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

:root {
    --primary: #fe2c55;
    --primary-dark: #e01d44;
    --secondary: #25f4ee;
    --dark: #121212;
    --dark-light: #1e1e1e;
    --dark-lighter: #2a2a2a;
    --text: #ffffff;
    --text-muted: #a8a8a8;
    --success: #00d9a0;
    --error: #ff4d4f;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-lg: rgba(0, 0, 0, 0.5);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, var(--dark) 0%, #1a0a1e 100%);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.header {
    text-align: center;
    padding: 40px 20px;
    margin-bottom: 40px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 15px;
}

.logo svg {
    width: 50px;
    height: 50px;
    color: var(--primary);
    filter: drop-shadow(0 0 10px rgba(254, 44, 85, 0.5));
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-top: 10px;
}

.main-content {
    background: var(--dark-light);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 10px 40px var(--shadow-lg);
    margin-bottom: 60px;
}

.input-section {
    margin-bottom: 30px;
}

.input-wrapper {
    display: flex;
    gap: 15px;
    margin-bottom: 10px;
}

#videoUrl {
    flex: 1;
    padding: 18px 24px;
    background: var(--dark-lighter);
    border: 2px solid transparent;
    border-radius: 50px;
    color: var(--text);
    font-size: 1rem;
    transition: all 0.3s ease;
    outline: none;
}

#videoUrl:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(254, 44, 85, 0.1);
}

#videoUrl::placeholder {
    color: var(--text-muted);
}

#downloadBtn {
    padding: 18px 40px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border: none;
    border-radius: 50px;
    color: var(--text);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(254, 44, 85, 0.3);
    position: relative;
    min-width: 140px;
}

#downloadBtn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(254, 44, 85, 0.4);
}

#downloadBtn:active:not(:disabled) {
    transform: translateY(0);
}

#downloadBtn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

#downloadBtn .loader {
    display: none;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

#downloadBtn.loading .btn-text {
    opacity: 0;
}

#downloadBtn.loading .loader {
    display: block;
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.hint {
    color: var(--text-muted);
    font-size: 0.9rem;
    padding-left: 24px;
}

.result-section {
    margin-top: 30px;
    animation: fadeIn 0.5s ease;
}

.result-section.hidden,
.error-message.hidden {
    display: none;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.video-info {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    padding: 20px;
    background: var(--dark-lighter);
    border-radius: 15px;
}

.video-thumbnail {
    flex-shrink: 0;
    width: 120px;
    height: 160px;
    border-radius: 10px;
    overflow: hidden;
    background: var(--dark);
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.video-details {
    flex: 1;
}

.video-details h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    line-height: 1.4;
}

.video-details p {
    color: var(--secondary);
    font-size: 1rem;
    margin-bottom: 15px;
}

.video-stats {
    display: flex;
    gap: 20px;
    font-size: 0.95rem;
    color: var(--text-muted);
}

.download-options h4 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    color: var(--text);
}

.quality-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.quality-btn {
    padding: 20px;
    background: var(--dark-lighter);
    border: 2px solid transparent;
    border-radius: 15px;
    color: var(--text);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 15px;
}

.quality-btn.video-btn {
    border-color: var(--primary);
    background: linear-gradient(135deg, rgba(254, 44, 85, 0.1) 0%, rgba(254, 44, 85, 0.05) 100%);
}

.quality-btn.video-btn:hover {
    border-color: var(--primary);
    background: linear-gradient(135deg, rgba(254, 44, 85, 0.2) 0%, rgba(254, 44, 85, 0.1) 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(254, 44, 85, 0.3);
}

.quality-btn.audio-btn {
    border-color: var(--secondary);
    background: linear-gradient(135deg, rgba(37, 244, 238, 0.1) 0%, rgba(37, 244, 238, 0.05) 100%);
}

.quality-btn.audio-btn:hover {
    border-color: var(--secondary);
    background: linear-gradient(135deg, rgba(37, 244, 238, 0.2) 0%, rgba(37, 244, 238, 0.1) 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(37, 244, 238, 0.3);
}

.quality-icon {
    font-size: 2rem;
    line-height: 1;
}

.quality-info {
    display: flex;
    flex-direction: column;
    gap: 5px;
    flex: 1;
}

.quality-label {
    font-size: 1.1rem;
    color: var(--text);
}

.quality-size {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.error-message {
    padding: 20px;
    background: rgba(255, 77, 79, 0.1);
    border: 2px solid var(--error);
    border-radius: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
    margin-top: 20px;
    animation: fadeIn 0.3s ease;
}

.error-message svg {
    width: 24px;
    height: 24px;
    color: var(--error);
    flex-shrink: 0;
}

.error-message p {
    color: var(--text);
    margin: 0;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.feature {
    text-align: center;
    padding: 30px 20px;
    background: var(--dark-light);
    border-radius: 15px;
    transition: transform 0.3s ease;
}

.feature:hover {
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.feature h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.feature p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.how-to {
    background: var(--dark-light);
    border-radius: 20px;
    padding: 40px;
    margin-bottom: 60px;
}

.how-to h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 40px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.step {
    text-align: center;
    padding: 20px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    font-weight: 700;
    margin: 0 auto 20px;
    box-shadow: 0 4px 15px rgba(254, 44, 85, 0.3);
}

.step h4 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.step p {
    color: var(--text-muted);
}

footer {
    text-align: center;
    padding: 30px 20px;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid var(--dark-lighter);
}

@media (max-width: 768px) {
    .logo h1 {
        font-size: 2rem;
    }

    .logo svg {
        width: 40px;
        height: 40px;
    }

    .main-content {
        padding: 25px;
    }

    .input-wrapper {
        flex-direction: column;
    }

    #downloadBtn {
        width: 100%;
    }

    .video-info {
        flex-direction: column;
    }

    .video-thumbnail {
        width: 100%;
        height: 200px;
    }

    .quality-buttons {
        grid-template-columns: 1fr;
    }

    .how-to {
        padding: 30px 20px;
    }
}