:root {
    --primary-color: #00f2ff;
    --secondary-color: #ff00f7;
    --bg-dark: #0f0f23;
    --bg-darker: #1a1a2e;
    --text-color: #ffffff;
    --text-muted: #a0a0c0;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(0, 242, 255, 0.2);
    --card-shadow: 0 8px 32px rgba(0, 242, 255, 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: radial-gradient(circle at top right, #1a1a2e 0%, #0f0f23 100%);
    color: var(--text-color);
    min-height: 100vh;
    padding: 40px 20px;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
}

.header {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
}

.header h1 {
    font-size: 56px;
    font-weight: 800;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -1px;
    text-shadow: 0 10px 30px rgba(0, 242, 255, 0.2);
}

.subtitle {
    font-size: 20px;
    color: var(--text-muted);
    font-weight: 400;
    max-width: 600px;
    margin: 0 auto;
}

.input-section {
    margin-bottom: 80px;
}

.input-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 50px;
    box-shadow: var(--card-shadow);
    backdrop-filter: blur(20px);
    position: relative;
    overflow: hidden;
}

.input-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(0, 242, 255, 0.1) 0%, transparent 70%);
    opacity: 0.5;
    pointer-events: none;
}

.input-card label {
    display: block;
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--primary-color);
    text-align: center;
}

#video-url {
    width: 100%;
    padding: 20px 24px;
    font-size: 18px;
    background: rgba(0, 0, 0, 0.2);
    border: 2px solid rgba(0, 242, 255, 0.3);
    border-radius: 16px;
    color: #ffffff;
    outline: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    margin-bottom: 24px;
}

#video-url:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(0, 242, 255, 0.1), 0 0 20px rgba(0, 242, 255, 0.2);
    background: rgba(0, 0, 0, 0.3);
}

#video-url::placeholder {
    color: rgba(255, 255, 255, 0.3);
}

#download-btn {
    width: 100%;
    padding: 20px 32px;
    font-size: 20px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border: none;
    border-radius: 16px;
    color: #ffffff;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 20px rgba(0, 242, 255, 0.3);
    position: relative;
    overflow: hidden;
}

#download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 40px rgba(0, 242, 255, 0.5);
    filter: brightness(1.1);
}

#download-btn:active {
    transform: translateY(1px);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.thumbnail-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 24px;
    box-shadow: var(--card-shadow);
    backdrop-filter: blur(10px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.thumbnail-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    border-color: var(--primary-color);
}

.quality-label {
    font-size: 14px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    display: inline-block;
    padding: 4px 12px;
    background: rgba(0, 242, 255, 0.1);
    border-radius: 20px;
}

.thumbnail-preview {
    width: 100%;
    border-radius: 12px;
    margin-bottom: 20px;
    background: rgba(0, 0, 0, 0.3);
    aspect-ratio: 16 / 9;
    object-fit: cover;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.download-link {
    display: block;
    text-align: center;
    padding: 14px 24px;
    background: rgba(0, 242, 255, 0.1);
    border: 1px solid var(--primary-color);
    border-radius: 12px;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

.download-link:hover {
    background: var(--primary-color);
    color: #000;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 242, 255, 0.3);
}

.content-section {
    max-width: 800px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.02);
    padding: 40px;
    border-radius: 24px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.content-section h2 {
    font-size: 32px;
    margin-bottom: 24px;
    background: linear-gradient(to right, #fff, #a0a0c0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.content-section h3 {
    font-size: 24px;
    margin: 40px 0 20px;
    color: var(--primary-color);
}

.content-section p {
    margin-bottom: 20px;
    color: #d0d0e0;
    font-size: 17px;
}

.content-section ul, .content-section ol {
    margin-bottom: 24px;
    padding-left: 24px;
}

.content-section li {
    margin-bottom: 12px;
    color: #d0d0e0;
}

.features-table {
    display: grid;
    gap: 20px;
    margin: 30px 0;
}

.feature-row {
    background: rgba(255, 255, 255, 0.03);
    padding: 20px;
    border-radius: 12px;
    border-left: 3px solid var(--primary-color);
}

.feature-name {
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
    font-size: 18px;
}

.feature-benefit {
    color: #a0a0c0;
    font-size: 15px;
}

.content-image {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 30px auto;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 36px;
    }
    
    .input-card {
        padding: 30px 20px;
    }

    .content-section {
        padding: 20px;
    }
}