:root {
  color-scheme: light dark;
  font-family: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  font-size: 16px;
  background-color: #f9fafb;
  color: #1f2933;
}

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

body {
  margin: 0;
  background: inherit;
  color: inherit;
}

[hidden],
.is-hidden {
  display: none !important;
}

a {
  color: #0052cc;
}

a:hover,
a:focus-visible {
  text-decoration: underline;
}

.wrapper {
  width: min(72rem, 92vw);
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 3vw, 2.5rem);
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 50%;
  transform: translate(-50%, -200%);
  background: #111827;
  color: #f9fafb;
  padding: 0.5rem 1rem;
  border-radius: 999px;
  text-decoration: none;
  transition: transform 160ms ease;
  z-index: 1000;
}

.skip-link:focus-visible {
  transform: translate(-50%, 0);
}

.page-header {
  background: #10172a;
  color: #f3f4f6;
  padding: clamp(2.5rem, 4vw + 1rem, 4rem) 0 clamp(2rem, 3vw, 3rem);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.page-header a {
  color: #bfdbfe;
}

.header-actions {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 1rem;
}

.home-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.42rem 1rem;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  background: rgba(148, 163, 184, 0.2);
  border: 1px solid rgba(148, 163, 184, 0.35);
  color: #f8fafc;
  text-decoration: none;
  transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.home-link:hover,
.home-link:focus-visible {
  background: #bfdbfe;
  border-color: transparent;
  color: #0f172a;
  transform: translateY(-1px);
}

.home-link:focus-visible {
  outline: 2px solid #bfdbfe;
  outline-offset: 2px;
}

.footer-actions {
  position: relative;
  height: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1.2rem;
  border-radius: 999px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  border: 1px solid rgba(148, 163, 184, 0.4);
  background: #f1f5f9;
  color: #0f172a;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.btn.ghost {
  background: transparent;
  color: inherit;
  border: 1px solid rgba(148, 163, 184, 0.4);
}

.btn:hover,
.btn:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.18);
  border-color: rgba(148, 163, 184, 0.6);
}

.btn.ghost:hover,
.btn.ghost:focus-visible {
  background: rgba(148, 163, 184, 0.65);
}

.back-to-top {
  letter-spacing: 0.08em;
  position: fixed;
  left: 50%;
  bottom: 1.75rem;
  transform: translateX(-50%);
  z-index: 900;
  background: rgba(15, 23, 42, 0.85);
  color: #f8fafc;
  border-color: rgba(148, 163, 184, 0.35);
  backdrop-filter: blur(10px);
  box-shadow: 0 14px 36px rgba(15, 23, 42, 0.32);
  padding-inline: 1.4rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover,
.back-to-top:focus-visible {
  transform: translateX(-50%);
}

.back-to-top::before {
  content: "\2191";
  font-size: 1.1rem;
  line-height: 1;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.75rem;
  margin: 0 0 0.75rem;
  color: rgba(255, 255, 255, 0.7);
}

.page-title {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 0 0 1rem;
}

.page-title h1 {
  margin: 0;
}

.title__icon {
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 1rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(148, 163, 184, 0.15);
  color: inherit;
  box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.25);
  flex-shrink: 0;
}

.title__icon svg {
  width: 2.6rem;
  height: 2.6rem;
}

@media (max-width: 40rem) {
  .header-actions {
    justify-content: flex-start;
  }

  .page-title {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }

  .title__icon {
    width: 3rem;
    height: 3rem;
  }

  .title__icon svg {
    width: 2.2rem;
    height: 2.2rem;
  }
}

.intro {
  margin-top: 0.5rem;
  margin-bottom: 1.75rem;
  max-width: 46ch;
}

.search-form {
  display: grid;
  gap: 0.5rem;
  max-width: 40rem;
}

.field-label {
  font-weight: 600;
}

.search-input {
  appearance: none;
  border: 2px solid rgba(255, 255, 255, 0.4);
  border-radius: 0.75rem;
  padding: 0.75rem 1.2rem;
  font-size: 1rem;
  color: inherit;
  background: rgba(255, 255, 255, 0.08);
  transition: border-color 160ms ease, background-color 160ms ease;
}

.search-input:focus-visible {
  outline: none;
  border-color: #38bdf8;
  background-color: rgba(56, 189, 248, 0.12);
}

