@layer reset, tokens, base, layout, components, states, responsive, print;

@layer reset {
  *, *::before, *::after { box-sizing: border-box; }
  html { color-scheme: light dark; scroll-behavior: smooth; }
  body, h1, h2, h3, p, figure, dl, dd { margin: 0; }
  button, input, select, textarea { font: inherit; }
  button, select { cursor: pointer; }
  img, svg { display: block; max-width: 100%; }
  table { border-collapse: collapse; border-spacing: 0; }
  [hidden] { display: none !important; }
}

@layer tokens {
  :root {
    --canvas: #ede7da;
    --surface: #f8f4eb;
    --surface-strong: #fffdf8;
    --surface-muted: #e8e0d1;
    --ink: #27251f;
    --ink-soft: #5d594f;
    --ink-faint: #6f695d;
    --line: #cfc6b5;
    --line-strong: #a99f8d;
    --accent: #b84616;
    --accent-strong: #a93a10;
    --accent-soft: #f8d9ca;
    --ready: #126f70;
    --ready-soft: #d5ece9;
    --good: #256a45;
    --good-soft: #dcecdf;
    --warning: #95620a;
    --warning-soft: #f4e7bf;
    --danger: #a63b32;
    --danger-soft: #f4d9d5;
    --focus: #075f9d;
    --shadow: 0 12px 36px rgb(45 36 20 / 9%);
    --shadow-small: 0 4px 16px rgb(45 36 20 / 8%);
    --radius-xs: .35rem;
    --radius-sm: .55rem;
    --radius-md: .85rem;
    --radius-lg: 1.15rem;
    --page: 86rem;
    --header-h: 4.4rem;
    --mono: ui-monospace, "SFMono-Regular", "Cascadia Code", "Roboto Mono", Consolas, monospace;
    --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  }

  :root[data-theme="dark"] {
    color-scheme: dark;
    --canvas: #11110f;
    --surface: #1b1a16;
    --surface-strong: #23211c;
    --surface-muted: #2b2923;
    --ink: #f5f0e6;
    --ink-soft: #c4bdaf;
    --ink-faint: #918a7e;
    --line: #454036;
    --line-strong: #665f52;
    --accent: #ff7a3d;
    --accent-strong: #ff9b6d;
    --accent-soft: #4a281b;
    --ready: #62c8c3;
    --ready-soft: #193d3a;
    --good: #78c99a;
    --good-soft: #1e3c2c;
    --warning: #e7b04c;
    --warning-soft: #47391b;
    --danger: #ef8177;
    --danger-soft: #472622;
    --focus: #7ac8ff;
    --shadow: 0 16px 46px rgb(0 0 0 / 35%);
    --shadow-small: 0 5px 18px rgb(0 0 0 / 28%);
  }

  @media (prefers-color-scheme: dark) {
    :root[data-theme="auto"] {
      color-scheme: dark;
      --canvas: #11110f;
      --surface: #1b1a16;
      --surface-strong: #23211c;
      --surface-muted: #2b2923;
      --ink: #f5f0e6;
      --ink-soft: #c4bdaf;
      --ink-faint: #918a7e;
      --line: #454036;
      --line-strong: #665f52;
      --accent: #ff7a3d;
      --accent-strong: #ff9b6d;
      --accent-soft: #4a281b;
      --ready: #62c8c3;
      --ready-soft: #193d3a;
      --good: #78c99a;
      --good-soft: #1e3c2c;
      --warning: #e7b04c;
      --warning-soft: #47391b;
      --danger: #ef8177;
      --danger-soft: #472622;
      --focus: #7ac8ff;
      --shadow: 0 16px 46px rgb(0 0 0 / 35%);
      --shadow-small: 0 5px 18px rgb(0 0 0 / 28%);
    }
  }
}

@layer base {
  body {
    min-width: 20rem;
    min-height: 100vh;
    background:
      radial-gradient(circle at 18% 0%, rgb(255 255 255 / 35%), transparent 28rem),
      var(--canvas);
    color: var(--ink);
    font-family: var(--sans);
    line-height: 1.5;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
  }

  a { color: inherit; text-decoration-thickness: .08em; text-underline-offset: .2em; }
  a:hover { color: var(--accent-strong); }

  h1, h2, h3 { line-height: 1.08; letter-spacing: -.035em; }
  h1 { font-size: clamp(2rem, 3.2vw, 2.75rem); font-weight: 760; }
  h2 { font-size: clamp(1.35rem, 2.1vw, 2rem); font-weight: 720; }
  h3 { font-size: 1.05rem; font-weight: 720; }
  strong { font-weight: 720; }

  button, input, select, textarea, dialog { color: inherit; }
  input, select, textarea {
    min-height: 2.75rem;
    border: 1px solid var(--line-strong);
    border-radius: var(--radius-sm);
    background: var(--surface-strong);
    padding: .62rem .72rem;
    outline: none;
  }
  input:hover, select:hover, textarea:hover { border-color: var(--ink-faint); }
  input:focus-visible, select:focus-visible, textarea:focus-visible, button:focus-visible, a:focus-visible, summary:focus-visible {
    outline: 2px solid var(--focus);
    outline-offset: 3px;
  }
  input[aria-invalid="true"], select[aria-invalid="true"] {
    border-color: var(--danger);
    box-shadow: 0 0 0 1px var(--danger);
  }
  input::placeholder { color: var(--ink-faint); opacity: .8; }
  select { padding-right: 2.1rem; }

  button { border: 0; }
  small { color: var(--ink-soft); font-size: .75rem; }
  summary { list-style: none; cursor: pointer; }
  summary::-webkit-details-marker { display: none; }
  dialog::backdrop { background: rgb(12 11 9 / 68%); backdrop-filter: blur(3px); }

