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

body {
  font-family: 'Segoe UI', Arial, sans-serif;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 16px;
  color: #222;
}

.card {
  background: #fff;
  border-radius: 18px;
  max-width: 480px;
  width: 100%;
  padding: 22px 18px 26px;
  box-shadow: 0 20px 50px rgba(0,0,0,0.3);
  margin-top: 10px;
}

h1 {
  text-align: center;
  font-size: 1.6rem;
  color: #1a3c5e;
  margin-bottom: 4px;
}

.subtitle {
  text-align: center;
  color: #666;
  font-size: 0.85rem;
  margin-bottom: 18px;
}

label {
  display: block;
  font-weight: 600;
  font-size: 0.85rem;
  margin: 14px 0 6px;
  color: #1a3c5e;
}

select, input {
  width: 100%;
  padding: 14px 12px;
  border: 1.5px solid #d0d7de;
  border-radius: 10px;
  font-size: 1rem;
  background: #f7f9fb;
  -webkit-appearance: none;
  appearance: none;
}

select:focus, input:focus {
  outline: none;
  border-color: #2c5364;
}

.row {
  display: flex;
  gap: 10px;
}
.row > div { flex: 1; }

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 16px;
}
.checkbox-row input {
  width: 22px;
  height: 22px;
}
.checkbox-row label {
  margin: 0;
  font-weight: 500;
  color: #444;
  font-size: 0.9rem;
}

button {
  width: 100%;
  margin-top: 24px;
  padding: 16px;
  background: linear-gradient(135deg,#ff6a00,#ee0979);
  color: #fff;
  font-weight: 700;
  font-size: 1.05rem;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: transform .15s;
}
button:active { transform: scale(0.97); }

#result {
  margin-top: 24px;
  display: none;
}

.flex-results {
  display: flex;
  gap: 12px;
}
.result-box {
  flex: 1;
  background: #f0f6fb;
  border-radius: 14px;
  padding: 16px 12px;
  border-left: 5px solid #2c5364;
  text-align: center;
}
.result-box h3 {
  font-size: 0.75rem;
  color: #555;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}
.pressure-value {
  font-size: 1.9rem;
  font-weight: 800;
  color: #1a3c5e;
}
.pressure-unit {
  font-size: 0.95rem;
  font-weight: 500;
  color: #888;
  margin-left: 4px;
}
.bar-value {
  font-size: 0.8rem;
  color: #777;
  margin-top: 4px;
}

.tip {
  font-size: 0.82rem;
  color: #5a4400;
  margin-top: 16px;
  background: #fff8e6;
  padding: 12px 14px;
  border-radius: 10px;
  border-left: 4px solid #f5a623;
  line-height: 1.4;
}

.footer {
  text-align: center;
  font-size: 0.75rem;
  color: #aaa;
  margin-top: 26px;
}

@media (max-width: 380px) {
  h1 { font-size: 1.4rem; }
  .pressure-value { font-size: 1.6rem; }
}