.about-page {
  max-width: 1100px;
}

.about-main {
  display: block !important;
  padding: 72px 0 96px;
}

.about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.75fr);
  column-gap: 80px;
  align-items: start;
  margin-bottom: 86px;
}

.about-hero h1 {
  max-width: 10ch;
  margin: 0;
  font-family: var(--en-font);
  font-size: clamp(2.8rem, 5.6vw, 5.25rem);
  font-weight: 600;
  line-height: 0.96;
  letter-spacing: -0.04em;
  color: var(--paper);
}

.about-hero h1 span {
  color: var(--vermillion);
}

.about-lead {
  margin: 6px 0 0;
  font-family: var(--en-font);
  font-size: 1.2rem;
  font-weight: 300;
  line-height: 1.9;
  color: var(--paper-dim);
}

.about-lead em,
.about-section strong,
.method-note strong {
  font-style: normal;
  color: var(--paper);
  font-weight: 400;
}

.about-section {
  margin-top: 86px;
}

.about-section:first-of-type {
  margin-top: 0;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  font-family: var(--en-font);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--vermillion);
}

.section-label::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--vermillion);
}

.about-section h2 {
  max-width: 780px;
  margin: 0 0 18px;
  font-family: var(--en-font);
  font-size: clamp(1.7rem, 3.4vw, 3.3rem);
  font-weight: 600;
  line-height: 1.03;
  letter-spacing: -0.025em;
  color: var(--paper);
}

.about-section > p,
.method-note,
.pipeline-card p,
.benchmark-card p,
.accuracy-copy p,
.principle-card p {
  font-family: var(--en-font);
  font-size: 1.08rem;
  font-weight: 300;
  line-height: 1.85;
  color: var(--paper-dim);
}

.metric-grid,
.pipeline-grid,
.principle-grid {
  display: grid;
  gap: 18px;
  margin-top: 34px;
}

.metric-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.pipeline-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

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

.metric-card,
.pipeline-card,
.benchmark-card,
.principle-card,
.method-note {
  background: var(--ink-soft);
  border: 1px solid rgba(127, 127, 127, 0.22);
}

.metric-card {
  padding: 24px;
  min-height: 128px;
}

.metric-value {
  display: block;
  margin-bottom: 10px;
  font-family: var(--en-font);
  font-size: clamp(1.8rem, 3.5vw, 3rem);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.035em;
  color: var(--paper);
}

.metric-value.accent {
  color: var(--vermillion);
}

.metric-label {
  display: block;
  font-family: var(--en-font);
  font-size: 0.68rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--paper-dim);
}

.pipeline-card,
.principle-card {
  padding: 28px;
}

.pipeline-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  margin-bottom: 22px;
  border: 1px solid var(--vermillion);
  color: var(--vermillion);
  font-family: var(--en-font);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
}

.pipeline-card h3,
.benchmark-card h3,
.principle-card h3 {
  margin: 0 0 12px;
  font-family: var(--en-font);
  font-size: clamp(1.2rem, 2vw, 1.55rem);
  font-weight: 500;
  line-height: 1.25;
  color: var(--paper);
}

.accuracy-layout {
  margin-top: 34px;
}

.benchmark-card {
  padding: 30px;
  border-left: 2px solid var(--vermillion);
}

.benchmark-download {
  display: inline-flex;
  margin-top: 22px;
  font-family: var(--en-font);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid var(--vermillion);
  padding-bottom: 6px;
  transition: color 0.15s ease;
}

.benchmark-download:hover {
  color: var(--vermillion);
}

.benchmark-note {
  margin-top: 12px;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--paper-dim);
}

.method-note {
  margin-top: 20px;
  padding: 24px 28px;
  border-left: 2px solid var(--vermillion);
}

.code-trace {
  margin-top: 30px;
  padding: 26px;
  background: var(--ink-soft);
  border: 1px solid rgba(127, 127, 127, 0.22);
  overflow-x: auto;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.82rem;
  line-height: 1.85;
  color: var(--paper-dim);
}

