/* ===========================
   FolderPlay — style.css
   =========================== */

:root {
  --bg:        #0d0d10;
  --bg2:       #13131a;
  --bg3:       #1a1a24;
  --border:    rgba(255,255,255,0.07);
  --border2:   rgba(255,255,255,0.12);
  --accent:    #00e5ff;
  --accent2:   #00b8cc;
  --accent-dim:rgba(0,229,255,0.12);
  --text:      #f0f0f5;
  --text2:     #9090a8;
  --text3:     #5a5a70;
  --font-mono: 'Space Mono', monospace;
  --font-sans: 'DM Sans', sans-serif;
  --radius:    12px;
  --radius-lg: 20px;
  --transition: 0.2s cubic-bezier(0.4,0,0.2,1);
}

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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  min-height: 100vh;
  overflow-x: hidden;
}

/* Background grid */
.bg-grid {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,229,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,229,255,0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
}

/* ======= NAV ======= */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  height: 60px;
  background: rgba(13,13,16,0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
  transition: color var(--transition);
}
.nav-logo:hover { color: var(--accent); }

.logo-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--accent-dim);
  border: 1px solid rgba(0,229,255,0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  color: var(--accent);
}

.nav-links {
  display: flex;
  gap: 4px;
}

.nav-link {
  padding: 6px 16px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text2);
  text-decoration: none;
  transition: all var(--transition);
}
.nav-link:hover {
  color: var(--text);
  background: rgba(255,255,255,0.05);
}
.nav-link.active {
  color: var(--accent);
  background: var(--accent-dim);
}

/* ======= MAIN LAYOUT ======= */
.app-container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 16px;
  max-width: 1100px;
  margin: 24px auto;
  padding: 0 16px 32px;
  min-height: calc(100vh - 60px - 48px);
}

.panel {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

/* ======= PLAYLIST PANEL ======= */
.playlist-panel {
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 120px);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 20px 16px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.panel-title {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 16px;
  background: var(--accent);
  color: #000;
  border: none;
  border-radius: 8px;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  text-decoration: none;
}
.btn-primary:hover {
  background: var(--accent2);
  transform: translateY(-1px);
}
.btn-primary:active { transform: scale(0.97); }

.song-count-bar {
  padding: 10px 20px;
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--text3);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

/* Song List */
.song-list {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 10px 10px;
}

.song-list::-webkit-scrollbar { width: 4px; }
.song-list::-webkit-scrollbar-track { background: transparent; }
.song-list::-webkit-scrollbar-thumb {
  background: var(--border2);
  border-radius: 4px;
}

/* Empty state */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 60px 20px;
  text-align: center;
  color: var(--text3);
}
.empty-icon {
  font-size: 2.5rem;
  color: var(--text3);
  margin-bottom: 6px;
}
.empty-state p {
  font-size: 0.9rem;
  color: var(--text2);
  font-weight: 500;
}
.empty-state span {
  font-size: 0.78rem;
  color: var(--text3);
  font-family: var(--font-mono);
}

/* Song Item */
.song-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 10px;
  cursor: pointer;
  transition: background var(--transition);
  list-style: none;
}
.song-item:hover { background: rgba(255,255,255,0.04); }
.song-item.active {
  background: var(--accent-dim);
  border: 1px solid rgba(0,229,255,0.15);
}

.song-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text3);
  width: 22px;
  text-align: right;
  flex-shrink: 0;
}
.song-item.active .song-num { color: var(--accent); }

.song-thumb {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  background: var(--bg3);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 0.9rem;
  color: var(--text3);
  overflow: hidden;
}
.song-item.active .song-thumb {
  background: var(--accent-dim);
  border-color: rgba(0,229,255,0.25);
  color: var(--accent);
}

.song-info {
  flex: 1;
  min-width: 0;
}
.song-name {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.song-item.active .song-name { color: var(--accent); }
.song-sub {
  font-size: 0.7rem;
  color: var(--text3);
  margin-top: 2px;
  font-family: var(--font-mono);
}