  .visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
  }

  .skip-link {
    position: fixed;
    z-index: 200;
    top: .7rem;
    left: .7rem;
    transform: translateY(-180%);
    background: var(--ink);
    color: var(--surface-strong);
    padding: .7rem 1rem;
    border-radius: var(--radius-sm);
  }
  .skip-link:focus { transform: none; }

  .eyebrow {
    color: var(--accent-strong);
    font-size: .72rem;
    font-weight: 780;
    letter-spacing: .12em;
    text-transform: uppercase;
  }
}

@layer layout {
  .site-header {
    position: relative;
    z-index: 20;
    min-height: var(--header-h);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    max-width: var(--page);
    margin: 0 auto;
    padding: .8rem clamp(1rem, 3vw, 2.25rem);
    border-bottom: 1px solid color-mix(in srgb, var(--line) 78%, transparent);
  }

  main, .site-footer {
    max-width: var(--page);
    margin-inline: auto;
    padding-inline: clamp(1rem, 3vw, 2.25rem);
  }

  .hero {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(18rem, 27rem);
    align-items: end;
    gap: 2rem;
    padding-block: clamp(1.65rem, 3vw, 3rem) clamp(1.1rem, 2vw, 1.8rem);
  }

  .tool-shell {
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(25rem, .92fr);
    gap: 1rem;
    align-items: start;
  }

  .project-bench, .answer-ledger {
    min-width: 0;
    border: 1px solid var(--line);
    background: var(--surface);
  }

  .project-bench {
    border-radius: var(--radius-lg) 0 0 var(--radius-lg);
    padding: clamp(1rem, 2vw, 1.45rem);
  }

  .answer-ledger {
    position: sticky;
    top: .75rem;
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    padding: clamp(1rem, 2vw, 1.45rem);
    box-shadow: var(--shadow);
  }

  .settings-dock {
    margin-block: 1rem 3rem;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    overflow: clip;
    background: var(--surface);
  }

  .method-section {
    display: grid;
    grid-template-columns: minmax(13rem, .7fr) minmax(0, 2fr);
    gap: 2.5rem;
    padding-block: clamp(2.5rem, 6vw, 5.5rem);
    border-top: 1px solid var(--line);
  }

  .site-footer {
    display: flex;
    justify-content: space-between;
    gap: 2rem;
    padding-block: 1.3rem 6rem;
    border-top: 1px solid var(--line);
    color: var(--ink-soft);
    font-size: .84rem;
  }
}

@layer components {
  .brand {
    display: inline-flex;
    align-items: center;
    gap: .7rem;
    color: var(--ink);
    text-decoration: none;
  }
  .brand:hover { color: var(--ink); }
  .brand-mark { width: 2.25rem; height: 2.25rem; color: var(--accent); fill: none; stroke: currentColor; stroke-width: 1.7; }
  .brand span { display: grid; line-height: 1.05; }
  .brand strong { font-size: .96rem; letter-spacing: -.02em; }
  .brand small { margin-top: .22rem; font-size: .66rem; letter-spacing: .025em; }

  .header-actions { display: flex; align-items: center; gap: .45rem; }

  .button {
    min-height: 2.75rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: .45rem;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    padding: .58rem .9rem;
    font-size: .84rem;
    font-weight: 720;
    white-space: nowrap;
    transition: background-color 120ms ease, border-color 120ms ease, transform 120ms ease;
  }
  .button:hover { transform: translateY(-1px); }
  .button:active { transform: translateY(0); }
  .button.primary { background: var(--accent); color: #fff; }
  .button.primary:hover { background: var(--accent-strong); }
  .button.secondary { border-color: var(--line-strong); background: var(--surface-strong); }
  .button.secondary:hover { border-color: var(--ink-faint); }
  .button.ghost { border-color: transparent; background: transparent; color: var(--ink-soft); }
  .button.ghost:hover { background: var(--surface-muted); color: var(--ink); }
  .button.danger { background: var(--danger); color: #fff; }
  .compact-button { min-height: 2.75rem; padding: .38rem .65rem; font-size: .76rem; }
  .danger-text { color: var(--danger) !important; }
  .icon-button { width: 2.65rem; padding: .55rem; }
  .icon-button svg { width: 1.1rem; height: 1.1rem; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; }

  .segmented {
    display: inline-flex;
    padding: .16rem;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    background: var(--surface-muted);
  }
  .segment {
    min-height: 2.75rem;
    min-width: 3.15rem;
    border-radius: .36rem;
    background: transparent;
    color: var(--ink-soft);
    padding: .38rem .62rem;
    font-size: .75rem;
    font-weight: 720;
  }
  .segment.is-active { background: var(--surface-strong); color: var(--ink); box-shadow: var(--shadow-small); }

  .hero h1 { margin-top: .2rem; }
  .hero-copy { max-width: 49rem; margin-top: .55rem; color: var(--ink-soft); font-size: clamp(1rem, 1.5vw, 1.2rem); }
  .hero-proof {
    align-self: end;
    border-left: 2px solid var(--accent);
    padding-left: 1rem;
    color: var(--ink-soft);
    font-size: .84rem;
  }
  .hero-proof strong { display: block; color: var(--ink); }

