/* =========================================================
   天火易經 — 古典書院風設計系統
   ========================================================= */

:root {
  /* Light — 米色宣紙 */
  --paper:        #f0e6cf;
  --paper-2:      #e9dcbb;
  --paper-3:      #e0cf9f;
  --paper-edge:   #c8b48a;
  --paper-shadow: rgba(60, 40, 18, 0.10);

  --ink:          #1a140c;
  --ink-2:        #3a2d1f;
  --ink-3:        #5a4732;
  --ink-muted:    #8a7956;
  --ink-faint:    rgba(26, 20, 12, 0.18);

  --vermilion:    #b54a35;   /* 朱砂 / 印章紅 */
  --vermilion-2:  #8c3120;
  --gold:         #a8843f;   /* 古銅金 */
  --celadon:      #5f7a5a;   /* 青瓷綠 */

  --line-yang:    var(--ink);
  --line-yin:     var(--ink);

  --rule:         rgba(26, 20, 12, 0.16);
  --rule-strong:  rgba(26, 20, 12, 0.32);

  /* Type scale */
  --font-serif:   "Noto Serif TC", "Source Han Serif TC", "STZhongsong", "PMingLiU", serif;
  --font-sans:    "Noto Sans TC", "Source Han Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;
  --font-display: "Noto Serif TC", "STKaiti", "DFKai-SB", "Kaiti TC", serif;
  --font-mono:    "JetBrains Mono", ui-monospace, Menlo, monospace;

  /* Sizing */
  --radius-sm: 2px;
  --radius:    4px;
  --radius-lg: 8px;

  /* Reading width */
  --measure: 38rem;
}

[data-theme="dark"] {
  /* Dark — 深墨夜空 */
  --paper:        #15110b;
  --paper-2:      #1d1812;
  --paper-3:      #28201a;
  --paper-edge:   #4a3d2e;
  --paper-shadow: rgba(0, 0, 0, 0.45);

  --ink:          #ece0c2;
  --ink-2:        #d4c499;
  --ink-3:        #b29f78;
  --ink-muted:    #8a7e60;
  --ink-faint:    rgba(236, 224, 194, 0.16);

  --vermilion:    #d9684e;
  --vermilion-2:  #a83c2a;
  --gold:         #d4ad5e;
  --celadon:      #8aa17e;

  --rule:         rgba(236, 224, 194, 0.14);
  --rule-strong:  rgba(236, 224, 194, 0.28);
}

/* ---------- paper texture (subtle) ---------- */
.paper-bg {
  background-color: var(--paper);
  background-image:
    radial-gradient(ellipse at 20% 10%, rgba(180, 140, 80, 0.06) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 70%, rgba(180, 140, 80, 0.05) 0%, transparent 50%),
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.35  0 0 0 0 0.25  0 0 0 0 0.10  0 0 0 0.06 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  background-blend-mode: multiply;
}
[data-theme="dark"] .paper-bg {
  background-image:
    radial-gradient(ellipse at 20% 10%, rgba(120, 90, 40, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 70%, rgba(120, 90, 40, 0.06) 0%, transparent 50%),
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.6  0 0 0 0 0.5  0 0 0 0 0.3  0 0 0 0.05 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  background-blend-mode: screen;
}

/* ---------- base ---------- */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--paper);
  font-size: 16px;
  line-height: 1.65;
  font-feature-settings: "palt" 1;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  transition: background-color .4s ease, color .4s ease;
}

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; padding: 0; }
a { color: inherit; text-decoration: none; }

::selection { background: var(--vermilion); color: var(--paper); }

/* ---------- typography ---------- */
.t-display { font-family: var(--font-display); letter-spacing: 0.08em; }
.t-serif   { font-family: var(--font-serif); }
.t-sans    { font-family: var(--font-sans); }
.t-mono    { font-family: var(--font-mono); }

.t-vertical {
  writing-mode: vertical-rl;
  text-orientation: upright;
  letter-spacing: 0.15em;
}

