/* Base styling */
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f7f9fc;
    color: #222;
}

/* Layout refinements */
.card {
    background-color: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 6px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.06);
    padding: 1.5rem;
}

.sources ul {
    padding-left: 1.2rem;
}
.sources li {
    margin-bottom: 0.5rem;
}

header {
    background: linear-gradient(90deg, #234e70, #3b82f6);
    color: #fff;
    padding: 1.5rem 1rem;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
header h1 {
    margin: 0;
    font-size: 2.2rem;
}
nav {
    margin-top: 0.5rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}
nav a {
    color: #fff;
    text-decoration: none;
    margin: 0.2rem 0.6rem;
    font-weight: 600;
    padding: 0.3rem 0.6rem;
    border-radius: 4px;
    transition: background-color 0.2s;
}
nav a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

main {
    padding: 1.5rem;
    max-width: 1000px;
    margin: auto;
}

.section {
    margin-bottom: 2.5rem;
}
.section h2 {
    border-bottom: 2px solid #234e70;
    padding-bottom: 0.4rem;
    margin-bottom: 1rem;
    color: #234e70;
}

.table-container {
    overflow-x: auto;
    margin-bottom: 1rem;
}
table {
    border-collapse: collapse;
    width: 100%;
    margin-top: 0.5rem;
}
table th, table td {
    border: 1px solid #ccc;
    padding: 0.5rem;
    text-align: left;
}
table th {
    background-color: #f0f5fa;
    font-weight: bold;
}

input[type="text"], input[type="number"], select {
    padding: 0.4rem;
    margin-right: 0.5rem;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 0.9rem;
}

button {
    padding: 0.5rem 1rem;
    background-color: #2563eb;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.2s;
}
button:hover {
    background-color: #1d4ed8;
}

.note {
    font-size: 0.85rem;
    color: #444;
    margin-top: 0.5rem;
}

.tool {
    margin-bottom: 1.5rem;
    padding: 1rem;
    border: 1px solid #ddd;
    background-color: #fff;
    border-radius: 4px;
}

/* Adjust input width for level helper */
.tool input[type="number"] {
    width: 160px;
}

.output {
    margin-top: 0.5rem;
    padding: 0.5rem;
    background-color: #eef3f8;
    border: 1px solid #d0d8e0;
    border-radius: 4px;
}

footer {
    background-color: #234e70;
    color: #fff;
    padding: 1rem;
    text-align: center;
    font-size: 0.8rem;
}