  .preset-rail {
    display: flex;
    align-items: center;
    gap: .75rem;
    margin-bottom: .8rem;
    min-width: 0;
  }
  .preset-label { flex: 0 0 auto; color: var(--ink-faint); font-size: .72rem; font-weight: 720; text-transform: uppercase; letter-spacing: .08em; }
  .preset-scroller {
    min-width: 0;
    display: flex;
    gap: .42rem;
    overflow-x: auto;
    padding: .25rem .2rem .35rem;
    scrollbar-width: thin;
    scroll-snap-type: x proximity;
  }
  .preset-chip {
    flex: 0 0 auto;
    min-height: 2.75rem;
    scroll-snap-align: start;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: color-mix(in srgb, var(--surface) 75%, transparent);
    color: var(--ink-soft);
    padding: .42rem .78rem;
    font-size: .76rem;
    font-weight: 680;
    white-space: nowrap;
  }
  .preset-chip:hover { border-color: var(--line-strong); color: var(--ink); }
  .preset-chip.is-active { border-color: var(--accent); background: var(--accent-soft); color: var(--accent-strong); }

  .notice {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-bottom: .8rem;
    border: 1px solid var(--danger);
    border-radius: var(--radius-md);
    background: var(--danger-soft);
    padding: .8rem 1rem;
    font-size: .84rem;
  }
  .notice div { display: grid; }

  .panel-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; margin-bottom: 1rem; }
  .panel-heading h2 { margin-top: .15rem; }
  .section-count, .result-state-badge, .settings-status {
    border: 1px solid var(--line);
    border-radius: 999px;
    background: var(--surface-strong);
    color: var(--ink-soft);
    padding: .28rem .58rem;
    font-size: .68rem;
    font-weight: 720;
    white-space: nowrap;
  }
  .result-state-badge { color: var(--good); border-color: color-mix(in srgb, var(--good) 40%, var(--line)); }

  .section-stack { display: grid; gap: .7rem; }
  .section-card {
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: var(--surface-strong);
  }
  .section-card.is-active { border-color: var(--line-strong); box-shadow: inset 3px 0 0 var(--accent); padding: 1rem; }
  .section-card.is-collapsed { display: flex; align-items: center; justify-content: space-between; gap: .9rem; padding: .72rem .8rem; }
  .collapsed-summary { min-width: 0; }
  .collapsed-summary strong, .collapsed-summary small { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .collapsed-summary small { font-family: var(--mono); font-size: .68rem; }
  .collapsed-actions { display: flex; flex: 0 0 auto; gap: .3rem; }

  .section-card-head {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(11rem, .8fr);
    gap: .75rem;
    align-items: end;
    margin-bottom: .9rem;
  }
  .field { display: grid; gap: .32rem; }
  .field > span, .field-group > label, .add-section-row > label, .project-rule-row > label, .settings-body label, .addon-body section > label {
    color: var(--ink-soft);
    font-size: .8125rem;
    font-weight: 720;
  }
  .field input, .field select { width: 100%; }
  .section-name-field input { font-weight: 720; }

  .active-section-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(14rem, .85fr);
    gap: 1rem;
    align-items: stretch;
  }
  .field-zone { min-width: 0; }
  .measurement-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: .72rem;
  }
  .field-group { min-width: 0; }
  .measurement-control, .paired-input, .suffix-input, .money-input { display: flex; min-width: 0; }
  .measurement-control input, .paired-input input { width: 100%; min-width: 0; border-radius: var(--radius-sm) 0 0 var(--radius-sm); }
  .measurement-control select, .paired-input select {
    flex: 0 0 4.25rem;
    border-left: 0;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    background: var(--surface-muted);
    padding-inline: .55rem;
    font-family: var(--mono);
    font-size: .74rem;
  }
  .field-hint { display: block; min-height: 1.25rem; padding-top: .2rem; font-family: var(--mono); font-size: .8125rem; }
  .field-error { color: var(--danger); font-family: var(--sans); font-weight: 650; }
  .quantity-field > input { width: 100%; }

  .quick-row {
    display: flex;
    align-items: center;
    gap: .35rem;
    margin-top: .7rem;
    color: var(--ink-faint);
    font-size: .68rem;
  }
  .mini-choice {
    min-height: 2.75rem;
    border: 1px solid var(--line);
    border-radius: var(--radius-xs);
    background: transparent;
    color: var(--ink-soft);
    padding: .3rem .5rem;
    font-size: .68rem;
  }
  .mini-choice.is-active { border-color: var(--accent); background: var(--accent-soft); color: var(--accent-strong); }
  .section-actions { display: flex; gap: .2rem; margin-top: .55rem; }

