:root {
  --primary: #173f5f;
  --primary-deep: color-mix(in srgb, var(--primary) 78%, #071923);
  --primary-soft: color-mix(in srgb, var(--primary) 9%, white);
  --accent: #e05a47;
  --accent-text: #b43e30;
  --accent-on-dark: color-mix(in srgb, var(--accent) 62%, white);
  --accent-soft: color-mix(in srgb, var(--accent) 10%, white);
  --focus-ring: #b43e30;
  --focus-ring-on-dark: #9de7da;
  --teal: #087f73;
  --teal-light: #9de7da;
  --navy: var(--primary);
  --white: #ffffff;
  --ink: #152b3a;
  --gray-50: #f8fafb;
  --gray-100: #f0f4f5;
  --gray-200: #dde6e9;
  --gray-300: #c7d3d7;
  --gray-500: #60727b;
  --gray-700: #344b55;
  --shadow: 0 10px 28px rgba(21, 43, 58, 0.08);
  --shadow-md: 0 18px 48px rgba(21, 43, 58, 0.12);
  --shadow-lg: 0 28px 80px rgba(13, 35, 49, 0.18);
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --max-width: 1160px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body {
  min-width: 320px;
  background: var(--gray-50);
  color: var(--ink);
  font-family: Inter, "Avenir Next", Avenir, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body.site-page {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}

body.site-page main {
  flex: 1;
}

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

button,
input,
select,
textarea {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
}

img,
svg,
video {
  max-width: 100%;
}

[hidden] {
  display: none !important;
}

.sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.skip-link {
  position: fixed;
  z-index: 9999;
  top: 10px;
  left: 10px;
  padding: 0.65rem 0.9rem;
  border-radius: 6px;
  background: var(--white);
  color: var(--primary);
  font-size: 0.82rem;
  font-weight: 800;
  box-shadow: var(--shadow-md);
  transform: translateY(-160%);
  transition: transform 0.15s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 3px;
}

.navbar :is(a, button):focus-visible,
.home-hero :is(a, button):focus-visible,
.session-hero :is(a, button):focus-visible,
.footer :is(a, button):focus-visible,
.presenter :is(a, button, [tabindex]):focus-visible {
  outline-color: var(--focus-ring-on-dark);
}

.container {
  width: min(calc(100% - 3rem), var(--max-width));
  margin-inline: auto;
}

.eyebrow {
  display: inline-block;
  color: var(--accent-text);
  font-size: 0.72rem;
  font-weight: 850;
  letter-spacing: 0.11em;
  line-height: 1.3;
  text-transform: uppercase;
}

.eyebrow.light {
  color: #a7efe3;
}

.navbar {
  position: sticky;
  z-index: 100;
  top: 0;
  min-height: 66px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  background: color-mix(in srgb, var(--primary-deep) 95%, transparent);
  color: var(--white);
  box-shadow: 0 4px 18px rgba(6, 25, 36, 0.12);
  backdrop-filter: blur(14px);
}

.nav-inner {
  width: min(calc(100% - 3rem), var(--max-width));
  min-height: 66px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.nav-brand,
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-size: 0.92rem;
  font-weight: 850;
  letter-spacing: -0.01em;
}

.nav-brand::before,
.footer-brand::before {
  width: 25px;
  height: 25px;
  border-radius: 7px 7px 7px 2px;
  background: linear-gradient(145deg, var(--accent), #f39b6d);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.3);
  content: "";
  transform: rotate(-4deg);
}

.nav-brand span {
  color: var(--teal-light);
}

.nav-links {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.2rem;
}

.nav-links a {
  min-height: 38px;
  padding: 0.55rem 0.72rem;
  border-radius: 8px;
  color: rgba(255, 255, 255, 0.74);
  display: inline-flex;
  align-items: center;
  font-size: 0.76rem;
  font-weight: 750;
  line-height: 1;
  transition: background 0.15s ease, color 0.15s ease;
}

.nav-links a:hover,
.nav-links a.active {
  background: rgba(255, 255, 255, 0.11);
  color: var(--white);
}

.nav-links a.nav-game {
  margin-left: 0.25rem;
  border: 1px solid rgba(255, 255, 255, 0.18);
  color: var(--white);
}

.nav-toggle {
  width: 42px;
  height: 42px;
  padding: 9px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 9px;
  background: rgba(255, 255, 255, 0.06);
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
}

