  font-family:var(--font-mono);font-size:.78rem;color:#94A0B0;
}
.code-head + pre{border-radius:0 0 12px 12px;margin-top:0}
.copy-btn{
  background:none;border:1px solid rgba(255,255,255,.18);
  color:#94A0B0;padding:3px 12px;border-radius:6px;
  font-family:var(--font-mono);font-size:.74rem;cursor:pointer;
  transition:all .15s;
}
.copy-btn:hover{border-color:rgba(255,255,255,.4);color:#E8EAF0}
.copy-btn.ok{color:var(--leaf);border-color:var(--leaf)}

/* ============================================================ Steps (PBL) */
.steps{counter-reset:step;list-style:none;padding:0;margin:24px 0}
.step{
  position:relative;padding:22px 24px 22px 76px;
  background:var(--paper-warm);
  border:1px solid var(--line);border-radius:var(--radius);
  margin-bottom:18px;counter-increment:step;
  transition:border-color .2s;
}
.step:hover{border-color:rgba(31,34,48,.2)}
.step::before{
  content:counter(step,decimal-leading-zero);
  position:absolute;left:22px;top:22px;
  font-family:var(--font-display);font-size:1.6rem;
  font-weight:600;color:var(--accent,var(--passion));
  line-height:1;
}
.step h3{margin:0 0 .4em;font-size:1.15rem}
.step p:last-child{margin-bottom:0}

/* ============================================================ Insight callouts */
.callout{
  border-left:3px solid var(--accent,var(--ink));
  background:var(--paper-warm);
  padding:18px 22px;border-radius:0 12px 12px 0;
  margin:22px 0;
}
.callout .label{
  font-size:.72rem;font-weight:700;letter-spacing:.16em;
  text-transform:uppercase;color:var(--accent,var(--ink-soft));
  margin-bottom:.4em;display:block;
}
.callout p{margin:0;font-size:.96rem;line-height:1.65}

/* ============================================================ Self-check rubric */
.rubric{
  background:linear-gradient(135deg,rgba(245,231,196,.35),rgba(255,252,244,.6));
  border:1px solid var(--taste-soft);
  border-radius:var(--radius);
  padding:24px 28px;margin:24px 0;
}
.rubric h3{
  margin-top:0;color:var(--taste-deep);
  font-size:1.05rem;
  font-family:var(--font-body);font-weight:700;letter-spacing:.04em;text-transform:uppercase;
}
.rubric ul{padding-left:0;list-style:none;margin:.5em 0 0}
.rubric li{
  position:relative;padding:8px 0 8px 32px;
  border-bottom:1px dashed rgba(198,138,45,.28);
  font-size:.95rem;
}
.rubric li:last-child{border-bottom:0}
.rubric li::before{
  content:"☐";position:absolute;left:0;top:8px;
  font-size:1.2rem;color:var(--taste);
}

/* ============================================================ Tag chips */
.chip{
  display:inline-flex;align-items:center;gap:6px;
  padding:5px 11px;border-radius:999px;
  background:var(--paper-warm);border:1px solid var(--line);
  font-size:.78rem;font-weight:600;color:var(--ink-soft);
  margin:0 4px 4px 0;
}
.chip.p{color:var(--passion-deep);border-color:var(--passion-soft);background:rgba(250,224,218,.4)}
.chip.e{color:var(--empathy-deep);border-color:var(--empathy-soft);background:rgba(221,234,239,.4)}
.chip.t{color:var(--taste-deep);border-color:var(--taste-soft);background:rgba(245,231,196,.4)}
.chip.l{color:var(--leaf-deep);border-color:var(--leaf-soft);background:rgba(221,231,211,.4)}