.code-trace .accent {
  color: var(--vermillion);
}



@media (max-width: 920px) {
  .about-hero {
    grid-template-columns: 1fr;
    row-gap: 32px;
  }

  .about-hero h1 {
    max-width: 11ch;
  }

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

@media (max-width: 720px) {
  .about-main {
    padding: 56px 0 76px;
  }

  .about-hero {
    margin-bottom: 64px;
  }

  .about-hero h1 {
    max-width: 100%;
    font-size: clamp(2.8rem, 13vw, 4.35rem);
  }

  .about-lead,
  .about-section > p,
  .method-note,
  .pipeline-card p,
  .benchmark-card p,
  .accuracy-copy p,
  .principle-card p {
    font-size: 1.02rem;
  }

  .metric-grid,
  .pipeline-grid,
  .principle-grid {
    grid-template-columns: 1fr;
  }

  .metric-card,
  .pipeline-card,
  .benchmark-card,
  .principle-card,
  .method-note {
    padding: 22px;
  }

  .benchmark-table th,
  .benchmark-table td {
    padding: 13px 12px;
  }
}



.pipeline-trace {
  --trace-line: rgba(127, 127, 127, 0.18);
  --trace-line-strong: rgba(127, 127, 127, 0.28);
  --trace-label-width: 138px;

  counter-reset: trace-step;
  margin-top: 42px;
  border: 1px solid var(--trace-line-strong);
  font-family: var(--en-font);
  position: relative;
}

.pipeline-row {
  counter-increment: trace-step;
  display: grid;
  grid-template-columns: var(--trace-label-width) minmax(0, 1fr);
  min-height: 92px;
  border-top: 1px solid var(--trace-line);
  position: relative;
}

.pipeline-row:first-child {
  border-top: 0;
}

.pipeline-row::before {
  content: "0" counter(trace-step);
  position: absolute;
  left: 24px;
  top: 24px;
  font-family: var(--mono-font, monospace);
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  color: var(--paper-dim);
  opacity: 0.72;
}

.pipeline-label {
  display: flex;
  align-items: flex-start;
  padding: 50px 18px 22px 24px;
  border-right: 1px solid var(--trace-line);
  font-family: var(--mono-font, monospace);
  font-size: 0.66rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--vermillion);
}

.pipeline-main {
  padding: 22px 28px;
  color: var(--paper-dim);
  font-size: 0.98rem;
  line-height: 1.7;
}

.pipeline-input .pipeline-main {
  display: flex;
  align-items: center;
  color: var(--paper);
  font-size: clamp(1.4rem, 2.4vw, 2rem);
  line-height: 1.4;
  letter-spacing: -0.04em;
}

.pipeline-chip {
  display: inline-flex;
  align-items: center;
  margin: 0 8px 8px 0;
  padding: 5px 10px 6px;
  border: 1px solid var(--trace-line-strong);
  color: var(--paper);
  font-size: 1rem;
  line-height: 1.2;
  position: relative;
}

.pipeline-chip:hover, .rule-token:hover {
  cursor: pointer;
}

.pipeline-chip::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: -1px;
  height: 1px;
  background: var(--vermillion);
  opacity: 0;
  transition: opacity 0.18s ease;
}

.pipeline-chip:hover::after {
  opacity: 1;
}

.pipeline-json {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-family: var(--mono-font, monospace);
  font-size: 0.92rem;
  color: var(--paper);
  letter-spacing: -0.03em;
}

.pipeline-json::before,
.pipeline-json::after {
  color: var(--vermillion);
}

.pipeline-output .pipeline-main {
  display: block;
  color: var(--paper);
  font-size: clamp(1.45rem, 2.4vw, 2.1rem);
  line-height: 2.1;
  letter-spacing: -0.04em;
}

.pipeline-output .word {
  margin-right: 0.04em;
}

/* Rule trace */

.pipeline-rules .pipeline-main {
  display: grid;
  gap: 0;
  padding-top: 26px;
  padding-bottom: 26px;
}

.rule-trace-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  color: var(--paper);
  font-size: 0.95rem;
}

.rule-trace-title::before {
  content: "";
  width: 18px;
  height: 1px;
  background: var(--vermillion);
}

