body {
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(120deg, #3a7bd5, #3a6073);
  margin: 0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  transition: background 0.3s, color 0.3s;
}

.container {
  background: rgba(255, 255, 255, 0.08);
  padding: 30px;
  width: 400px;
  text-align: center;
  border-radius: 15px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  transition: background 0.3s, color 0.3s;
}

.toggle-container {
  text-align: right;
}

#themeToggle {
  background: transparent;
  color: #fff;
  font-size: 18px;
  border: none;
  cursor: pointer;
  padding: 5px;
  transition: transform 0.3s;
}

#themeToggle:hover {
  transform: scale(1.2);
}

h1 {
  margin-bottom: 20px;
  font-size: 24px;
}

.input-group {
  display: flex;
  gap: 10px;
  justify-content: center;
}

input, select {
  padding: 10px;
  font-size: 16px;
  border: none;
  border-radius: 6px;
  width: 48%;
}

.result {
  margin: 20px 0;
  padding: 15px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  font-size: 18px;
  font-weight: bold;
}

.btn-group button {
  padding: 10px 20px;
  font-size: 16px;
  border: none;
  border-radius: 5px;
  margin: 5px;
  cursor: pointer;
  transition: 0.3s;
}

.btn-group button:hover {
  opacity: 0.8;
}

button {
  background: #4caf50;
  color: white;
}

.reset {
  background: #e74c3c;
}

ul {
  list-style: none;
  padding: 0;
  margin-top: 10px;
  text-align: left;
}

ul li {
  background: rgba(255, 255, 255, 0.12);
  padding: 6px;
  margin: 4px 0;
  border-radius: 4px;
  font-size: 14px;
}

/* 🌞 Light Mode */
.light-mode {
  background: linear-gradient(120deg, #f5f7fa, #c3cfe2);
  color: #000;
}

.light-mode .container {
  background: rgba(0, 0, 0, 0.05);
  color: #000;
}

.light-mode .result,
.light-mode ul li {
  background: rgba(0, 0, 0, 0.08);
  color: #000;
}

.light-mode #themeToggle {
  color: #000;
}