/* finesse · register=brand · A=mist-blue+slate-teal · B=Noto Serif TC/Noto Sans TC · C=longform editorial · D=CSS micro-feedback · E=porcelain+waterline · SOUL=8 SPECTACLE=3 DENSITY=4 */
:root {
  --page-bg: #f5fafb;
  --white: rgba(247, 251, 252, 0.84);
  --solid: #f7fbfc;
  --mist: #e9f5f8;
  --water: #3f9ab6;
  --water-2: #91d4e2;
  --deep: #28677f;
  --navy: #244d5a;
  --ink: #29434b;
  --muted: #607a82;
  --line: rgba(48, 125, 149, 0.15);
  --shadow: 0 22px 56px rgba(38, 100, 120, 0.1);
}

body { background: var(--page-bg); }
.topbar { background: rgba(48, 125, 149, 0.1); }
.topbar span {
  background: linear-gradient(90deg, #b8eaf0, #6cc2d6 55%, #4d9fb8);
  box-shadow: 0 0 14px rgba(80, 175, 197, 0.35);
}
.level-water { background: linear-gradient(180deg, #bcecf0, #82d2e0 48%, #57afc4); }
.drop {
  background: linear-gradient(160deg, #f7fbfc 0%, #afe3eb 45%, #5aaec4 100%);
  box-shadow: inset -5px -7px 0 rgba(247, 251, 252,0.5), 0 8px 16px rgba(69,151,174,0.2);
}
header.site {
  background: rgba(247, 252, 253, 0.82);
  border-bottom-color: rgba(247, 251, 252,0.9);
  box-shadow: 0 8px 26px rgba(38, 91, 108, 0.04);
}

.hero {
  color: var(--ink);
  background:
    radial-gradient(ellipse at 82% 16%, rgba(161, 222, 234, 0.48), transparent 37%),
    radial-gradient(ellipse at 8% 92%, rgba(214, 241, 245, 0.82), transparent 40%),
    linear-gradient(118deg, #f3fbfd 0%, #e5f5f9 55%, #d9eff4 100%);
}
.hero::before {
  border-color: rgba(69, 153, 175, 0.14);
  box-shadow: 0 0 0 34px rgba(69, 153, 175, 0.025), 0 0 0 82px rgba(69, 153, 175, 0.025);
}
.hero .kicker { color: #43899f; }
.hero h1 { color: #244d5a; }
.hero .sub { color: #56727b; }
.hero .btn.primary {
  color: #f7fbfc;
  background: linear-gradient(145deg, #66bdd0, #428faa);
  box-shadow: 0 10px 24px rgba(55, 135, 158, 0.2), inset 0 1px 0 rgba(247, 251, 252,0.42);
}
.hero .btn.ghost {
  color: #326e82;
  border-color: rgba(62, 145, 168, 0.22);
  background: rgba(247, 251, 252,0.72);
  box-shadow: 0 8px 20px rgba(42, 102, 120, 0.045);
}
.hero-photo {
  border: 1px solid rgba(247, 251, 252,0.92);
  box-shadow: 0 22px 54px rgba(42, 95, 112, 0.16), 0 0 0 1px rgba(247, 251, 252,0.45);
}
.hero-photo img { filter: none; }
.hero-photo::after { background: none; }
.hero-photo figcaption {
  color: #355965;
  background: rgba(250, 254, 255, 0.86);
  border: 1px solid rgba(247, 251, 252,0.9);
  box-shadow: 0 6px 18px rgba(36, 83, 99, 0.08);
}

