:root {
  --ink: #15314a;
  --muted: #5f7183;
  --paper: #eef7fc;
  --white: #ffffff;
  --deep: #004a83;
  --deep-2: #006ba8;
  --teal: #0078bf;
  --copper: #0078bf;
  --gold: #1aa6dc;
  --sage: #eaf6fd;
  --rose: #dff2fb;
  --bluewash: #d8edf8;
  --line: rgba(0, 74, 131, 0.16);
  --shadow: 0 24px 70px rgba(0, 74, 131, 0.16);
  --radius: 8px;
  --max: 1180px;
  --header: 74px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header) + 20px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Avenir Next", "Helvetica Neue", Arial, "Hiragino Sans", "Yu Gothic", "PingFang TC", sans-serif;
  line-height: 1.72;
  letter-spacing: 0;
  overflow-x: hidden;
}

html[lang="zh-Hant-TW"] body {
  font-family: "PingFang TC", "Microsoft JhengHei", "Hiragino Sans", "Avenir Next", Arial, sans-serif;
}

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

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

button {
  font: inherit;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  left: 1rem;
  top: -5rem;
  z-index: 1000;
  padding: 0.75rem 1rem;
  color: #fff;
  background: var(--deep);
  border-radius: var(--radius);
}

.skip-link:focus {
  top: 1rem;
}

.container {
  width: min(100% - 32px, var(--max));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  min-height: var(--header);
  background: rgba(238, 247, 252, 0.94);
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(18px) saturate(145%);
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
}

.header-inner {
  min-height: var(--header);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 0;
}

.brand-logo {
  width: 128px;
  height: 42px;
  object-fit: contain;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  color: #fff;
  background: var(--deep);
  border-radius: var(--radius);
  font-size: 0.66rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  overflow: hidden;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 1rem;
  line-height: 1.25;
}

.brand small {
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.35;
}

.header-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 1rem;
  min-width: 0;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(0.75rem, 1.8vw, 1.45rem);
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 800;
}

.nav a {
  padding: 0.32rem 0;
  border-bottom: 2px solid transparent;
  white-space: nowrap;
}

.nav a:hover {
  color: var(--deep);
  border-bottom-color: var(--copper);
}

.lang-toggle {
  display: inline-grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  min-width: 172px;
  padding: 0.2rem;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 999px;
  box-shadow: 0 10px 28px rgba(0, 74, 131, 0.08);
}

.lang-toggle a {
  display: grid;
  place-items: center;
  min-width: 0;
  min-height: 34px;
  border: 0;
  border-radius: 999px;
  color: var(--muted);
  background: transparent;
  font-size: 0.76rem;
  font-weight: 900;
  cursor: pointer;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.lang-toggle a[aria-current="page"] {
  color: #fff;
  background: var(--deep);
}

.hero {
  position: relative;
  min-height: min(760px, 78svh);
  display: grid;
  align-items: center;
  overflow: hidden;
  color: #fff;
  background: #003b66;
  border-bottom: 1px solid var(--line);
}

.hero-bg,
.hero-shade {
  position: absolute;
  inset: 0;
}

.hero-bg {
  background-color: #dceff7;
  background-image: url("../manual/assets/cutout/opera-implant-spine-bgless-trim-tight_white.png");
  background-repeat: no-repeat;
  background-size: min(62vw, 920px) auto;
  background-position: calc(100% - 4vw) 56%;
}

.hero-shade {
  background: rgba(0, 45, 78, 0.7);
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: clamp(3.5rem, 7vw, 6.5rem) 0 clamp(2.5rem, 5vw, 5rem);
}

.hero-logo {
  width: min(360px, 72vw);
  height: auto;
  margin: 0 0 1.35rem;
  filter: drop-shadow(0 18px 28px rgba(0, 0, 0, 0.32));
}

