:root {
  --color-bg:      #062f8a;
  --color-navy:    #0a3ca1;
  --color-accent:  #f4721e;
  --color-text:    #ffffff;
  --color-dim:     rgba(232,241,255,0.72);
  --color-border:  rgba(255,255,255,0.3);
  --color-grid-fine: rgba(214, 230, 255, 0.07);
  --color-grid-major: rgba(239, 246, 255, 0.18);
  --bottom-clearance: 36px;
  --right-panel-drop: 14px;
  --font-mono:     'IBM Plex Mono', 'OCR A Std', 'Courier New', monospace;
  --top-edge-space: 36px;
  --top-stack-gap: 24px;
  --brand-mark-name-gap: 22px;
  --brand-name-controls-gap: 24px;
  --row-gap-scale: 0.96;
}

@media (min-width: 981px) and (max-width: 1366px) {
  :root {
    --top-edge-space: 24px;
    --top-stack-gap: 18px;
    --brand-mark-name-gap: 16px;
    --brand-name-controls-gap: 18px;
    --row-gap-scale: 0.88;
  }
}

body, html {
  margin: 0;
  padding: 0;
  overflow: hidden;
  font-family: var(--font-mono);
  background: var(--color-bg);
  color: var(--color-text);
}

#app {
  position: relative;
  width: 100vw;
  height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  grid-template-rows: auto 1fr auto;
  column-gap: 20px;
  padding: 20px;
  padding-bottom: calc(20px + var(--bottom-clearance) + env(safe-area-inset-bottom, 0px));
  box-sizing: border-box;
}

@supports (height: 100dvh) {
  #app {
    height: 100dvh;
  }

  #definitions {
    height: calc(100dvh - 40px - var(--bottom-clearance) - var(--right-panel-drop));
  }
}

#background {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(circle at 18% 12%, rgba(178, 207, 255, 0.16), transparent 30%),
    radial-gradient(circle at 82% 86%, rgba(124, 169, 255, 0.12), transparent 34%),
    linear-gradient(165deg, #0a44b2 0%, #062f8a 48%, #05286f 100%);
  transition: background 3s ease;
  z-index: 0;
}

/* Fine + major blueprint mesh */
#background::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 50% 45%, transparent 42%, rgba(2, 13, 38, 0.25) 100%);
  pointer-events: none;
}

#background::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--color-grid-fine) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-grid-fine) 1px, transparent 1px),
    linear-gradient(var(--color-grid-major) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-grid-major) 1px, transparent 1px);
  background-size: 12px 12px, 12px 12px, 72px 72px, 72px 72px;
  background-position: 0 0, 0 0, -1px -1px, -1px -1px;
  pointer-events: none;
}

#particles {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

#app > *:not(#background):not(#particles) {
  position: relative;
  z-index: 2;
}

#top {
  position: relative;
  grid-column: 1;
  grid-row: 1;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: var(--top-stack-gap);
  padding-top: var(--top-edge-space);
  align-self: start;
}

#brand {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--brand-mark-name-gap);
  margin-bottom: var(--brand-name-controls-gap);
}

#brand-mark {
  display: block;
  height: 52px;
  color: var(--color-accent);
}

#brand-mark svg {
  display: block;
  height: 100%;
  width: auto;
  filter: drop-shadow(0 0 8px rgba(255, 106, 0, 0.2));
}

#brand-nameplate {
  --btn-frame-color: rgba(255, 255, 255, 0.42);
  display: inline-block;
  position: relative;
  border: none;
  padding: 5px 14px;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: clamp(12px, 1.2vw, 18px);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  line-height: 1;
  background-color: rgba(8, 38, 107, 0.18);
  background-image:
    linear-gradient(var(--btn-frame-color), var(--btn-frame-color)),
    linear-gradient(var(--btn-frame-color), var(--btn-frame-color)),
    repeating-linear-gradient(
      to bottom,
      var(--btn-frame-color) 0 3px,
      transparent 3px 11px
    ),
    repeating-linear-gradient(
      to bottom,
      var(--btn-frame-color) 0 3px,
      transparent 3px 11px
    );
  background-repeat: no-repeat;
  background-size: 100% 1px, 100% 1px, 1px 100%, 1px 100%;
  background-position: top left, bottom left, left top, right top;
  text-shadow: 0 0 4px rgba(189, 219, 255, 0.24);
}

.control-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.control-row.diagram-row {
  position: relative;
  justify-content: flex-start;
  flex-wrap: nowrap;
  gap: 0;
  padding-left: var(--row-offset, 0px);
  margin-top: calc(var(--row-gap-before, 0px) * var(--row-gap-scale));
  transform: translateX(var(--row-shift-x, 0px));
  width: auto;
  max-width: none;
  overflow-x: visible;
  overflow-y: visible;
}