.field-hint {
  margin: 0;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.75);
}

.search-status {
  margin: 1rem 0 0;
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.85);
}

.section-nav {
  background: #e2e8f0;
  border-bottom: 1px solid #cbd5e1;
}

.section-nav__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding: 0.75rem 0;
  margin: 0;
}

.section-nav__list a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 600;
  transition: background-color 120ms ease, transform 120ms ease;
}

.nav-pill {
  border: 1px solid transparent;
}

.section-nav__list .nav-pill--thermal {
  background: rgba(239, 68, 68, 0.16);
  border: 1px solid rgba(185, 28, 28, 0.25);
  color: #991b1b;
}

.section-nav__list .nav-pill--hydro {
  background: rgba(37, 99, 235, 0.16);
  border: 1px solid rgba(37, 99, 235, 0.22);
  color: #1d4ed8;
}

.section-nav__list .nav-pill--wind {
  background: rgba(34, 197, 94, 0.18);
  border: 1px solid rgba(16, 185, 129, 0.28);
  color: #047857;
}

.section-nav__list .nav-pill--solar {
  background: rgba(250, 204, 21, 0.2);
  border: 1px solid rgba(217, 119, 6, 0.28);
  color: #a16207;
}

.section-nav__list a:hover,
.section-nav__list a:focus-visible {
  background: rgba(203, 213, 225, 0.32);
  transform: translateY(-1px);
}

.card-grid {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
  padding-block: clamp(2rem, 4vw, 3rem);
}

@media (min-width: 52rem) {
  .card-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.glossary-card {
  --card-accent: #2563eb;
  background: #ffffff;
  border-radius: 1.25rem;
  padding: clamp(1.5rem, 2vw + 1rem, 2.25rem);
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.11);
  border: 1px solid rgba(15, 23, 42, 0.08);
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: relative;
  overflow: hidden;
  transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
  will-change: transform;
}

.glossary-card::before {
  content: "";
  position: absolute;
  inset: -1px;
  pointer-events: none;
  background: radial-gradient(160px circle at var(--mouse-x, 50%) var(--mouse-y, 50%),
      color-mix(in srgb, var(--card-accent) 28%, transparent),
      color-mix(in srgb, var(--card-accent) 12%, transparent) 40%,
      transparent 70%);
  opacity: 0;
  transition: opacity 200ms ease;
}

.glossary-card:hover,
.glossary-card:focus-within {
  transform: translateY(-4px);
  border-color: color-mix(in srgb, var(--card-accent) 45%, rgba(15, 23, 42, 0.12));
  box-shadow: 0 18px 36px color-mix(in srgb, var(--card-accent) 25%, rgba(15, 23, 42, 0.16));
}

.glossary-card:hover::before,
.glossary-card:focus-within::before {
  opacity: 1;
}

.glossary-card__header {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.glossary-card__heading {
  display: grid;
  gap: 0.4rem;
}

.glossary-card__header h2 {
  margin: 0;
}

.glossary-card__header p {
  margin: 0;
}

.glossary-card__icon {
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 0.9rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: inset 0 0 0 1px rgba(15, 23, 42, 0.12);
  color: var(--card-accent);
  background: color-mix(in srgb, var(--card-accent) 18%, transparent);
}

.glossary-card__icon svg {
  width: 2.25rem;
  height: 2.25rem;
}

#thermal {
  --card-accent: #b91c1c;
}

#hydro {
  --card-accent: #1d4ed8;
}

#wind {
  --card-accent: #047857;
}

#solar {
  --card-accent: #a16207;
}

@media (max-width: 40rem) {
  .glossary-card__header {
    flex-direction: column;
    align-items: flex-start;
  }

  .glossary-card__icon {
    width: 3rem;
    height: 3rem;
  }

  .glossary-card__icon svg {
    width: 2rem;
    height: 2rem;
  }
}

.glossary-card__eyebrow {
  letter-spacing: 0.12em;
  font-size: 0.75rem;
  font-weight: 600;
  color: #475569;
  margin: 0;
}

.term-list {
  margin: 0;
  padding: 0;
}

.term-pair {
  display: grid;
  gap: 0.5rem;
  padding: 1.1rem 1.2rem;
  border-radius: 1rem;
  background: #f1f5f9;
  border: 1px solid rgba(15, 23, 42, 0.06);
  margin-bottom: 1rem;
}

