:root {
  color-scheme: light dark;

  --color-bg: light-dark(hsl(37, 18%, 91%), hsl(37, 18%, 10%));
  --color-border: light-dark(hsl(37, 18%, 70%), hsl(37, 18%, 26%));
  --color-text-light: hsl(37, 18%, 28%);
  --color-text: light-dark(var(--color-text-light), hsl(37, 18%, 74%));
  --color-text-secondary: light-dark(hsl(37, 18%, 48%), hsl(37, 18%, 54%));
  --color-code-bg: light-dark(hsl(37, 12%, 84%), hsl(37, 10%, 17%));
  --color-highlight-bg: goldenrod;

  --spacing-xs: 4px;
  --spacing-s: 8px;
  --spacing-m: 16px;
  --spacing-l: 32px;
}

:root[data-color-scheme="light"] { color-scheme: light; }
:root[data-color-scheme="dark"]  { color-scheme: dark; }

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

::selection {
  background-color: var(--color-highlight-bg);
  color: var(--color-text-light);
}

body {
  margin: 0;
  font-family: 'Inter', Helvetica, Arial, system-ui, sans-serif;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

h1, h2, h3, h4, h5, h6, time {
  font-family: 'Roboto Mono', 'Courier New', Courier, monospace;
}

nav {
  display: flex;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--color-bg);
}

nav::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2rem;
  transform: translateY(100%);
  background: linear-gradient(to bottom, var(--color-bg), transparent);
  pointer-events: none;
}

nav ul {
  align-items: center;
  display: flex;
  font-family: 'Roboto Mono', 'Courier New', Courier, monospace;
  gap: var(--spacing-l);
  list-style: none;
  margin: 0;
  padding: var(--spacing-m) var(--spacing-l);
}
nav ul.nav-end {
  margin-left: auto;
}
nav ul.nav-end a,
nav ul.nav-end a:visited {
  color: var(--color-text);
  text-decoration: none;
}
nav ul.nav-end a:hover {
  text-decoration: underline;
}

#theme-toggle {
  background: none;
  border: none;
  color: var(--color-text);
  cursor: pointer;
  display: flex;
  align-items: center;
  padding: 0;
}

.icon-sun { display: none; }

/* Dark via OS preference, unless user forced light */
@media (prefers-color-scheme: dark) {
  :root:not([data-color-scheme="light"]) .icon-moon { display: none; }
  :root:not([data-color-scheme="light"]) .icon-sun  { display: block; }
}

/* Dark forced by user */
:root[data-color-scheme="dark"] .icon-moon { display: none; }
:root[data-color-scheme="dark"] .icon-sun  { display: block; }