/* =========================================================
   Composition — Bauhaus & De Stijl
   Graphic Design Museum / Room 02
   グリッド・タイポはスイス・スタイルの共通クロームを踏襲。
   ========================================================= */

:root {
  --unit: 8px;
  --baseline: 28px;
  --content: 1180px;
  --margin: 40px;

  /* スイス・スタイル共通クローム */
  --ink: #111111;
  --paper: #f4f2ec;
  --grey: #8a8780;
  --line: rgba(17, 17, 17, 0.14);

  /* デ・ステイル/バウハウスの三原色 */
  --ds-red: #d5231a;
  --ds-blue: #1c40a0;
  --ds-yellow: #f4c20d;
  --accent: var(--ds-red);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Inter", "Noto Sans JP", "Helvetica Neue", Arial, sans-serif;
  font-size: 18px;
  line-height: var(--baseline);
  font-feature-settings: "palt" 1;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

p { margin: 0 0 var(--baseline); }
em { font-style: normal; color: var(--accent); }
strong { font-weight: 700; }
b { font-weight: 700; }

.wrap {
  max-width: calc(var(--content) + var(--margin) * 2);
  margin-inline: auto;
  padding-inline: var(--margin);
}

/* =========================================================
   MASTHEAD
   ========================================================= */
.masthead {
  padding-block: calc(var(--baseline) * 3) calc(var(--baseline) * 2);
  border-bottom: 2px solid var(--ink);
}
.masthead .wrap {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  column-gap: 24px;
}
.masthead__meta {
  grid-column: 1 / -1;
  display: flex;
  gap: var(--unit);
  margin-bottom: calc(var(--baseline) * 2);
}
.tag {
  font-size: 12px; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--paper);
  background: var(--accent); padding: 4px 10px; border-radius: 2px;
}
.tag--muted { background: transparent; color: var(--grey); border: 1px solid var(--line); }

.masthead__title {
  grid-column: 1 / 9; margin: 0;
  font-size: clamp(64px, 13vw, 168px);
  line-height: 0.86; font-weight: 900; letter-spacing: -0.03em;
}
.masthead__sub {
  grid-column: 9 / -1; align-self: end; justify-self: end; margin: 0;
  font-size: 20px; font-weight: 700; color: var(--accent);
  writing-mode: vertical-rl;
}
.masthead__lede {
  grid-column: 1 / 8; margin-top: calc(var(--baseline) * 2);
  font-size: 20px; line-height: var(--baseline);
}
.masthead__index {
  grid-column: 9 / -1; margin: calc(var(--baseline) * 2) 0 0; padding: 0;
  list-style: none; border-top: 1px solid var(--line);
}
.masthead__index li {
  display: flex; gap: 14px; padding: 6px 0;
  border-bottom: 1px solid var(--line); font-size: 14px; font-weight: 500;
}
.masthead__index span { color: var(--accent); font-weight: 700; }

/* =========================================================
   SECTION
   ========================================================= */
.section { padding-block: calc(var(--baseline) * 3); border-bottom: 1px solid var(--line); }
.section__head {
  display: grid; grid-template-columns: repeat(12, 1fr); column-gap: 24px;
}
.section__num { grid-column: 1 / 2; margin: 0; font-size: 16px; font-weight: 700; color: var(--accent); }
.section__title {
  grid-column: 2 / 6; margin: 0;
  font-size: clamp(40px, 6vw, 72px); line-height: 0.92; font-weight: 900; letter-spacing: -0.02em;
}
.section__body { grid-column: 7 / -1; }
.lead { font-size: 22px; line-height: calc(var(--baseline) + 4px); font-weight: 500; }

.section--invert { background: var(--ink); color: var(--paper); border-bottom: none; }
.section--invert .section__title { color: var(--paper); }

