:root {
    --primary-color: #4A90E2;
    --background-color: #f4f7f6;
    --text-color: #333;
    --card-bg: #ffffff;
    --border-color: #e0e0e0;
    --success-color: #28a745;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    box-sizing: border-box;
}

.container {
    background: var(--card-bg);
    width: 100%;
    max-width: 700px;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    text-align: center;
}

/* নতুন স্টাইল এখানে যোগ করা হয়েছে */
.app-icon {
    width: 60px;
    height: auto;
    margin-bottom: 15px;
}

header h1 { font-size: 2rem; font-weight: 600; margin-top: 0; margin-bottom: 10px; color: var(--primary-color); } /* h1 থেকে margin-top: 0 করা হয়েছে */
header p { font-size: 1rem; color: #666; margin-bottom: 30px; }

.upload-area { border: 2px dashed var(--primary-color); border-radius: 12px; padding: 40px; cursor: pointer; transition: all 0.3s ease; }
.upload-area:hover, .upload-area.drag-over { background-color: #e9f2fd; border-color: #357ABD; }
.upload-icon { width: 60px; margin-bottom: 20px; opacity: 0.7; }
.upload-area p { margin: 0; font-size: 1.1rem; }
.upload-area p strong { color: var(--primary-color); }

.supported-formats {
    display: block;
    margin-top: 10px;
    font-size: 0.85rem;
    color: #888;
}

.file-list-section { margin-top: 20px; width: 100%; text-align: left; }
#file-list { max-height: 300px; overflow-y: auto; border: 1px solid var(--border-color); border-radius: 8px; padding: 10px; }
.file-item { display: flex; align-items: center; padding: 10px; border-bottom: 1px solid var(--border-color); }
.file-item:last-child { border-bottom: none; }
.file-item-thumbnail { width: 50px; height: 50px; border-radius: 5px; object-fit: cover; margin-right: 15px; background-color: #f0f0f0; }
.file-item-details { flex-grow: 1; }
.file-item-name { font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 300px; }
.file-item-size { font-size: 0.9rem; color: #555; }
.file-item-size .arrow { color: var(--primary-color); margin: 0 5px; }
.file-item-size .compressed { color: var(--success-color); font-weight: 600; }
.file-item-status .loader { width: 20px; height: 20px; border-width: 2px; }

.download-single-btn { background: none; border: 1px solid var(--primary-color); color: var(--primary-color); padding: 5px 10px; border-radius: 5px; cursor: pointer; font-size: 0.8rem; font-weight: 500; transition: all 0.2s ease; margin-left: 10px; }
.download-single-btn:hover { background: var(--primary-color); color: white; }
.download-single-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.loader { border: 4px solid #f3f3f3; border-top: 4px solid var(--primary-color); border-radius: 50%; width: 20px; height: 20px; animation: spin 1s linear infinite; }
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

.quality-control { margin-top: 30px; text-align: left; }
.quality-control label { font-weight: 600; color: var(--text-color); }
input[type="range"] { -webkit-appearance: none; appearance: none; width: 100%; height: 8px; background: #ddd; border-radius: 5px; outline: none; margin-top: 10px; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 20px; height: 20px; background: var(--primary-color); border-radius: 50%; cursor: pointer; }
input[type="range"]::-moz-range-thumb { width: 20px; height: 20px; background: var(--primary-color); border-radius: 50%; cursor: pointer; }

.action-buttons { margin-top: 20px; display: flex; gap: 15px; }
#download-all-btn { flex-grow: 1; padding: 15px; background-color: var(--primary-color); color: white; border: none; border-radius: 8px; font-size: 1.1rem; font-weight: 600; cursor: pointer; transition: background-color 0.3s ease; }
#download-all-btn:hover { background-color: #357ABD; }
#reset-btn { padding: 15px; background-color: #e0e0e0; color: #333; border: none; border-radius: 8px; font-size: 1rem; font-weight: 500; cursor: pointer; transition: background-color 0.3s ease; }
#reset-btn:hover { background-color: #c7c7c7; }

@media (max-width: 600px) {
    .container { padding: 20px; }
    .action-buttons { flex-direction: column; }
    .file-item-name { max-width: 120px; }
}