.eyebrow {
  margin: 0 0 0.85rem;
  color: var(--copper);
  font-size: 0.75rem;
  font-weight: 950;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #bfeeff;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.24;
  letter-spacing: 0;
}

h1 {
  max-width: 780px;
  font-size: 3.75rem;
  font-weight: 900;
}

html[lang="en"] h1 {
  max-width: 920px;
  font-size: 3.75rem;
}

h2 {
  font-size: 2.25rem;
}

h3 {
  font-size: 1.18rem;
}

.hero-lead {
  max-width: 670px;
  margin: 1.35rem 0 0;
  color: rgba(255, 255, 255, 0.86);
  font-size: 1.1rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 2rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.78rem 1.15rem;
  border: 1px solid currentColor;
  border-radius: var(--radius);
  font-weight: 900;
  transition: transform 180ms ease, background-color 180ms ease, color 180ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button.primary {
  color: #fff;
  background: var(--copper);
  border-color: var(--copper);
}

.button.secondary {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(10px);
}

.final-card .button.secondary,
.section .button.secondary {
  color: var(--deep);
  background: #fff;
}

.hero-note {
  max-width: 680px;
  margin: 1.2rem 0 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.86rem;
}

.signal-band {
  background: var(--deep);
  color: #fff;
}

.signal-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: rgba(255, 255, 255, 0.15);
}

.signal {
  min-height: 136px;
  padding: 1.25rem;
  background:
    linear-gradient(135deg, rgba(26, 166, 220, 0.16), transparent 65%),
    var(--deep);
}

.signal span {
  display: block;
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.74rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.signal strong {
  display: block;
  margin-top: 0.18rem;
  color: #fff;
  font-size: 1.8rem;
  line-height: 1.15;
}

.signal p {
  margin: 0.45rem 0 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.9rem;
}

.original-points {
  padding: clamp(2.2rem, 4vw, 3.8rem) 0;
  background: #fff;
  border-bottom: 1px solid var(--line);
}

.original-points-inner {
  display: grid;
  grid-template-columns: minmax(240px, 0.42fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

.original-points h2 {
  font-size: 1.65rem;
}

.original-points ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.65rem;
}

.original-points li {
  position: relative;
  padding: 0.9rem 1rem 0.9rem 2.2rem;
  background: #f8fbfb;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: #33464c;
  line-height: 1.75;
}

.original-points li::before {
  content: "▶";
  position: absolute;
  left: 0.95rem;
  top: 0.96rem;
  color: var(--copper);
  font-size: 0.75rem;
}

.section {
  padding: clamp(4rem, 7vw, 7.2rem) 0;
}

.section.alt {
  background:
    linear-gradient(90deg, rgba(0, 74, 131, 0.04) 1px, transparent 1px),
    linear-gradient(rgba(0, 74, 131, 0.04) 1px, transparent 1px),
    #eaf6fd;
  background-size: 44px 44px;
  border-block: 1px solid var(--line);
}

.section-head {
  max-width: 790px;
  margin-bottom: clamp(2rem, 4vw, 3.2rem);
}

.section-head.center {
  margin-inline: auto;
  text-align: center;
}

.section-head p:not(.eyebrow) {
  margin: 1rem 0 0;
  color: var(--muted);
}

.value-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.value-card {
  min-height: 265px;
  padding: 1.35rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 16px 44px rgba(0, 74, 131, 0.08);
}

.value-card span {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: 1rem;
  color: #fff;
  background: var(--deep);
  border-radius: var(--radius);
  font-size: 0.82rem;
  font-weight: 900;
}

.value-card:nth-child(2) span {
  background: var(--teal);
}

.value-card:nth-child(3) span {
  background: var(--copper);
}

.value-card:nth-child(4) span {
  background: var(--deep-2);
}

.value-card p,
.split-copy p,
.method-list p,
.timeline p,
.device-grid p,
.evidence-cards p,
.risk-copy p,
.risk-panel li,
.source-list span,
.final-card p,
.site-footer p,
figcaption {
  color: var(--muted);
}

