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

body {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  background: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);
}

.container {
  width: 100%;
  max-width: 380px;
  background-color: #ffffff;
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
  text-align: center;
}

h1 {
  margin-bottom: 1.5rem;
  color: #333;
}

.form-group {
  margin-bottom: 1.2rem;
  text-align: left;
}

label {
  display: block;
  margin-bottom: 0.4rem;
  font-weight: 600;
  color: #555;
}

input {
  width: 100%;
  padding: 0.6rem 0.8rem;
  font-size: 1rem;
  border-radius: 10px;
  border: 1px solid #ccc;
  outline: none;
  transition: border 0.2s, box-shadow 0.2s;
}

input:focus {
  border-color: #6c63ff;
  box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.2);
}

/* Button */
button {
  width: 100%;
  padding: 0.7rem;
  margin-top: 0.5rem;
  background-color: #6c63ff;
  color: #fff;
  font-size: 1.1rem;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background-color 0.2s;
}

button:hover {
  background-color: #574fd6;
  transform: translateY(-1px);
  box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

/* Results */
.results {
  margin-top: 1.2rem;
  font-size: 1.2rem;
  font-weight: 600;
  min-height: 1.5em;
}

/* Weight guide */
.guide {
  margin-top: 1.5rem;
  text-align: left;
}

.guide h3 {
  margin-bottom: 0.6rem;
  color: #333;
}

.guide ul {
  list-style: none;
  font-size: 0.95rem;
  color: #555;
}

.guide li {
  margin-bottom: 0.3rem;
}