@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600;700&display=swap');

:root {
    --bg-color: #101119;
    --surface-color: #1c1c2b;
    --primary-color: #a855f7;
    --accent-color: #2dd4bf;
    --text-color: #e0e0e0;
    --text-muted: #94a3b8;
    --border-color: rgba(255, 255, 255, 0.1);
}

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

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding: 40px 20px;
    position: relative;
    overflow-x: hidden;
}

.background-container { position: fixed; top: 0; left: 0; width: 100%; height: 100%; z-index: -1; pointer-events: none;}
.blob { position: absolute; border-radius: 50%; filter: blur(120px); opacity: 0.4; animation: move 25s infinite alternate; }
.blob1 { width: 400px; height: 400px; background: var(--primary-color); top: -100px; left: -100px; animation-duration: 25s; }
.blob2 { width: 500px; height: 500px; background: var(--accent-color); bottom: -150px; right: -150px; animation-duration: 30s; }
@keyframes move { 
    from { transform: translate(0, 0) scale(1) rotate(0deg); } 
    to { transform: translate(20vw, 30vh) scale(1.2) rotate(180deg); } 
}

.top-bar {
    position: absolute;
    top: 20px;
    left: 20px;
    right: 20px;
    width: calc(100% - 40px);
    max-width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 100;
}
.home-btn {
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--text-color);
    padding: 8px 15px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}
.home-btn:hover {
    background-color: rgba(255, 255, 255, 0.2);
    border-color: var(--accent-color);
}
.language-switcher { display: flex; gap: 10px; }
.lang-btn {
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--text-color);
    padding: 8px 12px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}
.lang-btn:hover { background-color: rgba(255, 255, 255, 0.2); border-color: var(--accent-color); }
.lang-btn.active { background-color: var(--accent-color); color: var(--bg-color); border-color: var(--accent-color); }


.main-container { width: 100%; max-width: 960px; text-align: center; background: rgba(16, 17, 25, 0.5); padding: 40px; border-radius: 24px; backdrop-filter: blur(15px); border: 1px solid var(--border-color); box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4); z-index: 1; animation: fadeIn 1s ease-out; margin-top: 60px; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
header h1 { font-size: 3em; font-weight: 700; margin-bottom: 8px; background: linear-gradient(45deg, var(--text-color), var(--accent-color)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
header p { font-size: 1.1em; color: var(--text-muted); margin-bottom: 30px; }


.controls { 
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    padding: 30px 0 20px 0;
    margin-bottom: 30px;
}
.filter-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}
.filter-group { text-align: left; position: relative; }
.filter-group label { display: block; margin-bottom: 8px; font-weight: 600; font-size: 0.9em; color: var(--text-muted); }

.filter-group select, .filter-group input {
    width: 100%; padding: 12px 15px; border-radius: 8px; border: 1px solid var(--border-color);
    background-color: rgba(0,0,0, 0.3); color: var(--text-color); font-size: 1rem;
    font-family: 'Poppins', sans-serif; box-sizing: border-box; -webkit-appearance: none; appearance: none;
    background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%2394a3b8%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-5%200-9.3%201.8-12.9%205.4A17.6%2017.6%200%200%200%200%2082.2c0%205%201.8%209.3%205.4%2012.9l128%20127.9c3.6%203.6%207.8%205.4%2012.8%205.4s9.2-1.8%2012.8-5.4L287%2095c3.5-3.5%205.4-7.8%205.4-12.8%200-5-1.9-9.2-5.5-12.8z%22%2F%3E%3C%2Fsvg%3E');
    background-repeat: no-repeat; background-position: right 15px top 50%; background-size: .65em auto; cursor: pointer;
}
.filter-group select option { background: var(--surface-color); color: var(--text-color); }
.filter-group select:disabled { opacity: 0.5; cursor: not-allowed; background-image: none; }
.filter-group select:focus, .filter-group input:focus {
    outline: none; border-color: var(--primary-color); box-shadow: 0 0 10px rgba(168, 85, 247, 0.5);
}

.lock-controls {
    display: flex; justify-content: center; gap: 15px; margin-top: 20px;
}
.lock-btn {
    display: inline-flex; align-items: center; gap: 8px; padding: 8px 15px; border: 1px solid var(--border-color);
    background: var(--surface-color); color: var(--text-muted); border-radius: 8px; cursor: pointer;
    font-family: 'Poppins', sans-serif; font-weight: 600; transition: all 0.3s ease;
}
.lock-btn .lock-icon {
    width: 16px; height: 16px; background-color: currentColor; transition: all 0.3s ease;
    -webkit-mask-size: contain; mask-size: contain; -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat; -webkit-mask-position: center; mask-position: center;
}
.lock-btn.locked { background: var(--accent-color); color: var(--bg-color); border-color: var(--accent-color); }
.lock-btn.locked .lock-icon { -webkit-mask-image: url('data:image/svg+xml;charset=UTF-8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="white"><path d="M12 17a2 2 0 0 0 2-2H10a2 2 0 0 0 2 2Zm6-9h-1V6c0-2.76-2.24-5-5-5S7 3.24 7 6v2H6c-1.1 0-2 .9-2 2v10c0 1.1.9 2 2 2h12c1.1 0 2-.9 2-2V10c0-1.1-.9-2-2-2Zm-6 9c-.55 0-1-.45-1-1s.45-1 1-1 1 .45 1 1-.45 1-1 1Zm-3-9V6c0-1.66 1.34-3 3-3s3 1.34 3 3v2H9Z"/></svg>');}
.lock-btn:not(.locked) .lock-icon { -webkit-mask-image: url('data:image/svg+xml;charset=UTF-8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="white"><path d="M12 17a2 2 0 0 0 2-2H10a2 2 0 0 0 2 2Zm6-9h-1V6c0-2.76-2.24-5-5-5S7 3.24 7 6h2c0-1.66 1.34-3 3-3s3 1.34 3 3v2H6c-1.1 0-2 .9-2 2v10c0 1.1.9 2 2 2h12c1.1 0 2-.9 2-2V10c0-1.1-.9-2-2-2Zm0 12H6V10h12v10Z"/></svg>');}

