/* ════════════════════════════════════════════════════════════
   基礎層：reset、元素預設樣式、版面容器、共用排版小工具
   ════════════════════════════════════════════════════════════ */

*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background-color: var(--paper);
  /* 極淡的朱紅／青瓷色暈，讓大面積白底不至於死板 */
  background-image:
    radial-gradient(ellipse 60% 45% at 82% 0%, rgba(63, 107, 98, .05), transparent 60%),
    radial-gradient(ellipse 55% 40% at 6% 4%, rgba(168, 52, 42, .045), transparent 58%);
  background-repeat: no-repeat;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.35;
  color: var(--ink);
}

p { margin: 0; }

a {
  color: var(--vermilion);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover { color: var(--vermilion-hover); }

img { max-width: 100%; height: auto; }

ul, ol { margin: 0; padding: 0; }

button { font: inherit; color: inherit; }

:focus-visible {
  outline: 2px solid var(--vermilion);
  outline-offset: 2px;
  border-radius: var(--radius-xs);
}

::selection {
  background: rgba(168, 52, 42, .16);
}

/* ── 版面容器 ── */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ── 無障礙小工具 ── */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 50%;
  top: -60px;
  transform: translateX(-50%);
  z-index: 200;
  padding: 10px 20px;
  background: var(--ink);
  color: var(--paper);
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  text-decoration: none;
  transition: top .2s var(--ease);
}

.skip-link:focus { top: 0; color: var(--paper); }

/* ── 共用排版元件 ── */
.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-size: .74rem;
  letter-spacing: .34em;
  color: var(--ink-3);
}

.eyebrow--tight { letter-spacing: .26em; }

.eyebrow__mark {
  display: block;
  width: 22px;
  height: 2px;
  flex: 0 0 auto;
  border-radius: 2px;
  background: var(--vermilion);
}

.section { padding-block: var(--section-y); }

.section + .section { border-top: 1px solid var(--line); }

.section__head { max-width: 44rem; margin-bottom: var(--space-10); }

.section__head--split {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-6);
  max-width: none;
  flex-wrap: wrap;
}

.section__title {
  margin: var(--space-3) 0 0;
  font-size: clamp(1.6rem, 3.4vw, 2.25rem);
  letter-spacing: .12em;
}

.section__lead {
  margin: var(--space-3) 0 0;
  color: var(--ink-3);
  line-height: 1.9;
}

.section__note {
  margin: var(--space-5) 0 0;
  font-size: .84rem;
  color: var(--ink-3);
  letter-spacing: .04em;
}

.prose {
  margin: var(--space-5) 0 0;
  color: var(--ink-2);
  line-height: 2.1;
}

.empty {
  padding: var(--space-8) 0;
  color: var(--ink-3);
  font-size: .92rem;
}

.page-main { padding-block: var(--space-12) var(--space-16); }

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: .92rem;
  letter-spacing: .1em;
  text-decoration: none;
  color: var(--vermilion);
}

.link-arrow__glyph { transition: transform .25s var(--ease); }

.link-arrow:hover .link-arrow__glyph { transform: translateX(4px); }

.back-link { margin-top: var(--space-8); }

.back-link:hover .link-arrow__glyph { transform: translateX(-4px); }

/* ── 尊重使用者的減少動態偏好 ── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  /* 跑馬燈改為可手動橫向捲動的靜態列 */
  .marquee__track { animation: none !important; }
  .marquee__row { overflow-x: auto; }
  .marquee__set[aria-hidden="true"] { display: none; }
}