.split-section {
  background: #f7fbfe;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.94fr) minmax(0, 1.06fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: center;
}

.figure-frame {
  margin: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.figure-frame img {
  width: 100%;
  aspect-ratio: 16 / 11;
  object-fit: contain;
  background: #fff;
}

.figure-frame figcaption {
  padding: 0.9rem 1rem 1rem;
  font-size: 0.8rem;
  border-top: 1px solid var(--line);
}

.method-list {
  display: grid;
  gap: 0.85rem;
  margin-top: 1.5rem;
}

.method-list div {
  padding: 1rem 1.1rem;
  background: #fff;
  border: 1px solid var(--line);
  border-left: 4px solid var(--gold);
  border-radius: var(--radius);
}

.method-list strong {
  display: block;
  color: var(--deep);
  font-size: 0.98rem;
}

.method-list p {
  margin: 0.35rem 0 0;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  padding: 0;
  margin: 0;
  list-style: none;
}

.timeline li {
  position: relative;
  min-height: 208px;
  padding: 1.25rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 34px rgba(0, 74, 131, 0.07);
}

.timeline span {
  display: block;
  margin-bottom: 1.05rem;
  color: var(--copper);
  font-size: 0.78rem;
  font-weight: 950;
  letter-spacing: 0.14em;
}

.timeline p {
  margin: 0.55rem 0 0;
  font-size: 0.92rem;
}

.device-section {
  background: #004a83;
  color: #fff;
}

.device-section .eyebrow {
  color: #bfeeff;
}

.device-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 0.78fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: center;
}

.device-grid p {
  color: rgba(255, 255, 255, 0.76);
}

.device-benefits {
  display: grid;
  gap: 0;
  margin: 1.4rem 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid rgba(255, 255, 255, 0.18);
}

.device-benefits li {
  display: grid;
  grid-template-columns: minmax(150px, 0.44fr) minmax(0, 1fr);
  gap: 1rem;
  padding: 0.9rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.18);
}

.device-benefits strong {
  color: #fff;
  font-size: 0.9rem;
}

.device-benefits span {
  color: rgba(255, 255, 255, 0.74);
  font-size: 0.86rem;
  line-height: 1.65;
}

.device-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  margin-top: 1.6rem;
}

.device-facts div {
  min-height: 96px;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
}

.device-facts span {
  display: block;
  color: rgba(255, 255, 255, 0.62);
  font-size: 0.75rem;
  font-weight: 900;
}

.device-facts strong {
  display: block;
  margin-top: 0.35rem;
  color: #fff;
  font-size: 0.96rem;
  overflow-wrap: anywhere;
}

.device-photo {
  margin: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius);
}

.device-photo img {
  width: 100%;
  aspect-ratio: 1 / 0.78;
  object-fit: contain;
  background: #fff;
}

.device-photo figcaption {
  padding: 0.9rem 1rem;
  background: #fff;
  color: var(--muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--line);
}

.manual-section {
  background: #f8fbfb;
}

.manual-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(360px, 0.72fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: center;
  margin-bottom: clamp(2rem, 5vw, 4rem);
}

.manual-hero-copy {
  max-width: 760px;
}

.manual-hero-copy p:not(.eyebrow),
.manual-flow-panel p,
.manual-value-grid p {
  color: var(--muted);
}

.manual-actions .button.secondary {
  color: var(--deep);
  background: #fff;
}

.manual-preview {
  margin: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.manual-preview img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  object-position: 50% 0;
  background: #dff2fb;
}

.manual-preview figcaption {
  padding: 0.9rem 1rem 1rem;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
}

.manual-value-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.manual-value-grid article {
  padding: 1rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 34px rgba(0, 74, 131, 0.07);
}

.manual-value-grid img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  margin-bottom: 1rem;
  background: #fff;
  border: 1px solid rgba(20, 32, 37, 0.08);
  border-radius: var(--radius);
}