  .diagram-card {
    min-width: 0;
    display: grid;
    grid-template-rows: auto minmax(8.8rem, 1fr) auto;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    background:
      linear-gradient(var(--line) 1px, transparent 1px),
      linear-gradient(90deg, var(--line) 1px, transparent 1px),
      var(--surface);
    background-size: 1.25rem 1.25rem;
    background-position: -1px -1px;
    overflow: hidden;
  }
  .diagram-heading {
    display: flex;
    justify-content: space-between;
    gap: .5rem;
    border-bottom: 1px solid var(--line);
    background: color-mix(in srgb, var(--surface) 91%, transparent);
    padding: .55rem .65rem;
    color: var(--ink-soft);
    font-size: .75rem;
  }
  .diagram-heading strong { color: var(--good); }
  .section-diagram { width: 100%; min-height: 9rem; color: var(--ink); }
  .section-diagram text { fill: var(--ink); font-family: var(--mono); font-size: 10px; }
  .section-diagram .diagram-muted, .section-diagram text[data-tone="muted"] { fill: var(--ink-soft); }
  .section-diagram text[data-tone="warning"] { fill: var(--warning); font-weight: 720; }
  .diagram-primary { fill: color-mix(in srgb, var(--accent) 10%, var(--surface)); stroke: var(--accent); stroke-width: 2; vector-effect: non-scaling-stroke; }
  .diagram-secondary { fill: color-mix(in srgb, var(--ready) 10%, var(--surface)); stroke: var(--ready); stroke-width: 1.5; }
  .diagram-post { fill: color-mix(in srgb, var(--ink) 18%, transparent); stroke: var(--ink); stroke-width: 1.5; }
  .diagram-dimension { fill: none; stroke: var(--ink-soft); stroke-width: 1; stroke-dasharray: 3 3; vector-effect: non-scaling-stroke; }
  .diagram-card figcaption { border-top: 1px solid var(--line); background: color-mix(in srgb, var(--surface) 91%, transparent); padding: .5rem .65rem; color: var(--ink-soft); font-size: .75rem; }

  .post-shape-row { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .35rem; }
  .post-shape-row button { min-height: 2.75rem; border: 1px solid var(--line); border-radius: var(--radius-sm); background: transparent; color: var(--ink-soft); font-size: .75rem; }
  .post-shape-row button.is-active { border-color: var(--accent); background: var(--accent-soft); color: var(--accent-strong); }

  .add-section-row, .project-rule-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-top: .8rem;
    border-top: 1px solid var(--line);
    padding-top: .8rem;
  }
  .add-section-row > div { display: flex; gap: .45rem; }
  .add-section-row select { min-width: 11rem; }
  .project-rule-row label span { display: block; color: var(--ink-faint); font-weight: 500; }
  .percent-control { display: flex; align-items: center; }
  .percent-control input { width: 5rem; border-radius: var(--radius-sm) 0 0 var(--radius-sm); text-align: right; font-family: var(--mono); }
  .percent-control span { min-height: 2.75rem; display: grid; place-items: center; border: 1px solid var(--line-strong); border-left: 0; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; background: var(--surface-muted); padding: 0 .7rem; font-family: var(--mono); }

  .answer-heading-row { margin-bottom: .7rem; }
  .requirement-block {
    border-block: 1px solid var(--line);
    padding-block: .9rem;
  }
  .requirement-block > p:first-child { color: var(--ink-soft); font-size: .74rem; font-weight: 680; }
  .requirement-number { display: flex; align-items: baseline; gap: .45rem; margin-top: -.05rem; }
  .requirement-number strong { font-family: var(--mono); font-size: clamp(2.5rem, 4vw, 3.5rem); line-height: 1; letter-spacing: -.08em; font-variant-numeric: tabular-nums; }
  .requirement-number span { color: var(--ink-soft); font-family: var(--mono); font-size: 1rem; }
  .unit-line { display: flex; gap: .45rem; color: var(--ink-soft); font-family: var(--mono); font-size: .75rem; }
  .net-line { margin-top: .55rem; color: var(--ink-soft); font-size: .72rem; }

  .verdict-card {
    position: relative;
    margin-top: .85rem;
    border-left: .3rem solid var(--accent);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    background: var(--accent-soft);
    padding: .9rem 1rem;
  }
  .verdict-card.is-ready { border-color: var(--ready); background: var(--ready-soft); }
  .verdict-card.is-close { border-color: var(--warning); background: var(--warning-soft); }
  .verdict-card.is-neutral { border-color: var(--line-strong); background: var(--surface-muted); }
  .verdict-eyebrow { color: var(--accent-strong); font-size: .75rem; font-weight: 760; text-transform: uppercase; letter-spacing: .05em; }
  .is-ready .verdict-eyebrow { color: var(--ready); }
  .is-close .verdict-eyebrow { color: var(--warning); }
  .is-neutral .verdict-eyebrow { color: var(--ink-soft); }
  .verdict-card h3 { margin-top: .3rem; font-family: var(--mono); font-size: clamp(1.1rem, 2vw, 1.45rem); letter-spacing: -.045em; }
  .verdict-card > p:last-of-type { margin-top: .35rem; color: var(--ink-soft); font-size: .76rem; }
  .text-action { min-height: 2.75rem; background: transparent; color: var(--accent-strong); padding: .25rem 0; font-size: .75rem; font-weight: 720; text-decoration: underline; text-underline-offset: .2em; }

  .answer-actions { display: grid; grid-template-columns: 1.25fr .85fr; gap: .5rem; margin-top: .8rem; }
  .effort-strip {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: .8rem;
    border-block: 1px solid var(--line);
  }
  .effort-strip span { min-width: 0; padding: .55rem .4rem; color: var(--ink-soft); font-size: .75rem; text-align: center; }
  .effort-strip span + span { border-left: 1px solid var(--line); }
  .effort-strip strong { display: block; overflow: hidden; color: var(--ink); font-family: var(--mono); font-size: .82rem; text-overflow: ellipsis; white-space: nowrap; }

