:root {
  --font-mono: 'Consolas', 'Courier New', monospace;
  --font-ui:   -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

.custom-wave-panel {
  --chassis:        #c8c9cc;
  --chassis-dark:   #a8a9ac;
  --chassis-light:  #dddee0;
  --chassis-deep:   #8e8f93;
  --panel-face:     #b4b5b9;
  --panel-top:      #cbccce;
  --btn-body:       #d4d6da;
  --btn-top:        #e8eaed;
  --btn-shadow:     #888a8e;
  --btn-press:      #bcbec2;
  --btn-text:       #1e2024;
  --btn-border:     #9a9ca0;
  --btn-blue:       #1a4a99;
  --btn-blue-top:   #2255bb;
  --btn-blue-sh:    #0e2f66;
  --btn-blue-tx:    #ddeeff;
  --btn-green:      #1a5a1a;
  --btn-green-top:  #226622;
  --btn-green-sh:   #0a2e0a;
  --btn-green-tx:   #aaffaa;
  --btn-amber:      #5a3a00;
  --btn-amber-top:  #7a5000;
  --btn-amber-sh:   #2a1a00;
  --btn-amber-tx:   #ffd880;
  --label-color:    #666870;
  --label-size:     9px;
  --radius-btn:     3px;
  --radius-panel:   4px;
  --transition:     0.1s ease;
}

/* ── POPUP WRAPPER ────────────────────────────────────── */
.custom-wave-panel {
  position: absolute;
  z-index: 4;
  top: 100px;
  left: 200px;
  display: none;
  width: 292px;
  transition: width 0.2s ease;
  background: linear-gradient(170deg, var(--panel-top) 0%, var(--panel-face) 100%);
  border: 1px solid var(--chassis-deep);
  border-radius: var(--radius-panel);
  box-shadow: inset 0 1px 0 #ffffff50, 0 6px 20px #00000050;
  font-family: var(--font-ui);
  font-size: 12px;
  color: var(--btn-text);
  user-select: none;
}

/* When advanced mode is active, widen the panel */
.custom-wave-panel.advanced-open {
  width: 570px;
}

/* ── HEADER (drag handle) ─────────────────────────────── */
.cw-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 10px;
  background: linear-gradient(180deg, var(--chassis-light) 0%, var(--chassis) 60%, var(--chassis-dark) 100%);
  border-bottom: 2px solid var(--chassis-dark);
  border-radius: var(--radius-panel) var(--radius-panel) 0 0;
  cursor: move;
  box-shadow: inset 0 1px 0 #ffffff60;
}

.cw-header-left { display: flex; align-items: center; gap: 10px; }

.cw-brand-icon  { font-size: 16px; color: var(--btn-blue); }
.cw-brand-name  {
  font-family: var(--font-ui); font-size: 13px; font-weight: 700;
  letter-spacing: 1px; color: #1e2024;
  text-shadow: 0 1px 0 #ffffff80;
}

.cw-header-right { display: flex; align-items: center; gap: 8px; }

/* Advanced button */
.cw-btn-mode {
  display: flex; align-items: center; gap: 5px;
  padding: 4px 8px;
  background: linear-gradient(180deg, var(--btn-blue-top) 0%, var(--btn-blue) 100%);
  border: 1px solid var(--btn-blue-sh);
  border-radius: var(--radius-btn);
  color: var(--btn-blue-tx);
  font-family: var(--font-ui); font-weight: 600; font-size: 9px; letter-spacing: 0.5px;
  cursor: pointer; transition: var(--transition); text-transform: uppercase;
  box-shadow: inset 0 1px 0 #ffffff30, 0 2px 3px #00000040, 0 1px 0 var(--btn-blue-sh);
}
.cw-btn-mode:hover { background: linear-gradient(180deg, #3377ee 0%, #2a66cc 100%); }
.cw-btn-mode:active, .cw-btn-mode.active {
  box-shadow: inset 0 2px 4px #00000050; transform: translateY(1px);
}