@media (min-width: 981px) and (max-height: 860px) {
  :root {
    --top-edge-space: 14px;
    --top-stack-gap: 14px;
    --brand-mark-name-gap: 12px;
    --brand-name-controls-gap: 14px;
    --row-gap-scale: 0.78;
  }

  #brand-mark {
    height: 44px;
  }

  #bottom {
    transform: translateY(-24px);
  }

  #center {
    min-height: clamp(180px, 23vh, 260px);
  }

  #wireframe-sphere {
    width: clamp(220px, 38vw, 420px);
    height: clamp(220px, 38vw, 420px);
  }

  #time {
    font-size: clamp(32px, 5vw, 48px);
  }
}

.diagram-node {
  position: relative;
  margin-right: calc(var(--link-len, 0px) + 10px);
  flex: 0 0 auto;
}

.diagram-node::after {
  content: "";
  position: absolute;
  pointer-events: none;
  top: 50%;
  left: calc(100% + 6px);
  width: var(--link-len, 0px);
  transform: translateY(-50%);
  border-top: 0.5px dashed rgba(255, 255, 255, 0.78);
}

.diagram-node.no-link {
  margin-right: 0;
}

.diagram-node.no-link::after {
  display: none;
}

button {
  --btn-frame-color: rgba(255, 255, 255, 0.42);
  border: none;
  border-radius: 0;
  padding: 6px 12px;

  background-color: rgba(8, 38, 107, 0.18);
  background-image:
    linear-gradient(var(--btn-frame-color), var(--btn-frame-color)),
    linear-gradient(var(--btn-frame-color), var(--btn-frame-color)),
    repeating-linear-gradient(
      to bottom,
      var(--btn-frame-color) 0 3px,
      transparent 3px 11px
    ),
    repeating-linear-gradient(
      to bottom,
      var(--btn-frame-color) 0 3px,
      transparent 3px 11px
    );
  background-repeat: no-repeat;
  background-size: 100% 1px, 100% 1px, 1px 100%, 1px 100%;
  background-position: top left, bottom left, left top, right top;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;

  transition: all 0.2s ease;
  cursor: pointer;
}

button:hover {
  --btn-frame-color: rgba(244, 114, 30, 0.95);
  color: var(--color-accent);
  background-color: rgba(244, 114, 30, 0.1);
}

button.active {
  --btn-frame-color: rgba(244, 114, 30, 1);
  color: var(--color-accent);
  background-color: rgba(244, 114, 30, 0.14);
  box-shadow: 0 0 12px rgba(244, 114, 30, 0.25);
}

#center {
  grid-column: 1;
  grid-row: 2;
  position: relative;
  text-align: center;
  width: 100%;
  min-height: clamp(220px, 28vh, 320px);
  display: flex;
  align-items: center;
  justify-content: center;
  justify-self: center;
}

#wireframe-sphere {
  width: clamp(260px, 45vw, 540px);
  height: clamp(260px, 45vw, 540px);
  display: block;
  opacity: 0.92;
  filter: drop-shadow(0 0 12px rgba(170, 208, 255, 0.25));
  pointer-events: none;
}

#timer {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  margin-top: 0;
  width: max-content;
}

#phase {
  font-size: 13px;
  color: var(--color-dim);
  text-transform: uppercase;
  letter-spacing: 3px;
  font-family: var(--font-mono);
}

#time {
  font-size: clamp(36px, 6vw, 56px);
  font-weight: 700;
  letter-spacing: 4px;
  font-family: var(--font-mono);
  color: var(--color-text);
}

#bottom {
  grid-column: 1;
  grid-row: 3;
  text-align: center;
  align-self: end;
  margin-bottom: 0;
  transform: translateY(-46px);
}

#intensity-control {
  display: inline-block;
  margin-left: 20px;
  vertical-align: middle;
}

#intensity-control label {
  margin-right: 8px;
  font-size: 14px;
  opacity: 0.8;
}

#intensity-slider {
  vertical-align: middle;
  width: 150px;
}

#definitions {
  grid-column: 2;
  grid-row: 1 / span 3;
  position: relative;
  width: 300px;
  height: calc(100vh - 40px - var(--bottom-clearance) - var(--right-panel-drop));
  margin-top: var(--right-panel-drop);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-right: 4px;
  box-sizing: border-box;
}

.definition-panel {
  width: 100%;
  box-sizing: border-box;
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: 0;
  background: rgba(11, 22, 48, 0.7);
  color: var(--color-dim);
}

