:root {
  color-scheme: light;
  --bg: #f4f4ef;
  --surface: #fbfbf8;
  --surface-soft: #eceee7;
  --ink: #1c1e1a;
  --muted: #676b61;
  --line: #d7d9d0;
  --accent: #c9d33a;
  --accent-ink: #1c1e1a;
  --radius: 14px;
  --shell: min(1180px, calc(100% - 48px));
  --nav-height: 72px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --bg: #1a1c19;
    --surface: #22251f;
    --surface-soft: #2a2e27;
    --ink: #f1f2ea;
    --muted: #b5b9ad;
    --line: #3c4238;
    --accent: #d1df3d;
    --accent-ink: #1c1e1a;
  }
}

:root[data-theme="light"] {
  color-scheme: light;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #1a1c19;
  --surface: #22251f;
  --surface-soft: #2a2e27;
  --ink: #f1f2ea;
  --muted: #b5b9ad;
  --line: #3c4238;
  --accent: #d1df3d;
  --accent-ink: #1c1e1a;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.55;
  text-rendering: optimizeLegibility;
}

body,
button,
a {
  -webkit-font-smoothing: antialiased;
}

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

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  font: inherit;
}

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

.shell {
  width: var(--shell);
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: var(--radius);
  background: var(--accent);
  color: var(--accent-ink);
  transform: translateY(-160%);
  transition: transform 180ms var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 4px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  min-height: var(--nav-height);
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}

.nav-wrap {
  min-height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  position: relative;
}

.brand {
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
}

.brand-name {
  color: var(--ink);
  font-size: 14px;
  font-weight: 750;
  letter-spacing: -0.025em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link,
.theme-toggle,
.menu-toggle {
  padding: 9px 11px;
  border: 1px solid transparent;
  border-radius: 10px;
  color: var(--muted);
  font-size: 13px;
  cursor: pointer;
  transition:
    color 180ms var(--ease),
    background 180ms var(--ease),
    border-color 180ms var(--ease),
    transform 180ms var(--ease);
}

.nav-link:hover,
.menu-toggle:hover {
  color: var(--ink);
  background: var(--surface-soft);
}

.theme-toggle {
  margin-left: 8px;
  background: transparent;
  border-color: var(--line);
  color: var(--ink);
  width: 38px;
  height: 38px;
  display: inline-grid;
  place-items: center;
  padding: 0;
  line-height: 1;
}

.theme-icon {
  display: none;
  width: 17px;
  height: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.theme-toggle:not(.is-dark) .theme-icon-moon,
.theme-toggle.is-dark .theme-icon-sun {
  display: block;
}

.theme-label {
  display: none;
}

.theme-toggle:hover {
  color: var(--ink);
  background: var(--surface-soft);
  border-color: var(--line);
}

.menu-toggle {
  display: none;
  background: transparent;
}

.hero {
  min-height: calc(100dvh - var(--nav-height));
  display: grid;
  grid-template-columns: minmax(0, 0.84fr) minmax(0, 1.16fr);
  align-items: center;
  gap: clamp(40px, 7vw, 104px);
  padding-top: 48px;
  padding-bottom: 56px;
}

.hero-copy {
  max-width: 520px;
}

.eyebrow {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.18em;
  line-height: 1.2;
  text-transform: uppercase;
}

.hero h1 {
  max-width: 9ch;
  margin: 0;
  font-size: clamp(4rem, 7.2vw, 6.5rem);
  font-weight: 700;
  letter-spacing: -0.075em;
  line-height: 0.92;
}

.hero-intro {
  max-width: 34rem;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 1.5vw, 1.22rem);
  line-height: 1.45;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 32px;
}

.button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 17px;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
  white-space: nowrap;
  transition:
    transform 180ms var(--ease),
    background 180ms var(--ease),
    color 180ms var(--ease),
    border-color 180ms var(--ease);
}

.button:hover {
  transform: translateY(-2px);
}

.button:active,
.theme-toggle:active,
.nav-link:active,
.menu-toggle:active {
  transform: translateY(1px) scale(0.98);
}

.button-primary {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--accent-ink);
}

.button-primary:hover {
  border-color: var(--ink);
  background: var(--ink);
  color: var(--bg);
}

.button-secondary {
  background: transparent;
  color: var(--ink);
}

.button-secondary:hover {
  background: var(--surface-soft);
}

.hero-visual {
  min-height: 430px;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 24px 72px rgba(35, 39, 29, 0.08);
}

.hero-visual img {
  width: 100%;
  height: 100%;
  min-height: 430px;
  object-fit: cover;
  transition:
    transform 900ms var(--ease),
    filter 900ms var(--ease);
}

.hero-visual:hover img {
  transform: scale(1.035);
}

:root[data-theme="dark"] .hero-visual img,
:root:not([data-theme]) .hero-visual img {
  filter: saturate(0.82) brightness(0.88);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme]) .hero-visual img {
    filter: none;
  }
}

.current-line {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 17px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.02em;
}

.section {
  padding-top: 124px;
  padding-bottom: 124px;
}

.section-soft {
  width: 100%;
  padding-right: max(24px, calc((100% - 1180px) / 2));
  padding-left: max(24px, calc((100% - 1180px) / 2));
  background: var(--surface-soft);
}

.section-heading {
  max-width: 620px;
  margin-bottom: 54px;
}

.section-heading h2,
.about-lead h2,
.contact-panel h2 {
  margin: 0;
  font-size: clamp(2.55rem, 4.7vw, 4.4rem);
  font-weight: 700;
  letter-spacing: -0.065em;
  line-height: 0.98;
}

.section-heading p,
.about-lead p {
  max-width: 42rem;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.experience-list {
  border-top: 1px solid var(--line);
}

.experience-item {
  display: grid;
  grid-template-columns: 132px minmax(190px, 0.78fr) minmax(0, 1.22fr);
  gap: 32px;
  padding: 28px 0 30px;
  border-bottom: 1px solid var(--line);
}

.experience-meta,
.tech-line {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.02em;
}

.experience-meta {
  line-height: 1.5;
}

.experience-role h3,
.stack-group h3,
.background-block h3,
.principle h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.025em;
}

.experience-role p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.experience-detail p {
  max-width: 40rem;
  margin: 0;
  color: var(--ink);
}

.experience-detail .tech-line {
  margin-top: 16px;
}

.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.96fr) minmax(0, 1.04fr);
  gap: clamp(48px, 9vw, 144px);
  align-items: start;
}

.about-lead {
  max-width: 520px;
}

.principles {
  border-top: 1px solid var(--line);
}

.principle {
  padding: 23px 0 25px;
  border-bottom: 1px solid var(--line);
}

.principle p {
  max-width: 34rem;
  margin: 8px 0 0;
  color: var(--muted);
}

.ai-section {
  padding-top: 0;
  padding-bottom: 104px;
}

.ai-copy {
  max-width: 820px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.ai-copy h2 {
  max-width: 12ch;
  margin: 0;
  font-size: clamp(2.55rem, 4.7vw, 4.4rem);
  font-weight: 700;
  letter-spacing: -0.065em;
  line-height: 0.98;
}

.ai-copy p {
  max-width: 48rem;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.ai-copy p + p {
  margin-top: 14px;
}

.stack-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 26px;
  border-top: 1px solid var(--line);
}

.stack-group {
  padding-top: 21px;
}

.stack-group p {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.section-compact {
  padding-top: 24px;
  padding-bottom: 126px;
}

.section-compact .section-heading {
  margin-bottom: 30px;
}

.section-compact .section-heading h2 {
  font-size: clamp(2rem, 3.6vw, 3.1rem);
}

.background-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 26px;
  border-top: 1px solid var(--line);
}

.background-block {
  padding-top: 21px;
}

.background-block p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.contact-section {
  padding-top: 0;
  padding-bottom: 124px;
}

.contact-panel {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 48px;
  padding: clamp(30px, 5vw, 64px);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--bg);
}

.contact-panel .eyebrow {
  color: color-mix(in srgb, var(--bg) 66%, transparent);
}

.contact-panel h2 {
  max-width: 12ch;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 5px;
  border-bottom: 1px solid var(--accent);
  color: var(--accent);
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  font-weight: 700;
  white-space: nowrap;
  transition:
    color 180ms var(--ease),
    border-color 180ms var(--ease),
    transform 180ms var(--ease);
}

.contact-link:hover {
  border-color: var(--bg);
  color: var(--bg);
  transform: translateY(-2px);
}

.site-footer {
  border-top: 1px solid var(--line);
}

.footer-wrap {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 24px;
  padding-top: 28px;
  padding-bottom: 30px;
}

.footer-name,
.footer-role {
  margin: 0;
}

.footer-name {
  font-size: 14px;
  font-weight: 700;
}

.footer-role {
  margin-top: 3px;
  color: var(--muted);
  font-size: 13px;
}

.footer-links {
  display: flex;
  gap: 22px;
  color: var(--muted);
  font-size: 13px;
}