.nav-toggle span {
  width: 100%;
  height: 2px;
  border-radius: 1px;
  background: white;
}

.btn {
  min-height: 46px;
  padding: 0.72rem 1.05rem;
  border: 1px solid transparent;
  border-radius: 9px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  font-size: 0.82rem;
  font-weight: 800;
  line-height: 1.2;
  transition: transform 0.16s ease, box-shadow 0.16s ease, background 0.16s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--primary);
  color: var(--white);
  box-shadow: 0 10px 22px color-mix(in srgb, var(--primary) 24%, transparent);
}

.btn-light {
  background: var(--white);
  color: var(--primary);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.16);
}

.btn-ghost-light {
  border-color: rgba(255, 255, 255, 0.28);
  background: rgba(255, 255, 255, 0.07);
  color: var(--white);
}

.home-hero {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(118deg, color-mix(in srgb, var(--primary) 95%, #071923) 0%, var(--primary) 52%, color-mix(in srgb, var(--primary) 70%, #087f73) 100%);
  color: var(--white);
}

.home-hero::after {
  position: absolute;
  right: -12%;
  bottom: -270px;
  width: 700px;
  height: 460px;
  border: 1px solid rgba(255, 255, 255, 0.09);
  border-radius: 50%;
  content: "";
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: min(calc(100% - 3rem), var(--max-width));
  min-height: 510px;
  margin-inline: auto;
  padding-block: 4.5rem 4.75rem;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(360px, 0.75fr);
  align-items: center;
  gap: clamp(2.5rem, 6vw, 6rem);
}

.hero-copy h1 {
  max-width: 730px;
  margin-top: 0.6rem;
  font-size: clamp(2.55rem, 6vw, 4.75rem);
  font-weight: 820;
  letter-spacing: -0.055em;
  line-height: 0.99;
}

.hero-lead {
  max-width: 680px;
  margin-top: 1.35rem;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(1rem, 1.5vw, 1.16rem);
  line-height: 1.65;
}

.course-meta {
  margin-top: 0.8rem;
  color: #a7efe3;
  font-size: 0.78rem;
  font-weight: 750;
}

.hero-actions {
  margin-top: 1.8rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.hero-preview {
  perspective: 1000px;
}

.preview-window {
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.95);
  color: var(--ink);
  box-shadow: var(--shadow-lg);
  transform: rotate(1.5deg);
}

.preview-toolbar {
  height: 40px;
  padding-inline: 1rem;
  border-bottom: 1px solid var(--gray-200);
  background: #f4f7f8;
  display: flex;
  align-items: center;
  gap: 6px;
}

.preview-toolbar i {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gray-300);
}

.preview-toolbar i:first-child {
  background: var(--accent);
}

.preview-content {
  padding: 1.2rem;
}

.preview-label {
  color: var(--gray-500);
  font-size: 0.66rem;
  font-weight: 800;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.preview-row {
  padding: 0.88rem 0;
  border-bottom: 1px solid var(--gray-200);
  display: grid;
  grid-template-columns: 34px 1fr;
  align-items: center;
  gap: 0.65rem;
}

.preview-row:last-child {
  border-bottom: 0;
}

.preview-row b {
  color: var(--accent-text);
  font-size: 0.72rem;
}

.preview-row span,
.preview-row strong,
.preview-row small {
  display: block;
}

.preview-row strong {
  color: var(--primary);
  font-size: 0.88rem;
}

.preview-row small {
  margin-top: 0.1rem;
  color: var(--gray-500);
  font-size: 0.7rem;
}

.hero-orbit {
  position: absolute;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 50%;
}

.hero-orbit-one {
  top: -230px;
  left: -160px;
  width: 520px;
  height: 520px;
}

.hero-orbit-two {
  top: -100px;
  left: -50px;
  width: 250px;
  height: 250px;
}

.intro-strip {
  border-bottom: 1px solid var(--gray-200);
  background: var(--white);
}

.intro-strip-inner {
  padding-block: 2rem;
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1fr);
  align-items: center;
  gap: 3rem;
}

.intro-strip h2,
.section-heading h2,
.study-path h2,
.content-heading h2 {
  color: var(--primary);
  letter-spacing: -0.035em;
  line-height: 1.15;
}

.intro-strip h2 {
  margin-top: 0.25rem;
  font-size: clamp(1.45rem, 3vw, 2rem);
}

