:root {
  --primary-color: #0ea5e9;
  --secondary-color: #84cc16;
  --bg-dark: #0f172a;
  --glass-bg: rgba(255, 255, 255, 0.03);
  --glass-border: rgba(255, 255, 255, 0.08);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --success: #10b981;
  --error: #ef4444;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background-image: 
    radial-gradient(circle at 15% 50%, rgba(14, 165, 233, 0.15), transparent 25%),
    radial-gradient(circle at 85% 30%, rgba(132, 204, 22, 0.15), transparent 25%);
  background-attachment: fixed;
}

.app-container {
  width: 100%;
  max-width: 600px;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.header {
  text-align: center;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
  color: var(--secondary-color);
}

h1 {
  font-family: 'Outfit', sans-serif;
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(to right, #84cc16, #38bdf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.main-content {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.glass-panel {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.glass-panel:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.2);
}

.upload-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 1rem;
  border: 2px dashed rgba(132, 204, 22, 0.3);
  cursor: pointer;
  transition: all 0.3s ease;
}

.upload-section.dragover {
  background: rgba(132, 204, 22, 0.1);
  border-color: var(--secondary-color);
}

.upload-icon {
  color: var(--secondary-color);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0% { transform: translateY(0px); }
  50% { transform: translateY(-8px); }
  100% { transform: translateY(0px); }
}

.upload-section h2 {
  font-size: 1.25rem;
  font-weight: 600;
}

.file-name {
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: var(--primary-color);
  background: rgba(14, 165, 233, 0.2);
  padding: 4px 12px;
  border-radius: 99px;
  display: none;
}

.controls-section {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.control-group label {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 600;
}

.select-wrapper {
  position: relative;
}

select {
  width: 100%;
  appearance: none;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--glass-border);
  color: var(--text-main);
  padding: 0.875rem 1rem;
  border-radius: 8px;
  font-family: inherit;
  font-size: 1rem;
  cursor: pointer;
  outline: none;
  transition: border-color 0.2s ease;
}

select:focus {
  border-color: var(--secondary-color);
}

select option, select optgroup {
  background-color: var(--bg-dark);
  color: var(--text-main);
}

.player-controls {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 0.5rem;
}

.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  outline: none;
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  box-shadow: 0 4px 14px rgba(14, 165, 233, 0.4);
}

.btn-primary:hover:not(:disabled) {
  transform: scale(1.05);
  box-shadow: 0 6px 20px rgba(14, 165, 233, 0.6);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-main);
}

.btn-secondary:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.15);
  transform: scale(1.05);
}

.status-bar {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.visualizer {
  display: flex;
  justify-content: center;
  align-items: flex-end;
  height: 40px;
  gap: 4px;
}

.bar {
  width: 6px;
  background: rgba(132, 204, 22, 0.5);
  border-radius: 3px;
  height: 10px;
  transition: height 0.1s ease-out;
}

.bar.active {
  background: var(--secondary-color);
  box-shadow: 0 0 10px var(--secondary-color);
}