  .result-details { border-bottom: 1px solid var(--line); }
  .result-details summary {
    position: relative;
    padding: .7rem 1.25rem .7rem 0;
    color: var(--ink-soft);
    font-size: .76rem;
    font-weight: 720;
  }
  .result-details summary::after { content: "+"; position: absolute; right: .15rem; top: .55rem; color: var(--ink-faint); font-size: 1rem; }
  .result-details[open] summary::after { content: "−"; }
  .comparison-table-wrap { overflow-x: auto; }
  .comparison-table { width: 100%; font-size: .69rem; }
  .comparison-table th, .comparison-table td { border-top: 1px solid var(--line); padding: .52rem .36rem; text-align: right; white-space: nowrap; }
  .comparison-table th:first-child { text-align: left; }
  .comparison-table thead th { color: var(--ink-soft); font-size: .6875rem; text-transform: uppercase; letter-spacing: .04em; }
  .comparison-table tbody th { font-weight: 660; }
  .comparison-table tbody th span { display: block; color: var(--good); font-size: .55rem; font-weight: 650; }
  .comparison-table tr.is-best { background: color-mix(in srgb, var(--good-soft) 65%, transparent); }

  .ready-mix-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: .8rem;
    border-top: 1px solid var(--line);
    padding: .65rem .35rem;
    font-size: .76rem;
  }
  .ready-mix-row > div { display: flex; align-items: center; gap: .55rem; }
  .ready-mix-row small { display: block; font-family: var(--mono); font-size: .62rem; }
  .path-icon { width: 1.5rem; height: 1.05rem; border: 1px solid var(--ready); border-radius: .18rem; background: var(--ready-soft); }
  .truck-icon::before, .truck-icon::after { content: ""; display: block; position: relative; width: .32rem; height: .32rem; border-radius: 50%; background: var(--ready); top: .84rem; }
  .truck-icon::before { left: .18rem; }
  .truck-icon::after { left: .96rem; top: .52rem; }
  .fee-lines { padding: 0 .35rem .6rem; color: var(--ink-soft); font-size: .66rem; }
  .fee-lines div { display: flex; justify-content: space-between; gap: 1rem; padding-block: .15rem; }
  .fee-lines dd { font-family: var(--mono); color: var(--ink); }

  .reality-checks { display: grid; gap: .45rem; padding: 0 0 .7rem; color: var(--ink-soft); font-size: .75rem; }
  .reality-checks strong { color: var(--ink); }
  .warnings { display: grid; gap: .45rem; margin-top: .7rem; }
  .warning-item { display: grid; grid-template-columns: 1.25rem 1fr; gap: .45rem; align-items: start; color: var(--ink-soft); font-size: .75rem; }
  .warning-item > span { width: 1.15rem; height: 1.15rem; display: grid; place-items: center; border-radius: 50%; background: var(--warning-soft); color: var(--warning); font-size: .63rem; font-weight: 800; }
  .warning-item strong { color: var(--ink); }

  .settings-section + .settings-section { border-top: 1px solid var(--line); }
  .settings-section > summary {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    padding: .9rem 1.1rem;
  }
  .settings-section > summary::before { content: "+"; flex: 0 0 auto; order: 3; color: var(--ink-faint); font-size: 1.2rem; }
  .settings-section[open] > summary::before { content: "−"; }
  .settings-section > summary span:first-child { display: grid; }
  .settings-section > summary strong { font-size: .86rem; }
  .settings-section > summary small { font-size: .68rem; }
  .settings-body { border-top: 1px solid var(--line); background: var(--surface-strong); padding: 1rem 1.1rem 1.2rem; }
  .settings-intro { display: flex; justify-content: space-between; gap: 1rem; align-items: center; margin-bottom: 1rem; color: var(--ink-soft); font-size: .72rem; }
  .settings-fieldset { border: 0; padding: 0; margin: 0 0 1.1rem; }
  .settings-fieldset legend { margin-bottom: .55rem; color: var(--ink); font-size: .78rem; font-weight: 730; }
  .money-grid, .settings-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: .65rem; }
  .settings-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .settings-grid.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .settings-body label { display: grid; gap: .3rem; }
  .settings-body input, .settings-body select { width: 100%; }
  .money-input b, .suffix-input b {
    display: grid;
    place-items: center;
    min-width: 2rem;
    border: 1px solid var(--line-strong);
    background: var(--surface-muted);
    color: var(--ink-soft);
    font-family: var(--mono);
    font-size: .68rem;
  }
  .money-input b { border-right: 0; border-radius: var(--radius-sm) 0 0 var(--radius-sm); }
  .money-input input { border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }
  .suffix-input input { min-width: 0; border-radius: var(--radius-sm) 0 0 var(--radius-sm); }
  .suffix-input b { border-left: 0; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; white-space: nowrap; padding-inline: .45rem; }
  .confirm-row, .switch-row { display: flex !important; grid-template-columns: auto 1fr; align-items: flex-start; gap: .65rem !important; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--surface); padding: .75rem; }
  .confirm-row input, .switch-row input { flex: 0 0 auto; width: 1.15rem; min-height: 1.15rem; margin-top: .15rem; accent-color: var(--accent); }
  .confirm-row span, .switch-row span { display: grid; }
  .confirm-row small, .switch-row small { font-weight: 500; }
  .settings-note { grid-column: 1 / -1; color: var(--ink-soft); font-size: .7rem; }

  .addon-body { display: grid; gap: 1rem; }
  .addon-body section { display: grid; gap: .6rem; }
  .addon-body section + section { border-top: 1px solid var(--line); padding-top: 1rem; }
  .addon-body section > label small { display: block; font-weight: 500; }
  .dependent-fields { margin-top: .25rem; }
  .addon-output { border-left: 3px solid var(--line-strong); background: var(--surface-muted); padding: .7rem .85rem; color: var(--ink-soft); font-size: .72rem; }
  .addon-output strong { color: var(--ink); }