.chapter-map { background: linear-gradient(180deg, #f8fcfd, #edf7f9); }
.chapter-map a {
  border-color: rgba(61, 139, 160, 0.12);
  background: linear-gradient(145deg, rgba(247, 251, 252,0.98), rgba(235,247,249,0.92));
  box-shadow: 0 12px 30px rgba(35, 94, 111, 0.05);
}
.chapter { background: #fbfdfe; }
.chapter:nth-child(even) { background: linear-gradient(180deg, #eef7f9, #f7fbfc); }
.chapter .lead { color: #56727b; }
.chapter figure img {
  border-radius: 18px;
  background: #eaf6f9;
  box-shadow: 0 12px 32px rgba(45, 106, 124, 0.08);
}
.chapter figure figcaption { color: #627b82; }
.card {
  border-color: rgba(56, 128, 148, 0.1);
  background: linear-gradient(160deg, rgba(247, 251, 252,0.98), rgba(238,248,249,0.92));
  box-shadow: 0 12px 30px rgba(35, 94, 111, 0.045);
}
.take { background: rgba(222, 243, 246, 0.8); }
.sources { background: #eaf5f7; }
.progress-links { background: rgba(250, 254, 255, 0.82); }

@media (max-width: 640px) {
  .hero { background: linear-gradient(150deg, #f2fbfd, #e1f2f6); }
  .hero-photo { box-shadow: 0 16px 34px rgba(42, 95, 112, 0.13); }
}

