* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: #f4f6f8;
    color: #263238;
}

.container {
    width: 92%;
    max-width: 1200px;
    margin: 40px auto;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    color: #1565c0;
    font-size: 34px;
    margin-bottom: 10px;
}

header p {
    color: #607d8b;
    font-size: 17px;
}

.upload-box {
    background: white;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    margin-bottom: 30px;
}

.upload-box h2 {
    margin-top: 0;
}

input[type="file"] {
    padding: 12px;
    margin: 10px;
}

.privacy {
    font-size: 13px;
    color: #607d8b;
}

.hidden {
    display: none;
}

.cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin: 25px 0 35px;
}

.card {
    background: white;
    border-radius: 10px;
    padding: 22px;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.07);
}

.card span {
    display: block;
    font-size: 32px;
    font-weight: bold;
    color: #1565c0;
}

.card p {
    margin-bottom: 0;
    color: #607d8b;
}

h2 {
    margin-top: 35px;
}

.table-container {
    overflow-x: auto;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

table {
    width: 100%;
    border-collapse: collapse;
}

th,
td {
    padding: 10px 12px;
    border-bottom: 1px solid #e0e0e0;
    text-align: left;
    white-space: nowrap;
}

th {
    background: #1565c0;
    color: white;
}

tr:nth-child(even) {
    background: #f7f9fb;
}

#columnAnalysis {
    background: white;
    padding: 20px;
    border-radius: 8px;
    line-height: 1.7;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

select {
    padding: 10px;
    margin: 10px 0 20px;
    min-width: 250px;
    border: 1px solid #b0bec5;
    border-radius: 6px;
}

.chart-container {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    margin-bottom: 40px;
}

@media (max-width: 700px) {
    .cards {
        grid-template-columns: 1fr;
    }

    header h1 {
        font-size: 26px;
    }

    .container {
        width: 96%;
    }
}