/* ============================================================ Demo box (in-page mini app) */
.demo{
  background:var(--paper-warm);
  border:2px dashed rgba(74,139,158,.35);
  border-radius:var(--radius);
  padding:24px 26px;margin:24px 0;
  position:relative;
}
.demo::before{
  content:"LIVE DEMO";position:absolute;top:-9px;left:18px;
  background:var(--paper);padding:1px 10px;
  font-family:var(--font-mono);font-size:.7rem;font-weight:600;
  letter-spacing:.16em;color:var(--empathy-deep);
}
.demo h4{margin:0 0 .6em;font-size:1rem;font-family:var(--font-body);font-weight:700}
.demo .row{display:flex;gap:10px;align-items:flex-start;flex-wrap:wrap;margin-bottom:10px}
.demo input[type=text],.demo textarea,.demo select{
  flex:1;min-width:200px;padding:9px 12px;
  background:var(--paper);border:1px solid var(--line);border-radius:8px;
  font:inherit;color:var(--ink);
  transition:border-color .15s;
}
.demo input[type=text]:focus,.demo textarea:focus,.demo select:focus{outline:none;border-color:var(--empathy)}
.demo textarea{min-height:84px;resize:vertical;font-family:var(--font-mono);font-size:.88rem}
.demo button{
  padding:9px 18px;background:var(--ink);color:var(--paper-warm);
  border:0;border-radius:8px;font-weight:600;font-size:.9rem;
  transition:background .15s;
}
.demo button:hover{background:var(--passion-deep)}
.demo .out{
  background:#1B1E2A;color:#E8EAF0;
  padding:14px 16px;border-radius:8px;
  font-family:var(--font-mono);font-size:.85rem;line-height:1.6;
  white-space:pre-wrap;min-height:60px;
  margin-top:8px;
}
.demo .out:empty::before{content:"// output will appear here…";color:#7A8090;font-style:italic}

/* ============================================================ Hero */
.hero{padding:5rem 0 4rem;text-align:center;border-bottom:1px solid var(--line)}
.hero .display{
  font-family:var(--font-display);font-weight:600;
  font-size:var(--size-display);line-height:1;
  letter-spacing:-.025em;color:var(--ink);
  margin:0 0 1.4rem;max-width:18ch;margin-inline:auto;
}
.hero .display em{
  font-style:italic;color:var(--passion-deep);
  position:relative;
}
.hero .sub{
  font-size:1.2rem;color:var(--ink-soft);
  max-width:54ch;margin:0 auto 2rem;line-height:1.65;
}
.hero .meta{
  display:inline-flex;align-items:center;gap:14px;
  padding:9px 20px;border-radius:999px;
  background:var(--paper-glass);backdrop-filter:blur(8px);
  border:1px solid var(--line);
  font-size:.85rem;color:var(--ink-soft);font-weight:500;
  margin-top:1rem;
}
.hero .meta .dot{width:5px;height:5px;border-radius:50%;background:var(--passion)}

/* ============================================================ Section */
section{padding:5rem 0}
section + section{border-top:1px solid var(--line)}
.section-head{margin-bottom:2.5rem;text-align:center}
.section-head h2{margin:0 0 .5em;max-width:24ch;margin-inline:auto}
.section-head p.sub{font-size:1.1rem;color:var(--ink-soft);max-width:52ch;margin:0 auto;line-height:1.65}

/* ============================================================ Grids */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
.grid-4{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
@media(min-width:920px){.grid-4{grid-template-columns:repeat(4,1fr)}}
@media(max-width:720px){.grid-3,.grid-2{grid-template-columns:1fr}}

/* ============================================================ Project page layout */
.project-head{
  padding:4rem 0 3rem;border-bottom:1px solid var(--line);
}
.project-head .breadcrumb{
  font-size:.82rem;color:var(--ink-faint);
  font-family:var(--font-mono);letter-spacing:.04em;
  margin-bottom:1.4rem;
}
.project-head .breadcrumb a{color:var(--ink-soft);text-decoration:underline;text-decoration-color:var(--line)}
.project-head h1{
  font-size:clamp(2rem,4.5vw,3.4rem);
  max-width:22ch;margin:0 0 .4em;
}
.project-head .blurb{
  font-size:1.2rem;color:var(--ink-soft);max-width:60ch;
  line-height:1.65;margin:0 0 1.5rem;
}
.project-head .meta-row{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:.8rem}

.project-body{
  display:grid;
  grid-template-columns:minmax(0,1fr) 280px;
  gap:60px;padding:3rem 0 4rem;
}
@media(max-width:980px){.project-body{grid-template-columns:1fr;gap:32px}}

.project-body .content h2{margin-top:2.4em}
.project-body .content h2:first-child{margin-top:0}
.project-body .content > p{font-size:1.05rem;line-height:1.75}
.project-body .content > p.lead{font-size:1.18rem;color:var(--ink)}