.manual-value-grid span {
  display: block;
  margin-bottom: 0.38rem;
  color: var(--copper);
  font-size: 0.72rem;
  font-weight: 950;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.manual-value-grid h3 {
  color: var(--deep);
  font-size: 1.06rem;
}

.manual-value-grid p {
  margin: 0.65rem 0 0;
  font-size: 0.9rem;
  line-height: 1.78;
}

.manual-flow-panel {
  margin-top: 1rem;
  padding: clamp(1.2rem, 3vw, 2rem);
  background: #f7fbfe;
  border: 1px solid rgba(26, 166, 220, 0.28);
  border-left: 4px solid var(--gold);
  border-radius: var(--radius);
}

.manual-flow-panel .section-head {
  margin-bottom: 1.25rem;
}

.manual-steps {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0.85rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.manual-steps li {
  min-height: 190px;
  padding: 1rem;
  background: #fff;
  border: 1px solid rgba(26, 166, 220, 0.22);
  border-radius: var(--radius);
}

.manual-steps span {
  display: block;
  color: var(--gold);
  font-size: 0.75rem;
  font-weight: 950;
  letter-spacing: 0.12em;
}

.manual-steps strong {
  display: block;
  margin-top: 0.7rem;
  color: var(--deep);
  line-height: 1.45;
}

.manual-steps p {
  margin: 0.5rem 0 0;
  font-size: 0.86rem;
  line-height: 1.72;
}

.manual-spec-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  gap: 1rem;
  margin-top: 1rem;
}

.manual-spec-card {
  padding: 1.25rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 34px rgba(0, 74, 131, 0.06);
}

.manual-spec-card h3 {
  color: var(--deep);
}

.manual-spec-card p:not(.eyebrow) {
  margin: 0.75rem 0 0;
  color: var(--muted);
}

.manual-mini-table {
  display: grid;
  gap: 0.45rem;
  margin-top: 1rem;
}

.manual-mini-table div {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 0.7rem;
  align-items: center;
  padding: 0.72rem 0.8rem;
  background: #f8fbfb;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.manual-mini-table strong {
  color: var(--deep);
  white-space: nowrap;
}

.manual-mini-table span {
  color: var(--muted);
  font-size: 0.9rem;
}

.manual-check-list {
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.55rem;
}

.manual-check-list li {
  position: relative;
  padding: 0.78rem 0.85rem 0.78rem 2rem;
  color: #33464c;
  background: #eef8fe;
  border: 1px solid rgba(26, 166, 220, 0.24);
  border-radius: var(--radius);
  line-height: 1.72;
}

.manual-check-list li::before {
  content: "";
  position: absolute;
  left: 0.85rem;
  top: 1.08rem;
  width: 0.48rem;
  height: 0.48rem;
  background: var(--gold);
  border-radius: 50%;
}

.evidence-layout {
  display: grid;
  grid-template-columns: minmax(340px, 0.8fr) minmax(0, 1.2fr);
  gap: 1.2rem;
  align-items: stretch;
}

.evidence-image img {
  aspect-ratio: 1 / 1.04;
}

.evidence-cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.evidence-cards article {
  min-height: 176px;
  padding: 1.2rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 34px rgba(0, 74, 131, 0.07);
}

.evidence-cards span {
  display: block;
  color: var(--deep);
  font-size: 2.1rem;
  font-weight: 900;
  line-height: 1;
}

.evidence-cards h3 {
  margin-top: 0.7rem;
}

.evidence-cards p {
  margin: 0.52rem 0 0;
  font-size: 0.92rem;
}

.evidence-cards .wide {
  grid-column: 1 / -1;
  min-height: auto;
  background: #eef8fe;
  border-left: 4px solid var(--gold);
}

.figure-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.figure-card {
  margin: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 14px 44px rgba(0, 74, 131, 0.08);
}

.figure-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  background: #fff;
}

.figure-card figcaption {
  min-height: 126px;
  padding: 0.9rem 1rem 1rem;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
}

.figure-card strong {
  display: block;
  color: var(--ink);
  margin-bottom: 0.35rem;
}

