:root {
  --bg: #ffffff;
  --text: #111111;
  --muted: #555555;
  --container: #e2e2e2;
  --button-bg: #000;
  --button-text: #fff;
}

[data-theme="dark"] {
  --bg: #111111;
  --text: #ffffff;
  --muted: #cccccc;
  --container: #222222;
  --button-bg: #fff;
  --button-text: #000;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: sans-serif;
  background-color: var(--bg);
  color: var(--text);
  transition: background-color 0.3s, color 0.3s;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--muted);
  background-color: var(--bg);
}

.logo-container {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo-container img {
  height: 40px;
}

.controls button {
  margin-left: 1rem;
  padding: 0.5rem 1rem;
  background: var(--button-bg);
  color: var(--button-text);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-weight: bold;
}

.container {
  max-width: 800px;
  margin: 2rem auto;
  background: var(--container);
  padding: 2rem;
  border-radius: 1rem;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

h1, h2 {
  margin-bottom: 1rem;
}

.subtitle {
  color: var(--muted);
  margin-bottom: 2rem;
}

ul {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.button {
  background: var(--button-bg);
  color: var(--button-text);
  padding: 0.7rem 1.2rem;
  border-radius: 8px;
  text-decoration: none;
  transition: 0.3s;
}

.button:hover {
  opacity: 0.8;
}

footer {
  text-align: center;
  margin-top: 2rem;
  padding: 2rem;
  color: var(--muted);
}