.term-pair:last-of-type {
  margin-bottom: 0;
}

dt {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.9rem;
  color: #0f172a;
  overflow-wrap: anywhere;
}

dd {
  margin: 0;
  color: #1f2937;
}

dd>p {
  margin: 0 0 0.5rem;
}

dd ul {
  margin: 0;
  padding-left: 1.1rem;
}

dd li {
  margin-bottom: 0.25rem;
}

.meta-label {
  font-weight: 600;
  color: #111827;
}

.page-footer {
  padding: 2rem 0 3rem;
  background: #10172a;
  color: #e2e8f0;
}

.page-footer a {
  color: #93c5fd;
}

@media (prefers-color-scheme: dark) {
  :root {
    background-color: #0b1220;
    color: #e2e8f0;
  }

  .page-header {
    background: #050b18;
    border-bottom-color: rgba(148, 163, 184, 0.22);
  }

  .section-nav {
    background: #111b2d;
    border-bottom-color: rgba(148, 163, 184, 0.24);
  }

  .section-nav__list .nav-pill--thermal {
    background: rgba(239, 68, 68, 0.2);
    border-color: rgba(248, 113, 113, 0.32);
    color: #fecaca;
  }

  .section-nav__list .nav-pill--hydro {
    background: rgba(37, 99, 235, 0.2);
    border-color: rgba(147, 197, 253, 0.32);
    color: #c7d2fe;
  }

  .section-nav__list .nav-pill--wind {
    background: rgba(34, 197, 94, 0.22);
    border-color: rgba(134, 239, 172, 0.32);
    color: #bbf7d0;
  }

  .section-nav__list .nav-pill--solar {
    background: rgba(250, 204, 21, 0.24);
    border-color: rgba(253, 224, 71, 0.38);
    color: #fde68a;
  }

  .btn {
    background: rgba(148, 163, 184, 0.18);
    border-color: rgba(148, 163, 184, 0.4);
    color: #f8fafc;
  }

  .btn.ghost {
    background: transparent;
    color: #f8fafc;
    border-color: rgba(148, 163, 184, 0.75);
  }

  .btn:hover,
  .btn:focus-visible {
    background: rgba(191, 219, 254, 0.2);
    border-color: rgba(191, 219, 254, 0.5);
  }

  .glossary-card {
    background: #111b2d;
    border-color: rgba(148, 163, 184, 0.16);
    box-shadow: 0 18px 36px rgba(2, 6, 23, 0.6);
  }

  .home-link {
    background: rgba(148, 163, 184, 0.3);
    border-color: rgba(148, 163, 184, 0.45);
    color: #f8fafc;
  }

  .home-link:hover,
  .home-link:focus-visible {
    background: rgba(191, 219, 254, 0.85);
    color: #050b18;
  }

  .back-to-top {
    background: rgba(15, 23, 42, 0.85);
    border-color: rgba(148, 163, 184, 0.45);
    color: #f8fafc;
    box-shadow: 0 14px 36px rgba(2, 6, 23, 0.75);
  }

  .back-to-top:hover,
  .back-to-top:focus-visible {
    background: rgba(30, 64, 175, 0.88);
    border-color: rgba(96, 165, 250, 0.5);
  }

  .term-pair {
    background: #0f1729;
    border-color: rgba(148, 163, 184, 0.14);
  }

  .glossary-card__icon {
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.24);
    background: color-mix(in srgb, var(--card-accent) 32%, transparent);
    color: color-mix(in srgb, var(--card-accent) 80%, #f9fafb);
  }

  .glossary-card::before {
    background: radial-gradient(160px circle at var(--mouse-x, 50%) var(--mouse-y, 50%),
        color-mix(in srgb, var(--card-accent) 38%, transparent),
        color-mix(in srgb, var(--card-accent) 18%, transparent) 45%,
        transparent 75%);
  }

  .title__icon {
    background: rgba(148, 163, 184, 0.22);
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.32);
  }

  dt {
    color: #cbd5f5;
  }

  dd {
    color: #e2e8f0;
  }

  .meta-label {
    color: #f8fafc;
  }

  .page-footer {
    background: #050b18;
    color: #cbd5f5;
  }
}