/* Simple & Modern Fuel Tracker Styles */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f8f9fa;
    color: #333;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

section {
    background: #ffffff;
    padding: 25px;
    margin-bottom: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

h1,
h2 {
    color: #2b2d42;
    margin-top: 0;
}

ul {
    list-style: none;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

button {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

button:hover {
    background-color: #0056b3;
}

button:active {
    transform: scale(0.98);
}

input {
    width: 100%;
    padding: 12px;
    margin: 10px 0 20px 0;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    box-sizing: border-box;
    font-size: 16px;
}

input:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}

.result-box {
    background-color: #e9ecef;
    padding: 15px;
    border-radius: 8px;
    font-weight: 700;
    min-height: 1.5em;
    margin-bottom: 15px;
    transition: background-color 0.3s;
}

p {
    margin-bottom: 8px;
}

footer {
    text-align: center;
    padding: 20px;
    color: #adb5bd;
    font-size: 14px;
}

#reset {
    background-color: #6c757d;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;

}

#reset:hover {
    background-color: #5a6268;

}

nav {
    color: black;
    background-color: #ffffff;
    padding: 10px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 25px;
}

nav ul {
    display: flex;
    gap: 15px;
    padding: 10px;
    margin: 0;
}

nav li {
    list-style: none;
    border: 2px solid #007bff;
    border-radius: 8px;
    transition: all 0.3s ease;
}

nav li:hover,
nav li.active {
    background-color: #007bff;
}

nav a {
    color: #000000;
    text-decoration: none;
    font-size: 14px;
    font-weight: 700;
    padding: 8px 16px;
    display: block;
    transition: color 0.3s ease;
}

nav li:hover a,
nav li.active a {
    color: white;
}

.two-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
}

.two-columns .col {
    display: flex;
    flex-direction: column;
}

.two-columns .col section {
    margin-bottom: 25px;
}

.two-columns .col section:last-child {
    margin-bottom: 0;
    flex-grow: 1;
}

@media (max-width: 768px) {
    .two-columns {
        grid-template-columns: 1fr;
    }
}