  .method-section > div:first-child h2 { max-width: 17ch; margin-top: .4rem; }
  .method-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.8rem 2.2rem; }
  .method-grid article { position: relative; padding-left: 2rem; }
  .method-grid article > span { position: absolute; left: 0; top: .1rem; color: var(--accent); font-family: var(--mono); font-size: .66rem; }
  .method-grid h3 { margin-bottom: .35rem; }
  .method-grid p { color: var(--ink-soft); font-size: .8rem; }
  .source-row { grid-column: 2; display: flex; flex-wrap: wrap; gap: 1rem; align-items: center; border-top: 1px solid var(--line); padding-top: 1rem; font-size: .72rem; }

  .mobile-decision-bar { display: none; }
  .copy-fallback {
    position: fixed;
    z-index: 120;
    right: 1rem;
    bottom: 1rem;
    width: min(35rem, calc(100vw - 2rem));
    min-height: 12rem;
    box-shadow: var(--shadow);
  }

  .dialog {
    width: min(34rem, calc(100vw - 2rem));
    max-height: min(42rem, calc(100dvh - 2rem));
    border: 1px solid var(--line-strong);
    border-radius: var(--radius-lg);
    background: var(--surface-strong);
    padding: 0;
    box-shadow: var(--shadow);
  }
  .dialog form { padding: 1.15rem; }
  .dialog-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: .6rem; }
  .icon-close { width: 2.75rem; height: 2.75rem; border-radius: 50%; background: transparent; color: var(--ink-soft); font-size: 1.5rem; }
  .icon-close:hover { background: var(--surface-muted); }
  .dialog h2 { margin-bottom: .65rem; }
  .dialog h3 { margin-top: 1rem; margin-bottom: .3rem; }
  .dialog p { color: var(--ink-soft); font-size: .8rem; }
  .dialog > form > label:not(.confirm-row) { display: block; margin-top: 1rem; color: var(--ink-soft); font-size: .72rem; font-weight: 720; }
  .dialog .confirm-row { margin-top: 1rem; }
  .dialog-actions { display: flex; justify-content: flex-end; gap: .5rem; margin-top: 1.2rem; }
  .copy-url-row { display: grid; grid-template-columns: 1fr auto; gap: .45rem; margin-top: .35rem; }
  .copy-url-row input { min-width: 0; font-family: var(--mono); font-size: .68rem; }
  .dialog-status { min-height: 1.4rem; margin-top: .4rem; color: var(--good) !important; }
  .legal-dialog { width: min(44rem, calc(100vw - 2rem)); }
  .print-meta { display: none; color: var(--ink-soft); font-family: var(--mono); font-size: .62rem; }

  .error-page {
    min-height: calc(100vh - var(--header-h));
    display: grid;
    place-content: center;
    justify-items: start;
    max-width: 50rem;
    padding-block: 4rem 8rem;
  }
  .error-page .error-code { color: var(--line-strong); font-family: var(--mono); font-size: clamp(5rem, 18vw, 11rem); font-weight: 800; line-height: .75; letter-spacing: -.12em; }
  .error-page h1 { max-width: 15ch; margin-top: .45rem; }
  .error-page > p:not(.eyebrow) { max-width: 42rem; margin-block: 1rem 1.3rem; color: var(--ink-soft); }

  .noscript-note {
    position: fixed;
    z-index: 100;
    inset: auto 1rem 1rem;
    max-width: 54rem;
    margin-inline: auto;
    border: 1px solid var(--warning);
    border-radius: var(--radius-md);
    background: var(--warning-soft);
    color: var(--ink);
    padding: .8rem 1rem;
    font-size: .8rem;
    box-shadow: var(--shadow);
  }
}

@layer states {
  .section-card[data-state="invalid"] { border-color: var(--danger); }
  .section-card[data-state="partial"] { border-color: var(--warning); }
  .answer-ledger[data-result-state="invalid"] .result-state-badge { color: var(--danger); border-color: var(--danger); }
  .answer-ledger[data-result-state="partial"] .result-state-badge { color: var(--warning); border-color: var(--warning); }
  .answer-ledger[data-result-state="empty"] .result-state-badge { color: var(--ink-soft); }
  .answer-ledger.is-stale .requirement-block,
  .answer-ledger.is-stale .verdict-card,
  .answer-ledger.is-stale .answer-actions,
  .answer-ledger.is-stale .effort-strip,
  .answer-ledger.is-stale .result-details,
  .answer-ledger.is-stale .warnings { opacity: .58; }
  .answer-ledger.is-stale .verdict-card.is-neutral .verdict-eyebrow,
  .answer-ledger.is-stale .verdict-card.is-neutral > p:last-of-type { color: var(--ink); }
  .previous-result-strip {
    border: 1px solid var(--warning);
    border-radius: var(--radius-sm);
    background: var(--warning-soft);
    padding: .55rem .7rem;
    margin-bottom: .7rem;
    color: var(--ink);
    font-size: .7rem;
  }
  .unapplied-input-notice {
    border: 1px solid var(--warning);
    border-radius: var(--radius-sm);
    background: var(--warning-soft);
    padding: .55rem .7rem;
    margin-bottom: .7rem;
    font-size: .8125rem;
  }
  .empty-answer {
    min-height: 24rem;
    display: grid;
    place-items: center;
    text-align: center;
    color: var(--ink-soft);
    padding: 2rem;
  }
  .empty-answer h3 { color: var(--ink); margin-bottom: .35rem; }
  .empty-preset-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: .4rem; margin-top: 1rem; }
  .undo-toast {
    position: fixed;
    z-index: 110;
    left: 50%;
    bottom: 1.2rem;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: .8rem;
    border: 1px solid var(--line-strong);
    border-radius: var(--radius-md);
    background: var(--ink);
    color: var(--surface-strong);
    padding: .65rem .75rem .65rem 1rem;
    box-shadow: var(--shadow);
    font-size: .76rem;
  }
  .undo-toast button { min-height: 2.75rem; border-radius: var(--radius-xs); background: var(--surface-strong); color: var(--ink); padding: .35rem .6rem; font-size: .75rem; font-weight: 720; }
  .result-flash { animation: result-flash 240ms ease-out; }
  @keyframes result-flash { from { opacity: .55; } to { opacity: 1; } }
}

