:root {
  --gptl-bg: #F6F8FC;
  --gptl-surface: #FFFFFF;
  --gptl-surface-soft: #F8FAFF;
  --gptl-text: #182033;
  --gptl-text-soft: #5E6882;
  --gptl-border: #DCE3F0;
  --gptl-accent: #5B5FF8;
  --gptl-accent-2: #7C4DFF;
  --gptl-danger: #DF5F5F;
  --gptl-shadow: 0 24px 60px rgba(34, 58, 114, 0.08);
}

body {
  background:
    radial-gradient(circle at top left, rgba(124, 77, 255, 0.10), transparent 22%),
    linear-gradient(180deg, #ffffff 0%, var(--gptl-bg) 100%);
}

.gptl-introduce-shell {
  width: min(1380px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 72px;
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr) 74px;
  gap: 24px;
}

.gptl-sticky {
  position: sticky;
  top: 94px;
}

.gptl-toc-label {
  margin: 0 0 14px;
  color: var(--gptl-text-soft);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.gptl-toc-nav {
  display: grid;
  gap: 6px;
  padding-right: 18px;
  border-right: 1px solid var(--gptl-border);
}

.gptl-toc-nav a {
  padding: 10px 12px;
  border-left: 2px solid transparent;
  color: var(--gptl-text-soft);
  font-size: 0.95rem;
  font-weight: 700;
  text-decoration: none;
}

.gptl-toc-nav a.is-active,
.gptl-toc-nav a:hover {
  border-left-color: var(--gptl-accent);
  color: var(--gptl-accent);
}

.gptl-side-card {
  margin-top: 24px;
  padding: 22px;
  border: 1px solid var(--gptl-border);
  border-radius: 24px;
  background: var(--gptl-surface);
  box-shadow: var(--gptl-shadow);
}

.gptl-side-icon {
  width: 42px;
  height: 42px;
  margin-bottom: 14px;
  color: var(--gptl-accent);
}

.gptl-side-icon svg {
  width: 100%;
  height: 100%;
  fill: currentColor;
}

.gptl-side-card h3 {
  margin-bottom: 8px;
  font-size: 1.8rem;
  letter-spacing: -0.05em;
}

.gptl-side-card p {
  color: var(--gptl-text-soft);
  margin-bottom: 18px;
}

.gptl-side-card .button {
  width: 100%;
}

.gptl-introduce-article {
  min-width: 0;
  padding-left: 14px;
  border-left: 1px solid rgba(220, 227, 240, 0.9);
}

.gptl-guide-head {
  padding: 8px 0 22px;
}

.gptl-guide-kicker {
  margin: 0 0 18px;
  color: var(--gptl-accent-2);
  font-size: 0.86rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.gptl-guide-head h1 {
  max-width: 900px;
  color: var(--gptl-text);
  font-size: clamp(3rem, 5vw, 4.5rem);
  line-height: 1.03;
  letter-spacing: -0.06em;
  white-space: normal;
}

.gptl-guide-summary {
  max-width: 860px;
  margin-top: 22px;
  color: var(--gptl-text-soft);
  font-size: 1.2rem;
  line-height: 1.7;
}

.gptl-guide-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--gptl-border);
  color: var(--gptl-text-soft);
  font-weight: 700;
}

.gptl-guide-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 9px;
}

.gptl-guide-meta-item svg {
  width: 18px;
  height: 18px;
  flex: 0 0 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.gptl-guide-body {
  display: grid;
  gap: 22px;
}

.gptl-section {
  display: grid;
  gap: 14px;
}

.gptl-section h2 {
  margin: 0;
  color: var(--gptl-text);
  font-size: clamp(2rem, 3vw, 2.55rem);
  letter-spacing: -0.05em;
}

.gptl-section p {
  max-width: 900px;
  color: var(--gptl-text-soft);
  font-size: 1.03rem;
  line-height: 1.7;
}

.gptl-goal-card,
.gptl-audio-card,
.gptl-compare-card,
.gptl-faq-item,
.gptl-section-soft {
  border: 1px solid var(--gptl-border);
  border-radius: 24px;
  background: var(--gptl-surface);
  box-shadow: var(--gptl-shadow);
}

.gptl-goal-card {
  display: flex;
  gap: 10px;
  align-items: center;
  padding: 18px 20px;
  background: linear-gradient(135deg, rgba(91, 95, 248, 0.08), rgba(124, 77, 255, 0.04));
}

.gptl-goal-card strong {
  color: var(--gptl-accent);
}

.gptl-goal-card span {
  color: var(--gptl-text);
  font-weight: 600;
}

.gptl-compare-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.gptl-compare-card {
  padding: 24px 22px;
}

.gptl-compare-card h3 {
  margin: 0 0 14px;
  font-size: 1.25rem;
  letter-spacing: -0.03em;
}

.gptl-compare-card ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.gptl-compare-card li {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--gptl-text);
  font-weight: 600;
}

