@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@500;700;800&display=swap');

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

body {
  font-family: 'Manrope', sans-serif;
  background:
    radial-gradient(circle at 14% 20%, #ffd5b8 0%, transparent 35%),
    linear-gradient(125deg, #101215 0%, #1f2836 100%);
  color: #f8fafc;
  min-height: 100vh;
}

nav {
  display: flex;
  justify-content: center;
  padding: 1rem;
}

nav a {
  text-decoration: none;
  color: #fff;
  background: #de5d2a;
  border-radius: 999px;
  padding: 0.55rem 1.25rem;
  font-weight: 700;
}

.container {
  width: min(640px, 92vw);
  margin: 3rem auto;
  padding: 2rem;
  background: rgba(17, 22, 30, 0.72);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 20px;
  backdrop-filter: blur(8px);
  box-shadow: 0 26px 48px rgba(0, 0, 0, 0.35);
}

h1 {
  text-align: center;
  margin-bottom: 1.4rem;
  font-size: clamp(1.7rem, 4vw, 2.4rem);
}

form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

label {
  font-size: 1.02rem;
  font-weight: 700;
}

input[type='text'] {
  margin-top: 0.4rem;
  width: 100%;
  padding: 0.8rem;
  border-radius: 12px;
  border: 1px solid #475569;
  background: #131923;
  color: #f8fafc;
  font-family: inherit;
}

button {
  margin-top: 0.5rem;
  width: 100%;
  padding: 0.85rem;
  border-radius: 12px;
  border: 0;
  cursor: pointer;
  background: linear-gradient(130deg, #e8622d, #f39b3b);
  color: #fff;
  font-weight: 800;
  font-size: 1rem;
}

#results {
  font-size: 1.8rem;
  text-align: center;
  color: #facc15;
  min-height: 2rem;
}

#weight-guide {
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: rgba(4, 8, 13, 0.55);
  border-radius: 14px;
  padding: 1rem;
}

#weight-guide h3 {
  margin-bottom: 0.5rem;
  color: #fed7aa;
}

#weight-guide p {
  margin: 0.22rem 0;
  color: #dbe1ea;
}