/* ---------- 印章 stamp ---------- */
.seal {
  display: inline-grid;
  place-items: center;
  font-family: var(--font-display);
  color: var(--paper);
  background: var(--vermilion);
  border: 2px solid var(--vermilion);
  letter-spacing: 0;
  line-height: 1;
  user-select: none;
  box-shadow:
    0 0 0 2px var(--paper),
    0 0 0 3px var(--vermilion),
    1px 1px 0 1px rgba(0,0,0,0.05);
}
.seal--sm { width: 28px; height: 28px; font-size: 12px; }
.seal--md { width: 44px; height: 44px; font-size: 18px; }
.seal--lg { width: 64px; height: 64px; font-size: 24px; }

/* ---------- thin rule ---------- */
.rule       { border-top: 1px solid var(--rule); }
.rule-strong{ border-top: 1px solid var(--rule-strong); }
.rule-double{
  border-top: 1px solid var(--rule-strong);
  box-shadow: 0 3px 0 -2px var(--rule-strong);
}

/* ---------- corner brackets (古書框) ---------- */
.brackets {
  position: relative;
  padding: 20px;
}
.brackets::before,
.brackets::after,
.brackets > .br-tr,
.brackets > .br-bl {
  content: "";
  position: absolute;
  width: 14px; height: 14px;
  border: 1px solid var(--ink-2);
}
.brackets::before { top: 0; left: 0; border-right: 0; border-bottom: 0; }
.brackets::after  { bottom: 0; right: 0; border-left: 0; border-top: 0; }
.brackets > .br-tr{ top: 0; right: 0; border-left: 0; border-bottom: 0; }
.brackets > .br-bl{ bottom: 0; left: 0; border-right: 0; border-top: 0; }

/* ========================================================
   header / nav
   ======================================================== */
.app-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  border-bottom: 1px solid var(--rule);
}
.app-header__inner {
  max-width: 1320px;
  margin: 0 auto;
  padding: 14px 32px;
  display: flex;
  align-items: center;
  gap: 28px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
}
.brand__mark {
  width: 38px; height: 38px;
  display: grid; place-items: center;
}
.brand__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: 0.15em;
}
.brand__sub {
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: 0.4em;
  color: var(--ink-muted);
  margin-top: 2px;
}
.nav {
  display: flex;
  gap: 4px;
  margin-left: 8px;
}
.nav__link {
  padding: 8px 14px;
  font-family: var(--font-serif);
  font-size: 15px;
  letter-spacing: 0.12em;
  color: var(--ink-2);
  border-radius: var(--radius);
  transition: all .2s;
  position: relative;
}
.nav__link:hover { color: var(--ink); }
.nav__link.is-active { color: var(--vermilion); }
.nav__link.is-active::after {
  content: "";
  position: absolute;
  left: 14px; right: 14px;
  bottom: 2px;
  height: 2px;
  background: var(--vermilion);
}

.header-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 12px;
}

/* search */
.search {
  position: relative;
  width: 260px;
}
.search input {
  width: 100%;
  font: inherit;
  color: inherit;
  font-family: var(--font-serif);
  background: var(--paper-2);
  border: 1px solid var(--rule);
  padding: 8px 12px 8px 36px;
  border-radius: var(--radius);
  letter-spacing: 0.05em;
  outline: none;
  transition: border-color .2s, background .2s;
}
.search input:focus {
  border-color: var(--vermilion);
  background: var(--paper);
}
.search__icon {
  position: absolute;
  left: 10px; top: 50%;
  transform: translateY(-50%);
  color: var(--ink-muted);
  font-size: 14px;
  pointer-events: none;
}
.search__kbd {
  position: absolute;
  right: 8px; top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--ink-muted);
  border: 1px solid var(--rule);
  padding: 1px 6px;
  border-radius: 3px;
  pointer-events: none;
}

/* icon buttons */
.icon-btn {
  width: 36px; height: 36px;
  display: grid; place-items: center;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  color: var(--ink-2);
  transition: all .2s;
  background: transparent;
}
.icon-btn:hover {
  color: var(--ink);
  border-color: var(--rule-strong);
  background: var(--paper-2);
}
.icon-btn.is-active {
  color: var(--vermilion);
  border-color: var(--vermilion);
}

/* ========================================================
   yao (line) primitive — SVG based; wrapper only
   ======================================================== */
.yao {
  position: relative;
  width: 100%;
  display: block;
}

