:root {
  --bg-color: #0f172a;
  --surface-color: rgba(30, 41, 59, 0.7);
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-color: #38bdf8;
  --key-white: #f1f5f9;
  --key-black: #1e293b;
  --key-active: #facc15;
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
}

body {
  font-family:
    system-ui,
    -apple-system,
    sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  transition: background-color 0.5s ease;
}

.container {
  text-align: center;
  background-color: var(--surface-color);
  padding: 3rem;
  border-radius: 24px;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  max-width: 800px;
  width: 90%;
}

h1 {
  font-weight: 200;
  letter-spacing: -0.025em;
  margin-bottom: 2rem;
  background: linear-gradient(to right, #fff, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.controls {
  margin-bottom: 3rem;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
}

label {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

select {
  appearance: none;
  padding: 0.75rem 2.5rem 0.75rem 1rem;
  border-radius: 12px;
  background-color: rgba(0, 0, 0, 0.2);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 1rem;
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2394a3b8'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'%3E%3C/path%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1rem;
  transition: all 0.2s;
}

select:hover {
  border-color: var(--accent-color);
}

select:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

.instructions {
  margin-bottom: 2rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  background: rgba(0, 0, 0, 0.2);
  padding: 1.5rem;
  border-radius: 16px;
  text-align: left;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.5rem;
}

.instructions p {
  margin: 0;
}

#visual-keyboard {
  display: flex;
  justify-content: center;
  position: relative;
  padding: 1rem 0;
  overflow-x: auto;
}

.key {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
  cursor: pointer;
  user-select: none;
  transition: all 0.1s cubic-bezier(0.4, 0, 0.2, 1);
  padding-bottom: 1rem;
}

.key span {
  pointer-events: none;
  font-size: 0.75rem;
  font-weight: 600;
}

.key-label {
  font-size: 0.65rem !important;
  opacity: 0.6;
  margin-top: 0.25rem;
}

.key.white {
  width: 3.5rem;
  height: 12rem;
  background-color: var(--key-white);
  color: var(--bg-color);
  border-radius: 0 0 8px 8px;
  z-index: 1;
  border: 1px solid #cbd5e1;
  margin: 0 1px;
  box-shadow: 0 4px 0 #cbd5e1;
}

.key.white:active,
.key.white.key-active {
  background-color: var(--accent-color);
  transform: translateY(4px);
  box-shadow: 0 0 0 transparent;
  color: white;
  border-color: transparent;
}

.key.black {
  width: 2.5rem;
  height: 7.5rem;
  background-color: var(--key-black);
  color: var(--text-secondary);
  border-radius: 0 0 6px 6px;
  z-index: 2;
  margin: 0 -1.25rem;
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 4px 0 #0f172a;
}

.key.black:active,
.key.black.key-active {
  background-color: var(--key-active);
  color: var(--bg-color);
  transform: translateY(4px);
  box-shadow: 0 0 0 transparent;
}