.intro-strip p {
  color: var(--gray-700);
  font-size: 0.92rem;
}

.session-section {
  padding-block: 5rem 4rem;
}

.section-heading {
  margin-bottom: 2rem;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 2rem;
}

.section-heading h2 {
  margin-top: 0.3rem;
  font-size: clamp(1.8rem, 3.5vw, 2.65rem);
}

.section-heading > p {
  max-width: 470px;
  color: var(--gray-500);
  font-size: 0.88rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.1rem;
}

.dashboard-empty {
  min-height: 220px;
  padding: 1.5rem;
  border: 1px dashed var(--gray-300);
  border-radius: var(--radius);
  background: var(--white);
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.dashboard-empty > span {
  width: 38px;
  height: 38px;
  flex: 0 0 38px;
  border-radius: 10px;
  background: var(--accent-soft);
  color: var(--accent-text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 850;
}

.dashboard-empty h3 {
  color: var(--primary);
  font-size: 1rem;
}

.dashboard-empty p {
  margin-top: 0.4rem;
  color: var(--gray-500);
  font-size: 0.82rem;
}

.dashboard-empty code {
  color: var(--primary);
  font-weight: 750;
}

.session-card {
  position: relative;
  min-height: 350px;
  padding: 1.5rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 3px 0 rgba(21, 43, 58, 0.02);
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.session-card::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  border-radius: var(--radius) 0 0 var(--radius);
  background: var(--accent);
  content: "";
  opacity: 0;
  transition: opacity 0.2s ease;
}

.session-card:hover {
  border-color: color-mix(in srgb, var(--primary) 28%, var(--gray-200));
  box-shadow: var(--shadow-md);
  transform: translateY(-5px);
}

.session-card:hover::before {
  opacity: 1;
}

.session-card-top {
  margin-bottom: 2.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.session-card-number {
  color: var(--accent-text);
  font-size: 1.15rem;
  font-weight: 850;
  letter-spacing: -0.03em;
}

.session-card-arrow {
  width: 34px;
  height: 34px;
  border: 1px solid var(--gray-200);
  border-radius: 50%;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  transition: background 0.15s ease, color 0.15s ease;
}

.session-card:hover .session-card-arrow {
  border-color: var(--primary);
  background: var(--primary);
  color: var(--white);
}

.session-card-kicker {
  color: var(--gray-500);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.session-card h3 {
  margin-top: 0.35rem;
  color: var(--primary);
  font-size: 1.45rem;
  letter-spacing: -0.035em;
  line-height: 1.18;
}

.session-card > p {
  margin-top: 0.75rem;
  color: var(--gray-700);
  font-size: 0.84rem;
  line-height: 1.6;
}

.session-card-footer {
  margin-top: auto;
  padding-top: 1.2rem;
  border-top: 1px solid var(--gray-200);
}

.session-card-footer span,
.session-card-footer strong {
  display: block;
}

.session-card-footer span {
  color: var(--gray-500);
  font-size: 0.64rem;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.session-card-footer strong {
  margin-top: 0.15rem;
  color: var(--primary);
  font-size: 0.76rem;
}

.game-card {
  border-color: color-mix(in srgb, var(--teal) 24%, var(--gray-200));
  background: linear-gradient(145deg, #f4fffc, var(--white));
}

.game-card::before {
  background: var(--teal);
}

.game-card .session-card-number,
.game-card .session-card-kicker {
  color: var(--teal);
}

.game-mark {
  font-size: 1.25rem;
}

.study-path {
  margin-bottom: 5rem;
  padding: clamp(1.7rem, 4vw, 3rem);
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--primary), color-mix(in srgb, var(--primary) 76%, var(--teal)));
  color: var(--white);
  display: grid;
  grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr);
  align-items: center;
  gap: 3rem;
  box-shadow: var(--shadow-md);
}

.study-path .eyebrow {
  color: var(--teal-light);
}

.study-path h2 {
  margin-top: 0.35rem;
  color: var(--white);
  font-size: clamp(1.65rem, 3vw, 2.35rem);
}

.study-path-copy p {
  margin-top: 0.8rem;
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.86rem;
}

.study-steps {
  list-style: none;
  display: grid;
  gap: 0.7rem;
}

.study-steps li {
  padding: 0.9rem;
  border: 1px solid rgba(255, 255, 255, 0.13);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.07);
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 0.8rem;
}

.study-steps li > span {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--accent);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.76rem;
  font-weight: 850;
}

