:root{
  --paper: #EDEFF2;
  --paper-line: #C8CDD6;
  --ink: #12181F;
  --ink-soft: #4A5361;
  --card-bg: #FFFFFF;
  --accent: #FF4B12;
  --accent-ink: #7A1F00;
  --blueprint: #1F4CFF;
  --success: #1E8E5A;
  --warning: #C97A00;
  --danger: #D82C2C;
  --mono: 'IBM Plex Mono', monospace;
  --sans: 'IBM Plex Sans', sans-serif;
  --radius: 6px;
}

[data-theme="dark"]{
  --paper: #12161C;
  --paper-line: #2B323C;
  --ink: #EDEFF2;
  --ink-soft: #9AA4B2;
  --card-bg: #1A1F27;
  --accent: #FF6A38;
  --accent-ink: #FFB89A;
  --blueprint: #6C8BFF;
  --success: #3FBE86;
  --warning: #E3A83B;
  --danger: #FF5A5A;
}

@media (prefers-reduced-motion: reduce){
  *{ animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

*{ box-sizing: border-box; }

body{
  margin:0;
  background:
    linear-gradient(var(--paper-line) 1px, transparent 1px) 0 0/100% 40px,
    var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  line-height:1.5;
  -webkit-font-smoothing: antialiased;
  transition: background .2s ease, color .2s ease;
}

a{ color: var(--blueprint); }

:focus-visible{
  outline: 2px solid var(--blueprint);
  outline-offset: 2px;
}

.wrap{
  max-width: 1100px;
  margin: 0 auto;
  padding: 48px 24px 120px;
}

/* ---------- Cover header ---------- */
header.cover{
  border: 1.5px solid var(--ink);
  background: var(--card-bg);
  padding: 32px 28px;
  margin-bottom: 56px;
  position: relative;
  transition: background .2s ease, border-color .2s ease;
}
header.cover::before{
  content: "REV. 6 — VANILLA JS";
  position: absolute;
  top: -11px;
  left: 24px;
  background: var(--paper);
  padding: 0 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}
.theme-toggle-btn{
  position: absolute;
  top: 24px; right: 24px;
}
.cover-eyebrow{
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--accent-ink);
  text-transform: uppercase;
  margin: 0 0 10px;
}
header.cover h1{
  font-family: var(--mono);
  font-size: clamp(28px, 4vw, 42px);
  margin: 0 12px 12px 0;
  letter-spacing: -0.01em;
  max-width: 80%;
}
header.cover p{
  max-width: 62ch;
  color: var(--ink-soft);
  margin: 0;
  font-size: 15px;
}
.cover-meta{
  display:flex;
  gap: 28px;
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px dashed var(--paper-line);
  flex-wrap: wrap;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--ink-soft);
}
.cover-meta strong{ color: var(--ink); display:block; font-size:12.5px; }

/* ---------- Section / spec block ---------- */
section.part{
  margin-bottom: 72px;
}
.part-label{
  display:flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 4px;
  font-family: var(--mono);
}
.part-code{
  font-size: 13px;
  background: var(--ink);
  color: var(--paper);
  padding: 3px 8px;
  letter-spacing: 0.04em;
}
.part-label h2{
  font-family: var(--mono);
  font-size: 20px;
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.part-desc{
  font-size: 14px;
  color: var(--ink-soft);
  margin: 6px 0 20px;
  max-width: 70ch;
}

.spec-frame{
  position: relative;
  border: 1.5px solid var(--ink);
  background: var(--card-bg);
  padding: 36px 28px 28px;
  transition: background .2s ease, border-color .2s ease;
}
.spec-frame::before, .spec-frame::after,
.spec-frame .corner-br, .spec-frame .corner-bl{
  content:"";
  position:absolute;
  width: 14px; height: 14px;
  border-color: var(--accent);
  border-style: solid;
}
.spec-frame::before{ top:-1.5px; left:-1.5px; border-width: 2px 0 0 2px; }
.spec-frame::after{ top:-1.5px; right:-1.5px; border-width: 2px 2px 0 0; }
.corner-bl{ bottom:-1.5px; left:-1.5px; border-width: 0 0 2px 2px; }
.corner-br{ bottom:-1.5px; right:-1.5px; border-width: 0 2px 2px 0; }

.frame-tag{
  position:absolute;
  top: -11px; left: 26px;
  background: var(--paper);
  padding: 0 6px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
  text-transform: uppercase;
}

.copy-snippet{
  position:absolute;
  top: -13px; right: 26px;
  background: var(--paper);
  border: 1px solid var(--paper-line);
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 3px 9px;
  border-radius: 999px;
  cursor: pointer;
}
.copy-snippet:hover{ color: var(--ink); border-color: var(--ink); }
.copy-snippet.copied{ color: var(--success); border-color: var(--success); }

