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

:root {
  --bg: #101214;
  --panel: #17191c;
  --panel2: #1e2126;
  --border: #2b3036;
  --text: #d6d9dd;
  --dim: #8b929a;
  --accent: #e8b81a;
  --play: #3fd0ff;
}

html, body { height: 100%; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Helvetica Neue", Arial, sans-serif;
  font-size: 14px;
  user-select: none;
  -webkit-user-select: none;
}

.app { display: flex; flex-direction: column; height: 100vh; }

/* ---------------- header ---------------- */

header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 14px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

h1 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-right: 6px;
}

.field { display: flex; flex-direction: column; gap: 2px; }
.field > span {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--dim);
}

input, select, button {
  font: inherit;
  color: var(--text);
  background: var(--panel2);
  border: 1px solid var(--border);
  border-radius: 0;
  padding: 4px 8px;
}

input[type="number"] { width: 70px; }
select { cursor: pointer; }

input[type="range"] { width: 110px; padding: 0; accent-color: var(--accent); }
.slider { display: flex; align-items: center; gap: 6px; }
.slider-val { width: 3ch; text-align: right; font-variant-numeric: tabular-nums; }
.slider-end {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--dim);
}

.btn-group { display: flex; }
.btn-group button { padding: 4px 9px; border-left-width: 0; }
.btn-group button:first-child { border-left-width: 1px; }
.btn-group button.sel {
  background: var(--accent);
  color: #14110a;
  border-color: var(--accent);
}

button { cursor: pointer; }
button:hover { border-color: var(--dim); }

button.play {
  min-width: 90px;
  padding: 8px 14px;
  font-weight: 700;
  background: var(--accent);
  color: #14110a;
  border-color: var(--accent);
}
button.play.active { background: var(--play); border-color: var(--play); }

button.export {
  margin-left: auto;
  padding: 8px 14px;
  font-weight: 700;
  border-color: var(--accent);
  color: var(--accent);
  background: transparent;
}
button.export:hover { background: var(--accent); color: #14110a; }

button.help {
  width: 34px;
  height: 34px;
  padding: 0;
  font-weight: 700;
  color: var(--dim);
}
button.help:hover { color: var(--text); }

/* ---------------- midi import ---------------- */

.drop-overlay {
  position: fixed;
  inset: 0;
  background: rgba(16, 18, 20, 0.85);
  border: 3px dashed var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  letter-spacing: 1px;
  color: var(--accent);
  z-index: 20;
  pointer-events: none;
}

.import-msg {
  position: fixed;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--panel);
  border: 1px solid var(--accent);
  padding: 8px 16px;
  z-index: 20;
}

/* ---------------- credits modal ---------------- */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
}

.modal {
  position: relative;
  width: 480px;
  max-width: calc(100vw - 40px);
  max-height: calc(100vh - 80px);
  overflow-y: auto;
  background: var(--panel);
  border: 1px solid var(--border);
  padding: 24px;
  user-select: text;
  -webkit-user-select: text;
}

.modal h2 {
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--accent);
  margin-bottom: 14px;
}

.modal h3 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--dim);
  margin: 14px 0 4px;
}

.modal p { line-height: 1.5; }
.modal a { color: var(--accent); }

.modal-close {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 28px;
  height: 28px;
  padding: 0;
  font-size: 16px;
  line-height: 1;
  color: var(--dim);
  background: transparent;
  border: none;
}
.modal-close:hover { color: var(--text); }

/* ---------------- layout ---------------- */

.main { display: flex; flex: 1; min-height: 0; }

/* ---------------- sidebar ---------------- */

aside {
  width: 220px;
  overflow-y: auto;
  background: var(--panel);
  border-right: 1px solid var(--border);
  padding: 8px;
  flex-shrink: 0;
}

.section-title {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--dim);
  padding: 10px 4px 4px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 6px;
  cursor: pointer;
}
.section-title:hover { color: var(--text); }

.beat {
  padding: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  margin-bottom: 4px;
}
.beat:hover { background: var(--panel2); border-color: var(--border); }
.beat.selected { border-color: var(--accent); background: var(--panel2); }
.beat-name { font-size: 12px; margin-bottom: 4px; }
.beat.selected .beat-name { color: var(--accent); }

.preview {
  display: block;
  image-rendering: pixelated;
  height: 32px;
  width: auto;
  max-width: 100%;
  border: 1px solid var(--border);
}

/* ---------------- grid board ---------------- */

.board {
  flex: 1;
  overflow: auto;
  padding: 18px;
}

.lane { display: flex; margin-bottom: 2px; }

.lane-label {
  width: 92px;
  flex-shrink: 0;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--dim);
  display: flex;
  align-items: center;
}

.cell {
  position: relative;
  width: 30px;
  height: 26px;
  flex-shrink: 0;
  background: var(--panel2);
  border: 1px solid var(--border);
  border-left-width: 0;
  cursor: pointer;
}
.lane .cell:first-of-type { border-left-width: 1px; }
.cell.beat-start { border-left-width: 2px; border-left-color: #3d444d; }
.cell.bar-start { border-left-width: 3px; border-left-color: #4d565f; }
.cell:hover { background: #2a2f36; }
.cell.on { background: #26241c; }
.cell.on:hover { background: #34301f; }

/* velocity bar: fills the tile bottom-up */
.hit-fill {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  background: var(--accent);
  pointer-events: none;
  z-index: 2;
}

/* staggered position: translucent copy of the bar where the hit really lands */
.hit-shadow {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  background: var(--accent);
  opacity: 0.35;
  pointer-events: none;
  z-index: 1;
}

.cell.playhead::after {
  content: '';
  position: absolute;
  inset: -1px;
  background: rgba(63, 208, 255, 0.18);
  box-shadow: inset 0 -3px 0 var(--play);
  pointer-events: none;
  z-index: 3;
}