/* Close button */
[id^="customWavePanelClose"] {
  width: 20px; height: 20px;
  background: linear-gradient(180deg, #c44 0%, #a22 100%);
  border: 1px solid #811; border-radius: var(--radius-btn);
  color: #ffcccc; font-size: 12px; font-weight: 700;
  cursor: pointer; line-height: 1;
  box-shadow: inset 0 1px 0 #ffffff20, 0 1px 0 #611;
  transition: var(--transition);
}
[id^="customWavePanelClose"]:hover  { filter: brightness(1.2); }
[id^="customWavePanelClose"]:active { transform: translateY(1px); }

/* ── BODY ─────────────────────────────────────────────── */
.cw-body {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 8px 8px 9px;
}

/* Top area: equation always full-width */
.cw-eq-section {
  width: 100%;
}

/* Middle row: calculator buttons always stay left, advanced panel appears to the right */
.cw-main-grid {
  display: flex;
  flex-direction: row;
  gap: 7px;
  align-items: flex-start;
}

/* Left column: operators + functions + constants stacked */
.cw-calc-cols {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex-shrink: 0;
  width: 254px;
}

.cw-box {
  background: rgba(255,255,255,0.80);
  border: 1px solid rgba(138, 145, 156, 0.28);
  border-radius: var(--radius-btn);
  padding: 7px;
  box-shadow: inset 0 1px 1px rgba(255,255,255,0.68);
}

/* Advanced panel sits to the right of the calc buttons */
.cw-advanced-panel-container {
  flex: 1;
  min-width: 0;
  align-self: stretch;
}

.cw-action-section { width: 100%; }

/* ── SECTION LABELS ───────────────────────────────────── */
.cw-section-label {
  font-family: var(--font-ui); font-size: var(--label-size);
  font-weight: 700; letter-spacing: 1px;
  color: var(--label-color); margin-bottom: 5px;
  text-transform: uppercase; text-shadow: 0 1px 0 #ffffff70;
}

.cw-section { background: transparent; border: none; padding: 0; }
.cw-section + .cw-section {
  padding-top: 7px;
  border-top: 1px solid var(--chassis-dark);
}
.cw-eq-section { border-top: none !important; padding-top: 0 !important; }

/* ── EQUATION INPUT ───────────────────────────────────── */
.cw-equation-row { display: flex; align-items: flex-start; gap: 6px; }

.cw-eq-prefix {
  font-family: var(--font-mono); font-size: 12px;
  color: var(--label-color); padding-top: 7px; white-space: nowrap;
}

.cw-equation-input {
  flex: 1; min-height: 38px; resize: vertical;
  background: #f5f6f0; border: 1px solid #aab0a8; border-radius: 3px;
  color: #1a2a1a; font-family: var(--font-mono); font-size: 12px;
  padding: 6px 8px; outline: none; line-height: 1.5;
  caret-color: #226622;
  box-shadow: inset 0 1px 3px #00000018;
  transition: var(--transition);
}
.cw-equation-input:focus {
  border-color: #6a9a6a;
  box-shadow: inset 0 1px 3px #00000018, 0 0 0 2px #6a9a6a44;
}
.cw-equation-input::placeholder { color: #aab8a8; }

.cw-eq-error {
  margin-top: 4px; font-family: var(--font-mono); font-size: 10px;
  color: #cc2222; padding: 3px 6px;
  background: #fff0f0; border-left: 2px solid #cc2222; border-radius: 2px;
}
.hidden { display: none !important; }

/* ── BUTTON GRIDS ─────────────────────────────────────── */
.cw-btn-grid { display: grid; gap: 3px; }
.cw-operators-grid  { grid-template-columns: repeat(4, 1fr); }
.cw-functions-grid  { grid-template-columns: repeat(3, 1fr); }
.cw-constants-grid  { grid-template-columns: repeat(2, 1fr); }
.cw-variable-grid   { grid-template-columns: repeat(1, 1fr); }