.study-steps strong {
  display: block;
  font-size: 0.86rem;
}

.study-steps p {
  margin-top: 0.1rem;
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.73rem;
  line-height: 1.45;
}

.session-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 86% 24%, rgba(255, 255, 255, 0.1) 0 8%, transparent 8.4%),
    radial-gradient(circle at 89% 32%, rgba(255, 255, 255, 0.06) 0 16%, transparent 16.4%),
    linear-gradient(128deg, var(--primary-deep), var(--primary));
  color: var(--white);
}

.session-hero-inner {
  position: relative;
  min-height: 335px;
  padding-block: 2rem 3.2rem;
}

.breadcrumb {
  margin-bottom: 2.4rem;
  color: rgba(255, 255, 255, 0.55);
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.72rem;
}

.breadcrumb a {
  color: rgba(255, 255, 255, 0.82);
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.session-number {
  position: absolute;
  right: 0;
  bottom: -0.18em;
  color: rgba(255, 255, 255, 0.055);
  font-size: clamp(10rem, 22vw, 18rem);
  font-weight: 900;
  letter-spacing: -0.09em;
  line-height: 0.8;
  user-select: none;
}

.session-hero h1 {
  position: relative;
  max-width: 780px;
  margin-top: 0.35rem;
  font-size: clamp(2.3rem, 5vw, 4rem);
  font-weight: 820;
  letter-spacing: -0.055em;
  line-height: 1;
}

.session-hero h1 + p {
  position: relative;
  max-width: 720px;
  margin-top: 1rem;
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.96rem;
}

.objective-list {
  position: relative;
  max-width: 900px;
  margin-top: 1.4rem;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.objective-list li {
  padding: 0.4rem 0.65rem;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.07);
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.69rem;
  font-weight: 650;
}

.session-content {
  padding-block: 3rem 5rem;
}

.session-layout {
  display: grid;
  grid-template-columns: 205px minmax(0, 1fr);
  align-items: start;
  gap: clamp(2rem, 5vw, 4.5rem);
}

.session-sidebar {
  position: sticky;
  top: 92px;
}

.session-outline {
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--gray-200);
  display: grid;
  gap: 0.2rem;
}

.session-outline > span {
  margin-bottom: 0.45rem;
  color: var(--gray-500);
  font-size: 0.65rem;
  font-weight: 850;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.session-outline a {
  padding: 0.36rem 0.55rem;
  border-left: 2px solid transparent;
  color: var(--gray-700);
  font-size: 0.78rem;
  font-weight: 650;
}

.session-outline a:hover {
  border-left-color: var(--accent);
  background: var(--accent-soft);
  color: var(--primary);
}

.session-tip {
  margin-top: 1.2rem;
  padding: 0.8rem;
  border-radius: 10px;
  background: var(--primary-soft);
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 0.55rem;
}

.session-tip > span {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.68rem;
  font-weight: 850;
}

.session-tip p {
  color: var(--gray-700);
  font-size: 0.69rem;
  line-height: 1.5;
}

.session-tip strong {
  display: block;
  color: var(--primary);
}

.session-main {
  min-width: 0;
}

.content-section {
  padding-block: 0 3.8rem;
  margin-bottom: 3.8rem;
  border-bottom: 1px solid var(--gray-200);
}

.content-heading {
  max-width: 720px;
  margin-bottom: 1.5rem;
}

.content-heading h2 {
  margin-top: 0.25rem;
  font-size: clamp(1.7rem, 3vw, 2.35rem);
}

.content-heading > p {
  margin-top: 0.55rem;
  color: var(--gray-500);
  font-size: 0.85rem;
}

.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.8rem;
}

.concept-card {
  min-height: 200px;
  padding: 1.25rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.concept-marker {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: var(--accent-soft);
  color: var(--accent-text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 850;
}

.concept-card h3 {
  margin-top: 1.2rem;
  color: var(--primary);
  font-size: 1rem;
  line-height: 1.25;
}

.concept-card p {
  margin-top: 0.45rem;
  color: var(--gray-700);
  font-size: 0.78rem;
  line-height: 1.6;
}

.diagram-block {
  overflow: hidden;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  box-shadow: var(--shadow);
}

.diagram-title {
  padding: 1.15rem 1.4rem;
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.diagram-title h3 {
  color: var(--primary);
  font-size: 0.95rem;
}

