/* ============================================================
   base.css — reset + 全站基礎 + 照片 filter 規則
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  background: radial-gradient(circle at 80% 20%, #13100e 0%, var(--bg) 75vw) no-repeat fixed;
  background-color: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-weight: 300;
  font-size: var(--text-body);
  line-height: var(--leading-body);
  letter-spacing: var(--tracking-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* 全站底片顆粒 overlay — 極淡, 固定 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9000;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

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

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

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: var(--tracking-wide);
  line-height: 1.02;
}

::selection { background: var(--warm); color: var(--bg); }

/* 鍵盤焦點 — 暖色細框, 無圓角 */
:focus-visible { outline: 1px solid var(--warm); outline-offset: 3px; }
:focus:not(:focus-visible) { outline: none; }

/* ---- 照片處理規範 — 萊卡 Monochrom 經典黑白 (SPEC §2.5) ---- */
.photo {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 0;                 /* 禁止圓角 */
  /* 萊卡 Monochrom：預設遮照化深度沉降（0.65 亮度），營造沉靜神秘感 */
  filter: grayscale(100%) contrast(1.38) brightness(0.65);
  transition: filter var(--dur-slow) var(--ease-shutter),
              transform var(--dur-slow) var(--ease-shutter);
}
/* hover 緩慢「顯影」— 還原色彩並將亮度提升至 1.08，前後對比顯著 */
.photo-wrap:hover .photo,
.photo:hover {
  filter: grayscale(0%) contrast(1.08) brightness(1.08);
}
/* 強制保持純黑白但在 hover 時顯亮 */
.photo[data-mono="true"]:hover,
.photo-wrap[data-mono="true"]:hover .photo {
  filter: grayscale(100%) contrast(1.38) brightness(1.08);
}

@media (prefers-reduced-motion: reduce) {
  .photo { transition: none; }
}

/* ---- 共用容器 ---- */
.shell {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--grid-margin);
}

/* 12 欄格線基底 */
.grid12 {
  display: grid;
  grid-template-columns: repeat(var(--grid-columns), 1fr);
  gap: var(--grid-gutter);
}

/* 區塊標頭索引 (·· 01 / WORKS 樣式) */
.section-mark {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: var(--text-caption);
  letter-spacing: var(--tracking-wide);
  color: var(--ink-dim);
  text-transform: uppercase;
  display: flex;
  align-items: center;
  gap: 0.9rem;
}
.section-mark::before {
  content: "";
  width: clamp(1.4rem, 3vw, 3rem);
  height: 1px;
  background: var(--warm);
}

/* 通用無障礙隱藏 */
.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}