/* Urine-color guide: each label maps to one vial and keeps the uncertainty clear. */
.urine-guide-figure { margin-top: 24px; }
.urine-scale {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 10px;
  margin: 12px 18px 8px;
  padding: 0;
  list-style: none;
}
.urine-scale li {
  display: grid;
  justify-items: center;
  align-content: start;
  gap: 8px;
  min-width: 0;
  min-height: 118px;
  padding: 14px 9px;
  border: 1px solid rgba(56, 128, 148, 0.11);
  border-radius: 15px;
  background: linear-gradient(160deg, rgba(247, 251, 252,0.98), rgba(239,248,249,0.92));
  text-align: center;
}
.urine-scale-swatch {
  display: block;
  width: 24px;
  height: 24px;
  flex: 0 0 24px;
  border: 1px solid rgba(78, 91, 72, 0.16);
  border-radius: 50%;
  background: var(--urine-color);
  box-shadow: inset 0 1px 3px rgba(247, 251, 252,0.65), 0 2px 5px rgba(52,91,98,0.08);
}
.urine-scale li div { display: grid; gap: 5px; }
.urine-scale strong { color: #355e69; font-size: 13px; line-height: 1.35; }
.urine-scale li span { color: #667e85; font-size: 12px; line-height: 1.55; }
.urine-guide-figure figcaption { padding-top: 9px; }
@media (max-width: 820px) {
  .urine-scale { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .urine-scale { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin: 10px 12px 6px; }
  .urine-scale li { min-height: 84px; grid-template-columns: 22px 1fr; justify-items: start; align-items: center; gap: 9px; padding: 11px; text-align: left; }
  .urine-scale-swatch { width: 21px; height: 21px; flex-basis: 21px; }
  .urine-scale li div { gap: 3px; }
  .urine-scale strong { font-size: 12px; }
  .urine-scale li span { font-size: 11px; }
  .urine-guide-figure figcaption { padding: 11px 14px 15px; font-size: 12px; }
}
/* Nobel 2003 aquaporin feature: an original, offline-ready science card. */
.nobel-feature {
  margin: 24px 0 30px;
  overflow: hidden;
  border: 1px solid rgba(56, 128, 148, 0.13);
  border-radius: 22px;
  background: linear-gradient(150deg, rgba(247, 251, 252,0.98), rgba(231,245,248,0.95));
  box-shadow: 0 14px 34px rgba(45, 106, 124, 0.075);
}
.chapter .nobel-feature img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 0;
  box-shadow: none;
}
.nobel-feature figcaption {
  padding: 14px 20px 17px;
  color: #58737a;
  font-size: 13px;
  line-height: 1.75;
}
.nobel-feature figcaption a {
  display: inline-block;
  margin-left: 6px;
  color: #28677f;
  font-weight: 700;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
.nobel-feature figcaption a:focus-visible {
  outline: 2px solid #3f9ab6;
  outline-offset: 3px;
}
@media (max-width: 640px) {
  .nobel-feature { margin: 20px 0 24px; border-radius: 17px; }
  .nobel-feature figcaption { padding: 12px 14px 14px; font-size: 12px; }
  .nobel-feature figcaption a { margin: 5px 0 0; }
}
/* Water-balance explainer: a compact bridge between the body journey and cell chapters. */
.balance-loop { margin: 30px 0; padding: clamp(20px, 3.5vw, 34px); border: 1px solid rgba(56, 128, 148, 0.14); border-radius: 22px; background: linear-gradient(145deg, rgba(246,252,253,0.98), rgba(231,245,248,0.95)); box-shadow: 0 14px 34px rgba(45, 106, 124, 0.055); }
.balance-loop-head { max-width: 700px; margin-bottom: 20px; }
.balance-loop-head .eyebrow { margin-bottom: 8px; color: #5a8995; font-size: 11px; letter-spacing: .12em; }
.balance-loop-head h3 { margin: 0 0 8px; color: #315d68; font-size: clamp(20px, 2.5vw, 27px); line-height: 1.4; }
.balance-loop-head > p:last-child { margin: 0; color: #607a82; line-height: 1.75; }
.balance-steps { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin: 0; padding: 0; list-style: none; }
.balance-steps li { min-width: 0; padding: 18px 17px; border: 1px solid rgba(56, 128, 148, 0.11); border-radius: 16px; background: rgba(247, 251, 252,0.78); }
.balance-step-no { display: inline-grid; width: 30px; height: 30px; place-items: center; margin-bottom: 11px; border-radius: 50%; background: #dff0f3; color: #357a8d; font-size: 11px; font-weight: 700; letter-spacing: .04em; }
.balance-steps h4 { margin: 0 0 7px; color: #315d68; font-size: 15px; }
.balance-steps p { margin: 0; color: #607a82; font-size: 13px; line-height: 1.7; }
.balance-loop-note { margin: 15px 0 0; padding-top: 13px; border-top: 1px solid rgba(56, 128, 148, 0.12); color: #667e85; font-size: 12px; line-height: 1.7; }
@media (max-width: 760px) {
  .balance-steps { grid-template-columns: 1fr; gap: 9px; }
  .balance-steps li { display: grid; grid-template-columns: 30px minmax(0,1fr); column-gap: 11px; align-items: start; padding: 14px; }
  .balance-step-no { grid-row: 1 / span 2; margin: 1px 0 0; }
  .balance-steps h4 { margin-bottom: 4px; }
  .balance-steps p { grid-column: 2; }
}
@media (max-width: 640px) {
  .balance-loop { margin: 24px 0; padding: 18px 15px; border-radius: 18px; }
  .balance-loop-head h3 { font-size: 20px; }
  .balance-steps li { padding: 12px; }
}
/* Aquaporin scale and official Nobel award photo. */
.aquaporin-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(260px, 0.75fr);
  gap: clamp(18px, 2.6vw, 30px);
  align-items: center;
  max-width: 1040px;
  margin: 24px 0 32px;
}
.aquaporin-art img { display: block; width: 100%; aspect-ratio: 1; object-fit: cover; }
.channel-scale {
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid rgba(56, 128, 148, 0.14);
  border-radius: 22px;
  background: linear-gradient(150deg, rgba(247, 251, 252,0.98), rgba(231,245,248,0.96));
  box-shadow: 0 14px 34px rgba(45, 106, 124, 0.06);
}
.channel-scale .eyebrow { margin: 0 0 8px; color: #5a8995; font-size: 11px; letter-spacing: .12em; }
.channel-scale h3 { margin: 0 0 8px; color: #315d68; font-size: clamp(19px, 2.2vw, 24px); }
.channel-scale-value { display: flex; flex-wrap: wrap; align-items: baseline; gap: 8px 14px; margin: 8px 0 12px; color: #28758a; }
.channel-scale-value strong { font-size: clamp(54px, 6vw, 76px); line-height: 1; letter-spacing: -.045em; }
.channel-scale-value strong span { font-size: .45em; letter-spacing: 0; }
.channel-scale-conversion { color: #68858d; font-size: 15px; }
.channel-scale-detail { margin: 0 0 18px; color: #58737a; font-size: 14px; line-height: 1.8; }
.channel-scale-detail b { color: #315d68; }
.channel-scale-note { margin: 0; padding-top: 16px; border-top: 1px solid rgba(56, 128, 148, 0.14); color: #58737a; font-size: 13px; line-height: 1.8; }
.channel-scale-note strong { color: #315d68; }
.nobel-feature { display: grid; grid-template-columns: minmax(260px, .42fr) minmax(0, 1fr); align-items: center; }
.chapter .nobel-feature img { width: 100%; height: 360px; padding: 12px; object-fit: contain; background: #e9f1f2; }
.nobel-feature figcaption { padding: clamp(20px, 3.5vw, 36px); }
@media (max-width: 760px) {
  .aquaporin-layout { grid-template-columns: minmax(0, 1fr); }
  .channel-scale { padding: 22px; }
  .nobel-feature { grid-template-columns: minmax(0, 1fr); }
  .chapter .nobel-feature img { height: min(108vw, 420px); min-height: 240px; }
}
@media (max-width: 640px) {
  .aquaporin-layout { margin: 18px 0 24px; }
  .channel-scale { padding: 19px 17px; border-radius: 18px; }
  .channel-scale-value strong { font-size: 58px; }
}

