:root {
  --paper: #f4f1e9;
  --surface: #fffdf8;
  --ink: #14213d;
  --copy: #465269;
  --line: #d8d2c6;
  --accent: #28756f;
  --content: 1120px;
  --reading: 760px;
  --gutter: clamp(1rem, 3vw, 2rem);
  --section-space: clamp(3.5rem, 6vw, 5.25rem);
}

* {
  box-sizing: border-box;
}

details:not([open]) > :not(summary) {
  display: none !important;
}

html {
  scroll-behavior: smooth;
  overflow-x: clip;
}

body {
  margin: 0;
  overflow-x: clip;
  background: var(--paper);
  color: var(--ink);
  font-family: "Noto Sans TC", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.75;
}

a {
  color: inherit;
}

img,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
}

button,
input,
select,
textarea {
  font: inherit;
}

.skip-link {
  position: fixed;
  top: -5rem;
  left: 1rem;
  z-index: 100;
  padding: .65rem 1rem;
  background: var(--ink);
  color: #fff;
}

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

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--line);
  background: rgba(244, 241, 233, .95);
  backdrop-filter: blur(14px);
}

.nav {
  width: min(var(--content), calc(100% - 2 * var(--gutter)));
  min-height: 68px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: .75rem;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
}

.brand-mark {
  width: 34px;
  height: 34px;
  flex: 0 0 34px;
  display: grid;
  place-items: center;
  background: var(--ink);
  color: #fff;
  font: 700 1rem/1 Georgia, serif;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(.9rem, 2.5vw, 1.5rem);
}

.nav-links a {
  color: var(--copy);
  font-size: .9rem;
  font-weight: 600;
  text-decoration: none;
}

.nav-links a[aria-current="page"],
.nav-links a:hover {
  color: var(--accent);
}

.menu-button {
  display: none;
  min-height: 44px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  padding: .45rem .7rem;
}

.page,
.integrated-page main {
  min-width: 0;
}

.page {
  width: min(var(--content), calc(100% - 2 * var(--gutter)));
  margin-inline: auto;
}

.hero {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(250px, .92fr);
  gap: clamp(2rem, 6vw, 4.5rem);
  align-items: center;
  padding-block: var(--section-space);
  border-bottom: 1px solid var(--line);
}

.hero-copy,
.feature-copy,
.section-head > div {
  min-width: 0;
}

.eyebrow,
.section-no,
.index-code,
.activity-index span {
  color: var(--accent);
  font: 700 .78rem/1.5 "JetBrains Mono", monospace;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.eyebrow {
  margin: 0 0 1rem;
}

.display {
  max-width: 35.5rem;
  margin: 0;
  font-family: "Noto Sans TC", system-ui, sans-serif;
  font-size: clamp(3.25rem, 5vw, 4.25rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.055em;
  overflow-wrap: anywhere;
}

.display-name {
  display: block;
}

.display-focus {
  display: flex;
  flex-wrap: wrap;
  column-gap: .3em;
}

.display-focus > span {
  white-space: nowrap;
}

.lead {
  max-width: 46rem;
  margin: 1.5rem 0 0;
  color: var(--copy);
  font-size: 1.05rem;
}

.portrait {
  width: min(100%, 380px);
  margin: 0;
  justify-self: start;
}

.portrait img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  object-position: center 24%;
  border-bottom: 4px solid var(--accent);
}

.portrait p,
.caption {
  margin: .7rem 0 0;
  color: var(--copy);
  font-size: .82rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.75rem;
}

.button {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .65rem 1rem;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
}

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

.section {
  min-width: 0;
  padding-block: var(--section-space);
  border-bottom: 1px solid var(--line);
}

.section-head {
  max-width: var(--reading);
  margin-bottom: clamp(2rem, 4vw, 3rem);
}

.section-no {
  display: block;
  margin-bottom: .85rem;
}

.section h1,
.section h2,
.skills-index h2 {
  max-width: 20ch;
  margin: 0;
  font-family: "Noto Sans TC", system-ui, sans-serif;
  font-size: clamp(2.25rem, 4.2vw, 3.65rem);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -.04em;
  overflow-wrap: anywhere;
}

