body {
    font-family: Arial, sans-serif;
    background: #f8f9fa;
    color: #222;
    margin: 0;
    padding: 0;
    min-height: 100vh;
}

.container {
    max-width: 900px;
    margin: auto;
    padding: 20px;
}

h1 {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 5px;
}

.tool-header {
  background-color: #4a90e2;
  color: white;
  padding: 2rem 1rem;
  text-align: center;
}

.tool-title {
  margin: 0;
  font-size: 2rem;
}

.tool-subtitle {
  margin: 0.5rem 0 0;
}

.unit-group {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 10px;
    margin-bottom: 15px;
}

.unit-group label {
    display: flex;
    flex-direction: column;
    font-size: 0.9rem;
    background: white;
    padding: 8px;
    border-radius: 6px;
    box-shadow: 0 1px 2px rgba(0,0,0,0.1);
    margin: 4px;
}

.unit-group input {
    margin-top: 4px;
    padding: 6px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1rem;
}

/* Collapsible button */
.collapsible {
    background-color: #007bff;
    color: white;
    cursor: pointer;
    padding: 12px;
    width: 100%;
    border: none;
    text-align: left;
    outline: none;
    font-size: 1rem;
    border-radius: 6px;
    margin-top: 10px;
}

.collapsible:hover {
    background-color: #0056b3;
}

.content {
    padding: 10px;
    display: none;
    overflow: hidden;
    background-color: #f1f1f1;
    border-radius: 0 0 6px 6px;
}

section h2 {
    margin-top: 0;
    background: #28a745;
    color: white;
    padding: 8px;
    border-radius: 6px;
    font-size: 1.1rem;
}


.hub-footer {
  background-color: #222;
  color: #aaa;
  text-align: center;
  padding: 1rem;
  font-size: 0.9rem;
  margin-top: auto;
  bottom: 0;
}

.hub-footer-text {
  margin: 0;
}