body {
  font-family: 'Segoe UI', sans-serif;
  background: #eaf6ff;
  color: #333;
  margin: 0;
  padding: 0;
  transition: 0.3s;
}

body.dark {
  background: #121212;
  color: #f0f0f0;
}

.container {
  max-width: 700px;
  margin: 2rem auto;
  padding: 1rem;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#logo {
  font-size: 2rem;
  cursor: pointer;
  transition: transform 0.4s ease;
}

#logo.spin {
  transform: rotate(360deg);
}

form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  background: #fff;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 0 8px rgba(0,0,0,0.1);
}

body.dark form {
  background: #1e1e1e;
}

input, select {
  padding: 0.6rem;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 1rem;
}

button {
  padding: 0.8rem;
  font-size: 1rem;
  background: #0288d1;
  color: white;
  border: none;
  border-radius: 10px;
  cursor: pointer;
}

button:hover {
  background: #0277bd;
}

.hidden {
  display: none;
}

#result {
  margin-top: 2rem;
  background: #e0f7fa;
  padding: 1rem;
  border-radius: 12px;
}

body.dark #result {
  background: #263238;
}

#tips ul {
  padding-left: 1rem;
}

ul li {
  margin-bottom: 0.5rem;
}

ul li.highlight {
  font-weight: bold;
  color: #00e676;
}

/* Toggle Switch */
.switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 26px;
}

.switch input { display: none; }

.slider {
  position: absolute;
  cursor: pointer;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: #ccc;
  border-radius: 34px;
  transition: .4s;
}

.slider:before {
  position: absolute;
  content: "🌙";
  height: 22px;
  width: 22px;
  left: 3px;
  bottom: 2px;
  background: white;
  border-radius: 50%;
  text-align: center;
  line-height: 22px;
  transition: .4s;
}

input:checked + .slider {
  background-color: #66bb6a;
}

input:checked + .slider:before {
  transform: translateX(24px);
  content: "☀️";
}