.gptl-compare-icon {
  display: inline-grid;
  place-items: center;
  flex: 0 0 18px;
  width: 18px;
  height: 18px;
  border-radius: 999px;
}

.gptl-compare-icon svg {
  width: 14px;
  height: 14px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.gptl-compare-icon-x {
  color: var(--gptl-danger);
  background: rgba(223, 95, 95, 0.14);
  box-shadow: 0 0 0 5px rgba(223, 95, 95, 0.09);
}

.gptl-compare-icon-check {
  color: var(--gptl-accent);
  background: rgba(91, 95, 248, 0.14);
  box-shadow: 0 0 0 5px rgba(91, 95, 248, 0.09);
}

.gptl-compare-card li > span:last-child {
  flex: 1;
}

.gptl-section-soft {
  padding: 22px;
  background: linear-gradient(180deg, var(--gptl-surface) 0%, var(--gptl-surface-soft) 100%);
}

.gptl-inline-link {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid rgba(91, 95, 248, 0.18);
  border-radius: 999px;
  background: rgba(91, 95, 248, 0.08);
  color: var(--gptl-accent);
  font-weight: 800;
  text-decoration: none;
}

.gptl-audio-card {
  padding: 24px;
  background: linear-gradient(180deg, #ffffff 0%, #f8faff 100%);
}

.gptl-audio-card h2 {
  margin-bottom: 8px;
}

.gptl-audio-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
  margin-top: 18px;
}

.gptl-audio-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.gptl-audio-row {
  display: flex;
  align-items: center;
  gap: 14px;
}

.gptl-play-button {
  flex: 0 0 44px;
  width: 44px;
  height: 44px;
  border: 0;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--gptl-accent), var(--gptl-accent-2));
  box-shadow: 0 18px 36px rgba(91, 95, 248, 0.22);
  cursor: pointer;
}

.gptl-play-button::before {
  content: "";
  display: block;
  width: 0;
  height: 0;
  margin: 0 auto;
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  border-left: 11px solid #fff;
}

.gptl-wave-svg {
  flex: 1;
  height: 56px;
  overflow: visible;
}

.gptl-wave-svg-old .gptl-wave-bar {
  fill: url(#gptlWaveOldGradient);
}

.gptl-wave-svg-new .gptl-wave-bar {
  fill: url(#gptlWaveNewGradient);
}

.gptl-faq {
  display: grid;
  gap: 10px;
}

.gptl-faq-item {
  overflow: hidden;
}

.gptl-faq-button {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 20px;
  border: 0;
  background: transparent;
  color: var(--gptl-text);
  text-align: left;
  font-size: 1.02rem;
  font-weight: 800;
  cursor: pointer;
}

.gptl-faq-chevron {
  display: inline-grid;
  place-items: center;
  flex: 0 0 18px;
  width: 18px;
  height: 18px;
  color: var(--gptl-accent);
  transition: transform 160ms ease;
}

.gptl-faq-chevron svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.gptl-faq-button[aria-expanded="true"] .gptl-faq-chevron {
  transform: rotate(180deg);
}

.gptl-faq-answer {
  padding: 0 20px 18px;
}

.gptl-faq-answer p {
  color: var(--gptl-text-soft);
}

.gptl-introduce-rail {
  position: relative;
}

.gptl-rail-line {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 1px;
  transform: translateX(-50%);
  background: linear-gradient(180deg, rgba(91, 95, 248, 0.08), rgba(91, 95, 248, 0.36), rgba(91, 95, 248, 0.08));
}

.gptl-rail-pill {
  position: absolute;
  left: 50%;
  width: 24px;
  height: 92px;
  border-radius: 999px;
  transform: translateX(-50%);
  background: linear-gradient(180deg, rgba(91, 95, 248, 0.18), rgba(124, 77, 255, 0.45));
}

.gptl-rail-pill-top {
  top: 18px;
}

.gptl-rail-pill-bottom {
  bottom: 120px;
}

@media (max-width: 1180px) {
  .gptl-introduce-shell {
    grid-template-columns: 220px minmax(0, 1fr);
  }

  .gptl-introduce-rail {
    display: none;
  }
}

@media (max-width: 920px) {
  .gptl-introduce-shell {
    grid-template-columns: 1fr;
  }

  .gptl-sticky {
    position: static;
  }

  .gptl-toc-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    border-right: 0;
    padding-right: 0;
  }

  .gptl-introduce-article {
    padding-left: 0;
    border-left: 0;
  }

  .gptl-compare-grid,
  .gptl-audio-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .gptl-introduce-shell {
    width: min(100%, calc(100% - 24px));
    padding-top: 18px;
  }

  .gptl-toc-nav {
    grid-template-columns: 1fr;
  }

  .gptl-side-card,
  .gptl-audio-card,
  .gptl-compare-card,
  .gptl-section-soft,
  .gptl-faq-item {
    border-radius: 20px;
  }

  .gptl-guide-meta {
    gap: 12px;
  }
}