.demo-row{
  display:flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
  margin-bottom: 18px;
}
.demo-row:last-child{ margin-bottom: 0; }
.demo-row-label{
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  width: 100%;
  margin-bottom: -4px;
}

.cards-grid{
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(220px,1fr));
  gap: 16px;
}

/* spec table (props) */
.spec-table{
  margin-top: 26px;
  border-top: 1px dashed var(--paper-line);
  padding-top: 16px;
}
.spec-table table{
  width:100%;
  border-collapse: collapse;
  font-family: var(--mono);
  font-size: 12px;
}
.spec-table th{
  text-align:left;
  color: var(--ink-soft);
  text-transform: uppercase;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 4px 10px 8px 0;
  border-bottom: 1px solid var(--ink);
}
.spec-table td{
  padding: 7px 10px 7px 0;
  border-bottom: 1px solid var(--paper-line);
  color: var(--ink);
  vertical-align: top;
}
.spec-table code{
  background: var(--paper);
  padding: 1px 5px;
  border-radius: 3px;
}

/* ---------- Button component ---------- */
.btn{
  font-family: var(--sans);
  font-weight: 600;
  font-size: 14px;
  border-radius: var(--radius);
  border: 1.5px solid transparent;
  cursor: pointer;
  display: inline-flex;
  align-items:center;
  gap: 8px;
  transition: transform .12s ease, box-shadow .12s ease, background .12s ease;
}
.btn:active{ transform: translateY(1px); }
.btn[disabled]{ opacity: .45; cursor: not-allowed; transform:none; }

.btn-sm{ padding: 6px 12px; font-size: 12.5px; }
.btn-md{ padding: 10px 18px; }
.btn-lg{ padding: 13px 24px; font-size: 15.5px; }

.btn-primary{ background: var(--ink); color: var(--paper); }
.btn-primary:hover:not([disabled]){ background: var(--accent); color:#fff; }

.btn-secondary{ background: var(--card-bg); color: var(--ink); border-color: var(--ink); }
.btn-secondary:hover:not([disabled]){ background: var(--paper); }

.btn-ghost{ background: transparent; color: var(--ink); border-color: transparent; }
.btn-ghost:hover:not([disabled]){ background: var(--paper); }

.btn-danger{ background: var(--danger); color: #fff; }
.btn-danger:hover:not([disabled]){ background: #b31f1f; }

.btn-spinner{
  width: 13px; height: 13px;
  border-radius: 50%;
  border: 2px solid currentColor;
  border-top-color: transparent;
  animation: btn-spin .7s linear infinite;
  flex-shrink: 0;
}
@keyframes btn-spin{ to{ transform: rotate(360deg); } }

/* ---------- Card component ---------- */
.card{
  background: var(--card-bg);
  border: 1px solid var(--paper-line);
  border-radius: var(--radius);
  padding: 20px;
  display:flex;
  flex-direction: column;
  gap: 10px;
  transition: background .2s ease, border-color .2s ease;
}
.card-outlined{ border: 1.5px solid var(--ink); }
.card-elevated{ border-color: transparent; box-shadow: 0 6px 18px rgba(18,24,31,0.12); }
.card-tag{
  align-self:flex-start;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  background: var(--paper);
  padding: 3px 8px;
  border-radius: 3px;
  color: var(--ink-soft);
}
.card h3{ margin: 2px 0 0; font-size: 16.5px; }
.card p{ margin: 0; font-size: 13.5px; color: var(--ink-soft); }
.card-footer{ margin-top: 6px; display:flex; gap:8px; }

/* ---------- Badge component ---------- */
.badge{
  display:inline-flex;
  align-items:center;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  padding: 3px 10px;
  border-radius: 999px;
  border: 1px solid transparent;
}
.badge-neutral{ background: var(--paper); color: var(--ink-soft); border-color: var(--paper-line); }
.badge-info{ background: rgba(31,76,255,0.12); color: var(--blueprint); }
.badge-success{ background: rgba(30,142,90,0.14); color: var(--success); }
.badge-warning{ background: rgba(201,122,0,0.16); color: var(--warning); }
.badge-danger{ background: rgba(216,44,44,0.12); color: var(--danger); }

