*, *::before, *::after {
  box-sizing: border-box;
}

:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --bg-color: #f3f4f6;
  --card-bg: #ffffff;
  --text-main: #1f2937;
  --text-muted: #6b7280;
  --border-color: #e5e7eb;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  margin: 0;
  padding: 0;
  line-height: 1.5;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

header {
  margin-bottom: 2rem;
  text-align: center;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  color: #111827;
}

header p {
  color: var(--text-muted);
}

.layout {
  display: grid;
  grid-template-columns: 350px 1fr;
  gap: 2rem;
}

@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }

  header h1 {
    font-size: 1.75rem;
  }

  .layout {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

.card {
  background: var(--card-bg);
  border-radius: 0.75rem;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  padding: 1.5rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
}

select, input[type="number"], input[type="text"] {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
  font-size: 1rem;
  background-color: #fff;
}

.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.checkbox-group label {
    font-weight: normal;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

input[type="checkbox"] {
    width: auto;
}

button.primary-btn {
  width: 100%;
  padding: 0.75rem;
  background-color: var(--primary);
  color: white;
  border: none;
  border-radius: 0.375rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s;
}

button.primary-btn:hover {
  background-color: var(--primary-hover);
}

button.secondary-btn {
  padding: 0.5rem 1rem;
  background-color: white;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  border-radius: 0.375rem;
  cursor: pointer;
  font-weight: 500;
}

button.secondary-btn:hover {
  background-color: #f9fafb;
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.table-container {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  min-width: 600px; /* Ensure table doesn't squish too much */
}

th, td {
  text-align: left;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-color);
}

th {
  background-color: #f9fafb;
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

tr:hover td {
    background-color: #f9fafb;
}

footer {
    margin-top: 3rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Utilities */
.text-center { text-align: center; }
.p-4 { padding: 1rem; }
.text-sm { font-size: 0.875rem; }
.hint { font-size: 0.75rem; color: var(--text-muted); margin-top: 0.25rem; }
/* Additions for About Section */
.subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.about-section {
    background-color: #fff;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.5rem 1rem;
    text-align: left;
    max-width: 800px;
    margin: 0 auto;
}

.about-section summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--primary);
}

.about-content {
    margin-top: 1rem;
    font-size: 0.95rem;
    color: var(--text-main);
}

.about-content ul {
    list-style-type: disc;
    padding-left: 1.5rem;
    margin: 0.5rem 0;
}

.about-content li {
    margin-bottom: 0.25rem;
}