body {
    background: #0f0f0f;
    color: #f1f1f1;
    font-family: 'Roboto', sans-serif;
}
.download-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}
.video-preview {
    background: #272727;
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
}
.resolution-option {
    background: #272727;
    border: 2px solid #3f3f3f;
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: all 0.3s;
}
.resolution-option:hover {
    border-color: #3ea6ff;
    background: #3f3f3f;
}
.resolution-option.selected {
    border-color: #3ea6ff;
    background: #1f4b7a;
}
.countdown-circle {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: conic-gradient(#3ea6ff 0deg, #272727 0deg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
    position: relative;
}
.countdown-inner {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: #0f0f0f;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: bold;
}
.btn-download {
    background: #3ea6ff;
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
    width: 100%;
    font-size: 1.1rem;
}
.btn-download:hover {
    background: #2d8dd8;
}
.btn-download:disabled {
    background: #3f3f3f;
    cursor: not-allowed;
}
.error-message {
    background: #d32f2f;
    color: white;
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}
.loading-spinner {
    border: 4px solid #3f3f3f;
    border-top: 4px solid #3ea6ff;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 2rem auto;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}