.hex { display: block; }
.trigram { display: block; }

/* changing line marker */
.yao--changing::after {
  content: "";
  position: absolute;
  right: -10px;
  top: 50%;
  transform: translateY(-50%);
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--vermilion);
}

/* hover‑state interactive hex */
.hex--interactive { cursor: pointer; transition: transform .25s ease; }
.hex--interactive:hover { transform: translateY(-2px) scale(1.05); }

/* ========================================================
   buttons
   ======================================================== */
.btn {
  font-family: var(--font-serif);
  font-size: 14px;
  letter-spacing: 0.15em;
  padding: 10px 22px;
  border: 1px solid var(--ink-2);
  color: var(--ink);
  background: transparent;
  border-radius: var(--radius);
  transition: all .2s;
  cursor: pointer;
}
.btn:hover { background: var(--ink); color: var(--paper); }
.btn--primary {
  background: var(--vermilion);
  border-color: var(--vermilion);
  color: var(--paper);
}
.btn--primary:hover { background: var(--vermilion-2); border-color: var(--vermilion-2); color: var(--paper); }
.btn--ghost { border-color: var(--rule); color: var(--ink-2); }
.btn--ghost:hover { background: var(--paper-2); color: var(--ink); }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--ink-2);
  background: var(--paper-2);
  cursor: pointer;
  transition: all .2s;
}
.chip:hover { border-color: var(--rule-strong); color: var(--ink); }
.chip.is-active { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.chip--vermilion.is-active { background: var(--vermilion); border-color: var(--vermilion); }

/* ========================================================
   layout helpers
   ======================================================== */
.container {
  max-width: 1320px;
  margin: 0 auto;
  padding: 0 32px;
}
.stack { display: flex; flex-direction: column; }
.row   { display: flex; }
.center{ display: grid; place-items: center; }

/* ========================================================
   Hero / 圓圖
   ======================================================== */
.hero {
  position: relative;
  padding: 60px 0 40px;
  text-align: center;
}
.hero__eyebrow {
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: 0.6em;
  color: var(--ink-muted);
  margin-bottom: 18px;
}
.hero__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 56px;
  letter-spacing: 0.4em;
  margin: 0 0 14px;
  line-height: 1;
}
.hero__subtitle {
  font-family: var(--font-serif);
  font-size: 15px;
  letter-spacing: 0.18em;
  color: var(--ink-2);
  margin-bottom: 32px;
}
.hero__divider {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  color: var(--ink-muted);
  font-size: 12px;
  letter-spacing: 0.4em;
  margin: 18px 0 8px;
}
.hero__divider::before, .hero__divider::after {
  content: "";
  height: 1px;
  width: 60px;
  background: var(--rule-strong);
}

/* the round 64-gua diagram */
.roundgua {
  width: 760px;
  height: 760px;
  margin: 0 auto;
  position: relative;
}
.roundgua__svg {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
}
.roundgua__hex {
  position: absolute;
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: transform .25s ease;
  transform: translate(-50%, -50%);
}
.roundgua__hex:hover { transform: translate(-50%, -50%) scale(1.4); z-index: 5; }
.roundgua__hex .hex { width: 30px; }
.roundgua__hex .hex .yao { --thick: 2.5px; }
.roundgua__label {
  position: absolute;
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--ink-2);
  background: var(--paper);
  border: 1px solid var(--rule-strong);
  padding: 4px 10px;
  border-radius: var(--radius);
  pointer-events: none;
  opacity: 0;
  transform: translate(-50%, -50%);
  transition: opacity .2s;
  white-space: nowrap;
  z-index: 10;
  box-shadow: 0 4px 12px var(--paper-shadow);
}
.roundgua__label.is-show { opacity: 1; }
.roundgua__center {
  position: absolute;
  left: 50%; top: 50%;
  width: 280px; height: 280px;
  transform: translate(-50%, -50%);
  display: grid;
  place-items: center;
  text-align: center;
}

/* taiji symbol (drawn pure CSS / SVG) */
.taiji {
  width: 180px;
  height: 180px;
}

