:root {
    --accent: #29f7ff;
    --bg-dark: #0e0f1a;
    --bg-glass: rgba(255, 255, 255, 0.03);
    --text: #eaeaea;
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: 'Segoe UI', sans-serif;
    background: var(--bg-dark);
    color: var(--text);
    min-height: 100vh;
    padding-top: 10px;
    overflow-x: hidden;
    position: relative;
  }
  
  /* Background */
  .app-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 400%;
    height: 400%;
    background: linear-gradient(
      -45deg,
      #29f7ff,
      #1a68ff,
      #9429ff,
      #29f7ff
    );
    background-size: 600% 600%;
    animation: gradientFlow 30s ease infinite;
    z-index: -1;
    opacity: 0.2;
  }
  @keyframes gradientFlow {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
  }
  
  
  @keyframes glowMove {
    0% { transform: rotate(0deg) scale(1); }
    100% { transform: rotate(360deg) scale(1.1); }
  }
  
  /* About */
  .about-wrapper {
    display: flex;
    justify-content: center;
    margin-top: 1.5rem;
    padding: 0 1rem;
  }
  
  .about-box {
    width: 100%;
    max-width: 640px;
    background: rgba(255, 255, 255, 0.02);
    color: #ccc;
    border: 1px solid var(--accent);
    border-radius: 8px;
    padding: 1rem;
    font-size: 0.95rem;
    box-shadow: 0 0 10px rgba(41, 247, 255, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
  }
  
  .about-box summary {
    font-weight: bold;
    color: var(--accent);
    font-size: 1rem;
    list-style: none;
    outline: none;
  }
  
  .about-box[open] {
    background-color: rgba(41, 247, 255, 0.02);
    border-color: var(--accent);
  }
  
  .about-box p {
    margin-top: 1rem;
    line-height: 1.6;
    text-align: justify;
  }
  
  /* Player */
  .player-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
  }
  
  .header {
    text-align: center;
  }
  
  .avatar {
    width: 150px;
    margin: 0 auto 10px;
    display: block;
    border-radius: 50%;
    border: 2px solid var(--accent);
    box-shadow: 0 0 16px var(--accent);
  }
  
  .main-title {
    font-size: 16px;
    padding: 10px;
    color: #ccc;
  }
  
  /* Swiper */
  .swiper-container {
    width: 100%;
    max-width: 600px;
    margin: 1.5rem auto;
  }
  
  .swiper-slide {
    width: 240px;
    height: 360px;
    opacity: 0.3;
    transform: scale(0.8);
    transition: all 0.4s ease;
    filter: blur(1px);
  }
  
  .swiper-slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 12px;
    border: 2px solid transparent;
  }
  
  .swiper-slide-active {
    opacity: 1;
    transform: scale(1);
    filter: none;
    z-index: 2;
  }
  
  .swiper-slide-active img {
    border-color: var(--accent);
    box-shadow: 0 0 12px var(--accent);
  }
  
  /* Track Info */
  .track-info {
    text-align: center;
    margin-top: 1rem;
  }
  
  .track-info h2 {
    font-size: 1.4rem;
    margin-bottom: 0.3rem;
  }
  
  .track-info p {
    font-size: 0.9rem;
    color: #bbb;
  }
  
  #emotion-tag {
    display: inline-block;
    font-size: 0.8rem;
    color: var(--accent);
  }
  
  /* Waveform */
  .waveform {
    width: 100%;
    height: 100px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 8px;
    margin-top: 1rem;
  }
  
  /* Controls */
  .controls {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-top: 1rem;
  }
  
  .controls button {
    font-size: 1.4rem;
    background: none;
    border: none;
    color: var(--text);
    cursor: pointer;
    transition: transform 0.2s;
  }
  
  .controls button:hover {
    color: var(--accent);
    transform: scale(1.2);
  }
  
  /* Toggle menu button (always visible now) */
  .toggle-menu-btn {
    position: fixed;
    top: 1rem;
    left: 1rem;
    background: var(--accent);
    color: #0e0f1a;
    padding: 0.5rem 1rem;
    font-weight: bold;
    border: none;
    border-radius: 6px;
    z-index: 101;
  }
  
  /* Song menu panel */
  .song-menu {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 300px;
    background: rgba(255, 255, 255, 0.03);
    border-left: 1px solid var(--accent);
    backdrop-filter: blur(6px);
    padding: 1rem;
    overflow-y: auto;
    z-index: 10;
    transform: translateX(100%);
    transition: transform 0.3s ease;
  }
  
  .song-menu.active {
    transform: translateX(0%);
  }
  
  .menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
  }
  
  .menu-header h3 {
    font-size: 1.1rem;
    color: var(--accent);
  }
  
  #sort-select {
    background: transparent;
    color: #ccc;
    border: 1px solid var(--accent);
    padding: 4px 8px;
    border-radius: 6px;
  }
  
  #song-list {
    list-style: none;
    padding: 0;
  }
  
  #song-list li {
    margin-bottom: 10px;
    cursor: pointer;
    font-size: 0.9rem;
    color: #ddd;
    border-bottom: 1px solid rgba(255,255,255,0.05);
    padding-bottom: 6px;
  }
  
  #song-list li:hover {
    color: var(--accent);
  }
  .site-footer {
    margin-top: 3rem;
    padding: 1.2rem 2rem;
    text-align: center;
    font-size: 0.85rem;
    color: #aaa;
    background: rgba(255, 255, 255, 0.02);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(6px);
    box-shadow: 0 -2px 8px rgba(0, 255, 255, 0.06);
  }
  
  .site-footer a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
  }
  
  .site-footer a:hover {
    color: #fff;
  }
  
  .heart {
    color: red;
    animation: pulse 1.5s infinite ease-in-out;
  }
  
  @keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.2); }
  }
  .art-toggle {
    margin-top: 1rem;
    font-size: 0.85rem;
    color: #ccc;
    display: flex;
    justify-content: center;
    align-items: center;
  }
  
  .art-toggle input[type="checkbox"] {
    margin-right: 8px;
    transform: scale(1.2);
    cursor: pointer;
  }