:root {
  --ink: #10243f;
  --muted: #5e6f86;
  --line: #dbe4ef;
  --paper: #ffffff;
  --wash: #f5f8fb;
  --blue: #2769c8;
  --blue-soft: #e8f1ff;
  --gold: #c8962f;
  --gold-soft: #fff5d9;
  --sage: #2f7d6d;
  --coral: #bf594f;
  --shadow: 0 18px 55px rgba(16, 36, 63, 0.09);
  --radius: 8px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

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

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

svg {
  width: 1.1em;
  height: 1.1em;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 74px;
  padding: 0 clamp(18px, 4vw, 54px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid rgba(219, 228, 239, 0.82);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 190px;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  color: #fff;
  font-weight: 800;
  background: linear-gradient(135deg, var(--blue), var(--sage));
  border-radius: var(--radius);
  box-shadow: 0 10px 28px rgba(39, 105, 200, 0.22);
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 0.98rem;
  letter-spacing: 0;
}

.brand small {
  color: var(--muted);
  font-size: 0.78rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  padding: 0 13px;
  color: #314963;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 650;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--ink);
  background: var(--wash);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  place-items: center;
  color: var(--ink);
  background: var(--wash);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.container {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}

.home-hero {
  min-height: min(760px, calc(100vh - 126px));
  display: flex;
  align-items: center;
  padding: clamp(34px, 6vw, 70px) clamp(20px, 5vw, 72px);
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.98) 0%, rgba(255, 255, 255, 0.9) 48%, rgba(255, 255, 255, 0.48) 78%),
    url("assets/excel-course-map.png") center right / cover no-repeat;
  border-bottom: 1px solid var(--line);
}

.hero-content {
  width: min(760px, 100%);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 24px;
  font-size: clamp(2.25rem, 4.25vw, 4rem);
  line-height: 1.02;
  letter-spacing: 0;
  overflow-wrap: break-word;
}

h2,
h3,
p,
a,
button {
  overflow-wrap: break-word;
}

.home-hero p,
.page-hero p,
.section-header p,
.split p {
  color: var(--muted);
  font-size: clamp(1.02rem, 1.6vw, 1.18rem);
}

.home-hero p {
  max-width: 680px;
  margin-bottom: 30px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 0 17px;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 760;
  box-shadow: 0 12px 30px rgba(16, 36, 63, 0.08);
}

.button.primary {
  color: #fff;
  background: var(--blue);
  border-color: var(--blue);
}

.button.subtle {
  background: rgba(255, 255, 255, 0.76);
}

.section {
  padding: clamp(58px, 8vw, 104px) 0;
}

.band {
  background:
    linear-gradient(180deg, rgba(245, 248, 251, 0.86), rgba(245, 248, 251, 0.98)),
    radial-gradient(circle at top left, rgba(39, 105, 200, 0.08), transparent 34%);
  border-block: 1px solid var(--line);
}

.section-header {
  max-width: 760px;
  margin-bottom: 34px;
}

.section-header.center {
  margin-inline: auto;
  text-align: center;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(2rem, 4vw, 3.55rem);
  line-height: 1;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.08rem;
  line-height: 1.2;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

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

.feature-card,
.roadmap-card,
.term-card,
.tool-grid article,
.resource-card,
.homework-panel,
.engine-stage {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 8px 30px rgba(16, 36, 63, 0.05);
}

.feature-card {
  min-height: 218px;
  padding: 24px;
}

.feature-card p,
.roadmap-card li,
.term-card li,
.tool-grid p,
.resource-card p,
.site-footer p,
.homework-panel li,
.engine-stage li {
  color: var(--muted);
}

.feature-icon {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  margin-bottom: 28px;
  color: var(--blue);
  background: var(--blue-soft);
  border-radius: var(--radius);
}

.feature-icon svg {
  width: 22px;
  height: 22px;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: clamp(28px, 7vw, 80px);
  align-items: center;
}