/* ========================================================
   trigram ring (八卦)
   ======================================================== */
.bagua-ring {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.bagua-ring__node {
  position: absolute;
  transform: translate(-50%, -50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  pointer-events: auto;
  cursor: pointer;
  color: var(--ink-muted);
  transition: color .2s;
}
.bagua-ring__node:hover { color: var(--vermilion); }
.bagua-ring__node .trigram { --w: 26px; --thick: 2.5px; --gap: 3px; }
.bagua-ring__name {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.1em;
}

/* ========================================================
   feature row (below hero)
   ======================================================== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 40px;
}
.feature {
  padding: 22px;
  border: 1px solid var(--rule);
  background: var(--paper-2);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all .2s;
}
.feature:hover {
  border-color: var(--ink-2);
  background: var(--paper);
  transform: translateY(-2px);
  box-shadow: 0 6px 18px var(--paper-shadow);
}
.feature__icon { color: var(--vermilion); margin-bottom: 14px; height: 28px; }
.feature__title {
  font-family: var(--font-serif);
  font-size: 17px;
  letter-spacing: 0.15em;
  font-weight: 600;
  margin: 0 0 4px;
}
.feature__desc {
  font-size: 13px;
  color: var(--ink-muted);
  line-height: 1.6;
  margin: 0;
}

/* recently viewed strip */
.recent {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  border: 1px dashed var(--rule);
  border-radius: var(--radius);
  margin-top: 32px;
  background: var(--paper-2);
}
.recent__label {
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--ink-muted);
  white-space: nowrap;
}
.recent__items {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.recent__item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px 4px 6px;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-serif);
  font-size: 13px;
  background: var(--paper);
  transition: all .2s;
}
.recent__item:hover { border-color: var(--ink-2); }
.recent__item .hex { width: 18px; --thick: 1.5px; --gap: 1.5px; }

/* ========================================================
   Detail page
   ======================================================== */
.detail-grid {
  display: grid;
  grid-template-columns: 360px 1fr 240px;
  gap: 40px;
  padding: 40px 0 80px;
  align-items: start;
}
.detail-sidebar { position: sticky; top: 100px; }

.gua-card {
  border: 1px solid var(--rule-strong);
  background: var(--paper-2);
  border-radius: var(--radius);
  padding: 32px 28px;
  text-align: center;
  position: relative;
}
.gua-card__number {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.4em;
  color: var(--ink-muted);
  margin-bottom: 8px;
}
.gua-card__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 48px;
  letter-spacing: 0.15em;
  margin: 0 0 6px;
}
.gua-card__pinyin {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.25em;
  color: var(--ink-muted);
  margin-bottom: 22px;
}
.gua-card__hex {
  display: grid;
  place-items: center;
  margin: 0 auto 22px;
}
.gua-card__hex .hex { width: 100px; --thick: 8px; --gap: 10px; }

.gua-card__trigrams {
  display: flex;
  justify-content: center;
  gap: 24px;
  padding: 18px 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  margin-bottom: 18px;
}
.gua-card__trigram {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: 0.15em;
  color: var(--ink-2);
}
.gua-card__trigram-label {
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ink-muted);
}

.gua-card__seal {
  position: absolute;
  top: 20px; right: 20px;
}

/* lines (爻) panel */
.yao-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid var(--rule);
  background: var(--paper-2);
  border-radius: var(--radius);
  overflow: hidden;
}
.yao-row {
  display: grid;
  grid-template-columns: 80px 60px 1fr;
  align-items: center;
  gap: 16px;
  padding: 14px 18px;
  border-top: 1px solid var(--rule);
  cursor: pointer;
  transition: background .2s;
  position: relative;
}
.yao-row:first-child { border-top: 0; }
.yao-row:hover { background: var(--paper); }
.yao-row.is-active { background: var(--paper); }
.yao-row.is-active::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--vermilion);
}
.yao-row__pos {
  font-family: var(--font-serif);
  font-size: 14px;
  letter-spacing: 0.15em;
  color: var(--ink-2);
}
.yao-row__pos-num {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--ink-muted);
  margin-top: 2px;
  letter-spacing: 0.2em;
}
.yao-row__line {
  display: grid;
  place-items: center;
}
.yao-row__line .yao { --thick: 5px; }
.yao-row__text {
  font-family: var(--font-serif);
  font-size: 15px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--ink);
}
.yao-row__expand {
  grid-column: 1 / -1;
  padding-top: 12px;
  margin-top: 10px;
  border-top: 1px dashed var(--rule);
  font-family: var(--font-serif);
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* transform switcher */
.transform-bar {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 24px;
}
.transform-item {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--paper-2);
  cursor: pointer;
  transition: all .2s;
}
.transform-item:hover {
  border-color: var(--vermilion);
  background: var(--paper);
}
.transform-item__label {
  display: flex;
  flex-direction: column;
  gap: 2px;
  text-align: left;
}
.transform-item__label-zh {
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: 0.2em;
}
.transform-item__label-desc {
  font-size: 11px;
  color: var(--ink-muted);
  letter-spacing: 0.1em;
}
.transform-item__hex {
  display: flex;
  align-items: center;
  gap: 8px;
}
.transform-item__hex .hex { width: 28px; --thick: 2px; --gap: 2px; }
.transform-item__hex-name {
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--ink-2);
}

