:root {
  --bg-page: #f6fdf5;
  --bg-card-green: #c2e0bc;
  --bg-card-white: #ffffff;
  --accent-brown: #612b06;
  --text-color: #612b06;
  --border-color: #612b06;
  --border-width: 1.5px;
  --radius-lg: 1.8rem;
  --radius-md: 1rem;
  --radius-pill: 50rem;
}

* {
  box-sizing: border-box;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--bg-page);
  color: var(--text-color);
}

.page-shell {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 1rem 0 2rem;
}

.container {
  width: min(100%, 900px);
  min-width: 0;
  text-align: center;
  background: var(--bg-card-white);
  border: var(--border-width) solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: 0 8px 30px rgba(97, 43, 6, 0.08);
}

h1 {
  margin: 0 0 0.75rem;
  color: var(--accent-brown);
  font-size: clamp(1.7rem, 3vw, 2.3rem);
}

.subtitle {
  margin: 0 0 1.5rem;
  color: var(--accent-brown);
  opacity: 0.85;
}

.result-card {
  background: linear-gradient(135deg, var(--bg-card-green), rgba(194, 224, 188, 0.55));
  border: var(--border-width) solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.5rem;
}

.result-card .label {
  font-size: 0.8rem;
  color: var(--accent-brown);
  text-transform: uppercase;
  letter-spacing: 1px;
  opacity: 0.8;
}

.result-card h2 {
  margin: 0.35rem 0 0.2rem;
  font-size: 1.6rem;
  color: var(--accent-brown);
}

.notes-info {
  margin: 0;
  color: var(--accent-brown);
  font-weight: 600;
}

.fretboard-wrapper {
  width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 0.25rem 0 0.7rem;
  scrollbar-color: var(--accent-brown) rgba(97, 43, 6, 0.12);
  scrollbar-width: thin;
}

.fretboard {
  --string-label-width: 62px;
  --fret-width: 48px;
  display: flex;
  flex-direction: column;
  background: linear-gradient(180deg, #fffdf8 0%, #f4efe7 100%);
  border: var(--border-width) solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem 0 0.5rem;
  width: calc(var(--string-label-width) + (var(--fret-width) * var(--fret-count)));
  min-width: 100%;
}

.fret-number-row {
  display: flex;
  align-items: end;
  height: 34px;
  border-bottom: 1px solid rgba(97, 43, 6, 0.18);
}

.fret-number-label,
.string-label {
  position: sticky;
  left: 0;
  flex: 0 0 var(--string-label-width);
  width: var(--string-label-width);
  background: #fffdf8;
}

.fret-number-label {
  z-index: 5;
  align-self: stretch;
  display: grid;
  place-items: center;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  opacity: 0.72;
}

.fret-number {
  flex: 0 0 var(--fret-width);
  width: var(--fret-width);
  padding-bottom: 0.45rem;
  color: var(--accent-brown);
  font-size: 0.72rem;
  font-weight: 800;
  line-height: 1;
  text-align: center;
  opacity: 0.75;
}

.string-row {
  display: flex;
  align-items: center;
  height: 46px;
  position: relative;
}

.string-row::before {
  content: '';
  position: absolute;
  left: var(--string-label-width);
  right: 0;
  top: 50%;
  height: 2px;
  background: var(--border-color);
  opacity: 0.7;
  z-index: 1;
}

.string-label {
  font-weight: 700;
  text-align: center;
  color: var(--accent-brown);
  opacity: 0.85;
  z-index: 4;
}

.fret-cell {
  flex: 0 0 var(--fret-width);
  width: var(--fret-width);
  height: 100%;
  border-right: 1.5px solid rgba(97, 43, 6, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  position: relative;
  z-index: 2;
}

.fret-cell:focus-visible {
  outline: 3px solid var(--bg-card-green);
  outline-offset: -4px;
}

.fret-cell.open-fret {
  border-right: none;
  background: rgba(194, 224, 188, 0.28);
}

.marker {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  transition: all 0.2s ease;
  border: var(--border-width) solid transparent;
}

.marker.muted {
  background-color: var(--accent-brown);
  color: #fff;
  border-color: var(--accent-brown);
}

.marker.pressed {
  background-color: var(--accent-brown);
  color: #fff;
  box-shadow: 0 0 0 4px rgba(97, 43, 6, 0.12);
}

.marker.open {
  background-color: var(--bg-card-green);
  color: var(--accent-brown);
  border-color: var(--border-color);
}

.btn-clear {
  margin-top: 1.5rem;
  padding: 0.8rem 1.2rem;
  background-color: var(--bg-card-green);
  color: var(--accent-brown);
  border: var(--border-width) solid var(--border-color);
  border-radius: var(--radius-pill);
  cursor: pointer;
  font-weight: 700;
  transition: transform 0.2s ease;
}

.btn-clear:hover {
  transform: scale(1.02);
}

.btn-clear:active {
  transform: scale(0.98);
}

@media (max-width: 640px) {
  .container {
    padding: 1.25rem;
  }

  .result-card {
    padding: 1rem;
  }
}