.split.align-start {
  align-items: start;
}

.signal-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.signal-list span,
.topic-grid span,
.check-list span {
  display: flex;
  min-height: 54px;
  align-items: center;
  padding: 14px 16px;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-weight: 720;
}

.page-hero {
  padding: clamp(42px, 7vw, 84px) 0 clamp(36px, 6vw, 70px);
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(135deg, #fff 0%, #fff 46%, rgba(232, 241, 255, 0.75) 100%);
}

.page-hero.reading-hero {
  background:
    linear-gradient(135deg, #fff 0%, #fff 45%, rgba(232, 241, 255, 0.8) 100%);
}

.page-hero.math-hero {
  background:
    linear-gradient(135deg, #fff 0%, #fff 45%, rgba(237, 249, 246, 0.88) 100%);
}

.page-hero.athena-hero {
  background:
    linear-gradient(135deg, #fff 0%, #fff 45%, rgba(255, 245, 217, 0.9) 100%);
}

.page-hero.expectations-hero {
  background:
    linear-gradient(135deg, #fff 0%, #fff 45%, rgba(244, 232, 231, 0.72) 100%);
}

.page-hero.resources-hero {
  background:
    linear-gradient(135deg, #fff 0%, #fff 45%, rgba(245, 248, 251, 0.98) 100%);
}

.page-hero h1 {
  max-width: 900px;
}

.page-hero p {
  max-width: 850px;
  margin-bottom: 0;
}

.tracks {
  display: grid;
  gap: 36px;
}

.track {
  position: relative;
  padding: clamp(18px, 3vw, 28px);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.track::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 6px;
  border-radius: var(--radius) 0 0 var(--radius);
}

.track.blue::before {
  background: var(--blue);
}

.track.white::before {
  background: var(--gold);
}

.track-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 20px;
  padding-left: 8px;
}

.track-heading h3 {
  margin-bottom: 0;
  font-size: clamp(1.4rem, 2vw, 2rem);
}

.track-heading p {
  max-width: 620px;
  margin-bottom: 0;
  color: var(--muted);
  text-align: right;
}

.term-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.term-card {
  display: flex;
  min-height: 100%;
  flex-direction: column;
  padding: 18px;
}

.term-card.blue {
  background: linear-gradient(180deg, #fff, rgba(232, 241, 255, 0.55));
}

.term-card.white {
  background: linear-gradient(180deg, #fff, rgba(255, 245, 217, 0.6));
}

.term-meta {
  display: flex;
  min-height: 44px;
  align-items: start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.term-meta strong {
  color: var(--ink);
  text-align: right;
}

.clean-list,
.numberless-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.clean-list li,
.numberless-list li {
  position: relative;
  padding-left: 17px;
  font-size: 0.92rem;
}

.clean-list li + li,
.numberless-list li + li {
  margin-top: 7px;
}

.clean-list li::before,
.numberless-list li::before {
  content: "";
  position: absolute;
  top: 0.7em;
  left: 0;
  width: 6px;
  height: 6px;
  background: var(--blue);
  border-radius: 50%;
}

.term-card.white .clean-list li::before {
  background: var(--gold);
}

.project-line {
  margin: auto 0 0;
  padding-top: 16px;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 780;
}

.engine {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.engine-stage {
  position: relative;
  min-height: 278px;
  padding: 22px;
  overflow: hidden;
}

.engine-stage::after {
  content: "";
  position: absolute;
  right: -24px;
  bottom: -24px;
  width: 96px;
  height: 96px;
  border: 18px solid rgba(39, 105, 200, 0.08);
  border-radius: 50%;
}

.engine-stage span {
  display: inline-flex;
  margin-bottom: 26px;
  color: var(--blue);
  font-weight: 850;
}

.roadmaps {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px;
  align-items: start;
}

.roadmap-column h2 {
  margin-bottom: 20px;
}

.roadmap-stack {
  display: grid;
  gap: 14px;
}

.roadmap-card {
  padding: 22px;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
}