.diagram-title p {
  max-width: 500px;
  color: var(--gray-500);
  font-size: 0.7rem;
  text-align: right;
}

.diagram-canvas {
  overflow-x: auto;
  padding: clamp(1.4rem, 4vw, 2.4rem);
  background:
    linear-gradient(rgba(23, 63, 95, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 63, 95, 0.025) 1px, transparent 1px),
    #fbfdfd;
  background-size: 22px 22px;
}

.flow-diagram,
.split-diagram,
.case-map,
.review-map,
.cycle-diagram {
  min-width: 650px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
}

.flow-node,
.split-input,
.split-output,
.case-center {
  min-width: 120px;
  padding: 1rem;
  border: 1px solid var(--gray-200);
  border-radius: 11px;
  background: var(--white);
  text-align: center;
  box-shadow: 0 5px 14px rgba(21, 43, 58, 0.06);
}

.flow-node > span {
  color: var(--accent-text);
  font-size: 0.66rem;
  font-weight: 850;
}

.flow-node strong,
.flow-node small,
.split-input strong,
.split-input span,
.split-output strong,
.split-output span,
.case-center strong,
.case-center small {
  display: block;
}

.flow-node strong,
.split-input strong,
.split-output strong,
.case-center strong {
  color: var(--primary);
  font-size: 0.84rem;
}

.flow-node small,
.split-input span,
.split-output span,
.case-center small {
  margin-top: 0.15rem;
  color: var(--gray-500);
  font-size: 0.65rem;
}

.flow-arrow {
  flex: 0 0 auto;
  color: var(--accent-text);
  font-size: 1.4rem;
  font-weight: 800;
}

.split-output.accent {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--gray-200));
  background: var(--accent-soft);
}

.cycle-diagram > div {
  width: 118px;
  height: 118px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
}

.cycle-diagram > div span {
  color: var(--teal-light);
  font-size: 0.66rem;
}

.cycle-diagram > div strong {
  font-size: 0.82rem;
}

.cycle-diagram > b {
  color: var(--accent-text);
  font-size: 1.3rem;
}

.case-sources,
.case-end {
  display: grid;
  gap: 0.45rem;
}

.case-sources span,
.case-end span {
  min-width: 150px;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--gray-200);
  border-radius: 8px;
  background: var(--white);
  color: var(--gray-700);
  font-size: 0.7rem;
  font-weight: 700;
  text-align: center;
}

.case-end span:last-child {
  border-color: color-mix(in srgb, var(--accent) 40%, var(--gray-200));
  background: var(--accent-soft);
  color: var(--accent-text);
}

.review-map span {
  min-width: 95px;
  padding: 0.75rem;
  border: 1px solid var(--gray-200);
  border-radius: 999px;
  background: var(--white);
  color: var(--primary);
  font-size: 0.74rem;
  font-weight: 800;
  text-align: center;
}

.review-map b {
  color: var(--gray-300);
}

.review-map .review-accent {
  border-color: var(--accent);
  background: var(--accent);
  color: white;
}

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

.resource-card {
  position: relative;
  min-height: 215px;
  padding: 1.2rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
  display: flex;
  flex-direction: column;
  transition: border-color 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
}

.resource-card:hover {
  border-color: color-mix(in srgb, var(--primary) 32%, var(--gray-200));
  box-shadow: var(--shadow);
  transform: translateY(-3px);
}

.resource-type {
  color: var(--accent-text);
  font-size: 0.65rem;
  font-weight: 850;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.resource-card h3 {
  margin-top: 0.5rem;
  color: var(--primary);
  font-size: 1.02rem;
  line-height: 1.25;
}

.resource-card p {
  margin-top: 0.45rem;
  color: var(--gray-500);
  font-size: 0.74rem;
  line-height: 1.55;
}

.resource-action {
  margin-top: auto;
  padding-top: 1rem;
  color: var(--primary);
  font-size: 0.72rem;
  font-weight: 800;
}

.optional-badge {
  position: absolute;
  top: 0.9rem;
  right: 0.9rem;
  padding: 0.25rem 0.45rem;
  border-radius: 999px;
  background: var(--gray-100);
  color: var(--gray-500);
  font-size: 0.58rem;
  font-weight: 750;
}

.presenter-card {
  border-color: transparent;
  background: linear-gradient(145deg, var(--primary), color-mix(in srgb, var(--primary) 78%, var(--teal)));
  color: var(--white);
  box-shadow: var(--shadow);
}