.cw-calc-btn {
  padding: 5px 2px;
  border-radius: var(--radius-btn);
  border: 1px solid var(--btn-border);
  font-family: var(--font-mono); font-size: 10px; font-weight: 700;
  cursor: pointer; transition: var(--transition);
  user-select: none;
  background: linear-gradient(180deg, var(--btn-top) 0%, var(--btn-body) 60%, var(--btn-press) 100%);
  color: var(--btn-text);
  box-shadow: inset 0 1px 0 #ffffff80, 0 2px 0 var(--btn-shadow), 0 3px 4px #00000030;
  text-shadow: 0 1px 0 #ffffff60;
}
.cw-calc-btn:hover  { background: linear-gradient(180deg, #f0f2f5 0%, #dcdee2 60%, #c8cacd 100%); }
.cw-calc-btn:active { transform: translateY(1px); box-shadow: inset 0 1px 3px #00000025, 0 1px 0 var(--btn-shadow); }

.cw-op-btn    { border-top: 2px solid #cc8800; }
.cw-fn-btn    { border-top: 2px solid #1a7799; font-size: 9.5px; }
.cw-const-btn { border-top: 2px solid #6633aa; font-size: 12px; }
.cw-var-btn   { border-top: 2px solid #227744; font-size: 12px; }

/* ── ACTION BUTTONS ───────────────────────────────────── */
.cw-action-section {
  display: flex; flex-direction: column; gap: 5px;
  border: none !important; padding-top: 7px !important;
}

.cw-action-btn {
  width: 100%; padding: 8px;
  border-radius: var(--radius-btn);
  font-family: var(--font-ui); font-size: 11px; font-weight: 700; letter-spacing: 1px;
  cursor: pointer; display: flex; align-items: center; justify-content: center; gap: 6px;
  transition: var(--transition); text-transform: uppercase;
}
.cw-action-icon { font-size: 12px; }

.cw-plot-btn {
  background: linear-gradient(180deg, var(--btn-green-top) 0%, var(--btn-green) 100%);
  border: 1px solid var(--btn-green-sh); color: var(--btn-green-tx);
  box-shadow: inset 0 1px 0 #ffffff20, 0 2px 0 var(--btn-green-sh), 0 3px 4px #00000040;
  text-shadow: 0 1px 1px #00000088;
}
.cw-plot-btn:hover  { filter: brightness(1.15); }
.cw-plot-btn:active { transform: translateY(1px); box-shadow: inset 0 2px 4px #00000060, 0 1px 0 var(--btn-green-sh); }

.cw-csv-btn {
  background: linear-gradient(180deg, var(--btn-amber-top) 0%, var(--btn-amber) 100%);
  border: 1px solid var(--btn-amber-sh); color: var(--btn-amber-tx);
  box-shadow: inset 0 1px 0 #ffffff20, 0 2px 0 var(--btn-amber-sh), 0 3px 4px #00000040;
  text-shadow: 0 1px 1px #00000088;
}
.cw-csv-btn:hover  { filter: brightness(1.15); }
.cw-csv-btn:active { transform: translateY(1px); box-shadow: inset 0 2px 4px #00000060, 0 1px 0 var(--btn-amber-sh); }

.cw-help-btn {
  background: linear-gradient(180deg, #3a3a4a 0%, #252530 100%);
  border: 1px solid #111; color: #aab8cc;
  box-shadow: inset 0 1px 0 #ffffff18, 0 2px 0 #111, 0 3px 4px #00000040;
  text-shadow: 0 1px 1px #00000088;
}
.cw-help-btn:hover  { filter: brightness(1.2); }
.cw-help-btn:active { transform: translateY(1px); }

