* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f5f7fb;
  color: #1f2937;
}

.container {
  max-width: 900px;
  margin: 40px auto;
  padding: 24px;
  background: #ffffff;
  border-radius: 12px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

h1 {
  margin: 0 0 8px;
  font-size: 1.8rem;
}

.subtitle {
  margin: 0 0 20px;
  color: #4b5563;
}

.table-wrap {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  border: 1px solid #d1d5db;
  padding: 12px;
  text-align: left;
}

th {
  background: #e5e7eb;
}

input[type="number"] {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid #9ca3af;
  border-radius: 6px;
}

output {
  font-weight: 700;
}

.total {
  margin-top: 18px;
  padding: 12px 14px;
  background: #eef2ff;
  border: 1px solid #c7d2fe;
  border-radius: 8px;
  font-size: 1.1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}