/* main scripture */
.scripture {
  border-left: 2px solid var(--ink);
  padding: 0 0 0 24px;
  margin: 0 0 28px;
}
.scripture__label {
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: 0.3em;
  color: var(--vermilion);
  margin-bottom: 8px;
}
.scripture__text {
  font-family: var(--font-serif);
  font-size: 22px;
  line-height: 2;
  letter-spacing: 0.08em;
  margin: 0;
  color: var(--ink);
}

.section-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 36px 0 18px;
}
.section-head__title {
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.3em;
  margin: 0;
}
.section-head__rule {
  flex: 1;
  height: 1px;
  background: var(--rule-strong);
}
.section-head__count {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--ink-muted);
}

/* commentary tabs */
.book-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--rule-strong);
  margin-bottom: 18px;
}
.book-tab {
  padding: 12px 18px;
  font-family: var(--font-serif);
  font-size: 14px;
  letter-spacing: 0.15em;
  color: var(--ink-muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: all .2s;
  cursor: pointer;
}
.book-tab:hover { color: var(--ink-2); }
.book-tab.is-active {
  color: var(--ink);
  border-bottom-color: var(--vermilion);
}

.commentary {
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 2;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  max-width: var(--measure);
}
.commentary p { margin: 0 0 1em; }
.commentary p:last-child { margin-bottom: 0; }

/* classical commentary paragraph styles */
.cmt-jing {
  margin: 0 0 0.9em;
  text-indent: 0;
}
.cmt-note {
  margin: 0 0 1em;
  padding-left: 1.4em;
  position: relative;
  color: var(--ink-3);
  font-size: 0.94em;
}
.cmt-note__tag {
  position: absolute;
  left: 0; top: 0.25em;
  width: 1.05em; height: 1.05em;
  display: inline-grid;
  place-items: center;
  font-size: 0.62em;
  color: var(--paper);
  background: var(--gold);
  border-radius: 2px;
  letter-spacing: 0;
}
.cmt-foot {
  margin: 0.4em 0 1em;
  font-size: 0.82em;
  color: var(--ink-muted);
  padding-left: 1.2em;
  border-left: 2px solid var(--rule);
}
.cmt-loading {
  font-family: var(--font-display);
  letter-spacing: 0.3em;
  color: var(--ink-muted);
  animation: cmtpulse 1.4s ease-in-out infinite;
}
@keyframes cmtpulse { 0%,100%{opacity:.4} 50%{opacity:1} }