/* Finesse refinement: pale-blue editorial finish */
:root {
  --page-bg: #f2f8f9;
  --white: rgba(248, 252, 253, 0.92);
  --solid: #f7fbfc;
  --mist: #e9f2f4;
  --water: #397f93;
  --water-2: #8bc8d5;
  --deep: #2e6274;
  --navy: #23404a;
  --ink: #263d45;
  --muted: #5b727a;
  --line: rgba(45, 101, 118, 0.15);
  --shadow: 0 20px 48px rgba(33, 77, 91, 0.08);
  --surface: rgba(248, 252, 253, 0.92);
  --surface-soft: rgba(236, 245, 247, 0.84);
  --shadow-soft: 0 9px 24px rgba(33, 78, 92, 0.055);
  --on-accent: #f5fafb;
  --hero-start: #eef7f9;
  --hero-mid: #e5f1f4;
  --hero-end: #edf6f8;
}

html,
body { overflow-x: clip; }
html { scroll-padding-top: 88px; }
body {
  background: var(--page-bg);
  color: var(--ink);
  line-height: 1.82;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 6;
  pointer-events: none;
  opacity: 0.022;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.78' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.22'/%3E%3C/svg%3E");
  mix-blend-mode: multiply;
}
h1,
h2,
h3,
h4 { min-width: 0; overflow-wrap: anywhere; }
:focus-visible { outline: 3px solid var(--water); outline-offset: 3px; }

.wrap { width: min(1160px, calc(100% - 64px)); }
header.site {
  min-height: 68px;
  padding: 12px clamp(20px, 3.4vw, 48px);
  border-bottom: 1px solid var(--line);
  background: rgba(245, 250, 251, 0.92);
  box-shadow: 0 7px 20px rgba(35, 75, 88, 0.045);
  backdrop-filter: blur(14px) saturate(1.12);
}
.brand { color: var(--navy); }
.nav-desk a,
.drawer a,
.btn { white-space: nowrap; }
.nav-desk a:hover,
.nav-desk a.is-on,
.drawer a.is-on { color: var(--deep); }
.menu-btn {
  min-height: 44px;
  border-color: var(--line);
  color: var(--deep);
  background: var(--surface);
  transition: background 180ms var(--ease), border-color 180ms var(--ease), transform 180ms var(--ease);
}
.menu-btn:hover { border-color: rgba(57, 127, 147, 0.34); background: var(--solid); }

