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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 800px;
    background-color: #fff;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    padding: 30px;
    margin: 20px auto;
}

.header {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin-bottom: 30px;
    text-align: center;
    gap: 10px;
}

.logo {
    width: auto;
    height: 48px;
    border-radius: 8px;
    object-fit: contain;
}

h1 {
    margin-bottom: 5px;
    color: #2c3e50;
    font-size: 2.5em;
}

.tagline {
    font-size: 1em;
    color: #7f8c8d;
    max-width: 600px;
    line-height: 1.5;
}

.upload-area {
    border: 2px dashed #3498db;
    border-radius: 12px;
    padding: 40px 30px;
    text-align: center;
    margin-bottom: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
    background-color: #fff;
}

.upload-area:hover {
    border-color: #2980b9;
    background-color: #f8f9fa;
}

.upload-area.dragover {
    border-color: #27ae60;
    background-color: #e8f5e8;
}

#fileInput {
    display: none;
}

.upload-text p {
    margin-bottom: 5px;
    color: #666;
    font-size: 1.2em;
}

.upload-text .subtext {
    font-size: 0.95em;
    color: #999;
}

.settings {
    background-color: #fff;
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 30px;
    border: 1px solid #e1e1e1;
}

.setting-group {
    margin-bottom: 15px;
}

.setting-group:last-child {
    margin-bottom: 0;
}

.setting-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
    font-size: 1.1em;
}

.setting-group input[type="range"] {
    width: 100%;
    height: 10px;
    margin: 20px 0;
    background: #e0e0e0;
    border-radius: 10px;
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}

.setting-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: #3498db;
    cursor: pointer;
    border: 3px solid #ffffff;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.2);
    transition: all 0.2s ease;
}

.setting-group input[type="range"]::-webkit-slider-thumb:hover {
    background: #2980b9;
    transform: scale(1.1);
}

.setting-group input[type="range"]::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: #3498db;
    cursor: pointer;
    border: 3px solid #ffffff;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.2);
    transition: all 0.2s ease;
}

.setting-group input[type="range"]::-moz-range-thumb:hover {
    background: #2980b9;
    transform: scale(1.1);
}

.setting-group input[type="range"]::-webkit-slider-track {
    width: 100%;
    height: 10px;
    background: linear-gradient(to right, #3498db 0%, #3498db var(--slider-progress, 80%), #e0e0e0 var(--slider-progress, 80%), #e0e0e0 100%);
    border-radius: 10px;
}

.setting-group input[type="range"]::-moz-range-track {
    width: 100%;
    height: 10px;
    background: #e0e0e0;
    border-radius: 10px;
    border: none;
}

.setting-group input[type="range"]::-moz-range-progress {
    background: #3498db;
    height: 10px;
    border-radius: 10px;
}

.setting-group input:focus {
    outline: none;
    border-color: #3498db;
}

.quality-info {
    font-size: 0.9em;
    color: #666;
    margin-top: 8px;
    text-align: center;
}

.compress-btn {
    width: 100%;
    padding: 16px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin-bottom: 20px;
}

.compress-btn:hover:not(:disabled) {
    background-color: #2980b9;
}

.compress-btn:disabled {
    background-color: #bdc3c7;
    cursor: not-allowed;
}

.loading {
    text-align: center;
    padding: 30px;
    color: #666;
    display: none;
}

.loading p {
    font-size: 1.2em;
    margin-bottom: 15px;
}

.spinner {
    border: 5px solid #f3f3f3;
    border-top: 5px solid #3498db;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.results {
    background-color: #fff;
    padding: 25px;
    border-radius: 12px;
    border: 1px solid #e1e1e1;
    margin-top: 30px;
    display: none;
}

.results h3 {
    margin-bottom: 20px;
    color: #2c3e50;
    text-align: center;
    font-size: 1.8em;
}

.result-item {
    padding: 15px;
    margin-bottom: 15px;
    border: 1px solid #e1e1e1;
    border-radius: 8px;
    background-color: #f8f9fa;
    transition: transform 0.2s ease;
}

.result-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.result-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    font-size: 1em;
}

.result-name {
    font-weight: 600;
    color: #2c3e50;
}

.result-size {
    color: #666;
    font-weight: 500;
}

.download-btn {
    width: 100%;
    padding: 12px;
    background-color: #27ae60;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

.download-btn:hover {
    background-color: #219a52;
}

.compression-ratio {
    font-size: 0.9em;
    color: #666;
    text-align: center;
    margin-top: 8px;
    font-weight: 500;
}

.ratio-good {
    color: #27ae60;
}

.ratio-average {
    color: #f39c12;
}

.ratio-poor {
    color: #e74c3c;
}

.download-all-btn {
    width: 100%;
    padding: 16px;
    background-color: #9b59b6;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    margin-bottom: 20px;
    transition: background-color 0.3s ease;
}

.download-all-btn:hover {
    background-color: #8e44ad;
}

.footer {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #e1e1e1;
    text-align: center;
    color: #7f8c8d;
    font-size: 0.9em;
    line-height: 1.6;
}

.footer a {
    color: #3498db;
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .container {
        padding: 20px;
        margin: 10px;
    }

    h1 {
        font-size: 2em;
    }

    .tagline {
        font-size: 0.95em;
    }

    .upload-area {
        padding: 30px 20px;
    }

    .upload-text p {
        font-size: 1.1em;
    }

    .settings {
        padding: 15px;
    }

    .setting-group label {
        font-size: 1em;
    }

    .compress-btn,
    .download-all-btn {
        padding: 14px;
        font-size: 16px;
    }

    .result-info {
        flex-direction: column;
        gap: 5px;
    }

    .result-name,
    .result-size {
        text-align: center;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }

    .container {
        padding: 15px;
    }

    h1 {
        font-size: 1.8em;
    }

    .logo {
        height: 40px;
    }

    .upload-area {
        padding: 25px 15px;
    }

    .upload-text p {
        font-size: 1em;
    }

    .setting-group input[type="range"] {
        height: 8px;
    }

    .setting-group input[type="range"]::-webkit-slider-thumb {
        width: 20px;
        height: 20px;
    }

    .spinner {
        width: 40px;
        height: 40px;
    }
}