/* 焦氏易林 */
.yilin__ben {
  border: 1px solid var(--rule-strong);
  background: var(--paper-2);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 18px;
}
.yilin__ben-label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--ink-2);
  margin-bottom: 10px;
}
.yilin__ben-text {
  font-family: var(--font-serif);
  font-size: 18px;
  line-height: 1.9;
  letter-spacing: 0.06em;
  margin: 0;
  color: var(--ink);
}
.yilin__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 10px;
}
.yilin__search {
  position: relative;
  margin: 4px 0 14px;
}
.yilin__search input {
  width: 100%;
  font: inherit;
  font-family: var(--font-serif);
  color: inherit;
  background: var(--paper-2);
  border: 1px solid var(--rule);
  padding: 9px 70px 9px 36px;
  border-radius: var(--radius);
  letter-spacing: 0.05em;
  outline: none;
  transition: border-color .2s, background .2s;
}
.yilin__search input:focus { border-color: var(--vermilion); background: var(--paper); }
.yilin__search-icon {
  position: absolute;
  left: 11px; top: 50%;
  transform: translateY(-50%);
  color: var(--ink-muted);
  pointer-events: none;
}
.yilin__search-count {
  position: absolute;
  right: 12px; top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.15em;
  color: var(--vermilion);
  pointer-events: none;
}
.yilin__card {
  text-align: left;
  border: 1px solid var(--rule);
  background: var(--paper-2);
  border-radius: var(--radius);
  padding: 12px 14px;
  cursor: pointer;
  transition: all .2s;
  display: flex;
  flex-direction: column;
  gap: 8px;
  color: inherit;
}
.yilin__card:hover {
  border-color: var(--vermilion);
  background: var(--paper);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--paper-shadow);
}
.yilin__card-head {
  display: flex;
  align-items: center;
  gap: 8px;
}
.yilin__card-name {
  font-family: var(--font-display);
  font-size: 14px;
  letter-spacing: 0.12em;
  color: var(--ink-2);
}
.yilin__card-text {
  font-family: var(--font-serif);
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  margin: 0;
  color: var(--ink-3);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.yilin__more {
  display: block;
  margin: 16px auto 0;
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--vermilion);
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 8px 22px;
  background: var(--paper-2);
  transition: all .2s;
}
.yilin__more:hover { border-color: var(--vermilion); background: var(--paper); }

/* 焦林斷辭 in divination result */
.yilin-judge {
  margin: 24px auto 0;
  max-width: 460px;
  border: 1px solid var(--vermilion);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--vermilion) 6%, var(--paper-2));
  padding: 16px 20px;
  text-align: left;
}
.yilin-judge__label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--vermilion);
  margin-bottom: 10px;
}
.yilin-judge__text {
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.95;
  letter-spacing: 0.06em;
  margin: 0;
  color: var(--ink);
}

/* right column toc */
.toc {
  position: sticky;
  top: 100px;
}
.toc__title {
  font-family: var(--font-serif);
  font-size: 11px;
  letter-spacing: 0.4em;
  color: var(--ink-muted);
  margin-bottom: 14px;
}
.toc__list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-family: var(--font-serif);
  font-size: 13px;
}
.toc__link {
  padding: 6px 10px;
  color: var(--ink-muted);
  cursor: pointer;
  border-left: 2px solid transparent;
  transition: all .15s;
  letter-spacing: 0.15em;
}
.toc__link:hover { color: var(--ink-2); }
.toc__link.is-active {
  color: var(--vermilion);
  border-left-color: var(--vermilion);
}

/* prev/next nav between hexagrams */
.hex-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 0;
  margin-top: 40px;
  border-top: 1px solid var(--rule-strong);
}
.hex-nav__link {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  padding: 8px 12px;
  border-radius: var(--radius);
  transition: background .2s;
}
.hex-nav__link:hover { background: var(--paper-2); }
.hex-nav__dir {
  font-family: var(--font-serif);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ink-muted);
}
.hex-nav__name {
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.15em;
}
.hex-nav__link .hex { width: 22px; --thick: 1.8px; --gap: 1.8px; }

/* ========================================================
   Compare page
   ======================================================== */
.compare-head {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 24px;
  align-items: center;
  padding: 32px 0;
  border-bottom: 1px solid var(--rule-strong);
}
.compare-head__hex { display: flex; align-items: center; gap: 18px; }
.compare-head__hex .hex { width: 56px; --thick: 5px; --gap: 6px; }
.compare-head__title {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.compare-head__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--ink-muted);
}
.compare-head__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 32px;
  letter-spacing: 0.2em;
}

.compare-controls {
  display: flex;
  gap: 12px;
  align-items: center;
  margin: 22px 0 8px;
  flex-wrap: wrap;
}
.compare-controls__label {
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--ink-muted);
}

