:root {
  color-scheme: light;
  --paper: #f5f7f4;
  --surface: #fff;
  --ink: #173e32;
  --muted: #52655d;
  --line: #d4ddd5;
  --accent: #24684f;
  --wash: #e6ede6;
  --focus: #145c3c;
  --space: clamp(1.25rem, 4vw, 4rem);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 1.5rem; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 1rem/1.65 "Manrope", sans-serif; }
::selection { background: #bed8b7; color: var(--ink); }
body { scrollbar-color: #9cac9e var(--paper); }
a { color: inherit; text-underline-offset: .25em; }
a:hover { text-decoration-thickness: 2px; }
button { font: inherit; cursor: pointer; }
a, button, summary { -webkit-tap-highlight-color: #bed8b7; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 5px; }
svg { flex-shrink: 0; }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { text-wrap: balance; }
[hidden] { display: none !important; }
.skip-link { position: fixed; top: 1rem; left: 1rem; z-index: 10; padding: .75rem 1rem; background: var(--ink); color: var(--surface); transform: translateY(-180%); }
.skip-link:focus { transform: translateY(0); }

.masthead { max-width: 1600px; margin: auto; padding: 1.25rem var(--space); display: flex; align-items: center; justify-content: space-between; gap: 2rem; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: .65rem; text-decoration: none; font-weight: 750; font-size: 1.15rem; letter-spacing: -.03em; }
.brand-mark { width: 37px; height: 37px; fill: currentColor; }
.masthead nav { display: flex; gap: 2rem; }
.masthead nav a { display: inline-flex; align-items: center; min-height: 44px; text-decoration: none; font-size: .85rem; font-weight: 650; }
.masthead nav a:hover { color: var(--accent); text-decoration: underline; }
.review-label { font-size: .75rem; color: var(--muted); }
main, .gallery-footer { max-width: 1600px; margin: auto; padding: 0 var(--space); }
.introduction { padding: clamp(3rem, 7vw, 6.5rem) 0 clamp(3rem, 6vw, 5.5rem); display: grid; grid-template-columns: 1fr minmax(240px, 320px); gap: 3rem; align-items: end; }
.introduction h1 { font-size: clamp(3.75rem, 7.25vw, 6rem); line-height: 1.02; font-weight: 650; letter-spacing: -.04em; }
.introduction h1 span { color: #58745b; }
.introduction-copy > p { margin-top: 1.75rem; font-size: clamp(1rem, 1.5vw, 1.2rem); line-height: 1.7; color: var(--muted); }
.review-context { padding-left: 1.5rem; border-left: 1px solid var(--line); }
.review-context p { font-weight: 650; font-size: 1.05rem; line-height: 1.55; }
.review-context > span { display: block; color: var(--muted); font-size: .85rem; margin: .8rem 0 1rem; }
.review-context a { display: inline-flex; gap: .7rem; align-items: center; min-height: 44px; font-size: .85rem; font-weight: 750; text-decoration: none; }
.review-context a svg { width: 18px; fill: none; stroke: currentColor; stroke-width: 1.6; }

.collection { padding-bottom: 4rem; }
.collection-heading { display: flex; justify-content: space-between; align-items: center; gap: 2rem; padding: 1.5rem 0; border-top: 1px solid var(--line); }
.collection-heading h2 { font-size: 1.35rem; font-weight: 750; letter-spacing: -.025em; }
.collection-heading p { margin-top: .3rem; color: var(--muted); font-size: .85rem; }
.view-switch { display: flex; gap: .25rem; padding: .25rem; background: var(--wash); border-radius: .4rem; flex-shrink: 0; }
.view-switch button { border: 0; background: transparent; color: var(--ink); border-radius: .25rem; display: flex; align-items: center; justify-content: center; gap: .5rem; padding: .65rem .9rem; min-height: 44px; font-size: .8rem; font-weight: 650; }
.view-switch button[aria-pressed="true"] { background: var(--surface); box-shadow: 0 2px 6px #173e3210; }
.view-switch button:hover { background: #d6e2d5; }
.view-switch button[aria-pressed="true"]:hover { background: var(--surface); }
.view-switch svg { width: 17px; height: 17px; stroke: currentColor; stroke-width: 1.5; fill: none; }
.gallery-status { padding: 1.5rem 0; color: var(--muted); }
