:root {
  --bg: #f4f1e8;
  --bg-accent: #fffdf7;
  --surface: rgba(255, 252, 246, 0.88);
  --surface-strong: #fffdf8;
  --surface-soft: rgba(242, 236, 226, 0.72);
  --text: #1f2937;
  --muted: #526070;
  --border: rgba(96, 122, 147, 0.2);
  --border-strong: rgba(0, 136, 204, 0.22);
  --primary: #0b79b7;
  --primary-strong: #075985;
  --good: #0f8d65;
  --warn: #c57a0e;
  --shadow: 0 22px 55px rgba(53, 65, 81, 0.12);
  --radius-xl: 1.5rem;
  --radius-lg: 1rem;
  --radius-md: 0.8rem;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(11, 121, 183, 0.12), transparent 34%),
    radial-gradient(circle at top right, rgba(225, 191, 113, 0.18), transparent 28%),
    linear-gradient(180deg, #fbfaf6 0%, var(--bg) 56%, #efe8dd 100%);
  color: var(--text);
  font-family: "Avenir Next", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--primary-strong);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.14em;
}

a:hover,
a:focus-visible {
  color: var(--primary);
}

button,
select {
  font: inherit;
}

button:focus-visible,
select:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(11, 121, 183, 0.28);
  outline-offset: 2px;
}

.page-shell {
  width: min(1160px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2.5rem 0 3rem;
}

.hero {
  margin-bottom: 1.75rem;
  padding: 1.8rem;
  border: 1px solid var(--border);
  border-radius: calc(var(--radius-xl) + 0.25rem);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(255, 252, 246, 0.86)),
    var(--surface-strong);
  box-shadow: var(--shadow);
}

.hero h1 {
  margin: 0.25rem 0 0.5rem;
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, serif;
  font-size: clamp(2.25rem, 4.8vw, 3.7rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  margin: 0;
  border-radius: 999px;
  padding: 0.28rem 0.72rem;
  background: rgba(11, 121, 183, 0.09);
  color: var(--primary-strong);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero__lede {
  max-width: 58rem;
}

.hero__epigraph {
  max-width: 42rem;
  margin: 1.15rem auto 1.2rem;
  text-align: center;
}

.hero__quote-toggle {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.hero__quote-button {
  display: block;
  width: 100%;
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
}

.hero__quote-text {
  display: block;
  max-width: 100%;
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, serif;
  font-size: clamp(1.08rem, 2vw, 1.32rem);
  font-style: italic;
  line-height: 1.45;
  color: #334155;
  text-align: center;
}

.hero__quote-button:hover .hero__quote-text,
.hero__quote-button:focus-visible .hero__quote-text {
  color: #1e293b;
}

.hero__quote-details {
  margin-top: 0.8rem;
  color: var(--muted);
}

.hero__quote-details[hidden] {
  display: none !important;
}

/* Compatibility guard for briefly cached HTML from the checkbox-based version. */
.hero__quote-toggle + .hero__quote-button + .hero__quote-details {
  display: none;
}

.hero__quote-toggle:checked + .hero__quote-button + .hero__quote-details {
  display: block;
}

.hero__quote-details p {
  margin: 0;
  font-size: 0.94rem;
}

.hero__copy {
  max-width: 64rem;
  margin: 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.notice {
  margin: 0 0 1.5rem;
  padding: 1rem 1.1rem;
  border-radius: var(--radius-md);
}

.notice--warning {
  border: 1px solid rgba(197, 122, 14, 0.28);
  background: rgba(245, 158, 11, 0.1);
  color: #92400e;
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.info-card {
  padding: 1.35rem 1.4rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background: var(--surface);
  box-shadow: 0 14px 34px rgba(53, 65, 81, 0.08);
  backdrop-filter: blur(10px);
}

.info-card h2 {
  margin-top: 0;
  margin-bottom: 0.75rem;
  font-size: 1.22rem;
}

.info-card ul {
  margin: 0;
  padding-left: 1.15rem;
}

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

.site-footer {
  margin-top: 1.75rem;
  padding: 0.25rem 0 1rem;
  text-align: center;
}