.compare-grid {
  display: grid;
  grid-template-columns: repeat(var(--cols, 3), 1fr);
  gap: 16px;
  padding: 24px 0 60px;
}
.compare-col {
  border: 1px solid var(--rule);
  background: var(--paper-2);
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.compare-col__head {
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--rule);
  background: var(--paper);
}
.compare-col__title {
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: 0.18em;
}
.compare-col__author {
  font-family: var(--font-serif);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--ink-muted);
}
.compare-col__body {
  padding: 18px 18px 22px;
  font-family: var(--font-serif);
  font-size: 14px;
  line-height: 1.95;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  max-height: 70vh;
  overflow-y: auto;
}
.compare-col__body p { margin: 0 0 1em; }
.compare-col__body h5 {
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--vermilion);
  margin: 18px 0 8px;
  font-weight: 600;
}
.compare-col__body h5:first-child { margin-top: 0; }

/* ========================================================
   Divination modal
   ======================================================== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(20, 14, 8, 0.5);
  backdrop-filter: blur(4px);
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 24px;
}
.modal {
  background: var(--paper);
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius-lg);
  max-width: 720px;
  width: 100%;
  max-height: 90vh;
  overflow: auto;
  padding: 32px 36px;
  position: relative;
  box-shadow: 0 30px 80px rgba(0,0,0,0.4);
}
.modal__close {
  position: absolute;
  top: 18px; right: 18px;
  width: 32px; height: 32px;
  display: grid; place-items: center;
  color: var(--ink-muted);
  border-radius: var(--radius);
}
.modal__close:hover { color: var(--ink); background: var(--paper-2); }
.modal__title {
  font-family: var(--font-display);
  font-size: 24px;
  letter-spacing: 0.3em;
  margin: 0 0 6px;
  text-align: center;
}
.modal__sub {
  text-align: center;
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--ink-muted);
  margin-bottom: 32px;
}

.coin {
  width: 64px; height: 64px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, var(--gold), color-mix(in srgb, var(--gold) 70%, var(--ink) 30%));
  position: relative;
  display: grid;
  place-items: center;
  box-shadow: inset -3px -4px 8px rgba(0,0,0,0.25), 0 4px 10px rgba(0,0,0,0.2);
  font-family: var(--font-display);
  color: var(--paper);
  font-size: 13px;
  letter-spacing: 0.1em;
}
.coin::before {
  content: "";
  position: absolute;
  width: 16px; height: 16px;
  background: var(--paper);
  border-radius: 1px;
}
.coin__face { position: relative; z-index: 2; font-size: 9px; color: var(--ink); }
.coin--flip { animation: coinflip 800ms ease-out; }
@keyframes coinflip {
  0%   { transform: translateY(0) rotateX(0deg); }
  50%  { transform: translateY(-80px) rotateX(540deg); }
  100% { transform: translateY(0) rotateX(1080deg); }
}

.coin-stage {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin: 24px 0 32px;
  min-height: 80px;
  align-items: center;
}
.divine-result {
  border-top: 1px solid var(--rule);
  padding-top: 24px;
  text-align: center;
}
.divine-yao-stack {
  display: flex;
  flex-direction: column-reverse;
  gap: 8px;
  width: 140px;
  margin: 16px auto;
}
.divine-yao-stack .yao { --thick: 8px; }
.divine-yao-stack .yao-step {
  display: grid;
  grid-template-columns: 28px 1fr 28px;
  align-items: center;
  gap: 10px;
}
.divine-yao-stack .yao-step__num {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--ink-muted);
  text-align: right;
}
.divine-yao-stack .yao-step__type {
  font-family: var(--font-serif);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--ink-muted);
}

/* tabs inside modal */
.modal-tabs {
  display: flex;
  justify-content: center;
  gap: 0;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--rule);
}
.modal-tab {
  padding: 10px 22px;
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--ink-muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  cursor: pointer;
}
.modal-tab.is-active {
  color: var(--vermilion);
  border-bottom-color: var(--vermilion);
}

/* ========================================================
   Reading mode
   ======================================================== */
body.reading-mode .app-header,
body.reading-mode .toc,
body.reading-mode .detail-sidebar,
body.reading-mode .feature-grid,
body.reading-mode .hex-nav {
  display: none !important;
}
body.reading-mode {
  font-size: 18px;
}
body.reading-mode .container { max-width: 720px; }
body.reading-mode .scripture__text { font-size: 26px; }
body.reading-mode .yao-row__text { font-size: 17px; }
body.reading-mode .commentary { font-size: 18px; }