.song-play-icon {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--bg3);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.65rem;
  color: var(--text3);
  flex-shrink: 0;
  transition: all var(--transition);
}
.song-item:hover .song-play-icon,
.song-item.active .song-play-icon {
  background: var(--accent);
  border-color: var(--accent);
  color: #000;
}

/* ======= PLAYER PANEL ======= */
.player-panel {
  display: flex;
  flex-direction: column;
  padding: 32px;
  gap: 28px;
}

/* Artwork area */
.artwork-area {
  display: flex;
  align-items: center;
  gap: 28px;
  flex: 1;
}

.artwork-ring {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  border: 2px solid var(--border2);
  background: var(--bg3);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  position: relative;
  transition: border-color var(--transition);
}
.artwork-ring.playing {
  border-color: var(--accent);
  animation: spin 12s linear infinite;
  box-shadow: 0 0 30px rgba(0,229,255,0.12);
}
@keyframes spin { to { transform: rotate(360deg); } }

.artwork-inner {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: var(--bg2);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  animation: reverse-spin 12s linear infinite;
  animation-play-state: paused;
}
.artwork-ring.playing .artwork-inner {
  animation-play-state: running;
}
@keyframes reverse-spin { to { transform: rotate(-360deg); } }

.artwork-icon {
  font-size: 1.6rem;
  color: var(--accent);
}
.artwork-label {
  font-family: var(--font-mono);
  font-size: 0.55rem;
  color: var(--text3);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.track-info { flex: 1; min-width: 0; }
.track-title {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  letter-spacing: -0.02em;
}
.track-sub {
  font-size: 0.82rem;
  color: var(--text3);
  margin-top: 6px;
  font-family: var(--font-mono);
}

/* Progress */
.progress-section {
  display: flex;
  align-items: center;
  gap: 12px;
}
.time-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text3);
  width: 36px;
  flex-shrink: 0;
}
#duration { text-align: right; }

.progress-track {
  flex: 1;
  height: 4px;
  background: var(--bg3);
  border-radius: 4px;
  position: relative;
  cursor: pointer;
}
.progress-track:hover .progress-thumb { opacity: 1; transform: translateX(-50%) scale(1); }

.progress-fill {
  position: absolute;
  left: 0; top: 0; height: 100%;
  width: 0%;
  background: var(--accent);
  border-radius: 4px;
  pointer-events: none;
  transition: width 0.1s linear;
}
.progress-thumb {
  position: absolute;
  top: 50%;
  left: 0%;
  transform: translateX(-50%) translateY(-50%) scale(0.7);
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px rgba(0,229,255,0.5);
  cursor: grab;
  opacity: 0;
  transition: opacity var(--transition), transform var(--transition);
  pointer-events: all;
}
.progress-thumb:active { cursor: grabbing; }

/* Controls */
.controls-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.ctrl-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 50%;
  color: var(--text);
  cursor: pointer;
  transition: all var(--transition);
  width: 44px;
  height: 44px;
  font-size: 1rem;
}
.ctrl-btn:hover {
  background: rgba(255,255,255,0.06);
  border-color: var(--border2);
  color: var(--accent);
}
.ctrl-btn.secondary {
  color: var(--text3);
  font-size: 0.85rem;
}
.ctrl-btn.secondary:hover { color: var(--accent); }
.ctrl-btn.secondary.on {
  color: var(--accent);
  background: var(--accent-dim);
  border-color: rgba(0,229,255,0.2);
}

.play-btn {
  width: 58px;
  height: 58px;
  font-size: 1.1rem;
  background: var(--accent);
  border-color: var(--accent);
  color: #000;
}
.play-btn:hover {
  background: var(--accent2);
  border-color: var(--accent2);
  color: #000;
  transform: scale(1.05);
}
.play-btn:active { transform: scale(0.97); }

/* Volume */
.volume-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.vol-icon-btn {
  background: none;
  border: none;
  color: var(--text3);
  cursor: pointer;
  font-size: 0.95rem;
  padding: 4px;
  transition: color var(--transition);
  flex-shrink: 0;
}
.vol-icon-btn:hover { color: var(--accent); }