/* =========================================================
   BUTTONS
   ========================================================= */
.btn {
  font-family: inherit; font-size: 15px; font-weight: 500; letter-spacing: 0.02em;
  background: var(--ink); color: var(--paper); border: 1px solid var(--ink);
  padding: 12px 22px; border-radius: 2px; cursor: pointer; transition: background 0.18s, color 0.18s;
}
.btn:hover { background: var(--accent); border-color: var(--accent); }
.btn--ghost { background: transparent; color: var(--ink); }
.btn--ghost:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }

/* =========================================================
   01 KANDINSKY
   ========================================================= */
.kand {
  margin-top: calc(var(--baseline) * 2);
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.kand__card {
  border: 1px solid var(--ink); padding: var(--baseline);
  display: flex; flex-direction: column; align-items: center; gap: var(--baseline);
}
.kand__name {
  font-size: 13px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--grey); margin: 0; align-self: flex-start;
}
.kand__shape { width: 120px; height: 120px; display: block; }
.kand__shape path,
.kand__shape rect,
.kand__shape polygon,
.kand__shape circle { transition: fill 0.25s ease; }
.kand__pick { display: flex; gap: 10px; }
.kand__pick button {
  width: 34px; height: 34px; border-radius: 50%; border: 2px solid var(--ink);
  cursor: pointer; padding: 0; transition: transform 0.12s, box-shadow 0.12s;
}
.kand__pick button:hover { transform: scale(1.12); }
.kand__pick button.is-on { box-shadow: 0 0 0 3px var(--paper), 0 0 0 5px var(--ink); }

.kand__actions { margin-top: calc(var(--baseline) * 1.5); display: flex; gap: 12px; }

.kand__answer {
  margin-top: calc(var(--baseline) * 1.5);
  border-top: 2px solid var(--ink); padding-top: var(--baseline);
}
.kand__answer-head { font-size: 14px; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--accent); }
.kand__theory { list-style: none; margin: 0 0 var(--baseline); padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.kand__theory li { border-left: 3px solid var(--ink); padding-left: 14px; }
.kand__theory b { display: block; font-size: 19px; margin-bottom: 4px; }
.kand__theory span { font-size: 15px; line-height: 1.6; color: var(--ink); }
.kand__note { font-size: 15px; line-height: 1.7; color: var(--grey); max-width: 60ch; }
.kand__verdict {
  display: inline-flex; align-items: center; gap: 6px; margin-left: 8px;
  font-size: 12px; font-weight: 700; padding: 2px 8px; border-radius: 2px;
}
.kand__verdict--hit { background: var(--ds-blue); color: #fff; }
.kand__verdict--miss { background: transparent; color: var(--grey); border: 1px solid var(--line); }

/* =========================================================
   02 PRINCIPLES
   ========================================================= */
.principles {
  margin-top: calc(var(--baseline) * 2);
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.principle { border-top: 2px solid var(--paper); padding-top: var(--unit); }
.principle__fig { height: 150px; border: 1px solid rgba(244,242,236,0.3); margin-bottom: var(--baseline); position: relative; overflow: hidden; }
.principle__fig--lines {
  background-image:
    repeating-linear-gradient(to right, transparent 0 33%, var(--paper) 33% calc(33% + 2px)),
    repeating-linear-gradient(to bottom, transparent 0 50%, var(--paper) 50% calc(50% + 2px));
}
.principle__fig--colors { display: flex; }
.principle__fig--colors::before { content: ""; flex: 2; background: var(--ds-red); }
.principle__fig--colors::after { content: ""; flex: 1; background: var(--ds-blue); border-left: 3px solid var(--paper); }
.principle__fig--balance { background: var(--paper); }
.principle__fig--balance::before { content: ""; position: absolute; left: 0; top: 0; width: 62%; height: 100%; background: var(--ds-yellow); border-right: 3px solid var(--ink); }
.principle__fig--balance::after { content: ""; position: absolute; right: 12px; bottom: 12px; width: 22px; height: 22px; background: var(--ink); }
.principle__h { font-size: 20px; font-weight: 700; margin: 0 0 6px; }
.principle__t { font-size: 15px; line-height: 1.7; color: #c9c6bf; margin: 0; }