.reading-bar {
  position: fixed;
  top: 50%;
  right: 24px;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 60;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s;
}
body.reading-mode .reading-bar {
  opacity: 1;
  pointer-events: auto;
}

/* footer */
.app-footer {
  border-top: 1px solid var(--rule);
  padding: 24px 0;
  margin-top: 60px;
  text-align: center;
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--ink-muted);
}

/* ========================================================
   Responsive
   ======================================================== */
@media (max-width: 1100px) {
  .detail-grid { grid-template-columns: 300px 1fr; gap: 28px; }
  .detail-grid > .toc { display: none; }
  .compare-grid { --cols: 2 !important; }
}

@media (max-width: 840px) {
  .container { padding: 0 18px; }
  .app-header__inner { padding: 12px 18px; gap: 14px; flex-wrap: wrap; }
  .detail-grid { grid-template-columns: 1fr; gap: 24px; padding: 24px 0 60px; }
  .detail-sidebar { position: static; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .search { width: 160px; }
  .hero { padding: 36px 0 28px; }
  .hero__title { font-size: 40px; letter-spacing: 0.3em; }
  .compare-grid { --cols: 1 !important; }
  .compare-col__body { max-height: none; }
  .compare-head { grid-template-columns: 1fr auto; gap: 14px; }
}

@media (max-width: 600px) {
  /* header → wrap into two rows, search full width below */
  .app-header__inner {
    display: grid;
    grid-template-columns: 1fr auto;
    grid-template-areas:
      "brand actions"
      "nav   nav"
      "search search";
    gap: 10px 12px;
  }
  .brand { grid-area: brand; }
  .brand__title { font-size: 19px; }
  .brand__sub { display: none; }
  .nav {
    grid-area: nav;
    margin-left: 0;
    justify-content: space-between;
    border-top: 1px solid var(--rule);
    padding-top: 8px;
  }
  .nav__link { padding: 6px 8px; font-size: 14px; letter-spacing: 0.08em; }
  .header-right { grid-area: actions; margin-left: 0; gap: 8px; }
  .search { grid-area: search; width: 100%; }
  .search__kbd { display: none; }
  .icon-btn { width: 38px; height: 38px; }

  .hero__title { font-size: 32px; letter-spacing: 0.2em; }
  .hero__subtitle { font-size: 13px; letter-spacing: 0.12em; }
  .hero__eyebrow { letter-spacing: 0.35em; font-size: 11px; }

  .feature-grid { grid-template-columns: 1fr; gap: 12px; }
  .feature { padding: 18px; }

  .gua-card { padding: 26px 20px; }
  .gua-card__name { font-size: 40px; }
  .scripture__text { font-size: 19px; line-height: 1.9; }
  .yao-row { grid-template-columns: 64px 48px 1fr; gap: 10px; padding: 12px 12px; }
  .yao-row__text { font-size: 14px; }
  .book-tabs { overflow-x: auto; }
  .book-tab { white-space: nowrap; padding: 12px 12px; }
  .section-head__title { font-size: 16px; letter-spacing: 0.2em; }

  .recent { flex-direction: column; align-items: flex-start; gap: 10px; }

  /* modal */
  .modal-backdrop { padding: 12px; }
  .modal { padding: 28px 20px; max-height: 92vh; }
  .modal__title { font-size: 20px; }
  .coin { width: 52px; height: 52px; }
  .coin-stage { gap: 16px; }
  .divine-result > div:nth-child(2) { gap: 24px !important; flex-wrap: wrap; }

  .reading-bar { right: 12px; }

  .app-footer .container { flex-direction: column; gap: 8px; }
  .app-footer .container > div:last-child { font-size: 9px; }
}

@media (max-width: 380px) {
  .hero__title { font-size: 27px; }
  .nav__link { font-size: 13px; padding: 6px 5px; }
}

/* touch: disable hover-scale that can feel janky, keep tap targets */
@media (hover: none) {
  .roundgua__hex:hover { transform: translate(-50%, -50%) scale(1.25); }
}