.definition-panel h3 {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  font-family: var(--font-mono);
}

.definition-panel p {
  margin: 6px 0;
  font-size: 11px;
  line-height: 1.5;
  font-family: var(--font-mono);
}

input[type=range] {
  appearance: none;
  height: 4px;
  background: rgba(255,255,255,0.2);
  border-radius: 5px;
}

input[type=range]::-webkit-slider-thumb {
  appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 0;
  background: var(--color-accent);
}

#textures {
  margin-top: 2px;
}

#modes {
  position: relative;
  align-items: center;
}

#binaural-anchor {
  position: relative;
  margin-right: 0;
}

#binaural-options {
  display: none;
  position: absolute;
  left: 50%;
  top: calc(100% + 10px);
  right: auto;
  margin-top: 0;
  padding-left: 0;
  transform: translateX(-50%);
  gap: 16px;
  flex-wrap: nowrap;
  justify-content: center;
  width: max-content;
  white-space: nowrap;
  z-index: 5;
}

#binaural-options.visible {
  display: flex;
}

#binaural-hint {
  display: none;
  position: absolute;
  left: 50%;
  top: calc(100% + 56px);
  right: auto;
  transform: translateX(-50%);
  width: max-content;
  max-width: none;
  white-space: nowrap;
  text-align: center;
  font-size: 12px;
  line-height: 1.35;
  color: rgba(255,255,255,0.72);
  z-index: 5;
}

#binaural-hint.visible {
  display: block;
}

#tones {
  align-items: flex-start;
  gap: 16px;
  transition: transform 0.2s ease;
}

#top.binaural-open #tones {
  transform: translate(calc(var(--row-shift-x, 0px)), 42px);
}

#tones label {
  font-size: 13px;
  opacity: 0.85;
  letter-spacing: 0.04em;
  margin-top: 4px;
}

#solfeggio-stack {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: clamp(220px, 22vw, 300px);
  align-items: flex-start;
}

#solfeggio-select {
  --btn-frame-color: rgba(255, 255, 255, 0.42);
  -webkit-appearance: none;
  appearance: none;
  border: none;
  border-radius: 0;
  padding: 6px 32px 6px 12px;
  min-width: 220px;
  width: clamp(220px, 22vw, 300px);
  background-color: rgba(8, 38, 107, 0.18);
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='rgba(255,255,255,0.5)' stroke-width='1.5' fill='none'/%3E%3C/svg%3E"),
    linear-gradient(var(--btn-frame-color), var(--btn-frame-color)),
    linear-gradient(var(--btn-frame-color), var(--btn-frame-color)),
    repeating-linear-gradient(
      to bottom,
      var(--btn-frame-color) 0 3px,
      transparent 3px 11px
    ),
    repeating-linear-gradient(
      to bottom,
      var(--btn-frame-color) 0 3px,
      transparent 3px 11px
    );
  background-repeat: no-repeat;
  background-size: 12px 8px, 100% 1px, 100% 1px, 1px 100%, 1px 100%;
  background-position: right 12px center, top left, bottom left, left top, right top;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: all 0.2s ease;
}

#solfeggio-select:hover {
  --btn-frame-color: rgba(244, 114, 30, 0.95);
  color: var(--color-accent);
  background-color: rgba(244, 114, 30, 0.1);
}

#solfeggio-select:focus {
  --btn-frame-color: rgba(244, 114, 30, 0.95);
  outline: none;
}

#solfeggio-select option {
  background: #0f1724;
  color: white;
}

#solfeggio-mix-control {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
}

#solfeggio-mix-control label {
  font-size: 12px;
  opacity: 0.8;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

#solfeggio-mix {
  width: 120px;
}

#solfeggio-hint {
  margin-top: 0;
  font-size: 12px;
  line-height: 1.35;
  min-height: 2.7em;
  text-align: left;
  max-width: 300px;
  color: rgba(255,255,255,0.72);
}

@media (max-width: 980px) {
  body, html {
    overflow-y: auto;
    overflow-x: hidden;
  }

  #app {
    min-height: 100svh;
    height: auto;
    display: block;
    padding:
      calc(env(safe-area-inset-top, 0px) + 16px)
      16px
      calc(env(safe-area-inset-bottom, 0px) + 24px);
    box-sizing: border-box;
  }

  #top,
  #center,
  #bottom,
  #definitions {
    position: relative;
    left: auto;
    right: auto;
    top: auto;
    bottom: auto;
    transform: none;
    width: 100%;
    max-width: 100%;
    margin: 0 auto;
  }