/* =========================================================
   03 BUILDER
   ========================================================= */
.builder {
  margin-top: calc(var(--baseline) * 2);
  display: grid; grid-template-columns: 1fr 320px; gap: 40px; align-items: start;
}
.builder__stage { aspect-ratio: 1 / 1; }
.canvas {
  --line: 12px;
  width: 100%; height: 100%;
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  grid-template-rows: repeat(6, 1fr);
  gap: var(--line);
  background: #141414;
  border: var(--line) solid #141414;
}
.cell {
  border: none; padding: 0; margin: 0; cursor: pointer;
  background: #f4f2ec; transition: background 0.15s ease;
}
.cell:hover { filter: brightness(0.94); }
.cell:focus-visible { outline: 3px solid var(--ds-yellow); outline-offset: -3px; }

.builder__panel { position: sticky; top: var(--baseline); }
.panel__label {
  font-size: 13px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--grey); margin: 0 0 12px;
}
.palette { display: flex; gap: 12px; margin-bottom: calc(var(--baseline) * 1.5); }
.swatch {
  width: 46px; height: 46px; border: 2px solid var(--ink); border-radius: 2px;
  background: var(--sw); cursor: pointer; padding: 0; transition: transform 0.12s;
}
.swatch:hover { transform: translateY(-3px); }
.swatch.is-active { box-shadow: 0 0 0 3px var(--paper), 0 0 0 5px var(--ink); }

.slider { width: 100%; margin: 0 0 calc(var(--baseline) * 1.5); accent-color: var(--accent); }

.panel__btns { display: flex; flex-direction: column; gap: 10px; margin-bottom: var(--baseline); }
.panel__btns .btn { width: 100%; }
.panel__hint { font-size: 14px; line-height: 1.7; color: var(--grey); margin: 0; }

/* pull quote */
.pull { margin: calc(var(--baseline) * 3) auto 0; }
.pull p {
  margin: 0; font-size: clamp(24px, 3.4vw, 38px); line-height: 1.3; font-weight: 700;
  letter-spacing: -0.01em; max-width: 24ch;
}
.pull cite { display: block; margin-top: var(--baseline); font-style: normal; font-size: 15px; color: var(--accent); font-weight: 700; }

/* =========================================================
   COLOPHON
   ========================================================= */
.colophon { background: var(--ink); color: var(--paper); padding-block: calc(var(--baseline) * 2); }
.colophon .wrap { display: grid; grid-template-columns: repeat(12, 1fr); column-gap: 24px; }
.colophon__brand { grid-column: 1 / 4; margin: 0; font-size: 22px; font-weight: 900; }
.colophon__txt { grid-column: 5 / 9; margin: 0; font-size: 14px; line-height: 1.6; color: #c9c6bf; }
.colophon__spec { grid-column: 9 / -1; margin: 0; font-size: 12px; color: var(--grey); text-align: right; font-weight: 500; }

/* =========================================================
   RESPONSIVE
   ========================================================= */
@media (max-width: 900px) {
  :root { --margin: 24px; }
  body { font-size: 16px; }
  .masthead__title { grid-column: 1 / -1; }
  .masthead__sub { grid-column: 1 / -1; writing-mode: horizontal-tb; justify-self: start; margin-top: var(--unit); }
  .masthead__lede, .masthead__index { grid-column: 1 / -1; }
  .section__num { grid-column: 1 / -1; }
  .section__title { grid-column: 1 / -1; margin-bottom: var(--baseline); }
  .section__body { grid-column: 1 / -1; }
  .kand, .kand__theory, .principles { grid-template-columns: 1fr; }
  .builder { grid-template-columns: 1fr; }
  .builder__panel { position: static; }
  .colophon__brand, .colophon__txt, .colophon__spec { grid-column: 1 / -1; text-align: left; margin-bottom: var(--unit); }
}

@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }