:root {
  --bg: #f3f1eb;
  --ink: #161513;
  --dim: #5a5750;
  --rule: #d2cec4;
  --rail: 13.25rem;
  --sans: "IBM Plex Sans", "IBM Plex Sans JP", sans-serif;
  --serif: "Shippori Mincho", "IBM Plex Sans JP", serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--bg);
  background-image: radial-gradient(rgba(22, 21, 19, 0.055) 0.65px, transparent 0.75px);
  background-size: 22px 22px;
  color: var(--ink);
  --lead: 1.7;
  font-family: var(--sans);
  font-weight: 400;
  font-size: 15px;
  line-height: var(--lead);
  letter-spacing: 0.01em;
}

html[lang="ja"] body {
  --lead: 1.9;
  font-size: 15.5px;
  line-height: var(--lead);
  letter-spacing: 0.04em;
  font-feature-settings: "palt" 1, "kern" 1;
}

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

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3rem;
  background: var(--ink);
  color: var(--bg);
  padding: 0.4rem 0.6rem;
}

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

.rail {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--rail);
  padding: 1.75rem 1.35rem 1.5rem;
  border-right: 1px dotted color-mix(in srgb, var(--ink) 18%, transparent);
  display: flex;
  flex-direction: column;
  z-index: 5;
  background-color: color-mix(in srgb, var(--bg) 94%, transparent);
  background-image: radial-gradient(rgba(22, 21, 19, 0.055) 0.65px, transparent 0.75px);
  background-size: 22px 22px;
}

.rail-progress {
  position: absolute;
  top: 0;
  right: -1px;
  width: 1px;
  height: 0;
  background: var(--ink);
}

.brand {
  font-weight: 500;
  font-size: 0.72rem;
  letter-spacing: 0.34em;
}

.loc {
  margin: 0.55rem 0 0;
  color: var(--dim);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  line-height: 1.5;
}

.index {
  margin-top: 2.4rem;
  display: grid;
  gap: 0.85rem;
}

.index-label {
  margin: 0 0 0.2rem;
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  color: var(--dim);
}

html[lang="en"] .index-label,
html[lang="en"] h3,
html[lang="en"] .kicker,
html[lang="en"] label,
html[lang="en"] button[type="submit"] {
  text-transform: uppercase;
}

.index a,
.mobile-nav a {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  font-size: 0.8rem;
  color: var(--dim);
  transition: color 0.25s ease;
}

.index a:hover,
.mobile-nav a:hover,
.index a.is-current {
  color: var(--ink);
}

.index span,
.mobile-nav span {
  flex: 0 0 1.35rem;
  font-size: 0.62rem;
  letter-spacing: 0.06em;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.index b,
.mobile-nav b {
  font-weight: 400;
  line-height: 1.45;
}

.body {
  margin: 1rem 0 0;
  max-width: 42rem;
  color: var(--dim);
}

.role {
  margin: 0.4rem 0 0;
  font-size: 0.78rem;
  color: var(--dim);
}

.bio {
  margin-top: 1.8rem;
  max-width: 42rem;
}

.bio p {
  margin: 0 0 1.15rem;
  color: var(--dim);
}

.bio p:last-child {
  margin-bottom: 0;
}

.lang {
  margin-top: auto;
  display: flex;
  align-items: baseline;
  gap: 0.35rem;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--dim);
}

.lang-btn {
  border: 0;
  background: none;
  padding: 0;
  font: inherit;
  color: var(--dim);
  cursor: pointer;
}

.lang-btn.is-active {
  color: var(--ink);
}

.mobile-bar,
.mobile-nav {
  display: none;
}

main {
  margin-left: var(--rail);
  padding: 2.25rem 4.5rem 4rem 3.25rem;
  max-width: calc(var(--rail) + 56rem);
}

.open {
  padding: 1.5rem 0 3rem;
}

.kicker {
  margin: 0 0 1.15rem;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--dim);
}

h1,
.name {
  font-family: var(--serif);
  font-weight: 500;
}

h1 {
  margin: 0;
  font-size: clamp(2.1rem, 3.8vw, 3.35rem);
  letter-spacing: 0.06em;
  line-height: 1.35;
  max-width: 12em;
}

html[lang="en"] h1 {
  letter-spacing: -0.03em;
  line-height: 1.12;
  max-width: 13ch;
  font-size: clamp(2.4rem, 4.4vw, 3.8rem);
}

.lede,
.ch-lead {
  margin: 1.35rem 0 0;
  max-width: 38rem;
  color: var(--ink);
  font-size: 1.02rem;
  font-weight: 400;
}

.ch-lead {
  color: var(--dim);
}

.chapter {
  padding: 2.8rem 0 0.6rem;
  border: 0;
}

.chapter::before {
  content: "";
  display: block;
  width: 2.1rem;
  height: 5px;
  margin: 0 0 1.85rem;
  background-image: radial-gradient(circle, var(--ink) 1.15px, transparent 1.25px);
  background-size: 0.7rem 5px;
  background-repeat: repeat-x;
  opacity: 0.38;
}

.ch-head {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  margin-bottom: 1.25rem;
}

.ch-head span {
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--dim);
  font-variant-numeric: tabular-nums;
}

.dots {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  max-width: 42rem;
}

.dots li {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  padding: 0.55rem 0;
}

.dots li::before {
  content: "";
  flex: 0 0 5px;
  width: 5px;
  height: 5px;
  margin-top: calc((var(--lead) * 1em - 5px) / 2);
  border-radius: 50%;
  background: var(--ink);
}

.split-text .dots {
  margin-top: 0;
}

.split-text .dots li {
  padding-left: 0;
}

.split-text ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  color: var(--dim);
}

.steps {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  max-width: 44rem;
  counter-reset: step;
}

.steps li {
  display: grid;
  grid-template-columns: 3.2rem 1fr;
  gap: 1.1rem;
  align-items: start;
  padding: 0.7rem 0;
  counter-increment: step;
  color: var(--dim);
  --fs: 1em;
}

.steps li::before {
  content: counter(step, decimal-leading-zero);
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1;
  height: 1.15rem;
  margin-top: calc((var(--lead) * var(--fs) - 1.15rem) / 2);
  color: var(--ink);
}

h2 {
  margin: 0;
  font-size: 1.2rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  line-height: 1.4;
}

h3 {
  margin: 0 0 0.9rem;
  font-size: 0.92rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--ink);
}

.sheet {
  margin: 1.5rem 0 0;
  padding: 0;
  max-width: 44rem;
}

.sheet div {
  display: grid;
  grid-template-columns: 7.5rem 1fr;
  gap: 1.5rem;
  padding: 0.55rem 0;
}

.sheet dt {
  font-weight: 500;
  font-size: 0.84rem;
}

.sheet dd {
  margin: 0;
  color: var(--dim);
}

.split-text {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.75rem;
  margin-top: 1.5rem;
  max-width: 48rem;
}

.name {
  margin: 0;
  font-size: 0.92rem;
  letter-spacing: 0.1em;
  line-height: 1.4;
}

.mail {
  margin: 2rem 0 1.8rem;
  display: grid;
  gap: 0.35rem;
}

.mail span {
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  color: var(--dim);
}

.mail a {
  font-size: 1.15rem;
  font-weight: 400;
}

.mail a:hover {
  box-shadow: inset 0 -1px 0 var(--ink);
}

form {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.3rem 1.8rem;
  max-width: 40rem;
}

form .wide,
form button,
.form-status {
  grid-column: 1 / -1;
}

.field-error {
  display: none;
  font-style: normal;
  font-size: 0.68rem;
  letter-spacing: 0.04em;
  text-transform: none;
  color: var(--ink);
  opacity: 0.5;
}

.field-error.is-on {
  display: block;
}

input.is-invalid,
textarea.is-invalid {
  border-bottom-color: var(--ink);
}

label {
  display: grid;
  gap: 0.35rem;
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  color: var(--dim);
}

input,
textarea {
  width: 100%;
  border: 0;
  border-bottom: 1px solid var(--rule);
  background: transparent;
  color: var(--ink);
  font: inherit;
  font-size: 0.95rem;
  letter-spacing: 0.02em;
  text-transform: none;
  padding: 0.45rem 0 0.55rem;
}

input:focus,
textarea:focus {
  outline: none;
  border-bottom-color: var(--ink);
}

button[type="submit"] {
  justify-self: start;
  margin-top: 0.3rem;
  border: 0;
  background: none;
  padding: 0 0 0.2rem;
  font: inherit;
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  cursor: pointer;
  box-shadow: inset 0 -1px 0 var(--ink);
}

.form-status {
  margin: 0;
}

footer {
  margin-top: 3.5rem;
  padding-top: 1.6rem;
  border: 0;
  color: var(--dim);
  font-size: 0.72rem;
}

footer::before {
  content: "";
  display: block;
  width: 2.1rem;
  height: 5px;
  margin: 0 0 1.1rem;
  background-image: radial-gradient(circle, var(--ink) 1.15px, transparent 1.25px);
  background-size: 0.7rem 5px;
  background-repeat: repeat-x;
  opacity: 0.38;
}

@media (max-width: 860px) {
  .rail {
    display: none;
  }

  .mobile-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 6;
    padding: 0.9rem 1.15rem;
    background: color-mix(in srgb, var(--bg) 94%, transparent);
    border-bottom: 1px solid var(--rule);
  }

  .menu-btn {
    border: 0;
    background: none;
    font: inherit;
    font-size: 0.72rem;
    letter-spacing: 0.14em;
    cursor: pointer;
  }

  .mobile-nav:not([hidden]) {
    display: grid;
    gap: 0.85rem;
    padding: 1rem 1.15rem 1.3rem;
    border-bottom: 1px solid var(--rule);
  }

  main {
    margin-left: 0;
    padding: 1rem 1.15rem 2.8rem;
    max-width: none;
  }

  .open {
    padding: 1.1rem 0 2.2rem;
  }

  h1 {
    font-size: clamp(1.85rem, 8.5vw, 2.5rem);
  }

  .sheet div,
  .split-text,
  form {
    grid-template-columns: 1fr;
    gap: 0.4rem;
  }
}

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