  #bottom {
    transform: none;
  }

  #top {
    padding-top: calc(env(safe-area-inset-top, 0px) + 20px);
    gap: max(10px, calc(var(--top-stack-gap) - 4px));
  }

  #brand {
    gap: max(8px, calc(var(--brand-mark-name-gap) - 2px));
    margin-bottom: max(8px, calc(var(--brand-name-controls-gap) - 2px));
  }

  #brand-mark {
    height: 44px;
  }

  #brand-nameplate {
    font-size: clamp(14px, 2.8vw, 20px);
    padding: 5px 12px;
  }

  #brand-right-link {
    display: none;
  }

  #top.binaural-open #tones {
    transform: none;
  }

  .control-row {
    gap: 8px;
  }

  .control-row.diagram-row {
    padding-left: min(var(--row-offset, 0px), 22px);
    transform: none;
    margin-top: 6px;
    max-width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
  }

  #binaural-options {
    position: static;
    right: auto;
    left: auto;
    top: auto;
    transform: none;
    gap: 8px;
    margin-top: 6px;
  }

  #binaural-hint {
    position: static;
    right: auto;
    top: auto;
    width: auto;
    max-width: none;
    white-space: normal;
    margin-top: 4px;
  }

  .diagram-node {
    margin-right: calc(var(--link-len, 0px) + 8px);
  }

  #tones {
    align-items: center;
    gap: 10px;
  }

  #tones label {
    margin-top: 0;
  }

  #solfeggio-stack {
    min-width: 0;
    width: min(100%, 420px);
    align-items: center;
  }

  #solfeggio-select {
    min-width: 0;
    width: min(100%, 260px);
  }

  #solfeggio-mix-control {
    width: min(100%, 260px);
    justify-content: center;
  }

  #solfeggio-mix {
    width: 100%;
  }

  #solfeggio-hint {
    min-height: 0;
    max-width: 420px;
    margin-top: 4px;
    text-align: center;
  }

  button {
    margin: 0;
    padding: 10px 14px;
    font-size: 15px;
  }

  #center {
    margin-top: 20px;
    margin-bottom: 20px;
    min-height: 220px;
    display: flex;
  }

  #timer {
    width: 100%;
  }

  #bottom {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
  }

  #intensity-control {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-left: 0;
    gap: 8px;
    width: min(100%, 320px);
  }

  #intensity-slider,
  input[type=range] {
    width: 100%;
    margin-top: 0;
  }

  #definitions {
    height: auto;
    overflow: visible;
    gap: 12px;
    padding-bottom: 24px;
  }

  .definition-panel {
    border-radius: 18px;
    padding: 14px 16px;
  }
}

@media (max-width: 600px) {
  #brand-nameplate {
    font-size: clamp(16px, 5.6vw, 22px);
    letter-spacing: 0.07em;
  }

  #center {
    min-height: 190px;
  }

  #timer {
    width: 100%;
  }

  #phase {
    font-size: 13px;
  }

  #time {
    font-size: clamp(28px, 10vw, 42px);
  }
}

#presets {
  min-width: 0;
  width: 100%;
  text-align: left;
}

#save-preset-btn {
  width: 100%;
}

#presetList {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-top: 2px;
}

#presetList .preset-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

#presetList .preset-load {
  flex: 1;
  text-align: left;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
}

#presetList .preset-detail {
  font-size: 10px;
  opacity: 0.55;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
  pointer-events: none;
}

#presetList .preset-delete {
  padding: 8px 10px;
}

#presetList .preset-empty {
  font-size: 12px;
  opacity: 0.7;
}

#feedback-details summary {
  cursor: pointer;
  font-size: 13px;
  letter-spacing: 0.03em;
  color: #ffffff;
  margin-bottom: 10px;
}

#feedback-details[open] summary {
  margin-bottom: 12px;
}

#feedback-form {
  display: flex;
  flex-direction: column;
}

#feedback-tally-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 100%;
  box-sizing: border-box;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 12px;
  padding: 10px 12px;
  background: rgba(255,255,255,0.1);
  color: #ffffff;
  text-decoration: none;
  font-size: 12px;
  letter-spacing: 0.02em;
  transition: background 0.18s ease, border-color 0.18s ease;
}

#feedback-tally-link:hover {
  background: rgba(255,255,255,0.16);
  border-color: rgba(255,255,255,0.35);
}

@media (max-width: 980px) {
  #presets {
    width: min(100%, 320px);
  }
}

@keyframes pulse {
  0% { transform: scale(1); opacity: 0.85; }
  50% { transform: scale(1.1); opacity: 1; }
  100% { transform: scale(1); opacity: 0.85; }
}