/* ============================================================
   base.css — 设计令牌 / 重置 / 排版 / 网格
   包豪斯配色：红·黄·蓝 + 黑白米，几何构成，无圆角，硬阴影
   ============================================================ */

:root {
  --bh-red: #e03a2f;
  --bh-yellow: #f2c230;
  --bh-blue: #1e4bd8;
  --bh-black: #111111;
  --bh-ink: #1a1a1a;
  --bh-paper: #f4f1e9;
  --bh-white: #ffffff;
  --bh-grey: #d9d5c9;
  --bh-grey-dark: #6f6b60;

  --border: 3px solid var(--bh-black);
  --border-thin: 2px solid var(--bh-black);
  --shadow: 8px 8px 0 var(--bh-black);
  --shadow-sm: 4px 4px 0 var(--bh-black);

  --nav-h: 72px;
  --maxw: 1240px;

  --font: "Helvetica Neue", Helvetica, Arial, "Noto Sans JP", "Hiragino Kaku Gothic ProN",
    "Microsoft YaHei", "Malgun Gothic", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bh-paper);
  color: var(--bh-ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  margin: 0;
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2.6rem, 6vw, 5rem); text-transform: uppercase; }
h2 { font-size: clamp(1.9rem, 3.6vw, 3.1rem); text-transform: uppercase; }
h3 { font-size: 1.25rem; }
p { margin: 0 0 1rem; }

a { color: inherit; text-decoration: none; }

img, svg { display: block; max-width: 100%; }

button { font-family: inherit; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: 88px 0; border-top: var(--border); }

.section--dark { background: var(--bh-black); color: var(--bh-paper); border-top: 0; }
.section--red { background: var(--bh-red); color: var(--bh-white); border-top: 0; }
.section--blue { background: var(--bh-blue); color: var(--bh-white); border-top: 0; }
.section--yellow { background: var(--bh-yellow); border-top: 0; }

.eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  padding: 6px 12px;
  border: var(--border-thin);
  background: var(--bh-white);
  color: var(--bh-black);
}

.section-head { margin-bottom: 40px; max-width: 760px; }
.section-head p { margin-top: 12px; font-size: 1.02rem; color: var(--bh-grey-dark); }
.section--dark .section-head p,
.section--blue .section-head p { color: rgba(255, 255, 255, 0.82); }

.grid { display: grid; gap: 24px; }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }

.mono { font-family: "SFMono-Regular", Consolas, monospace; }

.hl-red { color: var(--bh-red); }
.hl-blue { color: var(--bh-blue); }

@media (max-width: 720px) {
  .section { padding: 56px 0; }
  .container { padding: 0 16px; }
}