.hero {
  padding: clamp(72px, 8vw, 104px) 0 76px;
  color: var(--ink);
  background:
    radial-gradient(ellipse at 82% 17%, rgba(139, 200, 213, 0.18), transparent 44%),
    linear-gradient(124deg, var(--hero-start), var(--hero-mid) 55%, var(--hero-end));
}
.hero::before {
  border-color: rgba(57, 127, 147, 0.12);
  box-shadow: 0 0 0 28px rgba(57, 127, 147, 0.022), 0 0 0 66px rgba(57, 127, 147, 0.018);
}
.hero-grid { grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr); gap: clamp(36px, 5vw, 68px); }
.hero-grid > div { max-width: 600px; }
.hero .kicker {
  margin-bottom: 16px;
  color: var(--water);
  font-size: clamp(16px, 1.05vw, 18px);
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1.65;
}
.hero h1 {
  max-width: 12em;
  margin: 0 0 18px;
  color: var(--navy);
  font-size: clamp(40px, 4.35vw, 60px);
  font-weight: 600;
  line-height: 1.22;
  letter-spacing: -0.035em;
}
.hero .sub {
  max-width: 31em;
  margin-bottom: 26px;
  color: var(--muted);
  font-size: clamp(16px, 1.45vw, 18px);
  line-height: 1.85;
}
.hero .btn.primary {
  color: var(--on-accent);
  background: var(--deep);
  box-shadow: 0 8px 20px rgba(38, 91, 107, 0.16);
}
.hero .btn.primary::after { display: none; }
.hero .btn.ghost {
  color: var(--deep);
  border-color: rgba(46, 98, 116, 0.2);
  background: rgba(247, 251, 252, 0.76);
  box-shadow: none;
}
.hero .btn:hover,
.menu-btn:active,
.btn:active { transform: translateY(-1px); }
.hero-photo {
  min-height: 0;
  overflow: hidden;
  border: 1px solid rgba(45, 101, 118, 0.14);
  border-radius: 20px;
  background: var(--mist);
  box-shadow: 0 18px 42px rgba(38, 89, 105, 0.12);
}
.hero-photo img {
  min-height: 420px;
  filter: none;
}
.hero-photo::after { display: none; }
.hero-photo figcaption {
  left: 16px;
  bottom: 16px;
  color: var(--deep);
  background: rgba(247, 251, 252, 0.94);
  border: 1px solid rgba(45, 101, 118, 0.12);
  box-shadow: 0 4px 14px rgba(37, 78, 91, 0.07);
}

.chapter-map {
  padding: 54px 0 82px;
  background: linear-gradient(180deg, var(--page-bg), var(--mist));
}
.chapter-map h2 {
  margin-bottom: 26px;
  color: var(--navy);
  font-size: clamp(28px, 3.1vw, 38px);
  line-height: 1.3;
  letter-spacing: -0.02em;
}
.chapter-map ol {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}
.chapter-map a {
  min-height: 144px;
  padding: 22px 22px;
  border-color: var(--line);
  border-radius: 15px;
  background: var(--surface);
  box-shadow: var(--shadow-soft);
  transition: transform 190ms var(--ease), border-color 190ms var(--ease), box-shadow 190ms var(--ease), background 190ms var(--ease);
}
.chapter-map a::after {
  width: 92px;
  right: -22px;
  bottom: -42px;
  border-color: rgba(57, 127, 147, 0.11);
  box-shadow: 0 0 0 12px rgba(57, 127, 147, 0.018), 0 0 0 26px rgba(57, 127, 147, 0.014);
}
.chapter-map small {
  margin-bottom: 12px;
  color: var(--water);
  font-size: 27px;
  font-weight: 600;
  letter-spacing: -0.035em;
}
.chapter-map a:hover {
  transform: translateY(-2px);
  border-color: rgba(57, 127, 147, 0.3);
  background: var(--solid);
  box-shadow: 0 13px 30px rgba(35, 81, 96, 0.075);
}

