:root {
  --measure: 72ch;
  --font-body: "Source Sans 3", "Segoe UI", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --font-ui: "Source Sans 3", "Segoe UI", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #161b22;
  --muted: #4f5b68;
  --border: #d7dce3;
  --link: #0e4a84;
  --link-hover: #8a2f00;
  --button-bg: #eef3f9;
  --button-hover: #dfe8f5;
  --switch-track: #dde4ec;
  --switch-track-checked: #c7d8ec;
  --switch-border: #9aa8ba;
  --switch-knob: #ffffff;
  --switch-knob-border: #8694a8;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #111419;
    --surface: #181d24;
    --text: #f3f5f7;
    --muted: #b6bec9;
    --border: #2b3543;
    --link: #8dc1ff;
    --link-hover: #b7d9ff;
    --button-bg: #232d3a;
    --button-hover: #2d3a4a;
    --switch-track: #263241;
    --switch-track-checked: #324962;
    --switch-border: #4b5d72;
    --switch-knob: #f7f9fc;
    --switch-knob-border: #778aa1;
  }
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #161b22;
  --muted: #4f5b68;
  --border: #d7dce3;
  --link: #0e4a84;
  --link-hover: #8a2f00;
  --button-bg: #eef3f9;
  --button-hover: #dfe8f5;
  --switch-track: #dde4ec;
  --switch-track-checked: #c7d8ec;
  --switch-border: #9aa8ba;
  --switch-knob: #ffffff;
  --switch-knob-border: #8694a8;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #111419;
  --surface: #181d24;
  --text: #f3f5f7;
  --muted: #b6bec9;
  --border: #2b3543;
  --link: #8dc1ff;
  --link-hover: #b7d9ff;
  --button-bg: #232d3a;
  --button-hover: #2d3a4a;
  --switch-track: #263241;
  --switch-track-checked: #324962;
  --switch-border: #4b5d72;
  --switch-knob: #f7f9fc;
  --switch-knob-border: #778aa1;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: clamp(1rem, 0.2vw + 0.95rem, 1.125rem);
  line-height: 1.75;
}

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

.site-header,
main,
.footer-inner {
  width: min(var(--measure), calc(100% - 2.5rem));
  margin-left: auto;
  margin-right: auto;
}

.site-header {
  margin-top: 2.25rem;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 1rem;
}

h1 {
  font-family: var(--font-ui);
  margin: 0;
  font-size: clamp(1.85rem, 2.6vw, 2.6rem);
  font-weight: 700;
  line-height: 1.25;
}

.theme-switch {
  flex: none;
  position: relative;
  display: inline-flex;
  width: 2.9rem;
  height: 1.7rem;
  margin-top: 0.2rem;
  cursor: pointer;
}

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

#theme-toggle {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
}

.slider {
  width: 100%;
  height: 100%;
  border-radius: 999px;
  border: 1px solid var(--switch-border);
  background: var(--switch-track);
  transition: background 0.2s ease, border-color 0.2s ease;
}

.slider::before {
  content: "";
  position: absolute;
  left: 0.16rem;
  top: 50%;
  width: 1.16rem;
  height: 1.16rem;
  border-radius: 50%;
  border: 1px solid var(--switch-knob-border);
  background: var(--switch-knob);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.18);
  transform: translateY(-50%);
  transition: transform 0.2s ease;
}

#theme-toggle:checked + .slider {
  background: var(--switch-track-checked);
}

#theme-toggle:checked + .slider::before {
  transform: translate(1.18rem, -50%);
}

#theme-toggle:focus-visible + .slider {
  outline: 2px solid var(--link);
  outline-offset: 2px;
}

main {
  padding-bottom: 2.5rem;
}

article p {
  margin: 0 0 1.1rem;
}

article figure {
  margin: 2rem 0;
}

article img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 0.25rem;
}

.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  background: color-mix(in oklab, var(--surface), transparent 8%);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem 2rem;
  padding-top: 1.15rem;
  padding-bottom: 1.5rem;
}

.footer-left {
  text-align: left;
}

.footer-left p {
  margin: 0;
  font-family: var(--font-ui);
  font-size: 0.95rem;
  line-height: 1.6;
}

.license-wrap {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin-left: 0.2rem;
  flex-wrap: wrap;
}

.license-link,
.home-link {
  color: var(--link);
  text-decoration: none;
  transition: color 0.18s ease;
}

.license-link:hover,
.license-link:focus-visible,
.home-link:hover,
.home-link:focus-visible {
  color: var(--link-hover);
}

.license-icons {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
}

.license-icons img {
  display: block;
  width: 1.12rem;
  height: 1.12rem;
}

.home-link {
  flex: none;
  font-family: var(--font-ui);
  font-size: 0.95rem;
  font-weight: 600;
}

@media (max-width: 720px) {
  .site-header,
  main,
  .footer-inner {
    width: min(var(--measure), calc(100% - 1.5rem));
  }

  .site-header {
    margin-top: 1.5rem;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }

  .home-link {
    align-self: center;
  }
}

@media (max-width: 400px) {
  h1 {
    font-size: clamp(1.45rem, 5.2vw, 1.7rem);
  }
}