@layer responsive {
  @media (max-width: 74rem) {
    .tool-shell { grid-template-columns: minmax(0, 1fr) minmax(23rem, .86fr); }
    .active-section-grid { grid-template-columns: 1fr; }
    .diagram-card { grid-template-rows: auto 9rem auto; }
    .answer-ledger { position: relative; top: 0; }
  }

  @media (max-width: 58rem) {
    .hero { grid-template-columns: 1fr; gap: 1rem; }
    .hero-proof { max-width: 38rem; }
    .tool-shell { grid-template-columns: 1fr; }
    .project-bench, .answer-ledger { border-radius: var(--radius-lg); }
    .answer-ledger { margin-top: 0; }
    .method-section { grid-template-columns: 1fr; }
    .source-row { grid-column: 1; }
    .money-grid, .settings-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .site-footer { flex-direction: column; gap: .45rem; }
  }

  @media (max-width: 40rem) {
    :root { --header-h: 3.8rem; }
    body { padding-bottom: calc(5.2rem + env(safe-area-inset-bottom)); }
    .site-header { padding: .65rem .85rem; }
    .brand-mark { width: 2rem; height: 2rem; }
    .brand small { display: none; }
    .brand strong { font-size: .84rem; }
    .header-actions { gap: .2rem; }
    .brand span { display: none; }
    .header-actions #reset-button { display: inline-flex; }
    .header-actions .button { min-height: 2.75rem; padding: .4rem .5rem; font-size: .72rem; }
    .header-actions .segmented { display: inline-flex; }
    .header-actions .icon-button { width: 2.75rem; }

    main, .site-footer { padding-inline: .8rem; }
    .hero { padding-block: 1.1rem .75rem; }
    .hero .eyebrow { font-size: .62rem; }
    .hero h1 { font-size: 2.05rem; }
    .hero-copy { margin-top: .28rem; font-size: .88rem; line-height: 1.38; }
    .hero-proof { display: none; }
    .preset-rail { display: block; margin-inline: -.8rem; margin-bottom: .55rem; }
    .preset-label { display: block; padding-inline: .9rem; margin-bottom: .15rem; font-size: .6rem; }
    .preset-scroller { padding-inline: .8rem; }
    .preset-chip { min-height: 2.75rem; padding: .35rem .65rem; font-size: .68rem; }

    .notice { align-items: flex-start; padding: .65rem .7rem; font-size: .72rem; }
    .tool-shell { gap: .65rem; }
    .project-bench, .answer-ledger { padding: .85rem; border-radius: var(--radius-md); }
    .panel-heading { margin-bottom: .7rem; }
    .panel-heading h2 { font-size: 1.2rem; }
    .panel-heading .eyebrow { font-size: .6rem; }
    .section-card.is-active { padding: .75rem; box-shadow: inset 2px 0 0 var(--accent); }
    .section-card-head { grid-template-columns: 1.15fr .85fr; gap: .5rem; margin-bottom: .65rem; }
    .section-card-head input, .section-card-head select { min-height: 2.75rem; padding: .48rem .55rem; font-size: .8125rem; }
    .field > span, .field-group > label { font-size: .8125rem; }
    .active-section-grid { gap: .65rem; }
    .measurement-grid { gap: .52rem; }
    .measurement-control input, .measurement-control select, .quantity-field > input { min-height: 2.75rem; padding: .45rem .5rem; font-size: .8125rem; }
    .measurement-control select { flex-basis: 3.55rem; padding-inline: .35rem; }
    .field-hint { min-height: 1rem; padding-top: .08rem; font-size: .8125rem; }
    .quick-row { overflow-x: auto; white-space: nowrap; margin-top: .4rem; }
    .section-actions { margin-top: .35rem; }
    .diagram-card { grid-template-rows: auto 7.7rem auto; }
    .section-diagram { min-height: 7.7rem; }
    .diagram-heading, .diagram-card figcaption { padding: .38rem .48rem; font-size: .75rem; }
    .add-section-row { align-items: stretch; flex-direction: column; gap: .35rem; margin-top: .6rem; padding-top: .6rem; }
    .add-section-row > div { display: grid; grid-template-columns: 1fr auto; }
    .add-section-row select { min-width: 0; width: 100%; }
    .add-section-row select, .add-section-row button { min-height: 2.75rem; font-size: .8125rem; }
    .project-rule-row { margin-top: .55rem; padding-top: .55rem; }
    .project-rule-row label { font-size: .8125rem; }
    .percent-control input, .percent-control span { min-height: 2.75rem; }