.chapter {
  padding: clamp(74px, 7.2vw, 104px) 0;
  background: #f7fbfc;
}
.chapter:nth-child(even) { background: #edf5f7; }
.chapter::before {
  top: 22px;
  right: clamp(26px, 9vw, 148px);
  color: transparent;
  -webkit-text-stroke: 1px rgba(46, 98, 116, 0.09);
  font-size: clamp(130px, 18vw, 226px);
  font-weight: 600;
}
.chapter .wrap > h2 {
  max-width: 16em;
  margin-bottom: 16px;
  color: var(--navy);
  font-size: clamp(32px, 3.2vw, 45px);
  line-height: 1.28;
  letter-spacing: -0.025em;
}
.chapter .lead {
  max-width: 40em;
  margin-bottom: 34px;
  color: var(--muted);
  font-size: clamp(17px, 1.55vw, 19px);
  line-height: 1.88;
}
.chapter .wrap > p:not(.eyebrow):not(.lead),
.chapter .split > div > p { max-width: 40em; }
.split,
.two { grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr); }
.cards { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.flow { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.organ-layout,
.urine-layout { grid-template-columns: minmax(0, 230px) minmax(0, 1fr); }
.aquaporin-layout,
.nobel-feature { min-width: 0; }
.card,
.scene,
.note,
details.myth,
.balance-loop,
.channel-scale,
.nobel-feature,
.urine-scale li,
.source-list li {
  border-color: var(--line);
  background: var(--surface);
  box-shadow: var(--shadow-soft);
}
.card,
.scene,
.note,
.take,
details.myth,
.channel-scale,
.nobel-feature { border-radius: 15px; }
.card { padding: clamp(22px, 2.4vw, 29px); }
.card h3,
.balance-loop-head h3 { color: var(--deep); }
.scene,
.note,
.take {
  padding: 20px 22px;
  border: 1px solid var(--line);
  line-height: 1.82;
}
.take {
  border-left: 1px solid var(--line);
  background: var(--surface-soft);
}
.chapter figure img { border-radius: 15px; }
figure figcaption {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}
.card p,
.scene,
.note,
.take,
.chapter .wrap > p:not(.eyebrow):not(.lead) { line-height: 1.82; }
.organ-layout,
.urine-layout { gap: 20px; }
.organ-list button,
.urine-list button {
  min-height: 48px;
  border-color: var(--line);
  border-radius: 12px;
  background: rgba(247, 251, 252, 0.88);
  color: var(--ink);
}
.organ-list button[aria-selected="true"],
.urine-list button[aria-selected="true"] {
  border-color: rgba(57, 127, 147, 0.42);
  background: var(--mist);
  color: var(--deep);
  box-shadow: inset 3px 0 0 var(--water);
}
.organ-list button:hover,
.urine-list button:hover { background: var(--surface); }
.urine-scale { gap: 9px; }
.urine-scale li {
  min-height: 110px;
  border-radius: 13px;
  background: var(--surface);
}
.urine-scale strong { color: var(--deep); }
.urine-scale li span { color: var(--muted); }
.balance-loop {
  padding: clamp(22px, 3.2vw, 32px);
  border-radius: 17px;
}
.balance-steps { gap: 10px; }
.balance-steps li {
  border-color: var(--line);
  border-radius: 13px;
  background: rgba(247, 251, 252, 0.86);
}
.balance-step-no {
  background: var(--mist);
  color: var(--deep);
}
.channel-scale-value { color: var(--deep); }
.channel-scale-detail,
.channel-scale-note { color: var(--muted); }
.channel-scale-detail b,
.channel-scale-note strong { color: var(--deep); }
.nobel-feature { border-radius: 17px; }
.chapter .nobel-feature img { background: var(--mist); }
.nobel-feature figcaption { color: var(--muted); }

