/*
  Music Maker Web App - Core Styles
  Focus: Responsive layout, dark theme, and futuristic interactive elements.
*/

:root {
  /* Colors */
  --bg-dark: #0f172a;
  --bg-card: #1e293b;
  --bg-sidebar: #111827;
  --primary: #38bdf8; /* Neon Blue */
  --secondary: #818cf8; /* Neon Purple */
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --accent: #f472b6; /* Pink accent */
  
  /* Pad Colors */
  --pad-white: #e2e8f0;
  --pad-black: #334155;
  --pad-active: #38bdf8;
  
  /* Spacing & Borders */
  --radius: 8px;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --neon-shadow: 0 0 10px rgba(56, 189, 248, 0.4);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.5;
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* --- Layout --- */

header {
  height: 70px;
  background-color: var(--bg-sidebar);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding: 0 1rem;
  display: flex;
  align-items: center;
}

.notation-container {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--primary);
  border-radius: var(--radius);
  padding: 0.5rem;
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#notation-box {
  width: 100%;
  background: transparent;
  border: none;
  color: var(--primary);
  font-family: 'Courier New', Courier, monospace;
  font-size: 1.25rem;
  font-weight: 700;
  outline: none;
  letter-spacing: 0.05em;
  flex: 1;
}

.doc-link {
  color: var(--secondary);
  text-decoration: none;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.5rem 1rem;
  border-left: 1px solid rgba(255, 255, 255, 0.1);
  transition: all 0.2s ease;
  white-space: nowrap;
}

.doc-link:hover {
  color: var(--primary);
  text-shadow: 0 0 8px var(--primary);
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 1rem;
  gap: 1rem;
  overflow-y: auto;
}

.controls-section {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
}

.tempo-section {
  background: var(--bg-card);
  padding: 1rem;
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.grid-section {
  flex: 1;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(4, 1fr);
  gap: 0.75rem;
  min-height: 400px;
}

footer {
  background-color: var(--bg-sidebar);
  padding: 0.5rem 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.tabs-container {
  display: flex;
  justify-content: space-around;
  gap: 0.5rem;
}

/* --- Components --- */

button {
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid rgba(255, 255, 255, 0.1);
  padding: 0.75rem;
  border-radius: var(--radius);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

button:hover {
  background: #334155;
  border-color: var(--primary);
  box-shadow: var(--neon-shadow);
  transform: translateY(-1px);
}

button:active {
  transform: scale(0.95);
}

.tempo-slider-container {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.tempo-label {
  font-size: 0.875rem;
  color: var(--text-muted);
  min-width: 60px;
}

input[type="range"].tempo-slider {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  background: #334155;
  border-radius: 5px;
  outline: none;
}

input[type="range"].tempo-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  background: var(--primary);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 10px var(--primary);
}

.grid-pad {
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  position: relative;
  overflow: hidden;
}

.grid-pad::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: transparent;
}

.grid-pad.white-key {
  background: #f8fafc;
  color: #1e293b;
}

.grid-pad.black-key {
  background: #0f172a;
  color: #f1f5f9;
}

.grid-pad:hover {
  filter: brightness(1.1);
  transform: scale(1.02);
}

.grid-pad:active {
  background: var(--primary);
  color: white;
  box-shadow: 0 0 20px var(--primary);
}

.tab {
  flex: 1;
  text-align: center;
  padding: 0.75rem;
  font-size: 0.8rem;
  border-radius: 20px;
  background: transparent;
  border: none;
  color: var(--text-muted);
}

.tab.active {
  background: var(--bg-card);
  color: var(--primary);
  border: 1px solid var(--primary);
}

/* --- Desktop Layout Overrides --- */

@media (min-width: 768px) {
  main {
    display: grid;
    grid-template-columns: 150px 1fr 150px;
    grid-template-areas: "sidebar-l grid sidebar-r";
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    overflow: hidden;
  }

  .controls-section {
    grid-area: sidebar-l;
    display: flex;
    flex-direction: column;
    height: 100%;
    justify-content: center;
  }

  .grid-section {
    grid-area: grid;
    height: 100%;
    max-height: 600px;
  }

  .tempo-section {
    grid-area: sidebar-r;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: transparent;
  }

  .tempo-slider-container {
    flex-direction: column;
    height: 200px;
  }

  input[type="range"].tempo-slider {
    writing-mode: bt-lr; /* Vertical slider support in some browsers */
    appearance: slider-vertical;
    width: 6px;
    height: 100%;
  }

  footer {
    padding: 1rem;
  }

  .tabs-container {
    max-width: 600px;
    margin: 0 auto;
  }
}

/* --- Drum Pad State (Logic would handle label changes, CSS handles UI hide/disable) --- */
.drum-mode .tempo-section {
  opacity: 0.5;
  pointer-events: none;
}