/* ── STATUS MESSAGE ───────────────────────────────────── */
.customWaveMessage {
  font-family: var(--font-mono); font-size: 10px;
  color: #a8d8a8; min-height: 16px; padding: 0 2px;
}

/* ── ADVANCED PANEL ───────────────────────────────────── */
.cw-advanced-panel {
  border: 1px solid var(--chassis-deep);
  border-radius: var(--radius-panel);
  padding: 8px 9px;
  background: rgba(0,0,0,0.04);
  box-shadow: inset 0 1px 0 #ffffff40;
  animation: cwSlideIn 0.18s ease;
  min-width: 250px;
}
@keyframes cwSlideIn {
  from { opacity: 0; transform: translateX(-6px); }
  to   { opacity: 1; transform: translateX(0); }
}

.cw-adv-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 8px; padding-bottom: 6px;
  border-bottom: 1px solid var(--chassis-dark);
}
.cw-adv-hint {
  font-family: var(--font-mono); font-size: 8px;
  color: var(--label-color); letter-spacing: 1px;
}

.cw-wave-btns { display: flex; gap: 3px; flex-wrap: wrap; margin-bottom: 8px; }

.cw-wave-type-btn {
  padding: 3px 8px;
  background: linear-gradient(180deg, var(--btn-blue-top) 0%, var(--btn-blue) 100%);
  border: 1px solid var(--btn-blue-sh); border-radius: var(--radius-btn);
  color: var(--btn-blue-tx);
  font-family: var(--font-ui); font-weight: 600; font-size: 9px; letter-spacing: 0.5px;
  cursor: pointer; transition: var(--transition); text-transform: uppercase;
  box-shadow: inset 0 1px 0 #ffffff28, 0 2px 0 var(--btn-blue-sh), 0 3px 4px #00000030;
  text-shadow: 0 1px 1px #00000088;
}
.cw-wave-type-btn:hover  { filter: brightness(1.15); }
.cw-wave-type-btn:active { transform: translateY(1px); }
.cw-wave-type-btn.active {
  background: linear-gradient(180deg, #aaccff 0%, #88aaee 100%);
  color: #001133; box-shadow: inset 0 2px 4px #00000040; text-shadow: none;
}

.cw-params-grid {
  display: grid; grid-template-columns: 1fr; gap: 6px;
}

.cw-param-block {
  background: rgba(0,0,0,0.07);
  border: 1px solid var(--chassis-dark);
  border-radius: var(--radius-btn);
  padding: 5px 6px;
  box-shadow: inset 0 1px 2px #00000015;
}

.cw-param-label {
  display: block; font-family: var(--font-ui); font-size: 8px;
  font-weight: 700; letter-spacing: 0.5px; color: var(--label-color);
  margin-bottom: 5px; text-shadow: 0 1px 0 #ffffff70; text-transform: uppercase;
}
.cw-param-unit { color: #8899aa; font-weight: 400; }

.cw-param-input-row { display: flex; align-items: center; gap: 6px; }

.cw-param-slider {
  flex: 1; -webkit-appearance: none; appearance: none;
  height: 4px;
  background: linear-gradient(90deg, #888 0%, #aaa 100%);
  border-radius: 2px; outline: none; cursor: pointer;
  border: 1px solid #777; box-shadow: inset 0 1px 2px #00000040;
}
.cw-param-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 13px; height: 13px; border-radius: 50%;
  background: linear-gradient(135deg, #eef 0%, #bbc 100%);
  border: 1px solid #666;
  box-shadow: 0 1px 3px #00000050, inset 0 1px 0 #ffffff80;
  cursor: pointer;
}
.cw-param-slider::-moz-range-thumb {
  width: 13px; height: 13px; border-radius: 50%;
  background: linear-gradient(135deg, #eef 0%, #bbc 100%);
  border: 1px solid #666; cursor: pointer;
}

