/* ============================================
   Base Reset + Foundation
   ============================================ */

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-normal);
  color: var(--text-primary);
  background: var(--bg-primary);
  overflow-x: hidden;
  font-feature-settings: 'kern' 1, 'liga' 1;
}

img,
picture,
video,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

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

button {
  font: inherit;
  background: none;
  border: 0;
  cursor: pointer;
  color: inherit;
}

ul,
ol {
  list-style: none;
}

::selection {
  background: var(--signal-red);
  color: var(--bone-white);
}

/* ===== Compact preview mode (for screenshots) ===== */
html.compact .hero { min-height: auto !important; padding: var(--space-4xl) 0; }
html.compact .reveal,
html.compact .js .reveal { opacity: 1 !important; transform: none !important; }

/* ===== Film grain texture overlay ===== */
.grain-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: var(--z-overlay);
  opacity: var(--grain-opacity);
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.95' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.6'/%3E%3C/svg%3E");
  background-size: 200px 200px;
}

.grain-overlay--bone {
  opacity: 0.06;
  mix-blend-mode: multiply;
}

/* ===== Container ===== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}

.container--wide {
  max-width: 1600px;
}

.container--narrow {
  max-width: 980px;
}

/* ===== Section foundation ===== */
.section {
  position: relative;
  padding: var(--space-5xl) 0;
  overflow: hidden;
}

.section--dark {
  background: var(--ink-black);
  color: var(--bone-white);
}

.section--bone {
  background: var(--bone-white);
  color: var(--ink-black);
}

/* ===== Section header system ===== */
.section-label {
  font-family: var(--font-label);
  font-size: var(--fs-label);
  font-weight: var(--fw-medium);
  letter-spacing: var(--ls-widest);
  text-transform: uppercase;
  color: var(--signal-red);
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
}

.section-label::before {
  content: '';
  width: 32px;
  height: 1px;
  background: var(--signal-red);
}

.section-label--on-bone {
  color: var(--signal-red-deep);
}

.section-title {
  font-family: var(--font-display);
  font-weight: var(--fw-semibold);
  font-style: italic;
  font-size: var(--fs-display-xl);
  line-height: var(--lh-tight);
  letter-spacing: var(--ls-tight);
  margin-top: var(--space-md);
}

.section-title--display {
  font-size: var(--fs-hero);
}

.section-title-zh {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: var(--fw-regular);
  letter-spacing: var(--ls-wide);
  margin-top: var(--space-md);
  opacity: 0.92;
}

/* ===== Editorial chapter mark ===== */
.chapter-mark {
  position: absolute;
  top: var(--space-3xl);
  right: var(--container-pad);
  font-family: var(--font-label);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  letter-spacing: var(--ls-widest);
  text-transform: uppercase;
  color: var(--film-silver);
  writing-mode: vertical-rl;
  transform: rotate(180deg);
}

/* ===== Utility text ===== */
.lead {
  font-family: var(--font-body);
  font-size: var(--fs-lead);
  line-height: var(--lh-relaxed);
  font-weight: var(--fw-regular);
  max-width: 56ch;
  color: inherit;
  opacity: 0.85;
}

.lead--on-bone {
  color: var(--mid-grey);
}

.eyebrow {
  font-family: var(--font-label);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  letter-spacing: var(--ls-widest);
  text-transform: uppercase;
  color: var(--signal-red);
}

.eyebrow--mute {
  color: var(--film-silver);
}

/* ===== Scrollbar (subtle) ===== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--ink-black);
}

::-webkit-scrollbar-thumb {
  background: var(--film-silver-dark);
  border-radius: 0;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--signal-red);
}

/* ===== Reduce motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
}

/* ===== Reveal-on-scroll utility ===== */
/* Default: visible. JS will add .js-reveal to opt-in to the animation */
.reveal {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 1.1s var(--ease-editorial), transform 1.1s var(--ease-editorial);
}

.js .reveal:not(.is-visible) {
  opacity: 0;
  transform: translateY(28px);
}

.js .reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal--delay-1 { transition-delay: 0.1s; }
.reveal--delay-2 { transition-delay: 0.2s; }
.reveal--delay-3 { transition-delay: 0.3s; }
.reveal--delay-4 { transition-delay: 0.4s; }
.reveal--delay-5 { transition-delay: 0.5s; }
.reveal--delay-6 { transition-delay: 0.6s; }
.reveal--delay-7 { transition-delay: 0.7s; }
.reveal--delay-8 { transition-delay: 0.8s; }

/* ===== Bilingual pairs ===== */
.bilingual {
  display: flex;
  flex-direction: column;
  gap: var(--space-2xs);
}

.bilingual-en {
  font-family: var(--font-body);
  font-size: var(--fs-small);
  font-weight: var(--fw-medium);
  letter-spacing: var(--ls-wide);
  text-transform: uppercase;
  color: var(--film-silver);
  opacity: 0.7;
}

.bilingual-zh {
  font-family: var(--font-display);
  font-size: inherit;
  color: inherit;
}