.project-body .aside{
  align-self:start;position:sticky;top:90px;
  display:flex;flex-direction:column;gap:18px;
}
.project-body .aside .panel{padding:22px 24px;border-radius:var(--radius)}
.project-body .aside h4{
  margin:0 0 .6em;font-family:var(--font-body);
  font-size:.78rem;font-weight:700;letter-spacing:.18em;
  text-transform:uppercase;color:var(--ink-soft);
}
.project-body .aside p{margin:0 0 .5em;font-size:.92rem;line-height:1.55}
.project-body .aside ul{margin:0;padding-left:1.1em;font-size:.92rem;line-height:1.6}
.project-body .aside .toc a{
  display:block;padding:6px 0;font-size:.92rem;
  color:var(--ink-soft);border-bottom:1px solid var(--line-soft);
  transition:color .15s;
}
.project-body .aside .toc a:hover{color:var(--ink)}
.project-body .aside .toc a:last-child{border-bottom:0}

/* ============================================================ Footer */
.site-footer{
  padding:3.5rem 0 2.5rem;
  border-top:1px solid var(--line);
  background:rgba(255,252,244,.5);
  font-size:.9rem;color:var(--ink-soft);
}
.site-footer .row{
  display:flex;flex-wrap:wrap;justify-content:space-between;gap:24px;align-items:flex-start;
}
.site-footer .brand{font-size:1.05rem}
.site-footer p{margin:.4em 0 0}

/* ============================================================ Trait color helpers (apply to a section/page) */
.theme-passion{--accent:var(--passion);--accent-deep:var(--passion-deep);--accent-soft:var(--passion-soft)}
.theme-empathy{--accent:var(--empathy);--accent-deep:var(--empathy-deep);--accent-soft:var(--empathy-soft)}
.theme-taste{--accent:var(--taste);--accent-deep:var(--taste-deep);--accent-soft:var(--taste-soft)}
.theme-leaf{--accent:var(--leaf);--accent-deep:var(--leaf-deep);--accent-soft:var(--leaf-soft)}

/* ============================================================ Compare table (good vs bad) */
.compare{
  display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:20px 0;
}
@media(max-width:640px){.compare{grid-template-columns:1fr}}
.compare .col{
  padding:18px 22px;border-radius:12px;font-size:.95rem;line-height:1.6;
}
.compare .good{background:rgba(106,142,90,.08);border:1px solid var(--leaf-soft)}
.compare .good::before{content:"✓ Builder move";display:block;font-weight:700;color:var(--leaf-deep);font-size:.78rem;letter-spacing:.12em;margin-bottom:.4em}
.compare .bad{background:rgba(217,83,63,.06);border:1px solid var(--passion-soft)}
.compare .bad::before{content:"✕ AI-without-you move";display:block;font-weight:700;color:var(--passion-deep);font-size:.78rem;letter-spacing:.12em;margin-bottom:.4em}

/* ============================================================ Step nav (prev / next) */
.step-nav{
  display:flex;justify-content:space-between;gap:18px;
  padding:2rem 0;border-top:1px solid var(--line);margin-top:3rem;
}
.step-nav a{
  flex:1;padding:18px 22px;border:1px solid var(--line);
  border-radius:var(--radius);background:var(--paper-warm);
  font-size:.95rem;color:var(--ink);
  transition:transform .15s,box-shadow .15s,border-color .15s;
}
.step-nav a:hover{transform:translateY(-2px);box-shadow:var(--shadow-soft);border-color:rgba(31,34,48,.2)}
.step-nav a .lbl{font-size:.72rem;color:var(--ink-faint);letter-spacing:.14em;text-transform:uppercase;font-weight:700;display:block;margin-bottom:4px}
.step-nav a.next{text-align:right}

/* ============================================================ Animation utilities */
@keyframes rise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
@keyframes fade{from{opacity:0}to{opacity:1}}
.rise{animation:rise .6s ease both}
.rise-2{animation-delay:.08s}
.rise-3{animation-delay:.16s}
.fade{animation:fade .6s ease both}