/* ---------- Input field component ---------- */
.field{
  display:flex;
  flex-direction: column;
  gap: 6px;
  width: 100%;
  max-width: 280px;
}
.field label{
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
}
.field input{
  font-family: var(--sans);
  font-size: 14px;
  padding: 9px 11px;
  border: 1.5px solid var(--paper-line);
  border-radius: var(--radius);
  background: var(--card-bg);
  color: var(--ink);
}
.field input::placeholder{ color: var(--ink-soft); opacity: .7; }
.field input:focus-visible{ border-color: var(--blueprint); }
.field.has-error input{ border-color: var(--danger); }
.field-help{ font-size: 12px; color: var(--ink-soft); }
.field-help.field-error-text{ color: var(--danger); }

/* ---------- Modal component ---------- */
#modal-root{
  position: fixed; inset: 0;
  z-index: 900;
  pointer-events: none;
}
.modal-backdrop{
  position:absolute; inset:0;
  background: rgba(0,0,0,0.55);
  opacity:0;
  transition: opacity .18s ease;
  pointer-events: auto;
}
.modal-backdrop.showing{ opacity:1; }
.modal-box{
  position:absolute;
  top:50%; left:50%;
  width: min(440px, calc(100vw - 48px));
  background: var(--card-bg);
  color: var(--ink);
  border-radius: 10px;
  padding: 26px 26px 22px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.4);
  pointer-events:auto;
  opacity:0;
  transform: translate(-50%,-46%) scale(.97);
  transition: opacity .18s ease, transform .18s ease, background .2s ease;
}
.modal-box.showing{ opacity:1; transform: translate(-50%,-50%) scale(1); }
.modal-box header{
  display:flex; justify-content:space-between; align-items:flex-start;
  margin-bottom: 10px; gap: 12px;
}
.modal-box h3{ margin:0; font-size:17px; }
.modal-close{
  background:none; border:none; cursor:pointer;
  font-size: 18px; line-height:1; color: var(--ink-soft);
  padding: 2px 4px; border-radius: 4px;
}
.modal-close:hover{ background: var(--paper); color: var(--ink); }
.modal-body{ font-size: 14px; color: var(--ink-soft); margin-bottom: 20px; }
.modal-actions{ display:flex; justify-content:flex-end; gap:10px; }
.modal-partno{
  position:absolute; top:-9px; left:20px;
  font-family: var(--mono); font-size: 10px;
  background: var(--ink); color: var(--paper);
  padding: 2px 7px; letter-spacing:.05em;
}

/* ---------- Toast component ---------- */
#toast-root{
  position: fixed;
  bottom: 22px; right: 22px;
  z-index: 1000;
  display:flex;
  flex-direction: column-reverse;
  gap: 10px;
  width: min(340px, calc(100vw - 32px));
}
.toast{
  background: var(--ink);
  color: var(--paper);
  border-radius: 8px;
  padding: 13px 14px 13px 16px;
  display:flex;
  gap:10px;
  align-items:flex-start;
  box-shadow: 0 10px 26px rgba(0,0,0,0.35);
  position: relative;
  overflow:hidden;
  transform: translateX(120%);
  opacity: 0;
  transition: transform .22s ease, opacity .22s ease;
}
.toast.showing{ transform: translateX(0); opacity:1; }
.toast.leaving{ transform: translateX(120%); opacity:0; }
.toast-icon{ font-size: 15px; margin-top:1px; }
.toast-msg{ font-size: 13.5px; flex:1; }
.toast-x{
  background:none; border:none; color: rgba(255,255,255,.7);
  cursor:pointer; font-size:14px; padding:0 2px;
}
.toast-x:hover{ color:#fff; }
.toast-bar{
  position:absolute; left:0; bottom:0; height: 3px;
  background: rgba(255,255,255,.55);
  width: 100%;
  transform-origin: left;
  animation: toast-countdown linear forwards;
}
@keyframes toast-countdown{ from{ transform: scaleX(1);} to{ transform: scaleX(0);} }
.toast-info{ background: var(--ink); color: var(--paper); }
.toast-success{ background: var(--success); color: #fff; }
.toast-warning{ background: var(--warning); color: #fff; }
.toast-danger{ background: var(--danger); color: #fff; }

/* ---------- Reflection note ---------- */
.note{
  background: #FFF8DE;
  border: 1px solid #E4D48A;
  padding: 22px 24px;
  max-width: 760px;
  box-shadow: 3px 4px 0 rgba(18,24,31,0.08);
  transform: rotate(-0.4deg);
}
[data-theme="dark"] .note{
  background: #2B2717;
  border-color: #5A4E1F;
}
.note h2{
  font-family: var(--mono);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: .08em;
  margin: 0 0 10px;
  color: var(--accent-ink);
}
.note p{ margin: 0; font-size: 14.5px; color: var(--ink); }

footer.colophon{
  margin-top: 64px;
  padding-top: 18px;
  border-top: 1px dashed var(--paper-line);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-soft);
}