.figure-card span {
  display: block;
}

.figure-atlas {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.atlas-card {
  margin: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 14px 44px rgba(0, 74, 131, 0.08);
}

.atlas-card.large {
  grid-column: span 2;
}

.atlas-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  background: #fff;
}

.atlas-card.large img {
  aspect-ratio: 16 / 9;
}

.atlas-card figcaption {
  min-height: 132px;
  padding: 0.95rem 1rem 1.05rem;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
  line-height: 1.7;
}

.atlas-card strong {
  display: block;
  color: var(--deep);
  margin-bottom: 0.35rem;
}

.atlas-card span {
  display: block;
}

.risk-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

.risk-panel {
  padding: 1.35rem;
  background: #eef8fe;
  border: 1px solid rgba(0, 120, 191, 0.26);
  border-left: 4px solid var(--copper);
  border-radius: var(--radius);
}

.risk-panel h3 {
  color: #004a83;
}

.risk-panel ul {
  margin: 1rem 0 0;
  padding-left: 1.15rem;
}

.risk-panel li + li {
  margin-top: 0.65rem;
}

.source-text-section {
  background: #f7fbfe;
}

.source-text-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.source-text-card {
  padding: 1.35rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 34px rgba(0, 74, 131, 0.06);
}

.source-text-card.wide {
  grid-column: 1 / -1;
}

.source-text-card h3 {
  margin-bottom: 0.85rem;
  color: var(--deep);
}

.source-text-card p {
  margin: 0;
  color: #33464c;
  font-size: 0.95rem;
  line-height: 1.95;
  text-align: justify;
  overflow-wrap: anywhere;
}

.source-text-card p + p {
  margin-top: 0.8rem;
}

.tips-panel {
  margin-top: 1.2rem;
  padding: 1.25rem;
  background: #eef8fe;
  border: 1px solid rgba(26, 166, 220, 0.32);
  border-left: 4px solid var(--gold);
  border-radius: var(--radius);
}

.tips-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.85rem;
}

.tips-grid article {
  padding: 1rem;
  background: rgba(255, 255, 255, 0.76);
  border: 1px solid rgba(26, 166, 220, 0.24);
  border-radius: var(--radius);
}

.tips-grid h3 {
  color: #004a83;
  font-size: 1rem;
  margin-bottom: 0.45rem;
}

.tips-grid p {
  margin: 0;
  color: #445c70;
  font-size: 0.88rem;
  line-height: 1.82;
}

.source-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.source-list a {
  min-height: 148px;
  padding: 1.2rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 34px rgba(0, 74, 131, 0.06);
  transition: border-color 180ms ease, transform 180ms ease;
}

.source-list a:hover {
  border-color: var(--copper);
  transform: translateY(-1px);
}

.source-list strong,
.source-list span {
  display: block;
}

.source-list strong {
  color: var(--deep);
}

.source-list span {
  margin-top: 0.55rem;
  font-size: 0.9rem;
}

.final-cta {
  padding: clamp(4rem, 7vw, 7rem) 0;
  color: #fff;
  background-color: #004a83;
  background-image: url("../manual/assets/cutout/opera-implant-spine-bgless-trim-tight_white.png");
  background-repeat: no-repeat;
  background-size: min(48vw, 620px) auto;
  background-position: calc(100% - 4vw) 54%;
}

.final-card {
  max-width: 840px;
}

.final-card .eyebrow {
  color: #bfeeff;
}

.final-card p {
  color: rgba(255, 255, 255, 0.78);
}

.site-footer {
  padding: 1.35rem 0;
  background: #003b66;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.site-footer p {
  margin: 0;
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.78rem;
}

@media (max-width: 1040px) {
  .nav {
    display: none;
  }

  .value-grid,
  .figure-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .timeline,
  .source-text-grid,
  .source-list,
  .manual-value-grid,
  .manual-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .evidence-layout,
  .split,
  .device-grid,
  .original-points-inner,
  .risk-grid,
  .manual-hero,
  .manual-spec-grid {
    grid-template-columns: 1fr;
  }

