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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: #fff0db;
  color: #0f4c81;
  font-family: 'DM Sans', sans-serif;
  padding: 1.5rem;
  overflow: hidden;
}

#root {
  flex: 1;
  display: flex;
  flex-direction: column;
}

h1 {
  font-weight: 800;
  letter-spacing: -0.02em;
}

button {
  background: #0f4c81;
  color: #fff0db;
  border: none;
  border-radius: 6px;
  padding: 0.75rem 1.75rem;
  font-family: 'DM Sans', sans-serif;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: transform 0.15s ease, opacity 0.15s ease;
}

button:hover {
  transform: scale(1.04);
  opacity: 0.85;
}

button:active {
  transform: scale(0.97);
}

/* ---- Start / Loading / Error screens ---- */

.screen {
  flex: 1;
  display: flex;
  flex-direction: column;
  animation: fadeIn 0.4s ease-out;
}

.center-screen {
  align-items: center;
  justify-content: center;
  text-align: center;
}

.screen h1 {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
}

.subtitle {
  font-size: 1rem;
  line-height: 1.6;
  opacity: 0.6;
  margin-bottom: 1.5rem;
  max-width: 360px;
}

/* ---- Playing state: immersive camera + overlays ---- */

.playing-container {
  flex: 1;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: -1.5rem; /* bleed to viewport edges */
  background: #0f4c81;
  animation: fadeIn 0.4s ease-out;
  overflow: hidden;
}

.webcam-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scaleX(-1);
  opacity: 0.3;
  z-index: 0;
}

.landmark-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  pointer-events: none;
}

/* ---- Chord label (left hand) — follows hand X ---- */

.chord-label {
  position: absolute;
  top: 42%;
  transform: translate(-50%, -50%);
  font-size: 3.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff0db;
  opacity: 0.7;
  z-index: 2;
  pointer-events: none;
}

/* ---- Melody note label (right hand) — follows hand X ---- */

.melody-label {
  position: absolute;
  top: 42%;
  transform: translate(-50%, -50%);
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #fff0db;
  opacity: 0.55;
  z-index: 2;
  pointer-events: none;
}

/* ---- Bottom bar ---- */

.bottom-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  z-index: 3;
}

.scale-indicator {
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff0db;
  opacity: 0.4;
}

.bottom-bar .stop-btn {
  padding: 0.5rem 1.25rem;
  font-size: 0.85rem;
  background: rgba(255, 240, 219, 0.15);
  color: #fff0db;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.bottom-bar .stop-btn:hover {
  background: rgba(255, 240, 219, 0.25);
}

/* ---- Animation ---- */

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---- Responsive ---- */

@media (max-width: 600px) {
  body {
    padding: 1rem;
  }

  .screen h1 {
    font-size: 2rem;
  }

  .playing-container {
    margin: -1rem;
  }

  .chord-label {
    font-size: 2.5rem;
  }

  .melody-label {
    font-size: 1.75rem;
  }

  .bottom-bar {
    padding: 1rem;
  }

  .bottom-bar .stop-btn {
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
}