.rule-trace-line {
  display: grid;
  grid-template-columns: minmax(130px, 0.8fr) minmax(160px, 1fr) minmax(82px, auto);
  gap: 14px;
  align-items: center;
  min-height: 44px;
  padding: 8px 0;
  border-top: 1px solid rgba(127, 127, 127, 0.12);
  color: var(--paper-dim);
  font-family: var(--mono-font, monospace);
  font-size: 0.84rem;
}

.rule-trace-line:first-of-type {
  border-top: 0;
}

.rule-token {
  display: inline-flex;
  width: fit-content;
  padding: 3px 9px 4px;
  border: 1px solid var(--trace-line-strong);
  color: var(--paper);
  font-family: var(--ja-font);
  font-size: 0.98rem;
  line-height: 1.25;
}

.rule-code {
  color: var(--paper);
  white-space: nowrap;
}

.rule-muted {
  color: var(--paper-dim);
}

.rule-result {
  color: var(--vermillion);
  white-space: nowrap;
  text-align: right;
}

.rule-trace-final {
  margin-top: 8px;
  padding-top: 14px;
  border-top: 1px solid var(--trace-line-strong);
}

.rule-trace-final .rule-code {
  color: var(--paper);
}

.rule-trace-final .rule-result {
  font-weight: 600;
}

/* Optional: make the important rule decision feel selected */
.rule-trace-line:has(.rule-result) .rule-result {
  font-family: var(--mono-font, monospace);
}

@media (max-width: 720px) {
  .pipeline-trace {
    margin-top: 34px;
  }

  .pipeline-row {
    grid-template-columns: 1fr;
    min-height: 0;
  }

  .pipeline-row::before {
    left: 18px;
    top: 18px;
  }

  .pipeline-label {
    padding: 42px 18px 0;
    border-right: 0;
  }

  .pipeline-main {
    padding: 14px 18px 22px;
  }

  .pipeline-input .pipeline-main {
    font-size: 1.35rem;
  }

  .pipeline-output .pipeline-main {
    font-size: 1.35rem;
  }

  .rule-trace-line {
    grid-template-columns: 1fr;
    gap: 4px;
    padding: 12px 0;
  }

  .rule-code,
  .rule-result {
    white-space: normal;
    text-align: left;
  }
}

.pipeline-chip,
.rule-token {
  transition:
    color 0.18s ease,
    border-color 0.18s ease,
    transform 0.18s ease;
}

.pipeline-chip.is-linked-token,
.rule-token.is-linked-token {
  color: var(--paper);
  border-color: var(--vermillion);
}

.pipeline-chip.is-linked-token {
  transform: translateY(-2px);
}

.rule-token.is-linked-token {
  transform: translateY(-1px);
}

.pipeline-chip.is-linked-token::after {
  opacity: 1;
}

.pipeline-token-popup {
  position: absolute;
  z-index: 120;
  min-width: 240px;
  max-width: min(420px, 90vw);
  padding: 0.85rem 0.95rem;
  background: var(--ink-soft);
  color: var(--paper);
  border: 1px solid rgba(127, 127, 127, 0.28);
  font-size: 0.86rem;
  font-family: var(--en-font);
}

.pipeline-token-popup-title {
  margin-bottom: 0.65rem;
  font-family: var(--ja-font);
  font-size: 1.15rem;
  color: var(--paper);
}

.pipeline-token-popup-row {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 0.22rem 0;
  border-top: 1px solid rgba(127, 127, 127, 0.12);
}

.pipeline-token-popup-label {
  color: var(--paper-dim);
  font-family: var(--mono-font, monospace);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.pipeline-token-popup-value {
  color: var(--paper);
  text-align: right;
}

.pipeline-token-popup-note {
  margin-top: 0.7rem;
  padding-top: 0.65rem;
  border-top: 1px solid rgba(127, 127, 127, 0.18);
  color: var(--paper-dim);
  line-height: 1.55;
}

.pipeline-chip.is-popup-active,
.rule-token.is-popup-active {
  border-color: var(--vermillion);
  color: var(--paper);
}