.presenter-card .resource-type {
  color: var(--teal-light);
}

.presenter-card h3,
.presenter-card .resource-action {
  color: var(--white);
}

.presenter-card p {
  color: rgba(255, 255, 255, 0.68);
}

.problem-list {
  display: grid;
  gap: 1.25rem;
}

.problem-block {
  overflow: hidden;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  box-shadow: var(--shadow);
}

.problem-header {
  padding: 1rem 1.35rem 0;
  color: var(--accent-text);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.66rem;
  font-weight: 850;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.problem-level {
  padding: 0.22rem 0.5rem;
  border-radius: 999px;
  background: var(--accent-soft);
}

.problem-block > h3 {
  padding: 0.25rem 1.35rem 0;
  color: var(--primary);
  font-size: 1.35rem;
  letter-spacing: -0.025em;
}

.problem-context {
  margin: 0.8rem 1.35rem 1.15rem;
  padding: 0.9rem 1rem;
  border-left: 3px solid var(--teal);
  border-radius: 4px 9px 9px 4px;
  background: #eef9f7;
  color: var(--gray-700);
  font-size: 0.8rem;
}

.problem-parts {
  border-top: 1px solid var(--gray-200);
}

.problem-part + .problem-part {
  border-top: 1px solid var(--gray-200);
}

.part-question {
  padding: 1.1rem 1.35rem;
  display: grid;
  grid-template-columns: 30px 1fr;
  align-items: start;
  gap: 0.75rem;
}

.part-question > span {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: var(--primary-soft);
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 850;
}

.part-question p {
  color: var(--ink);
  font-size: 0.84rem;
  font-weight: 650;
}

.solution-toggle {
  width: 100%;
  padding: 0.72rem 1.35rem;
  border: 0;
  border-top: 1px solid var(--gray-100);
  background: #fbfcfc;
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.72rem;
  font-weight: 800;
  text-align: left;
  cursor: pointer;
}

.solution-toggle:hover,
.solution-toggle[aria-expanded="true"] {
  background: var(--primary-soft);
}

.solution-chevron {
  font-size: 1.05rem;
  font-weight: 500;
}

.solution-body {
  padding: 1.15rem 1.35rem 1.35rem 4.1rem;
  border-top: 1px solid var(--gray-200);
  background: var(--primary-soft);
  color: var(--gray-700);
  font-size: 0.8rem;
  animation: reveal 0.18s ease-out;
}

.solution-body p + p,
.solution-body ul + p,
.solution-body p + ul {
  margin-top: 0.65rem;
}

.solution-body ul,
.solution-body ol {
  padding-left: 1.1rem;
}

.solution-body li + li {
  margin-top: 0.3rem;
}

@keyframes reveal {
  from { opacity: 0; transform: translateY(-3px); }
  to { opacity: 1; transform: translateY(0); }
}

.reading-list {
  overflow: hidden;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
}

.reading-list a {
  min-height: 76px;
  padding: 1rem 1.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  transition: background 0.15s ease;
}

.reading-list a + a {
  border-top: 1px solid var(--gray-200);
}

.reading-list a:hover {
  background: var(--primary-soft);
}

.reading-list span,
.reading-list strong,
.reading-list small {
  display: block;
}

.reading-list strong {
  color: var(--primary);
  font-size: 0.82rem;
}

.reading-list small {
  margin-top: 0.15rem;
  color: var(--gray-500);
  font-size: 0.67rem;
}

.reading-list b {
  color: var(--accent-text);
}

.session-pagination {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.session-pagination a {
  padding: 1rem;
  border: 1px solid var(--gray-200);
  border-radius: 10px;
  background: var(--white);
}

.session-pagination a.next {
  text-align: right;
}

.session-pagination span,
.session-pagination strong {
  display: block;
}

.session-pagination span {
  color: var(--gray-500);
  font-size: 0.64rem;
  font-weight: 750;
  text-transform: uppercase;
}

.session-pagination strong {
  margin-top: 0.15rem;
  color: var(--primary);
  font-size: 0.78rem;
}

.not-found {
  max-width: 620px;
  margin: 5rem auto;
  padding: 3rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  text-align: center;
  box-shadow: var(--shadow);
}

.not-found > span {
  width: 52px;
  height: 52px;
  margin-inline: auto;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent-text);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 850;
}