.site-footer p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--muted);
}

.causal-tool {
  margin-top: 1.5rem;
}

.causal-tool__subtitle {
  margin: -0.1rem 0 1rem;
  color: #475569;
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: 0.01em;
  opacity: 0.92;
}

.causal-tool__hero-figure {
  margin: 1.5rem 0 0;
  padding: 1rem 1rem 0.8rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-xl);
  background: var(--surface-soft);
}

.causal-tool__hero-figure picture {
  display: block;
}

.causal-tool__hero-figure img {
  display: block;
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
}

.causal-tool__hero-figure figcaption {
  margin-top: 0.75rem;
  text-align: center;
  font-size: 0.92rem;
  color: var(--muted);
}

.causal-tool__grid {
  display: grid;
  grid-template-columns: minmax(300px, 0.95fr) minmax(0, 1.25fr);
  gap: 1.75rem;
  align-items: start;
}

.causal-tool__panel {
  min-width: 0;
  padding: 1.45rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  background: var(--surface);
  box-shadow: 0 16px 40px rgba(53, 65, 81, 0.08);
  backdrop-filter: blur(10px);
}

.causal-tool__panel-head h2,
.causal-tool__panel--details h2 {
  margin-top: 0;
  margin-bottom: 0.55rem;
  font-size: 1.28rem;
}

.causal-tool__panel-head p {
  margin-bottom: 0;
  color: var(--muted);
}

.causal-tool__section + .causal-tool__section {
  margin-top: 1.45rem;
}

.causal-tool__section h3 {
  margin-bottom: 0.85rem;
  font-size: 1.02rem;
  letter-spacing: 0.01em;
}

.causal-tool__field + .causal-tool__field {
  margin-top: 1rem;
}

.causal-tool__field label {
  display: block;
  margin-bottom: 0.35rem;
  font-weight: 700;
}

.causal-tool__field select {
  width: 100%;
  border: 1px solid rgba(96, 122, 147, 0.26);
  border-radius: 0.75rem;
  background: rgba(255, 255, 255, 0.88);
  color: inherit;
  padding: 0.78rem 0.9rem;
  appearance: none;
  box-shadow: inset 0 1px 1px rgba(255, 255, 255, 0.8);
}

.causal-tool__field p {
  margin: 0.35rem 0 0;
  font-size: 0.92rem;
  color: var(--muted);
}

.causal-tool__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.causal-tool__button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 999px;
  background: linear-gradient(180deg, var(--primary) 0%, #0a6ea8 100%);
  color: #fff;
  padding: 0.68rem 1rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 10px 22px rgba(11, 121, 183, 0.18);
  transition: transform 0.14s ease, box-shadow 0.14s ease, background-color 0.14s ease;
}

.causal-tool__button:hover,
.causal-tool__button:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 14px 28px rgba(11, 121, 183, 0.22);
}

.causal-tool__button--ghost {
  background: rgba(255, 255, 255, 0.55);
  color: var(--text);
  border: 1px solid rgba(96, 122, 147, 0.25);
  box-shadow: none;
}

.causal-tool__share-status {
  min-height: 1.25rem;
  font-size: 0.92rem;
  color: var(--muted);
}

.causal-tool__path {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 0 0 1rem;
}

.causal-tool__brief {
  margin-bottom: 1rem;
}

.causal-tool__brief-card {
  padding: 1rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  background: rgba(11, 121, 183, 0.06);
}

.causal-tool__brief-head h3 {
  margin: 0 0 0.35rem;
  font-size: 1.02rem;
}

.causal-tool__brief-head p {
  margin: 0;
  color: var(--muted);
}

.causal-tool__brief-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.85rem;
  margin-top: 1rem;
}

.causal-tool__brief-block {
  padding: 0.9rem;
  border-radius: 0.9rem;
  background: rgba(255, 255, 255, 0.56);
  border: 1px solid rgba(11, 121, 183, 0.12);
}

.causal-tool__brief-block strong {
  display: block;
  margin-bottom: 0.35rem;
}

.causal-tool__brief-block p {
  margin: 0;
  font-size: 0.94rem;
  color: var(--muted);
}