/* ============================================================ Tabs */
.tabs{
  background:var(--paper-warm);
  border:1px solid var(--line);
  border-radius:var(--radius);
  margin:24px 0;
  overflow:hidden;
}
.tabs-head{
  display:flex;gap:0;
  border-bottom:1px solid var(--line);
  background:rgba(31,34,48,.025);
  overflow-x:auto;
}
.tabs-head .tab{
  flex:0 0 auto;
  padding:13px 20px;
  background:transparent;border:none;
  font-family:var(--font-body);font-size:.92rem;font-weight:600;
  color:var(--ink-soft);cursor:pointer;
  border-bottom:2px solid transparent;
  transition:all .15s;white-space:nowrap;
}
.tabs-head .tab:hover{color:var(--ink);background:rgba(31,34,48,.04)}
.tabs-head .tab.active{color:var(--accent,var(--passion-deep));border-bottom-color:var(--accent,var(--passion-deep));background:var(--paper-warm)}
.tabs-body .pane{display:none;padding:22px 24px;animation:fade .25s ease}
.tabs-body .pane.active{display:block}
.tabs-body .pane > *:first-child{margin-top:0}
.tabs-body .pane > *:last-child{margin-bottom:0}

/* ============================================================ Accordion */
.accordion{margin:20px 0}
.acc-item{
  background:var(--paper-warm);
  border:1px solid var(--line);
  border-radius:var(--radius);
  margin-bottom:8px;
  overflow:hidden;
  transition:border-color .2s;
}
.acc-item:hover{border-color:rgba(31,34,48,.18)}
.acc-head{
  padding:14px 22px;cursor:pointer;
  display:flex;justify-content:space-between;align-items:center;
  font-weight:600;font-size:.98rem;color:var(--ink);
  user-select:none;
}
.acc-head::after{
  content:"+";color:var(--ink-soft);font-size:1.4rem;font-weight:300;
  transition:transform .2s;
  width:24px;text-align:center;
}
.acc-item.open .acc-head::after{transform:rotate(45deg)}
.acc-body{display:none;padding:0 22px 18px}
.acc-item.open .acc-body{display:block;animation:fade .25s ease}
.acc-body > *:first-child{margin-top:0}

/* ============================================================ Sandbox (iframe + 3 textareas) */
.sandbox{
  background:var(--paper-warm);
  border:2px dashed rgba(74,139,158,.4);
  border-radius:var(--radius);
  padding:24px 26px;margin:24px 0;
  position:relative;
}
.sandbox::before{
  content:"LIVE SANDBOX";position:absolute;top:-9px;left:18px;
  background:var(--paper);padding:1px 10px;
  font-family:var(--font-mono);font-size:.7rem;font-weight:600;
  letter-spacing:.16em;color:var(--empathy-deep);
}
.sandbox h4{margin:0 0 .8em;font-size:1rem;font-family:var(--font-body);font-weight:700}
.sandbox .editor-row{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-bottom:10px}
@media(max-width:780px){.sandbox .editor-row{grid-template-columns:1fr}}
.sandbox textarea{
  width:100%;min-height:130px;padding:10px;
  background:var(--paper);
  border:1px solid var(--line);border-radius:8px;
  font-family:var(--font-mono);font-size:.78rem;line-height:1.55;
  color:var(--ink);resize:vertical;
}
.sandbox textarea:focus{outline:none;border-color:var(--empathy)}
.sandbox .editor-label{
  display:block;font-size:.7rem;font-weight:700;letter-spacing:.14em;
  text-transform:uppercase;color:var(--ink-soft);margin-bottom:4px;
  font-family:var(--font-mono);
}
.sandbox iframe{
  width:100%;height:280px;
  background:#fff;border:1px solid var(--line);
  border-radius:8px;
}