.cw-param-num {
  width: 58px; background: #f5f6f0; border: 1px solid #aab0a8;
  border-radius: 2px; color: #1a2a1a;
  font-family: var(--font-mono); font-size: 11px;
  padding: 3px 5px; outline: none; text-align: right;
  transition: var(--transition); box-shadow: inset 0 1px 2px #00000015;
}
.cw-param-num:focus {
  border-color: #6a9a6a; box-shadow: inset 0 1px 2px #00000015, 0 0 0 2px #6a9a6a44;
}

/* ── HELP MODAL ───────────────────────────────────────── */
.cw-help-modal {
  position: fixed; inset: 0; z-index: 9999;
  display: flex; align-items: center; justify-content: center;
  background: rgba(0,0,0,0.55); backdrop-filter: blur(2px);
}

.cw-help-modal-inner {
  width: 460px; max-width: 95vw; max-height: 85vh;
  background: linear-gradient(170deg, var(--chassis-light, #dddee0) 0%, var(--chassis, #c8c9cc) 100%);
  border: 1px solid #8e8f93; border-radius: 6px;
  box-shadow: 0 8px 32px #00000060, inset 0 1px 0 #ffffff50;
  display: flex; flex-direction: column; overflow: hidden;
  font-family: var(--font-ui);
}

.cw-help-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 9px 14px;
  background: linear-gradient(180deg, #dddee0 0%, #c8c9cc 100%);
  border-bottom: 1px solid #a8a9ac;
}
.cw-help-title {
  font-size: 11px; font-weight: 700; letter-spacing: 1px; color: #666870;
  text-shadow: 0 1px 0 #ffffff70;
}
.cw-help-close {
  background: linear-gradient(180deg, #c44 0%, #a22 100%);
  border: 1px solid #811; border-radius: 3px;
  color: #ffcccc; font-size: 11px; font-weight: 700;
  width: 22px; height: 22px; cursor: pointer;
  box-shadow: inset 0 1px 0 #ffffff20, 0 1px 0 #611;
  transition: 0.1s ease;
}
.cw-help-close:hover  { filter: brightness(1.2); }
.cw-help-close:active { transform: translateY(1px); }

.cw-help-body {
  padding: 12px 14px; overflow-y: auto;
  display: flex; flex-direction: column; gap: 3px;
}

.cw-help-section-title {
  font-size: 9px; font-weight: 700; letter-spacing: 1px; color: #666870;
  text-shadow: 0 1px 0 #ffffff70; margin-top: 9px; margin-bottom: 2px;
  padding-bottom: 3px; border-bottom: 1px solid #a8a9ac; text-transform: uppercase;
}
.cw-help-section-title:first-child { margin-top: 0; }

.cw-help-row {
  display: flex; align-items: baseline; gap: 8px;
  font-family: var(--font-mono); font-size: 11px; padding: 2px 0;
}
.cw-help-row code { color: #1a3a8a; font-size: 11px; white-space: nowrap; min-width: 150px; }
.cw-help-row span { color: #666870; font-size: 10px; }

.cw-help-example {
  font-family: var(--font-mono); font-size: 11px;
  color: #1a4a1a; background: #eef4ee;
  border: 1px solid #aac8aa; border-radius: 3px;
  padding: 5px 10px; cursor: pointer;
  transition: 0.1s ease; box-shadow: inset 0 1px 2px #00000010;
}
.cw-help-example:hover { background: #d4ecd4; border-color: #6a9a6a; color: #0a2a0a; }
.cw-help-example::before { content: '▶  '; color: #6a9a6a; font-size: 9px; }
.cw-help-tag {
  font-family: sans-serif; font-size: 9px; font-weight: 600;
  color: #4a6a8a; background: #dde8f4; border: 1px solid #aabbd0;
  border-radius: 3px; padding: 1px 5px; margin-left: 6px;
  vertical-align: middle; letter-spacing: 0.5px; text-transform: uppercase;
}