:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-soft: #eef4fb;
  --surface-soft-2: #f6f9fd;
  --text: #24324a;
  --muted: #667792;
  --line: #dbe4f0;
  --blue-soft: #d7e6f8;
  --blue-main: #5d89bf;
  --blue-deep: #3f6fa7;
  --violet-soft: #e8e1f8;
  --violet-main: #7564b2;
  --green-soft: #dff0e5;
  --green-main: #5c8b68;
  --shadow: 0 18px 38px rgba(55, 82, 129, 0.08);
  --shadow-soft: 0 10px 22px rgba(55, 82, 129, 0.07);
  --max-width: 1160px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top right, rgba(104, 142, 199, 0.08), transparent 24%),
    linear-gradient(180deg, #fbfcfe 0%, var(--bg) 100%);
  line-height: 1.65;
}

button,
a {
  font: inherit;
}

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

button {
  cursor: pointer;
}

.page-shell,
.site-footer {
  width: min(var(--max-width), calc(100% - 2rem));
  margin: 0 auto;
}

.hero {
  padding: 2rem 0 1.2rem;
}

.hero__panel,
.content-card,
.mini-card,
.pathway-card,
.quick-panel,
.part-card {
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-soft);
}

.hero__panel {
  padding: 2rem 2rem 2.5rem;
  border-radius: 42px;
}

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

.hero__badge,
.section-tag,
.kicker,
.application-label {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  line-height: 1;
}

.hero__badge,
.section-tag {
  padding: 0.6rem 0.9rem;
  background: #f8fbff;
  color: var(--blue-main);
  border: 1px solid #e2eaf6;
}

.language-toggle {
  display: inline-flex;
  gap: 0.35rem;
  padding: 0.35rem;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.language-toggle__button {
  min-width: 78px;
  padding: 0.95rem 1.3rem;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--text);
  font-size: 1.05rem;
  font-weight: 800;
  transition: background-color 180ms ease, color 180ms ease, transform 180ms ease;
}

.language-toggle__button.is-active {
  background: #dfeaf9;
  color: #356ea8;
  box-shadow: inset 0 0 0 1px #c7d9f1;
}

.hero__eyebrow {
  margin: 1.6rem 0 0;
  font-size: 0.96rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #8ea5c5;
}

.hero__title {
  max-width: 16ch;
  margin: 0.55rem 0 0;
  font-size: clamp(2.7rem, 6vw, 5rem);
  line-height: 0.96;
  letter-spacing: -0.055em;
  color: var(--blue-main);
}

.hero__lead {
  max-width: 62ch;
  margin: 1.2rem 0 0;
  font-size: clamp(1.1rem, 1.8vw, 1.45rem);
  color: var(--muted);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.8rem;
}

.hero__cta,
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  width: fit-content;
  padding: 0.95rem 1.35rem;
  border-radius: 18px;
  border: 1px solid transparent;
  font-weight: 800;
  transition: transform 180ms ease, box-shadow 180ms ease, background-color 180ms ease;
}

.hero__cta,
.btn-primary {
  background: #4e82c5;
  color: #ffffff;
  box-shadow: 0 14px 24px rgba(66, 114, 182, 0.18);
}

.hero__cta--secondary,
.btn-secondary {
  background: #4e82c5;
  color: #ffffff;
  box-shadow: 0 14px 24px rgba(66, 114, 182, 0.18);
}

.content {
  display: grid;
  gap: 1.4rem;
  padding-bottom: 3.5rem;
}

.content-card {
  border-radius: 30px;
  padding: 1.8rem 1.8rem 2rem;
}

.section-title {
  margin: 0.8rem 0 0.7rem;
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  line-height: 1.08;
}

.section-intro,
.content-card p {
  margin: 0.65rem 0 0;
  color: var(--muted);
}

.content-card ul {
  margin: 0.9rem 0 0;
  padding-left: 1.15rem;
  color: var(--muted);
}

.content-card li + li {
  margin-top: 0.35rem;
}

.quick-panels,
.grid-2,
.parts-grid,
.pathways-grid,
.examples-grid {
  display: grid;
  gap: 1rem;
  margin-top: 1.2rem;
}

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

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

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

.examples-stack {
  display: grid;
  gap: 1rem;
  margin-top: 1.2rem;
}

.quick-panel,
.part-card,
.mini-card,
.pathway-card,
.example-card,
.method-card {
  border-radius: 24px;
  padding: 1.2rem;
}