.footer-links a {
  transition: color 180ms var(--ease);
}

.footer-links a:hover {
  color: var(--ink);
}

@media (max-width: 900px) {
  :root {
    --shell: min(100% - 40px, 720px);
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 48px;
    padding-top: 64px;
  }

  .hero-copy {
    max-width: 680px;
  }

  .hero h1 {
    max-width: 10ch;
  }

  .hero-visual,
  .hero-visual img {
    min-height: auto;
  }

  .experience-item {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 20px 24px;
  }

  .experience-detail {
    grid-column: 2;
  }

  .stack-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    row-gap: 34px;
  }

  .contact-panel {
    align-items: start;
    flex-direction: column;
  }
}

@media (max-width: 680px) {
  :root {
    --shell: calc(100% - 32px);
  }

  .site-header,
  .nav-wrap {
    min-height: 66px;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 1px);
    right: 0;
    left: 0;
    display: none;
    padding: 12px;
    border: 1px solid var(--line);
    border-top: 0;
    background: var(--surface);
    box-shadow: 0 18px 38px rgba(35, 39, 29, 0.08);
  }

  .site-nav.is-open {
    display: grid;
  }

  .nav-link,
  .theme-toggle {
    width: 100%;
    padding: 13px 12px;
    text-align: left;
  }

  .theme-toggle {
    margin: 4px 0 0;
    border-top: 1px solid var(--line);
    border-right-color: transparent;
    border-bottom-color: transparent;
    border-left-color: transparent;
    border-radius: 0;
    width: 100%;
    height: auto;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 10px;
    text-align: left;
    padding: 13px 12px;
  }

  .theme-toggle:hover {
    border-top-color: var(--line);
    border-right-color: transparent;
    border-bottom-color: transparent;
    border-left-color: transparent;
  }

  .theme-label {
    display: inline;
  }

  .menu-toggle {
    display: inline-block;
  }

  .hero {
    min-height: auto;
    gap: 38px;
    padding-top: 58px;
    padding-bottom: 48px;
  }

  .hero h1 {
    font-size: clamp(3.5rem, 18vw, 5.1rem);
  }

  .hero-intro {
    margin-top: 22px;
    font-size: 1rem;
  }

  .hero-actions {
    margin-top: 26px;
  }

  .current-line {
    align-items: start;
    flex-direction: column;
    gap: 4px;
    padding: 14px 0;
  }

  .section {
    padding-top: 86px;
    padding-bottom: 86px;
  }

  .ai-section {
    padding-top: 0;
    padding-bottom: 72px;
  }

  .section-soft {
    padding-right: 16px;
    padding-left: 16px;
  }

  .section-heading {
    margin-bottom: 38px;
  }

  .section-heading h2,
  .about-lead h2,
  .contact-panel h2 {
    font-size: clamp(2.5rem, 12vw, 3.6rem);
  }

  .section-heading p,
  .about-lead p {
    font-size: 16px;
  }

  .experience-item {
    display: block;
    padding: 24px 0 26px;
  }

  .experience-meta {
    margin-bottom: 15px;
  }

  .experience-detail {
    margin-top: 17px;
  }

  .about-grid,
  .background-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .stack-grid {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .stack-group {
    padding: 20px 0 22px;
    border-bottom: 1px solid var(--line);
  }

  .section-compact {
    padding-top: 10px;
    padding-bottom: 86px;
  }

  .contact-section {
    padding-bottom: 86px;
  }

  .contact-panel {
    padding: 28px 22px 30px;
  }

  .contact-link {
    font-size: 0.98rem;
  }

  .footer-wrap {
    align-items: start;
    flex-direction: column;
    gap: 20px;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

/* Variant 03: index studio. The accent bar and offset panel create hierarchy without decorative UI. */
:root[data-variant="index"] {
  color-scheme: light;
  --bg: #e9e9e2;
  --surface: #f7f7f1;
  --surface-soft: #dedfd8;
  --ink: #20231f;
  --muted: #686b63;
  --line: #c5c7bf;
  --accent: #5669d8;
  --accent-ink: #f7f7f1;
  --radius: 10px;
}

:root[data-variant="index"][data-theme="dark"] {
  color-scheme: dark;
  --bg: #1a1c22;
  --surface: #242731;
  --surface-soft: #2d303b;
  --ink: #f0f1ea;
  --muted: #b2b6c1;
  --line: #464b5a;
  --accent: #8c9cff;
  --accent-ink: #1b1e2a;
}

.variant-index .hero {
  grid-template-columns: minmax(0, 1.3fr) minmax(300px, 0.7fr);
  gap: clamp(40px, 5vw, 64px);
  align-items: end;
  padding-top: 74px;
  padding-bottom: 70px;
}