.sources {
  padding: clamp(64px, 7vw, 88px) 0;
  background: var(--mist);
}
.sources h2 { color: var(--navy); }
.source-list { gap: 9px; }
.source-list li {
  padding: 15px 17px;
  border: 1px solid var(--line);
  border-radius: 12px;
  line-height: 1.78;
}
.source-list a,
.nobel-feature figcaption a { color: var(--deep); }
footer.site {
  margin-top: 0;
  border-top: 1px solid var(--line);
  background: #e6f0f3;
  color: var(--muted);
  padding: 28px 0 36px;
}
footer.site a { color: var(--deep); }

.progress-links {
  gap: 5px;
  padding: 9px 6px;
  border-color: var(--line);
  background: rgba(247, 251, 252, 0.94);
  box-shadow: 0 6px 20px rgba(35, 78, 92, 0.075);
}
.progress-links a { width: 22px; height: 22px; }
.progress-links a::before { background: var(--solid); }
.progress-current { color: var(--deep); font-size: 10px; }
.progress-rail-label { color: var(--muted); }

.drawer {
  border-color: var(--line);
  border-radius: 16px;
  background: rgba(247, 251, 252, 0.98);
  box-shadow: 0 16px 40px rgba(32, 73, 86, 0.14);
}
.drawer a {
  min-height: 48px;
  border: 1px solid transparent;
  border-radius: 11px;
  background: rgba(239, 247, 249, 0.92);
  transition: background 170ms var(--ease), border-color 170ms var(--ease), color 170ms var(--ease);
}
.drawer a:hover,
.drawer a:focus-visible {
  border-color: rgba(57, 127, 147, 0.25);
  background: var(--surface);
}
.drawer a.is-on { border-color: rgba(57, 127, 147, 0.28); }

.next { color: var(--deep); }
.next:hover { gap: 5px; }
.progress-rail { color: var(--muted); }

.hero-grid > div > *,
.hero-photo,
.hero-photo img,
.hero-photo::after { animation: none; }
.rise,
.rise.in {
  opacity: 1;
  transform: none;
  transition: none;
}
figure:hover img { transform: none; }

@media (hover: hover) {
  .card,
  .scene,
  .take { transition: border-color 180ms var(--ease), box-shadow 180ms var(--ease), transform 180ms var(--ease); }
  .card:hover,
  .scene:hover,
  .take:hover {
    transform: translateY(-2px);
    border-color: rgba(57, 127, 147, 0.24);
    box-shadow: 0 13px 28px rgba(35, 81, 96, 0.07);
  }
}
@media (max-width: 1120px) {
  .progress-rail { display: none; }
}
@media (max-width: 980px) {
  .wrap { width: min(820px, calc(100% - 48px)); }
  .hero { padding: 66px 0 60px; }
  .hero-grid { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .hero-grid > div { max-width: 680px; }
  .hero-photo img { min-height: 360px; }
  .chapter-map { padding: 46px 0 66px; }
  .chapter-map ol { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .chapter-map a { min-height: 126px; }
  .split,
  .two,
  .organ-layout,
  .urine-layout,
  .cards,
  .flow { grid-template-columns: minmax(0, 1fr); }
  .flow { gap: 9px; }
}
@media (max-width: 640px) {
  html { scroll-padding-top: 76px; }
  body { font-size: 16px; line-height: 1.78; }
  header.site { min-height: 64px; padding: 9px 15px; }
  .wrap { width: calc(100% - 36px); }
  .hero { padding: 34px 0 38px; }
  .hero-grid { gap: 21px; }
  .hero .kicker { margin-bottom: 12px; font-size: 15px; letter-spacing: 0.04em; }
  .hero h1 { max-width: 13em; font-size: clamp(34px, 8.8vw, 42px); line-height: 1.28; }
  .hero .sub { font-size: 16px; line-height: 1.8; }
  .hero-photo,
  .hero-photo img { min-height: 0; }
  .hero-photo img { aspect-ratio: 1.2 / 1; object-fit: cover; }
  .hero-photo figcaption { left: 11px; bottom: 11px; padding: 7px 10px; font-size: 11px; }
  .actions { gap: 8px; }
  .btn { min-height: 46px; padding: 10px 13px; font-size: 13px; }
  .chapter-map { padding: 34px 0 48px; }
  .chapter-map h2 { margin-bottom: 18px; font-size: 27px; }
  .chapter-map ol { grid-template-columns: minmax(0, 1fr); gap: 8px; }
  .chapter-map a { min-height: 78px; padding: 14px 15px; }
  .chapter-map small { min-width: 34px; margin-right: 8px; font-size: 22px; }
  .chapter { padding: 60px 0; }
  .chapter::before { top: 18px; right: 10px; font-size: 128px; -webkit-text-stroke-width: 1px; opacity: 0.6; }
  .chapter .wrap > h2 { font-size: clamp(29px, 7.6vw, 36px); line-height: 1.32; }
  .chapter .lead { margin-bottom: 24px; font-size: 16.5px; line-height: 1.82; }
  .chapter .wrap > p:not(.eyebrow):not(.lead),
  .card p,
  .scene,
  .note,
  .take { font-size: 15.5px; }
  .card { padding: 18px; }
  .scene,
  .note,
  .take { padding: 15px 16px; }
  .chapter figure img { border-radius: 13px; }
  .drawer { inset: 68px 10px auto auto; width: calc(100vw - 20px); max-height: calc(100dvh - 80px); padding: 11px; }
  .drawer.open { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 6px; }
  .drawer a { min-height: 46px; padding: 8px 9px; font-size: 13px; }
  .sources { padding: 54px 0; }
  .source-list li { padding: 13px 14px; font-size: 13px; }
  .channel-scale { padding: 19px 16px; }
  .nobel-feature { margin: 19px 0 22px; }
  .balance-loop { margin: 22px 0; padding: 17px 14px; }
  footer.site { padding: 24px 0 30px; font-size: 13px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after { animation: none !important; transition: none !important; }
}


