* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', system-ui, sans-serif;
    background: #0f0f12;
    color: #e0e0e0;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 40px auto;
    padding: 20px;
}

h1 {
    text-align: center;
    margin-bottom: 8px;
    color: #00d4ff;
}

.subtitle {
    text-align: center;
    color: #888;
    margin-bottom: 30px;
}

.upload-area {
    border: 3px dashed #444;
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
}

.upload-area:hover {
    border-color: #00d4ff;
    background: #1a1a22;
}

.info-panel, .controls, .preview {
    background: #1a1a22;
    border-radius: 12px;
    padding: 20px;
    margin: 20px 0;
}

.form-group {
    margin: 15px 0;
}

label {
    display: block;
    margin-bottom: 6px;
    color: #aaa;
}

input[type="number"] {
    width: 100%;
    padding: 12px;
    background: #222;
    border: 1px solid #444;
    border-radius: 8px;
    color: white;
    font-size: 16px;
}

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    margin-top: 10px;
    width: 100%;
    font-weight: 600;
}

.primary {
    background: #00aaff;
    color: white;
}

.success {
    background: #00cc66;
    color: white;
}

.preview {
    background: #1a1a22;
}

.group-item {
    background: #222;
    padding: 12px 16px;
    margin: 8px 0;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.status {
    margin-top: 20px;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
    display: none;
}

.status.info   { background: #334455; color: #a0d0ff; }
.status.success { background: #225522; color: #90ff90; }
.status.error   { background: #552222; color: #ff9090; }

.download-link {
    color: #00d4ff;
    text-decoration: none;
    display: inline-block;
    margin: 6px 0;
}

.download-link:hover {
    text-decoration: underline;
}

.hidden {
    display: none;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        margin: 20px 10px;
        padding: 15px;
    }
    
    .upload-area {
        padding: 40px 15px;
    }
}