.not-found h1 {
  margin-top: 1rem;
  color: var(--primary);
}

.not-found p {
  margin: 0.5rem 0 1.4rem;
  color: var(--gray-500);
}

.footer {
  padding: 1.6rem max(1.5rem, calc((100% - var(--max-width)) / 2));
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  background: #0f2636;
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.72rem;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.footer-brand {
  color: var(--white);
}

.footer-brand::before {
  width: 20px;
  height: 20px;
  border-radius: 6px 6px 6px 2px;
}

@media (max-width: 960px) {
  .hero-inner {
    grid-template-columns: minmax(0, 1fr) 330px;
    gap: 2.5rem;
  }

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

  .session-layout {
    grid-template-columns: 1fr;
  }

  .session-sidebar {
    position: static;
  }

  .session-outline {
    padding: 0.65rem;
    border: 1px solid var(--gray-200);
    border-radius: 10px;
    background: var(--white);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.25rem;
  }

  .session-outline > span {
    width: 100%;
  }

  .session-outline a {
    border: 0;
    border-radius: 6px;
    background: var(--gray-100);
  }

  .session-tip {
    display: none;
  }
}

@media (max-width: 760px) {
  html {
    scroll-padding-top: 72px;
  }

  .container,
  .nav-inner,
  .hero-inner {
    width: min(calc(100% - 2rem), var(--max-width));
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: absolute;
    top: 65px;
    right: 1rem;
    left: 1rem;
    padding: 0.7rem;
    border: 1px solid rgba(255, 255, 255, 0.13);
    border-radius: 12px;
    background: #102f46;
    box-shadow: var(--shadow-lg);
    display: none;
    align-items: stretch;
    flex-direction: column;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    width: 100%;
    padding: 0.75rem;
  }

  .nav-links a.nav-game {
    margin: 0.35rem 0 0;
  }

  .hero-inner {
    min-height: auto;
    padding-block: 3.5rem;
    grid-template-columns: 1fr;
  }

  .hero-copy h1 {
    font-size: clamp(2.55rem, 13vw, 4rem);
  }

  .hero-preview {
    max-width: 480px;
  }

  .preview-window {
    transform: none;
  }

  .intro-strip-inner,
  .study-path {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .section-heading,
  .diagram-title {
    align-items: flex-start;
    flex-direction: column;
    gap: 0.65rem;
  }

  .diagram-title p {
    text-align: left;
  }

  .concept-grid,
  .resource-grid {
    grid-template-columns: 1fr;
  }

  .concept-card {
    min-height: 0;
  }

  .session-hero-inner {
    min-height: 350px;
  }

  .session-number {
    right: -0.05em;
    font-size: 12rem;
  }

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

  .objective-list li {
    background: transparent;
  }

  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
    gap: 0.8rem;
  }
}

@media (max-width: 560px) {
  .card-grid {
    grid-template-columns: 1fr;
  }

  .session-card {
    min-height: 315px;
  }

  .home-hero .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .home-hero .btn {
    width: 100%;
  }

  .study-path,
  .session-section {
    margin-bottom: 3.5rem;
  }

  .session-section {
    padding-block: 3.5rem 2.5rem;
  }

  .session-content {
    padding-block: 2rem 3.5rem;
  }

  .content-section {
    padding-bottom: 2.8rem;
    margin-bottom: 2.8rem;
  }

  .part-question {
    padding-inline: 1rem;
  }

  .problem-header,
  .problem-block > h3,
  .solution-toggle {
    padding-inline: 1rem;
  }

  .problem-context {
    margin-inline: 1rem;
  }

  .solution-body {
    padding-inline: 1rem;
  }

  .session-pagination {
    grid-template-columns: 1fr;
  }

  .session-pagination a.next {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

@media print {
  .navbar,
  .footer,
  .session-sidebar,
  .resource-grid,
  .solution-toggle,
  .session-pagination {
    display: none !important;
  }

  body,
  .session-content {
    background: white;
  }

  .session-hero {
    background: white;
    color: black;
  }

  .session-hero .eyebrow,
  .session-hero h1,
  .session-hero h1 + p,
  .breadcrumb,
  .objective-list li {
    color: black;
  }

  .session-number {
    display: none;
  }

  .session-layout {
    display: block;
  }

  .content-section,
  .problem-block,
  .concept-card,
  .diagram-block {
    break-inside: avoid;
    box-shadow: none;
  }
}