.variant-index .hero-copy {
  max-width: 720px;
  padding-left: 25px;
  border-left: 6px solid var(--accent);
}

.variant-index .eyebrow {
  color: var(--accent);
}

.variant-index .hero h1 {
  max-width: 100%;
  font-size: clamp(3.8rem, 6.8vw, 7.2rem);
  letter-spacing: -0.1em;
  line-height: 0.84;
}

.variant-index .hero-intro {
  max-width: 31rem;
  margin-top: 31px;
}

.variant-index .hero-visual {
  min-height: 590px;
  border-color: var(--ink);
  border-radius: var(--radius);
  box-shadow: 12px 12px 0 var(--accent);
  position: relative;
  isolation: isolate;
}

.variant-index .hero-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(
    circle at var(--pointer-x, 50%) var(--pointer-y, 50%),
    rgba(86, 105, 216, 0.2),
    transparent 28%
  );
  opacity: 0;
  transition: opacity 350ms var(--ease);
}

.variant-index .hero-visual:hover::after {
  opacity: 1;
}

.variant-index .hero-visual img {
  min-height: 590px;
  object-position: 77% center;
  filter: grayscale(0.82) contrast(1.12) saturate(0.82);
  animation: index-drift 16s ease-in-out infinite alternate;
}

.variant-index .hero-visual:hover img {
  transform: scale(1.025);
}

@keyframes index-drift {
  from {
    transform: scale(1.01) translate3d(0, 0, 0);
  }
  to {
    transform: scale(1.045) translate3d(-1.2%, -0.6%, 0);
  }
}

.variant-index .current-line {
  padding-top: 21px;
  padding-bottom: 21px;
  border-color: var(--ink);
  color: var(--ink);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.variant-index .section {
  padding-top: 126px;
  padding-bottom: 126px;
}

.variant-index .section-heading h2,
.variant-index .about-lead h2,
.variant-index .contact-panel h2 {
  font-size: clamp(3.1rem, 5.8vw, 6rem);
  letter-spacing: -0.095em;
  line-height: 0.88;
}

.variant-index .section-heading p,
.variant-index .about-lead p {
  max-width: 36rem;
}

.variant-index .section-soft {
  background: var(--surface-soft);
}

.variant-index .experience-list {
  border-top: 2px solid var(--ink);
}

.variant-index .experience-item {
  grid-template-columns: 164px minmax(210px, 0.8fr) minmax(0, 1.2fr);
  border-color: var(--ink);
  transition:
    background 260ms var(--ease),
    transform 260ms var(--ease);
}

.variant-index .experience-item:hover {
  background: var(--surface-soft);
  transform: translateX(10px);
}

.variant-index .experience-meta {
  color: var(--accent);
  font-weight: 700;
}

.variant-index .tech-line {
  color: var(--accent);
}

.variant-index .stack-grid,
.variant-index .background-grid,
.variant-index .principles {
  border-color: var(--ink);
}

.variant-index .stack-group,
.variant-index .background-block,
.variant-index .principle {
  border-color: var(--line);
}

.variant-index .contact-panel {
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  box-shadow: 12px 12px 0 var(--accent);
}

.variant-index .contact-panel .eyebrow {
  color: var(--accent);
}

.variant-index .contact-link {
  color: var(--accent);
  border-color: var(--accent);
}

.variant-index .contact-link:hover {
  color: var(--ink);
  border-color: var(--ink);
}

.variant-index [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 680ms var(--ease),
    transform 680ms var(--ease);
}

.variant-index [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 900px) {
  .variant-index .hero {
    grid-template-columns: 1fr;
    gap: 52px;
  }

  .variant-index .hero-visual,
  .variant-index .hero-visual img {
    min-height: 420px;
  }
}

@media (max-width: 680px) {
  .variant-index .hero {
    gap: 38px;
    padding-top: 56px;
    padding-bottom: 48px;
  }

  .variant-index .hero-copy {
    padding-left: 17px;
    border-left-width: 4px;
  }

  .variant-index .hero h1 {
    max-width: 100%;
    font-size: clamp(3.2rem, 16vw, 5.4rem);
  }

  .variant-index .hero-visual,
  .variant-index .hero-visual img {
    min-height: 320px;
  }

  .variant-index .experience-item:hover {
    transform: none;
  }

  .variant-index .contact-panel {
    box-shadow: 7px 7px 0 var(--accent);
  }
}

@media (prefers-reduced-motion: reduce) {
  .variant-index .hero-visual img {
    animation: none;
  }

  .variant-index [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .variant-index .hero-visual::after {
    display: none;
  }
}