:root {
  color-scheme: light;
  --bg: #f5f6f8;
  --text: #2f3439;
  --heading: #4a83f0;
  --button-bg: #f2f4f8;
  --button-text: #1e2327;
  --button-border: #d8dce2;
}

body[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f1215;
  --text: #d5d8dc;
  --heading: #4a83f0;
  --button-bg: #1a1f25;
  --button-text: #f2f4f7;
  --button-border: #2a3138;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background: var(--bg);
  color: var(--text);
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  text-rendering: optimizeLegibility;
}

.hero {
  text-align: center;
  padding: 48px 24px;
  max-width: 720px;
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(2.4rem, 4vw, 3.6rem);
  letter-spacing: -0.02em;
  color: var(--heading);
}

p {
  margin: 0;
  font-size: 1.1rem;
  line-height: 1.6;
}

.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  border-radius: 999px;
  border: 1px solid var(--button-border);
  background: var(--button-bg);
  color: var(--button-text);
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.theme-toggle:hover {
  transform: translateY(-1px);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--heading);
  outline-offset: 2px;
}