.gallery-status:empty { padding: 0; }
.gallery-status[role="alert"] { margin: .75rem 0 1.5rem; padding: 1rem; background: #fce7de; color: #743321; border: 1px solid #c98874; }
.concept-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 2.5rem 1.75rem; }
.concept { min-width: 0; background: var(--surface); border: 1px solid var(--line); border-radius: .35rem; }
.concept-preview { display: block; aspect-ratio: 1.6; position: relative; overflow: hidden; background: var(--preview-ground, var(--wash)); border-bottom: 1px solid var(--line); border-radius: .3rem .3rem 0 0; }
.concept-image { width: 100%; height: 100%; display: block; object-fit: cover; object-position: top; transition: filter .25s ease-out; }
.concept-preview:hover .concept-image { filter: brightness(.92); }
.concept-preview:focus-visible { outline-offset: -5px; }
.preview-affordance { position: absolute; bottom: 1rem; right: 1rem; display: inline-flex; align-items: center; gap: .65rem; background: var(--surface); color: var(--ink); font-weight: 750; font-size: .75rem; padding: .55rem .85rem; border-radius: .2rem; box-shadow: 0 3px 15px #173e3220; opacity: 0; transform: translateY(5px); transition: opacity .2s ease-out, transform .2s ease-out; }
.preview-affordance svg { width: 16px; stroke: currentColor; fill: none; stroke-width: 1.7; }
.concept-preview:hover .preview-affordance, .concept-preview:focus-visible .preview-affordance { opacity: 1; transform: translateY(0); }
.concept-grid[data-view="mobile"] .concept-image { width: auto; max-width: 100%; margin: auto; object-fit: contain; box-shadow: 0 2px 20px #173e3220; }
.concept-body { padding: 1.3rem 1.5rem 1.1rem; }
.concept-title-row { display: flex; justify-content: space-between; align-items: center; gap: .75rem; }
.concept h3 { display: flex; gap: .8rem; align-items: baseline; font-size: clamp(1.1rem, 1.5vw, 1.4rem); font-weight: 750; letter-spacing: -.025em; line-height: 1.4; }
.concept-number { flex-shrink: 0; color: var(--muted); font-weight: 500; font-size: .7em; font-variant-numeric: tabular-nums; letter-spacing: 0; }
.palette { display: inline-flex; flex-shrink: 0; gap: 4px; }
.palette span { height: 12px; width: 12px; border-radius: 50%; background: var(--swatch); border: 1px solid #173e321a; }
.concept-description { color: var(--muted); font-size: .85rem; line-height: 1.7; margin: .7rem 0 1rem; max-width: 65ch; }
.concept-details { border-top: 1px solid var(--line); }
.concept-details summary { min-height: 44px; list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 1rem; cursor: pointer; font-size: .75rem; color: var(--muted); }
.concept-details summary::-webkit-details-marker { display: none; }
.concept-details summary > svg { width: 16px; height: 16px; stroke: currentColor; stroke-width: 1.5; fill: none; }
.concept-details[open] summary > svg { transform: rotate(45deg); }
.concept-details summary:hover { color: var(--ink); }
.details-content { padding: 0 0 .8rem; color: var(--muted); font-size: .8rem; }
.details-content p + p { margin-top: .65rem; }
.concept-links { display: flex; flex-wrap: wrap; align-items: center; column-gap: 1.25rem; border-top: 1px solid var(--line); padding-top: .3rem; }
.concept-links a { display: inline-flex; align-items: center; gap: .35rem; min-height: 44px; font-size: .72rem; color: var(--muted); text-decoration: none; }
.concept-links a:first-child { margin-right: auto; color: var(--ink); font-weight: 800; }
.concept-links a:hover { text-decoration: underline; }
.concept-links svg { width: 15px; stroke: currentColor; fill: none; stroke-width: 1.6; }
.collection-closing { display: flex; flex-direction: column; justify-content: center; padding: clamp(2rem, 4vw, 4rem); background: var(--wash); border: 1px solid var(--line); border-radius: .35rem; }
.collection-closing svg { width: 40px; height: 40px; fill: var(--accent); margin-bottom: 2rem; }
.collection-closing h3 { font-size: clamp(1.8rem, 3vw, 2.75rem); letter-spacing: -.04em; line-height: 1.15; font-weight: 650; max-width: 12ch; }
