/* ==========================================================================
   STEM SEPARATOR & 4-TRACK MIXER CONSOLE (MOISES AI STYLE)
   ========================================================================== */

.modal-stems-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(10, 10, 14, 0.82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  box-sizing: border-box;
}

.modal-stems-card {
  background: var(--bg-surface-raised, #16171d);
  border: 1px solid var(--border-subtle, rgba(255, 255, 255, 0.12));
  border-radius: 20px;
  width: 100%;
  max-width: 860px;
  max-height: 92vh;
  overflow-y: auto;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.05);
  display: flex;
  flex-direction: column;
  color: var(--text-primary, #f0f0f5);
  animation: stemsModalPop 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes stemsModalPop {
  0% { transform: scale(0.96) translateY(12px); opacity: 0; }
  100% { transform: scale(1) translateY(0); opacity: 1; }
}

.stems-modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 24px 28px 16px;
  border-bottom: 1px solid var(--border-subtle, rgba(255, 255, 255, 0.08));
}

.stems-badge-ai {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: #38bdf8;
  background: rgba(56, 189, 248, 0.14);
  border: 1px solid rgba(56, 189, 248, 0.3);
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
}

.stems-modal-title {
  margin: 0 0 4px;
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.stems-modal-subtitle {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-secondary, #94a3b8);
}

.btn-close-stems {
  background: rgba(255, 255, 255, 0.06);
  border: none;
  color: var(--text-secondary, #94a3b8);
  font-size: 1.1rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.btn-close-stems:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
}

/* Upload Zone */
.stems-upload-zone {
  margin: 24px;
  padding: 40px 20px;
  border: 2px dashed rgba(56, 189, 248, 0.35);
  border-radius: 16px;
  background: rgba(56, 189, 248, 0.03);
  text-align: center;
  transition: all 0.2s ease;
}

.stems-upload-zone.drag-over {
  border-color: #38bdf8;
  background: rgba(56, 189, 248, 0.1);
}

.stems-upload-icon {
  font-size: 3rem;
  margin-bottom: 12px;
}

.stems-upload-actions {
  margin-top: 24px;
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-stems-select-file,
.btn-stems-demo-file {
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-stems-select-file {
  background: #38bdf8;
  color: #0f172a;
  border: none;
}

.btn-stems-select-file:hover {
  background: #7dd3fc;
  transform: translateY(-1px);
}

.btn-stems-demo-file {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary, #f0f0f5);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-stems-demo-file:hover {
  background: rgba(255, 255, 255, 0.15);
}

/* Processing View */
.stems-processing-view {
  padding: 50px 24px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stems-spinner-ring {
  width: 54px;
  height: 54px;
  border: 4px solid rgba(56, 189, 248, 0.15);
  border-top-color: #38bdf8;
  border-radius: 50%;
  animation: spinRing 0.8s linear infinite;
  margin-bottom: 20px;
}

@keyframes spinRing {
  100% { transform: rotate(360deg); }
}

.stems-proc-title {
  margin: 0 0 6px;
  font-size: 1.25rem;
}

.stems-proc-step {
  margin: 0 0 20px;
  color: #38bdf8;
  font-size: 0.9rem;
}

.stems-progress-track {
  width: 100%;
  max-width: 440px;
  height: 10px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 8px;
}

.stems-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #38bdf8, #818cf8);
  border-radius: 999px;
  transition: width 0.2s ease;
}

.stems-proc-percent {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-secondary, #94a3b8);
}

/* Mixer Console */
.stems-console-wrapper {
  padding: 20px 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.stems-transport-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  background: rgba(0, 0, 0, 0.25);
  padding: 12px 18px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.btn-stems-play-pause {
  padding: 8px 18px;
  border-radius: 10px;
  background: #38bdf8;
  color: #0f172a;
  border: none;
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

.btn-stems-play-pause:hover {
  background: #7dd3fc;
}

.stems-timeline-container {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 12px;
}

.stems-time-label {
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--text-secondary, #94a3b8);
  min-width: 44px;
}

.stems-timeline-slider {
  flex: 1;
  cursor: pointer;
  accent-color: #38bdf8;
}

/* 4-Channel Strips Grid */
.stems-channels-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

@media (max-width: 680px) {
  .stems-channels-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.stem-channel-strip {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  position: relative;
  overflow: hidden;
}

.stem-channel-strip::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
}

.stem-channel-vocals::before { background: #38bdf8; }
.stem-channel-drums::before { background: #fb923c; }
.stem-channel-bass::before { background: #a855f7; }
.stem-channel-guitar::before { background: #10b981; }

.stem-channel-header {
  display: flex;
  align-items: center;
  gap: 6px;
}

.stem-icon {
  font-size: 1.2rem;
}

.stem-name {
  font-size: 0.95rem;
}

.stem-meter-slot {
  width: 12px;
  height: 120px;
  background: rgba(0, 0, 0, 0.6);
  border-radius: 6px;
  overflow: hidden;
  display: flex;
  align-items: flex-end;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.stem-vu-meter {
  width: 100%;
  background: linear-gradient(0deg, #10b981 60%, #eab308 85%, #ef4444 100%);
  border-radius: 4px;
  transition: height 0.08s ease;
}

.stem-fader-slot {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  width: 100%;
}

.stem-volume-fader {
  width: 80%;
  cursor: pointer;
  accent-color: #38bdf8;
}

.stem-vol-text {
  font-size: 0.8rem;
  font-family: monospace;
  color: var(--text-secondary, #94a3b8);
}

.stem-channel-buttons {
  display: flex;
  gap: 8px;
}

.btn-stem-mute,
.btn-stem-solo {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  font-weight: 800;
  font-size: 0.82rem;
  cursor: pointer;
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-secondary, #94a3b8);
  transition: all 0.15s ease;
}

.btn-stem-mute.active {
  background: #ef4444;
  color: #fff;
  border-color: #ef4444;
  box-shadow: 0 0 10px rgba(239, 68, 68, 0.4);
}

.btn-stem-solo.active {
  background: #eab308;
  color: #000;
  border-color: #eab308;
  box-shadow: 0 0 10px rgba(234, 179, 8, 0.4);
}

/* Presets Rápidos */
.stems-quick-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  padding: 12px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.preset-label {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-secondary, #94a3b8);
  margin-right: 4px;
}

.btn-stem-preset {
  padding: 6px 12px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-primary, #f0f0f5);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-stem-preset:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: translateY(-1px);
}

/* Modal Footer */
.stems-modal-footer {
  padding: 16px 28px 24px;
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  border-top: 1px solid var(--border-subtle, rgba(255, 255, 255, 0.08));
  flex-wrap: wrap;
}

.btn-stems-action {
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-stems-action.secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary, #f0f0f5);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-stems-action.secondary:hover {
  background: rgba(255, 255, 255, 0.15);
}

.btn-stems-action.primary {
  background: #38bdf8;
  color: #0f172a;
  border: none;
}

.btn-stems-action.primary:hover {
  background: #7dd3fc;
  box-shadow: 0 4px 14px rgba(56, 189, 248, 0.3);
}