:root {
  --color-primary: #183a59;
  --color-secondary: #7a4e00;
  --color-background: #ffffff;
  --color-surface: #f7f4ee;
  --color-text: #17202a;
  --color-error: #b42318;
  --color-success: #0f6b4d;
  --color-border: #d8d2c7;
  --color-focus: #7a4e00;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --radius-sm: 0.5rem;
  --radius-md: 0.875rem;
  --radius-lg: 1.25rem;
  --shadow-soft: 0 1.25rem 3rem rgba(23, 32, 42, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  background: var(--color-background);
  color: var(--color-text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

body {
  margin: 0;
  min-width: 320px;
}

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

button {
  cursor: pointer;
}

button:focus-visible,
a:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

.site-header {
  position: relative;
  display: grid;
  gap: var(--space-6);
  padding: var(--space-8) clamp(var(--space-4), 5vw, var(--space-16));
  background:
    linear-gradient(135deg, rgba(24, 58, 89, 0.96), rgba(24, 58, 89, 0.86)),
    var(--color-primary);
  color: #ffffff;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.brand__logo {
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-sm);
  flex: 0 0 auto;
}

.elle-callout {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  max-width: min(24rem, 100%);
  margin: 0;
  padding: var(--space-2) var(--space-3);
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
}

.elle-callout__image {
  width: 5.125rem;
  height: 7.625rem;
  border: 2px solid #ffffff;
  border-radius: var(--radius-md);
  object-fit: cover;
}

.elle-callout p {
  margin: 0;
  font-size: clamp(1rem, 2vw, 1.25rem);
  font-weight: 700;
  line-height: 1.2;
}

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

h1 {
  margin-bottom: 0;
  font-size: clamp(2rem, 6vw, 3.5rem);
  line-height: 1;
  letter-spacing: -0.04em;
}

h2 {
  margin-bottom: var(--space-2);
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1.15;
  letter-spacing: -0.025em;
}

.eyebrow {
  margin-bottom: var(--space-2);
  color: inherit;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.header-summary {
  max-width: 72ch;
  margin-bottom: 0;
  font-size: 1.125rem;
}

.app-shell {
  display: grid;
  grid-template-columns: minmax(18rem, 24rem) minmax(0, 72ch);
  gap: var(--space-8);
  align-items: start;
  width: min(100%, 82rem);
  margin: 0 auto;
  padding: var(--space-8) clamp(var(--space-4), 5vw, var(--space-8)) var(--space-16);
}

.module-nav,
.module-panel {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-soft);
}

.module-nav {
  position: sticky;
  top: var(--space-4);
  max-height: calc(100vh - var(--space-8));
  overflow: auto;
}

.module-nav__header {
  padding: var(--space-6) var(--space-6) var(--space-3);
}

.module-nav__header h2 {
  font-size: 1.25rem;
}

.module-nav__header p {
  margin-bottom: 0;
  color: var(--color-secondary);
  font-size: 0.875rem;
  font-weight: 600;
}

.module-tabs {
  display: grid;
  gap: var(--space-2);
  padding: 0 var(--space-3) var(--space-3);
}

.module-tab {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-3);
  align-items: center;
  width: 100%;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  padding: var(--space-3);
  background: transparent;
  color: var(--color-text);
  text-align: left;
}

.module-tab:hover {
  border-color: var(--color-border);
  background: #ffffff;
}

.module-tab[aria-selected="true"] {
  border-color: var(--color-primary);
  background: var(--color-primary);
  color: #ffffff;
}

.module-tab__number {
  display: inline-grid;
  place-items: center;
  min-width: 2.25rem;
  min-height: 2.25rem;
  border-radius: 999px;
  background: rgba(24, 58, 89, 0.1);
  color: var(--color-primary);
  font-size: 0.875rem;
  font-weight: 700;
}

.module-tab[aria-selected="true"] .module-tab__number {
  background: #ffffff;
  color: var(--color-primary);
}

.module-tab__title {
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.25;
}

.module-panel {
  min-height: 28rem;
  padding: clamp(var(--space-6), 5vw, var(--space-12));
}

.module-panel .eyebrow {
  color: var(--color-secondary);
}

.module-description {
  max-width: 72ch;
  margin-bottom: 0;
  font-size: 1.125rem;
}

@media (max-width: 900px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .elle-callout {
    max-width: 100%;
    width: fit-content;
  }

  .module-nav {
    position: static;
    max-height: none;
  }

  .module-tabs {
    grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  }
}

@media (max-width: 640px) {
  .site-header {
    padding-top: var(--space-6);
  }

  .brand {
    align-items: flex-start;
  }

  .elle-callout {
    align-items: flex-start;
  }

  .elle-callout__image {
    width: 4rem;
    height: 6rem;
  }

  .module-tabs {
    grid-template-columns: 1fr;
  }
}

@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;
  }
}