.volume-track {
  flex: 1;
  height: 4px;
  background: var(--bg3);
  border-radius: 4px;
  position: relative;
  cursor: pointer;
}
.volume-track:hover .volume-thumb { opacity: 1; transform: translateX(-50%) scale(1); }

.volume-fill {
  position: absolute;
  left: 0; top: 0; height: 100%;
  width: 40%;
  background: var(--accent);
  border-radius: 4px;
  pointer-events: none;
}
.volume-thumb {
  position: absolute;
  top: 50%;
  left: 40%;
  transform: translateX(-50%) translateY(-50%) scale(0.7);
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  cursor: grab;
  opacity: 0;
  transition: opacity var(--transition), transform var(--transition);
}
.volume-thumb:active { cursor: grabbing; }

.vol-pct {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text3);
  width: 36px;
  text-align: right;
  flex-shrink: 0;
}

/* ======= ABOUT PAGE ======= */
.about-container {
  position: relative;
  z-index: 1;
  max-width: 860px;
  margin: 0 auto;
  padding: 60px 24px 80px;
}

.about-hero {
  text-align: center;
  margin-bottom: 64px;
}
.about-badge {
  display: inline-block;
  padding: 4px 12px;
  background: var(--accent-dim);
  border: 1px solid rgba(0,229,255,0.25);
  border-radius: 20px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 20px;
}
.about-title {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  color: var(--text);
}
.about-title em {
  font-style: italic;
  color: var(--accent);
}
.about-desc {
  font-size: 1.05rem;
  color: var(--text2);
  line-height: 1.7;
  max-width: 520px;
  margin: 0 auto 32px;
}
.about-cta {
  font-size: 0.9rem;
  padding: 12px 28px;
  border-radius: 10px;
}

/* About Cards Grid */
.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin-bottom: 60px;
}
.about-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: border-color var(--transition), transform var(--transition);
}
.about-card:hover {
  border-color: var(--border2);
  transform: translateY(-2px);
}
.about-card-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--accent-dim);
  border: 1px solid rgba(0,229,255,0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: var(--accent);
  margin-bottom: 16px;
}
.about-card h3 {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}
.about-card p {
  font-size: 0.85rem;
  color: var(--text2);
  line-height: 1.65;
}

/* Tech */
.about-section-title {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text3);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.about-tech { margin-bottom: 60px; }
.tech-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.tech-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 16px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text2);
  transition: all var(--transition);
}
.tech-pill:hover {
  border-color: var(--border2);
  color: var(--text);
}

/* Author */
.about-author {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 24px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.author-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--accent-dim);
  border: 2px solid rgba(0,229,255,0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  flex-shrink: 0;
}
.author-name {
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 4px;
}
.author-link {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text3);
  text-decoration: none;
  transition: color var(--transition);
}
.author-link:hover { color: var(--accent); }

/* ======= RESPONSIVE ======= */
@media (max-width: 768px) {
  .app-container {
    grid-template-columns: 1fr;
    margin: 12px auto;
    gap: 12px;
  }

  .playlist-panel {
    max-height: 400px;
  }

  .player-panel {
    padding: 24px 20px;
    gap: 22px;
  }

  .artwork-area {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .artwork-ring {
    width: 100px;
    height: 100px;
    align-self: center;
  }
  .artwork-inner {
    width: 64px;
    height: 64px;
  }
  .artwork-icon { font-size: 1.2rem; }

  .track-info { text-align: center; width: 100%; }
  .track-title { font-size: 1rem; }

  .controls-row { gap: 8px; }
  .ctrl-btn { width: 40px; height: 40px; font-size: 0.9rem; }
  .play-btn { width: 52px; height: 52px; }

  nav { padding: 0 16px; }

  .about-container { padding: 40px 16px 60px; }
  .about-hero { margin-bottom: 40px; }
}

@media (max-width: 400px) {
  .panel-header { flex-wrap: wrap; gap: 10px; }
  .panel-title { font-size: 0.85rem; }
}