.intro {
  max-width: var(--reading);
  margin: .85rem 0 0;
  color: var(--copy);
}

.index-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.index-row {
  min-width: 0;
  display: grid;
  grid-template-columns: 72px minmax(180px, .6fr) minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1.35rem 0;
  border-top: 1px solid var(--line);
}

.index-row:last-child {
  border-bottom: 1px solid var(--line);
}

.index-row strong {
  font-size: 1.08rem;
}

.index-row p {
  margin: 0;
  color: var(--copy);
}

.feature {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
  gap: clamp(2rem, 6vw, 4.5rem);
  align-items: center;
  padding: clamp(2.5rem, 5vw, 4rem) 0;
  border-top: 1px solid var(--line);
}

.feature-copy {
  max-width: var(--reading);
}

.feature:nth-of-type(even) .feature-media {
  order: 2;
}

.feature-media img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.feature-media img[src$="yian-it.webp"] {
  object-position: center 9%;
}

.feature:nth-of-type(3) .feature-copy h3 {
  max-width: none;
  font-size: clamp(1.9rem, 2.35vw, 2.1rem);
  white-space: nowrap;
}

.page > .section:last-child {
  padding-block: clamp(3rem, 5vw, 4.5rem);
}

.page > .section:last-child .section-head {
  margin-bottom: 0;
}

.feature-copy h2,
.feature-copy h3 {
  max-width: 18ch;
  margin: .35rem 0 1rem;
  font-family: "Noto Sans TC", system-ui, sans-serif;
  font-size: clamp(1.9rem, 3.3vw, 3rem);
  line-height: 1.18;
  letter-spacing: -.03em;
  overflow-wrap: anywhere;
}

.feature-copy p {
  color: var(--copy);
}

.feature-facts,
.case-reading-guide {
  display: grid;
  gap: .65rem;
  margin: 1.25rem 0;
}

.feature-facts > div,
.case-reading-guide > div {
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  gap: 1rem;
  padding-top: .65rem;
  border-top: 1px solid var(--line);
}

.feature-facts dt,
.case-reading-guide dt {
  color: var(--accent);
  font-weight: 800;
}

.feature-facts dd,
.case-reading-guide dd {
  margin: 0;
  color: var(--copy);
}

.meta {
  margin: 1rem 0 1.5rem;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .75rem 1.5rem;
}

.meta div {
  padding-top: .65rem;
  border-top: 1px solid var(--line);
}

.meta dt {
  color: var(--accent);
  font-size: .78rem;
  font-weight: 800;
}

.meta dd {
  margin: .2rem 0 0;
  color: var(--copy);
}

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

.photo-grid figure,
.video-list figure {
  min-width: 0;
  margin: 0;
}

.photo-grid img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.video-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
}

.video-list video {
  width: 100%;
  aspect-ratio: 9 / 16;
  object-fit: contain;
  background: #101827;
}

.video-list .landscape {
  grid-column: span 2;
}

.video-list .landscape video {
  aspect-ratio: 16 / 9;
}

.note {
  padding: 1rem 0;
  border-block: 1px solid var(--line);
  color: var(--copy);
}

.activity-index {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem 1rem;
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.activity-index a {
  color: var(--copy);
  font-weight: 700;
  text-underline-offset: .25rem;
}

#frame-running-title,
#ai-process-title {
  scroll-margin-top: 5.5rem;
}

.certificate-disclosure,
.media-disclosure {
  border-block: 1px solid var(--line);
}

.certificate-disclosure > summary,
.media-disclosure > summary {
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: .85rem 0;
  color: var(--ink);
  font-weight: 800;
  cursor: pointer;
}

.certificate-disclosure > summary::after,
.media-disclosure > summary::after {
  content: "+";
  color: var(--accent);
  font: 700 1.3rem/1 Georgia, serif;
}

.certificate-disclosure[open] > summary::after,
.media-disclosure[open] > summary::after {
  content: "−";
}

.certificate-disclosure .when-open,
.media-disclosure .when-open {
  display: none;
}

.certificate-disclosure[open] .when-closed,
.media-disclosure[open] .when-closed {
  display: none;
}

.certificate-disclosure[open] .when-open,
.media-disclosure[open] .when-open {
  display: inline;
}

