:root {
  --bg-color: #f0f2f5;
  --container-bg: white;
  --text-color: #333;
  --accent-color: #4a90e2;
  --button-hover: #357abd;
}

body.dark-mode {
  --bg-color: #1a1a1a;
  --container-bg: #2d2d2d;
  --text-color: #f0f2f5;
  --accent-color: #64b5f6;
  --button-hover: #42a5f5;
}

body {
  font-family: 'Arial', sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  min-height: 100vh;
  margin: 0;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.3s, color 0.3s;
  padding: 100px 0 3rem;
}

.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 100;
}

#theme-btn {
  background: var(--container-bg);
  border: 1px solid var(--text-color);
  color: var(--text-color);
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  cursor: pointer;
  border-radius: 20px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.form-container, .comments-container {
  width: 90%;
  max-width: 600px;
  background: var(--container-bg);
  padding: 2rem;
  border-radius: 15px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  transition: background-color 0.3s;
  margin-bottom: 2rem;
}

h2 {
  margin-top: 0;
  margin-bottom: 1.5rem;
  text-align: center;
}

.form-group {
  margin-bottom: 1.5rem;
  text-align: left;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: bold;
}

.form-group input[type="text"],
.form-group input[type="datetime-local"] {
  width: 100%;
  padding: 0.8rem;
  border: 1px solid #ccc;
  border-radius: 5px;
  background: var(--bg-color);
  color: var(--text-color);
  box-sizing: border-box;
}

.radio-group {
  display: flex;
  gap: 1.5rem;
  padding-top: 0.5rem;
}

.radio-group label {
  font-weight: normal;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  margin-bottom: 0;
}

.submit-btn {
  padding: 0.8rem 2rem;
  font-size: 1.1rem;
  background-color: var(--accent-color);
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.1s;
  width: 100%;
}

.submit-btn:hover {
  background-color: var(--button-hover);
}

.submit-btn:active {
  transform: translateY(2px);
}