    .answer-ledger { scroll-margin-top: .5rem; }
    .requirement-block { padding-block: .7rem; }
    .requirement-number strong { font-size: 2.375rem; }
    .verdict-card { padding: .75rem .8rem; }
    .verdict-eyebrow { font-size: .75rem; }
    .verdict-card h3 { font-size: 1rem; }
    .verdict-card > p:last-of-type { font-size: .68rem; }
    .answer-actions { grid-template-columns: 1fr 1fr; }
    .answer-actions .button { font-size: .72rem; padding-inline: .55rem; }
    .effort-strip span { padding-inline: .2rem; font-size: .75rem; }
    .effort-strip strong { font-size: .72rem; }
    .comparison-table { font-size: .75rem; }

    .settings-dock { margin-block: .65rem 2rem; border-radius: var(--radius-md); }
    .settings-section > summary { padding: .75rem .8rem; }
    .settings-section > summary strong { font-size: .75rem; }
    .settings-section > summary small { font-size: .75rem; }
    .settings-body { padding: .8rem; }
    .settings-intro { align-items: flex-start; }
    .money-grid, .settings-grid, .settings-grid.three { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .settings-body input, .settings-body select { min-height: 2.75rem; font-size: .8125rem; }
    .confirm-row, .switch-row { padding: .6rem; }

    .method-section { gap: 1.4rem; padding-block: 2.5rem; }
    .method-section > div:first-child h2 { max-width: none; }
    .method-grid { grid-template-columns: 1fr; gap: 1.25rem; }
    .source-row { gap: .75rem; }
    .site-footer { padding-bottom: 1rem; }

    .mobile-decision-bar {
      position: fixed;
      z-index: 80;
      inset: auto 0 0;
      display: block;
      border-top: 1px solid var(--line-strong);
      background: color-mix(in srgb, var(--surface-strong) 94%, transparent);
      padding: .48rem max(.7rem, env(safe-area-inset-right)) max(.48rem, env(safe-area-inset-bottom)) max(.7rem, env(safe-area-inset-left));
      box-shadow: 0 -8px 26px rgb(20 17 12 / 16%);
      backdrop-filter: blur(12px);
    }
    .mobile-decision-bar button {
      width: 100%;
      min-height: 3.55rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: .8rem;
      border-radius: var(--radius-sm);
      background: var(--ink);
      color: var(--surface-strong);
      padding: .55rem .7rem;
      text-align: left;
    }
    .mobile-decision-bar span { min-width: 0; display: grid; }
    .mobile-decision-bar strong { font-family: var(--mono); font-size: .9rem; }
    .mobile-decision-bar small { overflow: hidden; color: color-mix(in srgb, var(--surface-strong) 72%, transparent); font-size: .64rem; text-overflow: ellipsis; white-space: nowrap; }
    .mobile-decision-bar b { flex: 0 0 auto; color: #ffad83; font-size: .68rem; }

    .dialog { width: calc(100vw - 1rem); max-height: calc(100dvh - 1rem); }
    .dialog form { padding: .9rem; }
    .copy-url-row { grid-template-columns: 1fr; }
    .dialog-actions { flex-wrap: wrap; }
    .dialog-actions .button { flex: 1 1 auto; }
    .undo-toast { bottom: calc(5.3rem + env(safe-area-inset-bottom)); width: calc(100vw - 1.6rem); justify-content: space-between; }
  }

  @media (max-width: 25rem) {
    .brand span { display: none; }
    .measurement-grid { grid-template-columns: 1fr; }
    .section-card-head { grid-template-columns: 1fr; }
    .money-grid, .settings-grid, .settings-grid.three { grid-template-columns: 1fr; }
  }

  @media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  }
}

@layer print {
  @media print {
    :root { color-scheme: light; }
    body { background: #fff !important; color: #000 !important; padding: 0 !important; font-size: 10pt; }
    .site-header, .hero, .preset-rail, .notice, .project-bench, .settings-dock, .method-section, .site-footer, .mobile-decision-bar, .answer-actions, .text-action, .dialog, .noscript-note, .undo-toast { display: none !important; }
    main { max-width: none; padding: 0; }
    .tool-shell { display: block; }
    .answer-ledger {
      position: static;
      border: 0;
      border-radius: 0;
      box-shadow: none;
      padding: 0;
      background: #fff;
      color: #000;
    }
    .answer-ledger::before { content: "CONCRETE POUR SHEET"; display: block; margin-bottom: 8pt; border-bottom: 2pt solid #000; padding-bottom: 5pt; font-family: var(--mono); font-size: 16pt; font-weight: 800; letter-spacing: .08em; }
    .answer-ledger * { color: #000 !important; background: transparent !important; }
    .requirement-number strong { font-size: 34pt; }
    .verdict-card { border: 1pt solid #000; border-left-width: 4pt; break-inside: avoid; }
    .result-details { display: block; break-inside: avoid; }
    .result-details > summary { display: block; font-weight: 700; }
    .result-details > summary::after { display: none; }
    .comparison-table th, .comparison-table td, .ready-mix-row { border-color: #777; }
    .warnings { break-inside: avoid; }
    .print-meta { display: block !important; margin-top: 12pt; border-top: 1pt solid #777; padding-top: 6pt; }
    .warnings::after { content: "Material estimate only. Verify measurements, product labels, supplier quote, site conditions, structure and local requirements before purchase or work."; display: block; margin-top: 12pt; border-top: 1pt solid #000; padding-top: 8pt; font-size: 8pt; }
    @page { size: auto; margin: .55in; }
  }
}