.tool-grid article {
  padding: 20px;
}

.topic-grid,
.resource-grid,
.check-list {
  display: grid;
  gap: 14px;
}

.topic-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

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

.check-list span::before {
  content: "";
  flex: 0 0 auto;
  width: 9px;
  height: 9px;
  margin-right: 12px;
  background: var(--sage);
  border-radius: 50%;
}

.homework-panel {
  padding: 26px;
}

.homework-panel h2 {
  font-size: clamp(1.7rem, 3vw, 2.4rem);
}

.numberless-list li::before {
  background: var(--coral);
}

.ladder {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: ladder;
}

.ladder li {
  counter-increment: ladder;
  position: relative;
  min-height: 64px;
  padding: 18px 20px 18px 70px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  font-weight: 770;
  box-shadow: 0 8px 30px rgba(16, 36, 63, 0.05);
}

.ladder li + li {
  margin-top: 10px;
}

.ladder li::before {
  content: counter(ladder);
  position: absolute;
  left: 18px;
  top: 14px;
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  color: #fff;
  background: var(--blue);
  border-radius: 50%;
  font-size: 0.88rem;
}

.resource-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.resource-card {
  min-height: 192px;
  padding: 22px;
}

.resource-card h2 {
  font-size: 1.13rem;
  line-height: 1.2;
}

.resource-card button {
  width: 100%;
  min-height: 38px;
  margin-top: 12px;
  color: #7b8797;
  background: var(--wash);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font: inherit;
  font-size: 0.82rem;
  font-weight: 730;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 32px clamp(20px, 5vw, 72px);
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.site-footer strong {
  color: var(--ink);
}

.site-footer p {
  margin-bottom: 0;
}

.site-footer a {
  color: var(--ink);
  font-weight: 760;
}

@media (max-width: 1100px) {
  .feature-grid,
  .term-grid,
  .engine,
  .topic-grid,
  .resource-grid,
  .tool-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

.home-hero {
    min-height: min(680px, calc(100vh - 132px));
    background:
      linear-gradient(180deg, rgba(255, 255, 255, 0.96) 0%, rgba(255, 255, 255, 0.9) 54%, rgba(255, 255, 255, 0.7) 100%),
      url("assets/excel-course-map.png") center bottom / cover no-repeat;
  }
}

@media (max-width: 860px) {
  .site-header {
    min-height: 68px;
  }

  .nav-toggle {
    display: grid;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 1px);
    right: 14px;
    left: 14px;
    display: none;
    padding: 10px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
  }

  .site-nav.open {
    display: grid;
  }

  .site-nav a {
    min-height: 44px;
  }

  .home-hero {
    min-height: auto;
    padding-top: 38px;
    padding-bottom: 34px;
    align-items: start;
  }

  h1 {
    font-size: clamp(2rem, 8.6vw, 2.85rem);
    line-height: 1.04;
  }

  .hero-actions,
  .button {
    width: 100%;
  }

  .split,
  .roadmaps {
    grid-template-columns: 1fr;
  }

  .track-heading {
    display: block;
  }

  .track-heading p {
    margin-top: 8px;
    text-align: left;
  }
}

@media (max-width: 620px) {
  .container {
    width: min(100% - 28px, var(--max));
  }

  .feature-grid,
  .feature-grid.two-two,
  .term-grid,
  .engine,
  .topic-grid,
  .resource-grid,
  .tool-grid,
  .signal-list,
  .check-list {
    grid-template-columns: 1fr;
  }

  .home-hero {
    padding-inline: 16px;
  }

  .home-hero p,
  .page-hero p {
    font-size: 0.98rem;
  }

  .feature-card,
  .term-card,
  .roadmap-card,
  .tool-grid article,
  .resource-card,
  .homework-panel,
  .engine-stage {
    padding: 18px;
  }

  .term-meta {
    display: block;
  }

  .term-meta strong {
    display: block;
    margin-top: 3px;
    text-align: left;
  }

  .site-footer {
    display: block;
  }

  .site-footer a {
    display: inline-flex;
    margin-top: 16px;
  }
}