.collection-closing p { font-size: .85rem; color: var(--muted); margin-top: 1.25rem; max-width: 40ch; }
.collection-closing a { display: inline-flex; align-items: center; align-self: flex-start; min-height: 44px; font-size: .8rem; font-weight: 750; margin-top: 1rem; }

.review-guide { padding: 3rem 0 4rem; border-top: 1px solid var(--line); display: grid; grid-template-columns: 1fr 1fr; gap: clamp(2rem, 6vw, 6rem); }
.guide-intro h2 { font-size: clamp(2rem, 3.5vw, 3.3rem); line-height: 1.17; font-weight: 650; letter-spacing: -.035em; }
.guide-intro p { margin-top: 1.5rem; color: var(--muted); font-size: .95rem; max-width: 44ch; }
.review-questions { margin: 0; }
.review-questions > div { padding: 1rem 0; border-bottom: 1px solid var(--line); }
.review-questions > div:first-child { padding-top: 0; }
.review-questions dt { font-weight: 750; font-size: .95rem; }
.review-questions dd { margin: .4rem 0 0; color: var(--muted); font-size: .85rem; max-width: 65ch; }
.prototype-disclosure { display: flex; align-items: flex-start; gap: 1rem; background: var(--wash); padding: 1.5rem 1.75rem; margin-bottom: 3rem; border-radius: .3rem; }
.prototype-disclosure > svg { width: 22px; height: 22px; margin-top: .15rem; stroke: var(--accent); fill: none; stroke-width: 1.5; }
.prototype-disclosure h2 { font-size: .85rem; font-weight: 800; }
.prototype-disclosure p { max-width: 110ch; margin-top: .4rem; font-size: .8rem; color: var(--muted); }
.gallery-footer { display: flex; justify-content: space-between; align-items: center; gap: 1rem; padding-top: 1.5rem; padding-bottom: 1.75rem; border-top: 1px solid var(--line); font-size: .75rem; color: var(--muted); }
.gallery-footer a { display: inline-flex; align-items: center; min-height: 44px; }
.footer-divider { padding: 0 .6rem; color: #839488; }

@media (min-width: 1680px) {
  .concept-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .review-label { display: none; }
  .introduction { grid-template-columns: 1fr minmax(200px, 260px); gap: 2rem; }
  .concept-body { padding: 1.1rem; }
  .concept-title-row { align-items: flex-start; }
  .palette { padding-top: .35rem; }
}
@media (max-width: 650px) {
  .masthead { gap: 1rem; padding-top: .8rem; padding-bottom: .8rem; }
  .brand { font-size: .95rem; gap: .35rem; }
  .brand-mark { width: 30px; height: 30px; }
  .masthead nav { gap: .8rem; }
  .masthead nav a { font-size: .7rem; }
  .masthead nav a:first-child { display: none; }
  .introduction { grid-template-columns: 1fr; padding-top: 3rem; gap: 2rem; }
  .introduction h1 { font-size: clamp(3.4rem, 14vw, 5rem); }
  .review-context { display: none; }
  .collection-heading { flex-direction: column; align-items: flex-start; gap: 1rem; }
  .collection-heading p { max-width: 36ch; }
  .view-switch { align-self: stretch; }
  .view-switch button { flex: 1; }
  .concept-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .concept h3 { font-size: 1.15rem; }
  .concept-body { padding: 1rem 1.1rem; }
  .concept-description { font-size: .82rem; }
  .preview-affordance { display: none; }
  .collection-closing { padding: 2rem; }
  .collection-closing h3 { max-width: 15ch; }
  .review-guide { grid-template-columns: 1fr; gap: 2rem; padding-top: 2rem; }
  .prototype-disclosure { padding: 1.2rem; gap: .75rem; }
  .gallery-footer { flex-direction: column; align-items: flex-start; gap: .25rem; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .concept-image, .preview-affordance { transition: none; }
}
@media print {
  body { background: white; }
  .masthead nav, .view-switch, .preview-affordance, .skip-link { display: none; }
  .introduction { padding: 2rem 0; }
  .introduction h1 { font-size: 3.5rem; }
  .concept-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .concept, .prototype-disclosure { break-inside: avoid; }
  .collection-closing { display: none; }
  .review-guide { break-before: page; }
  a { text-decoration: none; }
}