.part-card {
  background: #ffffff;
  cursor: pointer;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.part-card:hover,
.part-card:focus-visible {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-color: #cddcf2;
  outline: none;
}

.pathway-card--discover {
  background: linear-gradient(180deg, #edf5ff 0%, #ffffff 100%);
}

.pathway-card--explore {
  background: linear-gradient(180deg, #f4efff 0%, #ffffff 100%);
}

.pathway-card--simulate {
  background: linear-gradient(180deg, #eef8f1 0%, #ffffff 100%);
}

.kicker {
  min-height: 2.1rem;
  padding: 0.42rem 0.76rem;
  background: var(--surface-soft);
  color: var(--blue-main);
}

.kicker:empty::before {
  content: "";
  display: block;
  width: 5rem;
  height: 0.7rem;
}

.part-card h3,
.mini-card h3,
.pathway-card h4 {
  margin: 0.9rem 0 0;
  font-size: 1.4rem;
  line-height: 1.18;
}

.part-card .kicker {
  display: none;
}

.callout {
  margin-top: 1.15rem;
  padding: 1.1rem 1.2rem;
  border-radius: 22px;
  background: var(--surface-soft-2);
  border: 1px solid var(--line);
  color: var(--text);
}

.mini-card details {
  margin-top: 1rem;
  padding-top: 0.8rem;
  border-top: 1px dashed #d5dfec;
}

.details-subtitle {
  margin: 1rem 0 0.2rem;
  font-size: 0.9rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #8ea0bb;
}

.method-list {
  display: grid;
  gap: 0.8rem;
  margin-top: 1rem;
}

.method-card {
  background: var(--surface-soft-2);
  border: 1px solid var(--line);
}

.method-card h4,
.example-card h3 {
  margin: 0.35rem 0 0;
  font-size: 1.15rem;
  line-height: 1.2;
}

.mini-card summary {
  cursor: pointer;
  font-weight: 800;
  color: var(--text);
}

.mini-card summary + * {
  margin-top: 0.8rem;
}

.mini-card ul {
  margin-top: 0.7rem;
}

.mini-card__actions {
  margin-top: 1.1rem;
}

.extension-card {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.extension-card__footer {
  display: grid;
  gap: 1rem;
  margin-top: auto;
  padding-top: 1.1rem;
}

.extension-card .mini-card__actions {
  margin-top: 0;
  padding-top: 0;
}

.pathway-card p {
  color: var(--muted);
}

.pathway-card p strong {
  color: var(--text);
}

.pathway-card__label,
.example-item__label {
  display: block;
  margin-bottom: 0.2rem;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #8ea0bb;
}

.example-card {
  background: linear-gradient(180deg, #f7faff 0%, #ffffff 100%);
}

.example-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
  width: 100%;
  margin-top: 1rem;
  padding: 0.9rem 1rem;
  border: 1px solid #c9d9ef;
  border-radius: 18px;
  background: #ffffff;
  color: var(--blue-deep);
  font-weight: 800;
  transition: transform 180ms ease, background-color 180ms ease, border-color 180ms ease;
}

.example-toggle[aria-expanded="true"] {
  background: #eef4fd;
}

.example-toggle__icon {
  font-size: 1.2rem;
}

.example-panel {
  margin-top: 1rem;
}

.example-items {
  display: grid;
  gap: 0.8rem;
}

.example-item {
  padding: 0.95rem 1rem;
  border-radius: 18px;
  background: var(--surface-soft-2);
  border: 1px solid var(--line);
}

.emphasis-card {
  background: linear-gradient(180deg, #edf5ff 0%, #ffffff 55%);
}

.site-footer {
  padding: 0 0 2.6rem;
  text-align: center;
  color: var(--muted);
}

.site-footer p {
  margin: 0.3rem 0;
}

@media (max-width: 960px) {
  .quick-panels,
  .grid-2,
  .parts-grid,
  .pathways-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .hero__panel {
    padding: 1.5rem 1.2rem 2rem;
    border-radius: 30px;
  }

  .hero__bar {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero__title,
  .hero__lead {
    max-width: none;
  }
}

@media (max-width: 640px) {
  .page-shell,
  .site-footer {
    width: min(var(--max-width), calc(100% - 1rem));
  }

  .content-card {
    padding: 1.35rem 1rem 1.45rem;
    border-radius: 24px;
  }

  .language-toggle__button {
    min-width: 68px;
    padding-inline: 1rem;
  }
}