  .tips-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  :root {
    --header: 68px;
  }

  .container {
    width: min(100% - 24px, var(--max));
  }

  .brand small {
    display: none;
  }

  .brand-mark {
    width: 40px;
    height: 40px;
    font-size: 0.56rem;
  }

  .brand-logo {
    width: 96px;
    height: 36px;
  }

  .lang-toggle {
    min-width: 148px;
  }

  .lang-toggle a {
    font-size: 0.7rem;
    min-height: 32px;
  }

  .hero {
    min-height: 74svh;
  }

  .hero-shade {
    background: rgba(0, 45, 78, 0.82);
  }

  .hero-bg {
    background-size: 150% auto;
    background-position: 64% 52%;
  }

  .signal-grid,
  .value-grid,
  .timeline,
  .device-facts,
  .evidence-cards,
  .figure-grid,
  .figure-atlas,
  .source-text-grid,
  .tips-grid,
  .source-list,
  .manual-value-grid,
  .manual-steps {
    grid-template-columns: 1fr;
  }

  .atlas-card.large {
    grid-column: auto;
  }

  .atlas-card figcaption {
    min-height: auto;
  }

  .source-text-card.wide {
    grid-column: auto;
  }

  .signal {
    min-height: auto;
  }

  .device-benefits li {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }

  .value-card,
  .timeline li,
  .manual-steps li {
    min-height: auto;
  }

  .evidence-layout {
    gap: 1rem;
  }

  .footer-inner {
    display: block;
  }
}

@media (max-width: 430px) {
  .header-inner {
    gap: 0.55rem;
  }

  .brand {
    gap: 0.5rem;
  }

  .brand strong {
    font-size: 0.92rem;
  }

  .lang-toggle {
    min-width: 132px;
  }

  .lang-toggle a {
    padding-inline: 0.28rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .button {
    width: 100%;
  }

  .manual-mini-table div {
    grid-template-columns: 1fr;
    gap: 0.2rem;
  }
}

.hero-subtitle {
  display: inline-block;
  margin-top: 0.5rem;
  font-size: 2rem;
  line-height: 1.45;
}

@media (max-width: 1200px) {
  .nav { display: none; }
}

.overview-section,
.faq-section {
  background: var(--white);
}

.definition-list {
  margin: 2rem 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 2rem;
}

.definition-list > div {
  border-top: 2px solid var(--deep-2);
  padding-top: 1rem;
}

.definition-list dt {
  font-weight: 800;
}

.definition-list dd {
  margin: 0.65rem 0 0;
  color: var(--muted);
}

.text-link,
.reference-links a {
  color: var(--deep);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.topic-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  border-top: 1px solid var(--line);
  padding-top: 0.75rem;
}

.topic-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--deep);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 0.25em;
}

.faq-list {
  max-width: 900px;
}

.faq-list article {
  padding: 1.5rem 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 6rem;
}

.faq-list h3 {
  font-size: 1.15rem;
  line-height: 1.6;
}

.faq-list p {
  margin: 0.65rem 0;
}

.source-list a,
.definition-list > div {
  min-width: 0;
  overflow-wrap: anywhere;
}

.source-list cite {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.85rem;
  font-style: normal;
  line-height: 1.6;
}

.source-list .reference-authors {
  margin-top: 0.65rem;
  color: var(--ink);
  font-size: 0.82rem;
}

.source-list .reference-id {
  margin-top: 0.65rem;
  font-size: 0.78rem;
}

@media (max-width: 720px) {
  .definition-list {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }

  h1,
  html[lang="en"] h1 {
    font-size: 2.5rem;
  }

  h2 {
    font-size: 1.65rem;
  }

  .hero-subtitle {
    font-size: 1.5rem;
  }

  .hero-lead {
    font-size: 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button { transition: none; }
}