/* ============================================================ Push further (challenge problems) */
.push{
  background:linear-gradient(135deg,rgba(31,34,48,.04),rgba(217,83,63,.05));
  border:1px solid rgba(31,34,48,.10);
  border-radius:var(--radius-lg);
  padding:28px 32px;margin:36px 0 24px;
}
@media(max-width:720px){.push{padding:22px 20px}}
.push h3{
  margin:0 0 .4em;font-family:var(--font-body);
  font-size:.78rem;font-weight:700;letter-spacing:.2em;
  text-transform:uppercase;color:var(--passion-deep);
  display:flex;align-items:center;gap:10px;
}
.push h3::before{content:"⚡";font-size:1rem}
.push .push-lead{
  font-family:var(--font-display);font-size:1.4rem;font-weight:600;
  margin:.4em 0 1em;line-height:1.25;letter-spacing:-.01em;
}
.push .push-lead em{color:var(--passion-deep)}
.push ol{counter-reset:ch;list-style:none;padding:0;margin:0}
.push ol li{
  counter-increment:ch;
  padding:14px 0 14px 56px;position:relative;
  border-top:1px dashed rgba(31,34,48,.12);
  font-size:.97rem;line-height:1.65;
}
.push ol li:first-child{border-top:0;padding-top:6px}
.push ol li::before{
  content:"CH" counter(ch,decimal-leading-zero);
  position:absolute;left:0;top:14px;
  font-family:var(--font-mono);font-size:.72rem;font-weight:700;
  letter-spacing:.05em;color:var(--passion-deep);
  background:var(--paper-warm);
  padding:3px 8px;border-radius:6px;
  border:1px solid var(--passion-soft);
}
.push ol li:first-child::before{top:6px}
.push ol li strong{display:block;margin-bottom:.3em;font-size:1rem;color:var(--ink)}

/* ============================================================ Spec / table card */
.spec{
  background:var(--paper-warm);
  border:1px solid var(--line);
  border-radius:var(--radius);
  margin:20px 0;overflow:hidden;
}
.spec-row{
  display:grid;grid-template-columns:160px 1fr;gap:16px;
  padding:12px 20px;
  border-bottom:1px solid var(--line-soft);
  font-size:.93rem;
}
.spec-row:last-child{border-bottom:0}
.spec-row .k{
  font-family:var(--font-mono);font-size:.78rem;
  color:var(--ink-soft);font-weight:600;letter-spacing:.04em;
  align-self:center;
}
.spec-row .v{color:var(--ink);line-height:1.55}
.spec-row .v code{font-size:.85em}
@media(max-width:600px){.spec-row{grid-template-columns:1fr;gap:4px;padding:10px 16px}}

/* ============================================================ File tree */
.tree{
  background:#1B1E2A;color:#E8EAF0;
  padding:16px 20px;border-radius:12px;
  font-family:var(--font-mono);font-size:.84rem;line-height:1.7;
  margin:18px 0;
}
.tree .dim{color:#7A8090}
.tree .dir{color:#E8B547}
.tree .file{color:#A6CD81}
.tree .com{color:#7A8090;font-style:italic}

/* ============================================================ Inline result area for demos */
.demo .result{
  margin-top:10px;padding:14px 16px;
  background:rgba(106,142,90,.07);
  border:1px solid var(--leaf-soft);
  border-left:3px solid var(--leaf);
  border-radius:8px;font-size:.92rem;line-height:1.6;
  display:none;
}
.demo .result.show{display:block;animation:fade .25s ease}
.demo .result.bad{
  background:rgba(217,83,63,.06);
  border-color:var(--passion-soft);
  border-left-color:var(--passion);
}
.demo .result.warn{
  background:rgba(198,138,45,.07);
  border-color:var(--taste-soft);
  border-left-color:var(--taste);
}

/* ============================================================ Inline KBD */
kbd{
  display:inline-block;padding:1px 7px;
  background:var(--paper-warm);
  border:1px solid var(--line);
  border-bottom-width:2px;
  border-radius:5px;
  font-family:var(--font-mono);font-size:.82em;
  color:var(--ink);
}

/* ============================================================ Inline diff (for code review widget) */
.diff{
  background:#1B1E2A;border-radius:12px;padding:14px 0;margin:16px 0;
  font-family:var(--font-mono);font-size:.84rem;line-height:1.7;
  overflow-x:auto;
}
.diff .line{padding:0 18px;white-space:pre}
.diff .add{background:rgba(106,142,90,.18);color:#C8E5B8}
.diff .rem{background:rgba(217,83,63,.18);color:#F4C2B6}
.diff .ctx{color:#94A0B0}
.diff .add::before{content:"+ ";color:#6A8E5A}
.diff .rem::before{content:"- ";color:#D9533F}
.diff .ctx::before{content:"  "}