* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 20px;
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #eaf6ff, #f7fbff);
  color: #1f2937;
}

.tool-card {
  max-width: 620px;
  margin: 0 auto;
  background: #ffffff;
  border-radius: 24px;
  padding: 28px;
  box-shadow: 0 15px 40px rgba(0, 65, 120, 0.12);
  border: 1px solid #e5eef7;
}

.header {
  text-align: center;
  margin-bottom: 24px;
}

.badge {
  display: inline-block;
  background: #e0f2fe;
  color: #0369a1;
  padding: 7px 14px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: bold;
  margin-bottom: 10px;
}

h1 {
  margin: 0;
  font-size: 30px;
  color: #0f172a;
}

.header p {
  margin: 10px 0 0;
  color: #64748b;
  font-size: 15px;
}

.form-grid {
  display: grid;
  gap: 18px;
}

.time-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.field label {
  display: block;
  font-weight: bold;
  margin-bottom: 7px;
  color: #334155;
}

input {
  width: 100%;
  border: 1px solid #cbd5e1;
  border-radius: 14px;
  padding: 14px;
  font-size: 17px;
  outline: none;
  background: #f8fafc;
}

input:focus {
  border-color: #0284c7;
  background: #ffffff;
  box-shadow: 0 0 0 4px rgba(2, 132, 199, 0.12);
}

.input-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
}

.input-wrap span {
  font-weight: bold;
  color: #475569;
}

button {
  width: 100%;
  margin-top: 22px;
  border: none;
  border-radius: 16px;
  padding: 16px;
  font-size: 18px;
  font-weight: bold;
  color: white;
  background: linear-gradient(135deg, #0284c7, #0ea5e9);
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 25px rgba(14, 165, 233, 0.3);
}

.result {
  margin-top: 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.result div {
  background: #f0f9ff;
  border: 1px solid #bae6fd;
  border-radius: 18px;
  padding: 18px;
  text-align: center;
}

.result span {
  display: block;
  font-size: 14px;
  color: #64748b;
  margin-bottom: 6px;
}

.result strong {
  font-size: 24px;
  color: #075985;
}

.error {
  color: #dc2626;
  text-align: center;
  font-weight: bold;
  margin-top: 15px;
}

.hidden {
  display: none;
}

@media (max-width: 520px) {
  body {
    padding: 12px;
  }

  .tool-card {
    padding: 22px;
    border-radius: 20px;
  }

  h1 {
    font-size: 25px;
  }

  .time-grid,
  .result {
    grid-template-columns: 1fr;
  }
}