/* Mobile-first styling for Seamless Loop Player */
:root {
  --bg: #0d1117;
  --bg-alt: #161b22;
  --panel: #1f252e;
  --accent: #4a90e2;
  --accent-glow: 180 82% 55%;
  --danger: #e24a6a;
  --text: #e6edf3;
  --text-dim: #9da7b3;
  --radius-sm: 6px;
  --radius: 12px;
  --shadow: 0 4px 16px -4px rgba(0,0,0,0.45);
  --transition: 140ms cubic-bezier(.4,.2,.2,1);
  --focus-ring: 0 0 0 3px rgba(74,144,226,0.35);
  --wave-bg: #0f141b;
  --font-stack: system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,sans-serif;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: var(--font-stack);
  background: radial-gradient(circle at 30% 20%, #182635, #0d1117 70%);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

h1 {
  font-size: clamp(1.6rem, 4.3vw, 2.4rem);
  margin: 0 0 1rem;
  letter-spacing: .5px;
  background: linear-gradient(90deg,#4a90e2,#6fa8ee 50%,#4a90e2);
  -webkit-background-clip: text;
  color: transparent;
}

.app-shell {
  max-width: 960px;
  margin: 0 auto;
  padding: 18px 18px 40px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.controls, .imports { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

button, .btn {
  appearance: none;
  border: none;
  background: var(--accent);
  color: #fff;
  padding: 12px 18px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .3px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  position: relative;
  transition: var(--transition);
  box-shadow: 0 2px 6px -2px rgba(0,0,0,.4),0 0 0 1px rgba(255,255,255,.05);
}
button:hover, .btn:hover { filter: brightness(1.12); }
button:active, .btn:active { transform: translateY(1px); }
button:focus-visible { outline: none; box-shadow: var(--focus-ring); }

button.secondary { background: var(--panel); color: var(--text); }
button.secondary:hover { background: #242b35; }
button.danger { background: var(--danger); }

.range-wrap { display: flex; align-items: center; gap: 8px; }
.range-wrap input[type=range] { width: 180px; accent-color: var(--accent); }

#status { font-size: .85rem; color: var(--text-dim); min-height: 1.2em; }
#loopInfo { font-size: .9rem; color: var(--text); font-weight: 500; }

#dropZone {
  border: 2px dashed #2a3542;
  padding: 16px 18px;
  border-radius: var(--radius);
  background: var(--panel);
  font-size: .85rem;
  color: var(--text-dim);
  transition: var(--transition);
}
#dropZone.drag-hover { border-color: var(--accent); background: #1b2734; color: var(--text); }

.settings-wave-wrap { display: flex; flex-direction: column; gap: 14px; }
@media (min-width: 860px) { .settings-wave-wrap { flex-direction: row; align-items: flex-start; } }

#wave {
  width: 100%;
  background: var(--wave-bg);
  border: 1px solid #1e2730;
  border-radius: var(--radius-sm);
  display: block;
}

fieldset.settings {
  border: 1px solid #1e2730;
  border-radius: var(--radius);
  padding: 14px 16px 18px;
  background: linear-gradient(145deg,#141b23,#0f141b 60%);
  min-width: 260px;
  flex: 0 0 300px;
  position: relative;
}
fieldset.settings legend { padding: 0 6px; font-weight: 600; letter-spacing: .4px; }
.settings-grid { display: grid; gap: 10px; }
.settings-grid .row { display: flex; gap: 10px; align-items: center; }
.settings-grid label { flex: 1; font-size: .75rem; text-transform: uppercase; letter-spacing: .8px; color: var(--text-dim); }
.settings-grid input { flex: 0 0 90px; background: #10171f; border: 1px solid #1e2730; color: var(--text); padding: 6px 8px; border-radius: var(--radius-sm); font-size: .8rem; }
.settings-grid input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px rgba(74,144,226,.3); }

.toggle-panel-btn { position: absolute; top: 6px; right: 6px; background: var(--panel); border: 1px solid #2a3542; padding: 4px 10px; font-size: .7rem; letter-spacing: .7px; border-radius: var(--radius-sm); }
.toggle-panel-btn:hover { background:#242f3b; }

.hidden { display: none !important; }

.url-input { min-width: 240px; flex: 1; padding: 10px 12px; border-radius: var(--radius-sm); border: 1px solid #2a3542; background: #10171f; color: var(--text); font-size: .85rem; }
.url-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px rgba(74,144,226,.3); }

.source-badge { display:inline-block; margin-left:4px; padding:2px 6px; font-size:.65rem; background:#243241; color:var(--text-dim); border-radius:999px; letter-spacing:.5px; }

.footer-note { margin-top: 24px; font-size: .65rem; text-transform: uppercase; letter-spacing: .8px; color: #5d6672; text-align: center; }

/* Smooth fade for dynamic states */
.fade { animation: fade .35s ease; }
@keyframes fade { from { opacity:0; transform: translateY(4px);} to { opacity:1; transform: translateY(0);} }

/* Scroll behavior for safe-area long pages */
html { scroll-behavior: smooth; }

/* Dark and high-contrast considerations */
@media (prefers-color-scheme: light) {
  :root { --bg: #f4f7fa; --bg-alt:#e8edf3; --panel:#ffffff; --text:#1d242b; --text-dim:#5a6672; --wave-bg:#ffffff; }
  body { background: linear-gradient(165deg,#ffffff,#e8edf3 70%); }
  #dropZone { background:#ffffff; }
  fieldset.settings { background: linear-gradient(145deg,#f4f7fa,#e8edf3); }
}

/* Responsive adjustments */
@media (max-width: 520px) {
  .controls button, .imports button { flex: 1 1 auto; }
  .range-wrap { width:100%; }
  .range-wrap input[type=range] { flex:1; }
  fieldset.settings { flex:1 1 100%; }
  .settings-wave-wrap { flex-direction: column; }
}