:root {
  --proof-ink: #171714;
  --proof-paper: #fffef9;
  --proof-soft: #f4f1e9;
  --proof-line: rgba(23, 23, 20, 0.16);
  --proof-gold: #9a6811;
  --proof-green: #1f7046;
  --proof-shadow: 0 24px 70px rgba(35, 28, 12, 0.09);
}

[data-theme="dark"] {
  --proof-ink: #f4f1e8;
  --proof-paper: #1a1a18;
  --proof-soft: #24231f;
  --proof-line: rgba(255, 255, 255, 0.16);
  --proof-gold: #e3b357;
  --proof-green: #70c99c;
  --proof-shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
}

.proof-page {
  color: var(--proof-ink);
  padding-bottom: clamp(4rem, 10vw, 8rem);
}

.proof-hero {
  max-width: 1040px;
  padding: clamp(2.4rem, 7vw, 6.4rem) 0 clamp(2rem, 5vw, 4rem);
}

.proof-kicker,
.proof-label {
  color: var(--proof-gold);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.proof-hero h1 {
  max-width: 1000px;
  margin: 0.45rem 0 1.2rem;
  font-size: clamp(2.75rem, 8vw, 6.7rem);
  line-height: 0.96;
  letter-spacing: -0.045em;
}

.proof-hero .proof-lede {
  max-width: 780px;
  margin: 0;
  font-size: clamp(1.08rem, 2vw, 1.45rem);
  line-height: 1.58;
}

.proof-promise {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  overflow: hidden;
  margin: 0 0 clamp(3rem, 7vw, 6rem);
  border: 1px solid var(--proof-line);
  border-radius: 24px;
  background: var(--proof-line);
  box-shadow: var(--proof-shadow);
}

.proof-promise article {
  min-height: 160px;
  padding: 1.5rem;
  background: var(--proof-paper);
}

.proof-promise strong {
  display: block;
  margin-bottom: 0.55rem;
  font-size: 1.05rem;
}

.proof-promise p {
  margin: 0;
  color: inherit;
  opacity: 0.75;
  line-height: 1.55;
}

.proof-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
}

.proof-card {
  display: flex;
  min-height: 330px;
  flex-direction: column;
  justify-content: space-between;
  padding: clamp(1.5rem, 4vw, 2.4rem);
  border: 1px solid var(--proof-line);
  border-radius: 24px;
  color: inherit;
  background: var(--proof-paper);
  box-shadow: var(--proof-shadow);
  text-decoration: none;
}

.proof-card:first-child {
  grid-column: 1 / -1;
}

.proof-card h2 {
  max-width: 720px;
  margin: 1rem 0 0.8rem;
  font-size: clamp(1.7rem, 4vw, 3rem);
  line-height: 1.05;
}

.proof-card p {
  max-width: 680px;
  margin: 0;
  opacity: 0.78;
  line-height: 1.55;
}

.proof-card .proof-action {
  margin-top: 2rem;
  color: var(--proof-gold);
  font-weight: 800;
}

.proof-direct-answer,
.proof-method,
.proof-finding,
.proof-kx {
  max-width: 1040px;
  margin: 0 0 1.25rem;
  padding: clamp(1.4rem, 4vw, 2.3rem);
  border: 1px solid var(--proof-line);
  border-radius: 24px;
  background: var(--proof-paper);
}

.proof-direct-answer {
  border-color: rgba(154, 104, 17, 0.34);
  background: color-mix(in srgb, var(--proof-paper) 86%, #f2cc7a 14%);
}

.proof-direct-answer h2,
.proof-method h2,
.proof-finding h2,
.proof-kx h2 {
  margin: 0.45rem 0 0.7rem;
  font-size: clamp(1.45rem, 3vw, 2.3rem);
}

.proof-direct-answer p,
.proof-method p,
.proof-finding p,
.proof-kx p {
  margin: 0;
  line-height: 1.65;
}

.proof-listening {
  max-width: 1180px;
  margin: clamp(2rem, 6vw, 5rem) 0;
}

.proof-listening > header {
  max-width: 780px;
  margin-bottom: 1.4rem;
}

.proof-listening > header h2 {
  margin: 0.45rem 0 0.7rem;
  font-size: clamp(2rem, 5vw, 4.2rem);
  line-height: 1;
}

.proof-listening > header p {
  line-height: 1.65;
}

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

.proof-audio-card {
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px solid var(--proof-line);
  border-radius: 22px;
  background: var(--proof-paper);
  box-shadow: var(--proof-shadow);
}

.proof-audio-card[data-condition="b"] {
  border-color: color-mix(in srgb, var(--proof-green) 45%, var(--proof-line));
}

.proof-audio-card h3 {
  margin: 0.45rem 0 0.7rem;
  font-size: clamp(1.3rem, 3vw, 2rem);
}

.proof-audio-card p {
  min-height: 3.2em;
  line-height: 1.55;
}

.proof-audio-card audio {
  width: 100%;
  margin-top: 0.7rem;
}

.proof-now-playing {
  min-height: 1.4em;
  margin: 0.8rem 0 0;
  color: var(--proof-green);
  font-size: 0.86rem;
  font-weight: 750;
}

.proof-checklist {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
  max-width: 1040px;
  margin: 2rem 0;
}

.proof-checklist section {
  padding: clamp(1.3rem, 3vw, 2rem);
  border-top: 2px solid var(--proof-ink);
}

.proof-checklist h2 {
  margin: 0 0 0.8rem;
  font-size: clamp(1.35rem, 3vw, 2rem);
}

.proof-checklist ul,
.proof-checklist ol {
  margin: 0;
  padding-left: 1.15rem;
}

.proof-checklist li {
  margin: 0 0 0.65rem;
  line-height: 1.5;
}

.proof-method dl {
  display: grid;
  grid-template-columns: minmax(150px, 0.35fr) 1fr;
  gap: 0.6rem 1rem;
  margin: 1rem 0 0;
}

.proof-method dt {
  font-weight: 800;
}

.proof-method dd {
  margin: 0;
  line-height: 1.55;
}

.proof-related {
  max-width: 1040px;
  margin-top: 2.5rem;
}

.proof-related h2 {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
}

.proof-related-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
}

.proof-related-list a {
  padding: 1rem 1.1rem;
  border: 1px solid var(--proof-line);
  border-radius: 14px;
  color: inherit;
  background: var(--proof-paper);
  text-decoration: none;
}

.proof-inline-bridge {
  margin: 1.4rem 0;
  padding: 1.2rem 1.3rem;
  border: 1px solid rgba(154, 104, 17, 0.35);
  border-radius: 18px;
  background: color-mix(in srgb, var(--proof-paper) 90%, #f2cc7a 10%);
}

.proof-inline-bridge strong,
.proof-inline-bridge span {
  display: block;
}

.proof-inline-bridge span {
  margin: 0.4rem 0 0.8rem;
  line-height: 1.5;
  opacity: 0.8;
}

.proof-inline-bridge a {
  color: var(--proof-gold);
  font-weight: 800;
}

@media (max-width: 820px) {
  .proof-promise,
  .proof-grid,
  .proof-pair,
  .proof-checklist,
  .proof-related-list {
    grid-template-columns: 1fr;
  }

  .proof-card:first-child {
    grid-column: auto;
  }

  .proof-promise article,
  .proof-card {
    min-height: auto;
  }

  .proof-method dl {
    grid-template-columns: 1fr;
  }

  .proof-method dd {
    margin-bottom: 0.7rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .proof-card,
  .proof-audio-card {
    scroll-behavior: auto;
  }
}