.main-actions { display: flex; gap: 15px; margin-bottom: 40px; }
#randomize-btn, #clear-filters-btn {
    flex-grow: 1; padding: 15px; font-size: 1.1rem; font-weight: 700; color: #fff; border: none; border-radius: 8px; cursor: pointer; transition: all 0.3s ease;
}
#randomize-btn { background: linear-gradient(45deg, var(--primary-color), var(--accent-color)); }
#randomize-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(45, 212, 191, 0.3); }
#clear-filters-btn { background: var(--surface-color); border: 1px solid var(--border-color); }
#clear-filters-btn:hover { border-color: var(--pink-color); color: var(--pink-color); }

#result-area { 
    display: grid; 
    gap: 20px;
    grid-template-columns: repeat(2, 1fr);
}
#result-area:has(.song-card:only-child) .song-card,
#result-area:has(.song-card:nth-last-child(3):first-child) .song-card:last-child {
    grid-column: 1 / -1;
}

.song-card {
    background-color: transparent; border-radius: 12px; padding: 0; position: relative; overflow: hidden; border: 2px solid transparent; transition: border-color 0.3s ease; animation: fadeInResult 0.5s ease;
}
@keyframes fadeInResult { from { opacity: 0; transform: scale(0.95); } to { opacity: 1; transform: scale(1); } }
.song-card.playing { border-color: var(--accent-color); }
.song-card::before {
    content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
    background: conic-gradient(transparent, rgba(45, 212, 191, 0.8), transparent 30%);
    animation: rotate-border 4s linear infinite; opacity: 0; transition: opacity 0.5s ease; z-index: 0;
}
.song-card.playing::before { opacity: 1; }

.card-content {
    background: var(--surface-color); position: relative; z-index: 1; inset: 2px;
    border-radius: 10px; padding: 15px; display: flex; gap: 15px; align-items: flex-start; height: 100%;
}
@keyframes rotate-border { from { transform: translate(-50%, -50%) rotate(0deg); } to { transform: translate(-50%, -50%) rotate(360deg); } }

.song-cover { width: 100px; height: 100px; border-radius: 6px; object-fit: cover; flex-shrink: 0; }
.song-info-wrapper { display: flex; flex-direction: column; flex-grow: 1; min-width: 0; text-align: left; }
.song-info h3 { margin: 0 0 2px 0; font-size: 1.3em; }
.song-info p { margin: 0 0 15px 0; color: var(--text-muted); font-size: 0.9em; }

.difficulty-details { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin-top: 10px; width: 100%; }
.difficulty-item { display: flex; align-items: center; gap: 10px; background: rgba(0,0,0,0.2); padding: 6px 10px; border-radius: 6px; }
.difficulty-name { color: var(--text-muted); font-size: 0.9em; flex-shrink: 0; width: 85px;}
.difficulty-level-img { height: 18px; }

.song-actions { margin-top: auto; padding-top: 15px; }
.preview-btn {
    color: var(--accent-color); cursor: pointer; border-color: var(--accent-color);
    background-color: transparent; transition: all 0.2s ease;
    padding: 8px 14px; border-radius: 6px; font-size: 0.9em;
    font-weight: 600; border: 1px solid var(--border-color);
}
.preview-btn:hover { background-color: var(--accent-color); color: var(--bg-color); box-shadow: 0 0 15px rgba(45, 212, 191, 0.4); }

.no-result { padding: 20px; color: var(--text-muted); grid-column: 1 / -1;}

.tooltip {
    position: fixed; background-color: #000; color: #fff; padding: 8px 12px;
    border-radius: 6px; font-size: 0.9em; z-index: 9999; pointer-events: none;
    opacity: 0; transform: scale(0.9); transition: opacity 0.2s, transform 0.2s;
}

@media (max-width: 980px) {
    #result-area { grid-template-columns: 1fr; }
    #result-area:has(.song-card:only-child) .song-card,
    #result-area:has(.song-card:nth-last-child(3):first-child) .song-card:last-child {
        max-width: none;
    }
}
@media (max-width: 540px) {
    .card-content { flex-direction: column; align-items: center; text-align: center; }
    .song-info-wrapper { align-items: center; }
}