:root {
  --background-color: oklch(98% 0.02 240);
  --text-color: oklch(25% 0.1 240);
  --primary-color: oklch(65% 0.2 260);
  --secondary-color: oklch(75% 0.25 280);
  --highlight-color: oklch(80% 0.28 300);
  --shadow-color: oklch(20% 0.1 240 / 40%);
  --card-background: white;

  --font-sans: 'Inter', sans-serif;
  --font-display: 'Poppins', sans-serif;
}

body.dark-mode {
  --background-color: oklch(20% 0.02 240);
  --text-color: oklch(90% 0.05 240);
  --primary-color: oklch(70% 0.18 260);
  --secondary-color: oklch(80% 0.22 280);
  --highlight-color: oklch(85% 0.25 300);
  --shadow-color: oklch(5% 0.01 240 / 40%);
  --card-background: oklch(25% 0.03 240);
}

@supports (font-variation-settings: normal) {
  :root {
    --font-sans: 'InterVariable', sans-serif;
  }
}

body {
  font-family: var(--font-sans);
  color: var(--text-color);
  background-color: var(--background-color);
  background-image:
    radial-gradient(oklch(from var(--background-color) calc(l + 0.02) c h) 1px, transparent 1px),
    radial-gradient(oklch(from var(--background-color) calc(l + 0.02) c h) 1px, var(--background-color) 1px);
  background-size: 40px 40px, 40px 40px;
  background-position: 0 0, 20px 20px;
  display: grid;
  place-content: center;
  min-height: 100vh;
  margin: 0;
  text-align: center;
  transition: background-color 0.3s ease, color 0.3s ease;
}

header {
  margin-bottom: 2rem;
  display: flex;
  align-items: center; /* Vertically center items */
  gap: 1rem; /* Space between title and button */
}

#theme-toggle {
  margin-left: auto; /* Pushes the button to the far right */
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
  transition: transform 0.2s ease-in-out;
}

#theme-toggle:hover {
  transform: scale(1.1);
}

h1 {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 10vw, 4rem);
  color: var(--primary-color);
  text-shadow: 0 4px 12px var(--shadow-color);
  margin: 0;
}

main {
  display: grid;
  gap: 2rem;
  justify-items: center;
}

#recommend-button {
  font-family: var(--font-sans);
  font-size: 1.25rem;
  font-weight: 600;
  color: white;
  background: linear-gradient(145deg, var(--secondary-color), var(--primary-color));
  border: none;
  border-radius: 12px;
  padding: 1rem 2rem;
  cursor: pointer;
  box-shadow:
    0 4px 8px -2px var(--shadow-color),
    0 8px 20px -4px var(--shadow-color);
  transition: all 0.3s ease;
}

#recommend-button:hover,
#recommend-button:focus-visible {
  transform: translateY(-2px);
  box-shadow:
    0 6px 12px -2px oklch(from var(--shadow-color) l c h / 50%),
    0 10px 24px -4px oklch(from var(--shadow-color) l c h / 50%),
    0 0 0 4px oklch(from var(--highlight-color) l c h / 30%);
  outline: none;
}

footer {
  margin-top: 3rem;
  font-size: 0.9rem;
  color: oklch(from var(--text-color) calc(l + 20) c h);
}

footer p {
  margin: 0;
}