* { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #f5f7fa;
  --panel: #ffffff;
  --ink: #1f2933;
  --muted: #6b7785;
  --brand: #2f6df0;
  --brand-soft: #e8f0fe;
  --line: #e3e8ef;
  --accent: #ff7043;
}
html, body { height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Top bar */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}
.brand { display: flex; align-items: center; gap: 12px; }
.back-home {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  text-decoration: none;
  font-size: 20px;
  line-height: 1;
}
.back-home:hover { border-color: var(--brand); color: var(--brand); }
.logo { font-size: 28px; }
.topbar h1 { font-size: 18px; font-weight: 700; }
.topbar .sub { font-size: 13px; color: var(--muted); margin-top: 2px; }
.menu-toggle {
  display: none;
  font-size: 22px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--ink);
}

/* Layout */
.layout {
  flex: 1;
  display: flex;
  align-items: stretch;
  overflow: hidden;
}
.sidebar {
  width: 260px;
  flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  padding: 16px 12px;
}
.search-box { margin-bottom: 14px; }
.search-box input {
  width: 100%;
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  font-size: 14px;
  outline: none;
}
.search-box input:focus { border-color: var(--brand); }

.unit-nav { display: flex; flex-direction: column; gap: 6px; }
.unit-nav .unit-btn {
  text-align: left;
  padding: 10px 12px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.unit-nav .unit-btn:hover { background: var(--brand-soft); }
.unit-nav .unit-btn.active { background: var(--brand); color: #fff; }
.unit-nav .unit-btn .count {
  font-size: 12px;
  color: var(--muted);
  background: var(--bg);
  border-radius: 999px;
  padding: 1px 8px;
}
.unit-nav .unit-btn.active .count { color: #fff; background: rgba(255,255,255,.25); }

.content { flex: 1; overflow-y: auto; padding: 20px; }
.track-list { max-width: 860px; margin: 0 auto; display: flex; flex-direction: column; gap: 10px; }
.track {
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 16px;
  cursor: pointer;
  transition: border-color .15s, box-shadow .15s;
}
.track:hover { border-color: var(--brand); box-shadow: 0 2px 10px rgba(47,109,240,.08); }
.track .idx {
  width: 34px; height: 34px;
  flex-shrink: 0;
  display: grid; place-items: center;
  background: var(--brand-soft);
  color: var(--brand);
  border-radius: 50%;
  font-weight: 700; font-size: 14px;
}
.track.playing { border-color: var(--accent); background: #fff6f2; }
.track.playing .idx { background: var(--accent); color: #fff; }
.track .title { font-size: 15px; font-weight: 600; }
.track .file { font-size: 12px; color: var(--muted); margin-top: 2px; }
.track .playing-icon { margin-left: auto; color: var(--accent); font-size: 18px; display: none; }
.track.playing .playing-icon { display: inline; }

/* Player */
.player {
  position: sticky;
  bottom: 0;
  background: var(--panel);
  border-top: 1px solid var(--line);
  padding: 12px 20px 16px;
  z-index: 30;
}
.player-meta {
  display: flex; justify-content: space-between; align-items: baseline;
  margin-bottom: 8px;
}
.now-playing { font-size: 14px; font-weight: 600; }
.times { font-size: 12px; color: var(--muted); }
.progress-wrap { margin-bottom: 10px; }
.seek { width: 100%; accent-color: var(--brand); cursor: pointer; }
.controls {
  display: flex; align-items: center; gap: 14px;
  flex-wrap: wrap;
}
.ctrl {
  width: 44px; height: 44px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--panel);
  font-size: 18px;
  cursor: pointer;
  color: var(--ink);
}
.ctrl.play { background: var(--brand); color: #fff; border-color: var(--brand); width: 52px; height: 52px; font-size: 22px; }
.ctrl:hover { filter: brightness(.97); }
.speed, .volume { display: flex; align-items: center; gap: 6px; font-size: 13px; color: var(--muted); }
.speed select { padding: 6px 8px; border-radius: 8px; border: 1px solid var(--line); background: #fff; }
.volume input { width: 90px; accent-color: var(--brand); }

/* Top bar auth */
.topbar-right { display: flex; align-items: center; gap: 12px; }
.login-btn {
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--panel);
  color: var(--ink);
  cursor: pointer;
}
.login-btn:hover { border-color: var(--brand); color: var(--brand); }
.login-btn svg { display: block; }
.user-box { display: flex; align-items: center; gap: 8px; }
.avatar { width: 30px; height: 30px; border-radius: 50%; object-fit: cover; background: var(--brand-soft); }
.uname { font-size: 13px; font-weight: 600; max-width: 120px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.logout-btn { padding: 5px 10px; border: 1px solid var(--line); border-radius: 999px; background: #fff; font-size: 12px; cursor: pointer; color: var(--muted); }

/* Favorites nav */
.unit-nav .unit-btn.fav { color: var(--accent); }
.unit-nav .unit-btn.fav.active { background: var(--accent); color: #fff; }

/* Track star */
.track .star {
  margin-left: auto;
  font-size: 20px;
  line-height: 1;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
  padding: 4px 6px;
}
.track .star.faved { color: #f5b301; }
.track .playing-icon { margin-left: 0; }

/* Cloud hint */
.cloud-hint { font-size: 12px; color: var(--muted); margin-top: 14px; line-height: 1.5; padding: 0 4px; }

/* Responsive */
@media (max-width: 720px) {
  .menu-toggle { display: block; }
  .sidebar {
    position: fixed;
    top: 60px; bottom: 0; left: 0;
    transform: translateX(-100%);
    transition: transform .2s;
    z-index: 25;
    box-shadow: 4px 0 20px rgba(0,0,0,.08);
  }
  .sidebar.open { transform: translateX(0); }
  .content { padding: 14px; }
  .controls { gap: 10px; }
  .volume { display: none; }
}