* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    min-height: 100vh;
    background: linear-gradient(135deg, #111827, #1f2937);
    color: #111827;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.container {
    width: 100%;
    max-width: 900px;
    display: grid;
    grid-template-columns: 1.3fr 1fr;
    gap: 24px;
}

.card {
    background: #ffffff;
    border-radius: 20px;
    padding: 32px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
}

h1, h2 {
    margin-bottom: 12px;
}

.subtitle {
    color: #6b7280;
    margin-bottom: 24px;
    line-height: 1.5;
}

.upload-form {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.drop-area {
    border: 2px dashed #9ca3af;
    border-radius: 18px;
    min-height: 220px;
    padding: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    text-align: center;
    cursor: pointer;
    transition: 0.2s ease;
    background: #f9fafb;
}

.drop-area.active,
.drop-area:hover {
    border-color: #2563eb;
    background: #eff6ff;
}

.drop-area input {
    display: none;
}

.icon {
    font-size: 48px;
    margin-bottom: 12px;
}

.drop-area strong {
    font-size: 20px;
    margin-bottom: 6px;
}

.drop-area small {
    color: #6b7280;
}

.file-name {
    margin-top: 14px;
    color: #2563eb;
    font-weight: bold;
    word-break: break-all;
}

button,
.download-button {
    border: none;
    background: #2563eb;
    color: #ffffff;
    padding: 15px 20px;
    border-radius: 12px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
    display: inline-block;
    transition: 0.2s ease;
}

button:hover,
.download-button:hover {
    background: #1d4ed8;
}

.download-card p {
    margin-bottom: 12px;
    color: #374151;
    word-break: break-all;
}

.download-button {
    margin-top: 12px;
    width: 100%;
}

.empty {
    color: #6b7280;
}

.alert {
    padding: 14px;
    border-radius: 12px;
    margin-bottom: 18px;
    font-weight: bold;
}

.success {
    background: #dcfce7;
    color: #166534;
}

.error {
    background: #fee2e2;
    color: #991b1b;
}

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

    .card {
        padding: 24px;
    }
}