:root {
  --bg-color: #1a1a1a;
  --text-color: #ffffff;
  --card-bg: rgba(255, 255, 255, 0.1);
  --card-hover: rgba(255, 255, 255, 0.15);
  --text-secondary: rgba(255, 255, 255, 0.6);
  --text-secondary-hover: rgba(255, 255, 255, 0.7);
}

[data-theme="light"] {
  --bg-color: #ffffff;
  --text-color: #000000;
  --card-bg: rgba(0, 0, 0, 0.08);
  --card-hover: rgba(0, 0, 0, 0.12);
  --text-secondary: rgba(0, 0, 0, 0.7);
  --text-secondary-hover: rgba(0, 0, 0, 0.8);
}

body {
  color: var(--text-color);
  font-family: Inter, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background-color: var(--bg-color);
  transition: background-color 0.3s ease, color 0.3s ease;
}

.theme-toggle {
  position: fixed;
  top: 0.8rem;
  right: 0.8rem;
  background: var(--card-bg);
  border: none;
  border-radius: 50%;
  width: 2.8rem;
  height: 2.8rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-color);
  font-size: 1.2rem;
  transition: background-color 0.2s ease;
  -webkit-tap-highlight-color: transparent;
  z-index: 1000;
}

.theme-toggle:hover {
  background: var(--card-hover);
}

.container {
  max-width: 800px;
  width: calc(100% - 2rem);
  padding: clamp(1rem, 2vw, 2.5rem);
  text-align: center;
  border-radius: 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 0.8rem auto;
  gap: 2rem;
  box-sizing: border-box;
}

.section {
  width: 100%;
  max-width: 600px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

h1 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin: 0;
  line-height: 1.2;
}

@media (max-width: 768px) {
  .container {
    width: calc(100% - 1.5rem);
    margin: 0.5rem auto;
    padding: 1rem;
    gap: 1.5rem;
  }

  .section {
    max-width: 100%;
  }

  .theme-toggle {
    top: 0.5rem;
    right: 0.5rem;
    width: 2.5rem;
    height: 2.5rem;
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .container {
    width: calc(100% - 1rem);
    margin: 0.3rem auto;
    padding: 0.8rem;
    gap: 1.2rem;
  }

  h1 {
    font-size: 1.8rem;
  }
}