:root {
    --bg-color: #f4f4f9;
    --text-color: #333;
    --card-bg: #fff;
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --border-color: #ddd;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a1a;
        --text-color: #f4f4f9;
        --card-bg: #2a2a2a;
        --primary-color: #3793ff;
        --primary-hover: #1e70d1;
        --border-color: #444;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 600px;
    margin: 2rem auto;
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

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

header h1 {
    margin: 0;
    color: var(--primary-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: bold;
}

input[type="file"],
input[type="number"],
select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--card-bg);
    color: var(--text-color);
    box-sizing: border-box;
}

button {
    width: 100%;
    padding: 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.2s;
}

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

#results {
    margin-top: 2rem;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.result-card {
    text-align: center;
    padding: 1rem;
    background: var(--bg-color);
    border-radius: 6px;
}

.result-card .label {
    display: block;
    font-size: 0.8rem;
    text-transform: uppercase;
    opacity: 0.8;
}

.result-card .value {
    display: block;
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--primary-color);
}

.hidden {
    display: none;
}

#loading {
    text-align: center;
    margin: 1rem 0;
    font-style: italic;
}

footer {
    margin-top: 2rem;
    text-align: center;
    font-size: 0.8rem;
    opacity: 0.6;
}

@media (max-width: 480px) {
    .form-grid, .results-grid {
        grid-template-columns: 1fr;
    }
}