.certificate {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(240px, .65fr) minmax(0, 1fr);
  gap: 2.5rem;
  align-items: start;
  padding-block: 1.75rem;
}

.certificate img,
.certificate-pdf {
  width: 100%;
  border: 1px solid var(--line);
}

.certificate-preview {
  display: block;
  min-width: 0;
}

.certificate-preview img {
  height: auto;
}

.certificate-pdf {
  min-height: clamp(28rem, 65vw, 52rem);
  background: var(--surface);
}

.media-disclosure .photo-grid,
.media-disclosure .video-list {
  padding-block: 1.75rem;
}

.skills-index {
  width: min(var(--content), calc(100% - 2 * var(--gutter)));
  margin-inline: auto;
  padding-block: var(--section-space);
  border-bottom: 1px solid var(--line);
}

.skills-ledger {
  margin: 1.75rem 0 0;
}

.skills-ledger > div {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(150px, .35fr) minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1rem 0;
  border-top: 1px solid var(--line);
}

.skills-ledger dt {
  color: var(--accent);
  font-weight: 800;
}

.skills-ledger dd {
  margin: 0;
  color: var(--copy);
}

.anchor-alias {
  position: relative;
  top: -5rem;
  display: block;
  visibility: hidden;
}

.site-footer {
  width: min(var(--content), calc(100% - 2 * var(--gutter)));
  min-height: 0;
  margin-inline: auto;
  padding-block: 1.5rem 2.5rem;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 1.5rem;
  border-top: 1px solid var(--line);
  color: var(--copy);
  font-size: .86rem;
}

.site-footer > :nth-child(2) {
  text-align: center;
}

.site-footer a {
  color: var(--accent);
}

@media (max-width: 760px) {
  :root {
    --gutter: 1rem;
    --section-space: 3.5rem;
  }

  .nav {
    min-height: 64px;
  }

  .brand {
    max-width: calc(100% - 4rem);
  }

  .brand > span:last-child {
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
  }

  .menu-button {
    display: block;
    flex: 0 0 auto;
  }

  .nav-links {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    display: none;
    padding: 1rem var(--gutter) 1.25rem;
    flex-direction: column;
    align-items: flex-start;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
  }

  .nav-links.open {
    display: flex;
  }

  .hero,
  .feature,
  .certificate {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero {
    gap: 2.25rem;
  }

  .section-head {
    grid-template-columns: minmax(0, 1fr);
    gap: .75rem;
  }

  .feature {
    gap: 1.5rem;
    padding-block: 2.25rem;
  }

  .feature-copy {
    max-width: 100%;
  }

  .hero-copy {
    order: 1;
  }

  .portrait {
    order: 2;
    width: min(100%, 340px);
    justify-self: center;
  }

  .display {
    max-width: 100%;
    font-size: clamp(2.55rem, 12vw, 3.45rem);
    line-height: 1.1;
  }

  .lead {
    font-size: 1rem;
  }

  .actions {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
  }

  .button {
    width: 100%;
  }

  .section h1,
  .section h2,
  .skills-index h2 {
    max-width: 100%;
    font-size: clamp(2.05rem, 9.5vw, 2.7rem);
  }

  .index-row,
  .skills-ledger > div,
  .feature-facts > div,
  .case-reading-guide > div {
    grid-template-columns: minmax(0, 1fr);
    gap: .35rem;
  }

  .feature:nth-of-type(even) .feature-media {
    order: 0;
  }

  .feature-copy h2,
  .feature-copy h3 {
    max-width: 100%;
    font-size: clamp(1.8rem, 8vw, 2.35rem);
  }

  .feature:nth-of-type(3) .feature-copy h3 {
    font-size: clamp(1.8rem, 8vw, 2.35rem);
    white-space: normal;
  }

  .meta,
  .photo-grid,
  .video-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .video-list .landscape {
    grid-column: auto;
  }

  .activity-index {
    flex-direction: column;
    align-items: flex-start;
  }

  .certificate {
    gap: 1.5rem;
  }

  .site-footer {
    padding-bottom: 2rem;
    grid-template-columns: minmax(0, 1fr);
    gap: .35rem;
  }

  .site-footer > :nth-child(2) {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}