.causal-tool__brief-label {
  display: inline-flex;
  align-items: center;
  margin-bottom: 0.45rem;
  border-radius: 999px;
  padding: 0.18rem 0.55rem;
  background: rgba(15, 23, 42, 0.08);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.causal-tool__chip {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  background: rgba(11, 121, 183, 0.08);
  border: 1px solid rgba(11, 121, 183, 0.18);
  font-size: 0.9rem;
}

.causal-tool__warning {
  margin-bottom: 1rem;
  padding: 0.95rem 1rem;
  border-radius: 0.95rem;
  background: rgba(245, 158, 11, 0.11);
  color: #92400e;
}

.causal-tool__warning ul {
  margin: 0.6rem 0 0;
}

.causal-tool__results {
  display: grid;
  gap: 1rem;
}

.causal-tool__method {
  padding: 1rem;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(96, 122, 147, 0.2);
  background: rgba(255, 255, 255, 0.48);
}

.causal-tool__method--best {
  border-color: rgba(11, 121, 183, 0.26);
  background: rgba(11, 121, 183, 0.09);
}

.causal-tool__method--good {
  border-color: rgba(15, 141, 101, 0.24);
  background: rgba(15, 141, 101, 0.08);
}

.causal-tool__method--conditional {
  border-color: rgba(197, 122, 14, 0.24);
  background: rgba(245, 158, 11, 0.07);
}

.causal-tool__method-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
}

.causal-tool__method-head h3 {
  margin: 0.45rem 0 0;
  font-size: 1.12rem;
}

.causal-tool__badge,
.causal-tool__family {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 0.24rem 0.62rem;
  font-size: 0.82rem;
  font-weight: 700;
}

.causal-tool__badge {
  background: rgba(15, 23, 42, 0.09);
}

.causal-tool__family {
  white-space: nowrap;
  background: rgba(255, 255, 255, 0.46);
}

.causal-tool__summary {
  margin: 0.85rem 0 1rem;
}

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

.causal-tool__method h4 {
  margin-bottom: 0.55rem;
  font-size: 0.98rem;
}

.causal-tool__method ul {
  margin-bottom: 0.85rem;
  padding-left: 1.15rem;
}

.causal-tool__packages {
  margin-top: 1rem;
}

.causal-tool__reference-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.causal-tool__reference-block {
  padding: 0.95rem 1rem;
  border: 1px solid rgba(15, 23, 42, 0.09);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.42);
}

.causal-tool__reference-block h4 {
  margin-bottom: 0.55rem;
}

.causal-tool__reference-list {
  margin: 0;
  padding-left: 1.15rem;
}

.causal-tool__reference-list li + li {
  margin-top: 0.65rem;
}

.causal-tool__reference-note {
  display: block;
  margin-top: 0.15rem;
  color: var(--muted);
}

.causal-tool__package-list {
  margin: 0.55rem 0 0.9rem;
  padding-left: 1.15rem;
}

.causal-tool__package-list li + li {
  margin-top: 0.55rem;
}

.causal-tool__package-note {
  display: inline;
  margin-left: 0.4rem;
  color: var(--muted);
}

.causal-tool__alternatives {
  margin-bottom: 0;
  color: var(--muted);
}

.causal-tool__method-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1rem;
}

.causal-tool__method-actions .causal-tool__button {
  padding: 0.58rem 0.95rem;
}

@media (max-width: 991.98px) {
  .page-shell {
    width: min(100%, calc(100% - 1.5rem));
    padding-top: 1.5rem;
  }

  .hero {
    padding: 1.35rem;
  }

  .causal-tool__grid,
  .content-grid,
  .causal-tool__columns,
  .causal-tool__reference-grid,
  .causal-tool__brief-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 767.98px) {
  .hero h1 {
    font-size: clamp(2rem, 11vw, 2.9rem);
  }

  .hero__copy,
  .causal-tool__subtitle {
    font-size: 0.98rem;
  }

  .causal-tool__panel {
    padding: 1.1rem;
  }

  .causal-tool__method-head {
    flex-direction: column;
  }

  .causal-tool__package-note {
    display: block;
    margin: 0.18rem 0 0;
  }

  .causal-tool__actions {
    align-items: stretch;
  }

  .causal-tool__button,
  .causal-tool__method-actions .causal-tool__button {
    width: 100%;
  }
}