/* Chapter labels stay visible but read as navigation markers, not repeated mini-headings. */
.chapter-index {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 15px;
  color: var(--water);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  line-height: 1.45;
}
.chapter-index::before {
  content: "";
  width: 24px;
  height: 1px;
  flex: 0 0 24px;
  background: var(--water-2);
}
.take { border-left: 1px solid var(--line); }
@media (max-width: 640px) {
  .chapter-index { margin-bottom: 12px; font-size: 11px; }
}
/* Pointer feedback and image breath */
@keyframes image-breath {
  0%, 100% { transform: scale(1.012); }
  50% { transform: scale(1.026); }
}
.hero-photo img,
.chapter figure img {
  transform-origin: center;
  transition: transform 520ms var(--ease);
}
.chapter-map a,
.card,
.scene,
.take {
  transition: transform 220ms var(--ease), border-color 220ms var(--ease), box-shadow 220ms var(--ease);
}
.chapter-map a:focus-visible {
  outline: 2px solid var(--water-2);
  outline-offset: 3px;
}
.chapter-map a:active,
.card:active,
.scene:active,
.take:active {
  transform: scale(0.985);
}
.hero-photo:active,
.chapter figure:active {
  transform: scale(0.995);
}
@media (hover: hover) and (pointer: fine) and (prefers-reduced-motion: no-preference) {
  .hero-photo:hover img,
  .hero-photo:focus-within img,
  .chapter figure:hover img,
  .chapter figure:focus-within img {
    animation: image-breath 2.8s ease-in-out infinite;
  }
  .chapter-map a:hover small { transform: translateY(-1px); }
}
@media (prefers-reduced-motion: reduce) {
  .chapter-map a:hover,
  .chapter-map a:focus-visible,
  .chapter-map a:active,
  .card:hover,
  .card:active,
  .scene:hover,
  .scene:active,
  .take:hover,
  .take:active,
  .hero-photo:active,
  .chapter figure:active {
    transform: none;
  }
}
.chapter-map small { transition: transform 220ms var(--ease); }
@media (prefers-reduced-motion: reduce) {
  .chapter-map a:hover small { transform: none; }
}