/* ===== Base & Background ===== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: #1a1d21;
  /* Subtle carbon-fiber / noise texture */
  background-image: 
    radial-gradient(circle at 25% 25%, rgba(255,255,255,0.02) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, rgba(255,255,255,0.015) 0%, transparent 50%),
    linear-gradient(135deg, #1a1d21 0%, #121417 100%);
  color: #e8eaed;
  min-height: 100vh;
  padding: 40px 20px;
  line-height: 1.5;
}

/* ===== Main container with 3-D effect ===== */
.container {
  max-width: 720px;
  margin: 0 auto;
  background: #252a31;
  border-radius: 16px;
  padding: 40px 36px;
  box-shadow: 
    0 25px 50px -12px rgba(0, 0, 0, 0.7),
    0 0 0 1px rgba(255, 255, 255, 0.05),
    inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

/* ===== Typography ===== */
h1 {
  font-size: 1.9rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 1.05rem;
  font-weight: 500;
  color: #9aa0a6;
  margin-bottom: 20px;
}

/* ===== Input ===== */
.display {
  width: 100%;
  max-width: 220px;
  padding: 14px 18px;
  font-size: 1.35rem;
  font-weight: 600;
  color: #ffffff;
  background: #1a1d21;
  border: 2px solid #3c434d;
  border-radius: 10px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.display:focus {
  border-color: #22A1C4;
  box-shadow: 0 0 0 3px rgba(34, 161, 196, 0.25);
}

.display::placeholder {
  color: #6b7280;
  font-weight: 400;
}

/* ===== Buttons ===== */
button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 28px;
  margin: 18px 12px 18px 0;
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
}

/* Primary Submit button */
button[onclick="cryoCalc()"] {
  background: linear-gradient(180deg, #2bb8d9 0%, #1e8fad 100%);
  color: white;
}

button[onclick="cryoCalc()"]:hover {
  background: linear-gradient(180deg, #34c6e8 0%, #22A1C4 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 15px -3px rgba(34, 161, 196, 0.4);
}

button[onclick="cryoCalc()"]:active {
  transform: translateY(0);
}

/* Clear / danger button */
button[onclick="clearAllData()"] {
  background: linear-gradient(180deg, #e05a5a 0%, #c43c3c 100%);
  color: white;
}

button[onclick="clearAllData()"]:hover {
  background: linear-gradient(180deg, #f06a6a 0%, #d44a4a 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 15px -3px rgba(196, 60, 60, 0.4);
}

/* ===== Results list ===== */
.displayData {
  margin-top: 28px;
  background: #1a1d21;
  border-radius: 12px;
  padding: 8px 0;
  border: 1px solid #2d333b;
}

#cryoList {
  list-style: none;
}

#cryoList li {
  padding: 14px 20px;
  border-bottom: 1px solid #2d333b;
  font-size: 0.95rem;
  color: #d1d5db;
  font-variant-numeric: tabular-nums;
}

#cryoList li:last-child {
  border-bottom: none;
}

#cryoList li:first-child {
  color: #ffffff;
  font-weight: 500;
}

/* ===== Footer ===== */
.copy {
  margin-top: 36px;
  text-align: center;
  font-size: 0.85rem;
  color: #6b7280;
}

.copy a {
  color: #22A1C4;
  text-decoration: none;
  font-weight: 500;
}

.copy a:hover {
  text-decoration: underline;
}

/* Small green text leftovers (if any) */
.green {
  color: #34d399;
}