:root {
  --bg: #f7f3ea;
  --panel: #fffaf1;
  --panel-strong: #fff5df;
  --ink: #24211c;
  --muted: #71695f;
  --line: #ded3c0;
  --green: #2f6f58;
  --green-dark: #1f5140;
  --amber: #d18b22;
  --red: #b75c4a;
  --blue: #2f5f8f;
  --shadow: 0 18px 45px rgba(54, 42, 26, 0.12);
  --radius: 8px;
  --font: "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(36, 33, 28, 0.035) 1px, transparent 1px),
    linear-gradient(180deg, rgba(36, 33, 28, 0.025) 1px, transparent 1px),
    var(--bg);
  background-size: 32px 32px;
  font-family: var(--font);
}

button,
input,
select {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

.app-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 22px;
  padding: 24px;
  border-right: 1px solid var(--line);
  background: rgba(255, 250, 241, 0.9);
  position: sticky;
  top: 0;
  height: 100vh;
}

.brand {
  display: flex;
  gap: 14px;
  align-items: center;
}

.brand h1,
.section-head h2,
.panel-heading h3 {
  margin: 0;
  letter-spacing: 0;
}

.brand h1 {
  font-size: 19px;
  line-height: 1.25;
}

.brand p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.brand-mark {
  width: 46px;
  height: 70px;
  border: 2px solid var(--ink);
  border-radius: 22px 22px 8px 8px;
  background: linear-gradient(#b56f32, #6d3d22);
  position: relative;
  box-shadow: inset 0 0 0 5px rgba(255, 255, 255, 0.14);
}

.brand-mark::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 20px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 2px solid #231b13;
  background: #3a2418;
}

.brand-mark span {
  position: absolute;
  top: 3px;
  bottom: 3px;
  width: 1px;
  background: rgba(255, 247, 226, 0.75);
}

.brand-mark span:nth-child(1) { left: 10px; }
.brand-mark span:nth-child(2) { left: 15px; }
.brand-mark span:nth-child(3) { left: 20px; }
.brand-mark span:nth-child(4) { left: 25px; }
.brand-mark span:nth-child(5) { left: 30px; }
.brand-mark span:nth-child(6) { left: 35px; }

.tabs {
  display: grid;
  gap: 8px;
}

.tab-button {
  min-height: 48px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 14px;
  border-radius: var(--radius);
  background: transparent;
  color: var(--muted);
  text-align: left;
}

.tab-button span {
  width: 22px;
  text-align: center;
  font-size: 18px;
}

.tab-button.active {
  color: #fff;
  background: var(--green);
}

.mini-stats {
  margin-top: auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.mini-stats div,
.stat-block {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.mini-stats strong,
.stat-block strong {
  display: block;
  font-size: 27px;
  line-height: 1;
}

.mini-stats span,
.stat-block span {
  display: block;
  margin-top: 7px;
  color: var(--muted);
  font-size: 12px;
}

main {
  min-width: 0;
  padding: max(30px, env(safe-area-inset-top)) max(30px, env(safe-area-inset-right)) max(30px, env(safe-area-inset-bottom)) max(30px, env(safe-area-inset-left));
}

.view {
  display: none;
}

.view.active {
  display: block;
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  margin-bottom: 18px;
}

.section-head.tight {
  margin-bottom: 12px;
}

.section-head h2 {
  font-size: clamp(26px, 3vw, 42px);
  line-height: 1.05;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--green);
  font-weight: 700;
  font-size: 12px;
  text-transform: uppercase;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(3, 52px);
  min-height: 42px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.segment {
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
}

.segment.active {
  background: var(--ink);
  color: #fff;
}

.today-layout,
.session-grid,
.records-layout {
  display: grid;
  gap: 18px;
}

.today-layout {
  grid-template-columns: minmax(0, 1.5fr) minmax(280px, 0.8fr);
}

.practice-panel,
.tool-panel,
.timer-panel,
.task-detail-panel,
.switch-trainer,
.chart-panel,
.history-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 250, 241, 0.94);
  box-shadow: var(--shadow);
}

.practice-panel {
  padding: 20px;
}

.side-stack {
  display: grid;
  gap: 18px;
  align-content: start;
}

.focus-meter {
  display: grid;
  gap: 12px;
  margin-bottom: 18px;
}

.focus-meter > div:first-child {
  display: flex;
  justify-content: space-between;
  gap: 10px;
}

.focus-meter span,
.next-task span,
.switch-stage span {
  color: var(--muted);
  font-size: 13px;
}

.progress-track {
  height: 10px;
  border-radius: 999px;
  background: #e7dcc8;
  overflow: hidden;
}

.progress-track div {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--green), var(--amber));
  transition: width 0.25s ease;
}

.task-list {
  display: grid;
  gap: 10px;
}

.task-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  min-height: 70px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fffdf8;
}

.task-index {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  color: #fff;
  background: var(--blue);
  font-weight: 800;
}

.task-item.done .task-index {
  background: var(--green);
}

.task-item h3 {
  margin: 0 0 4px;
  font-size: 16px;
}

.task-item p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.task-steps {
  display: grid;
  gap: 8px;
  margin: 12px 0 0;
  padding-left: 22px;
  color: var(--ink);
  font-size: 14px;
  line-height: 1.65;
}

.task-steps[hidden] {
  display: none;
}

.task-steps li::marker {
  color: var(--green-dark);
  font-weight: 800;
}

.task-minutes {
  color: var(--green-dark);
  font-weight: 800;
  white-space: nowrap;
}

.action-row,
.session-actions,
.tool-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.action-row {
  margin-top: 18px;
}

.primary-action,
.secondary-action,
.ghost-action,
.text-button,
.icon-button {
  min-height: 42px;
  border-radius: var(--radius);
  font-weight: 700;
}

.primary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-width: 170px;
  padding: 0 16px;
  color: #fff;
  background: var(--green);
}

.primary-action:hover,
.secondary-action:hover,
.tab-button:hover,
.ghost-action:hover,
.text-button:hover,
.icon-button:hover {
  filter: brightness(0.96);
}

.secondary-action {
  min-width: 96px;
  padding: 0 14px;
  color: #fff;
  background: var(--ink);
}

.ghost-action {
  min-width: 96px;
  padding: 0 14px;
  color: var(--ink);
  border: 1px solid var(--line);
  background: var(--panel);
}

.text-button {
  padding: 0 10px;
  color: var(--green);
  background: transparent;
}

.icon-button {
  display: grid;
  place-items: center;
  width: 42px;
  color: #fff;
  background: var(--blue);
  font-size: 24px;
  line-height: 1;
}

.tool-panel,
.task-detail-panel,
.switch-trainer,
.chart-panel,
.history-panel {
  padding: 18px;
}

.panel-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.panel-heading h3 {
  font-size: 17px;
}

.switch-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.panel-heading span,
.task-chip {
  color: var(--muted);
  font-size: 13px;
}

.bpm-readout {
  display: grid;
  grid-template-columns: 42px 1fr 42px;
  align-items: center;
  gap: 10px;
}

.bpm-readout strong {
  text-align: center;
  font-size: 46px;
  line-height: 1;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--green);
}

select,
input[type="number"],
input[type="search"] {
  min-height: 42px;
  width: 100%;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  background: #fffdf8;
}

.tool-row {
  margin-top: 12px;
}

.tool-row select {
  flex: 1;
  min-width: 100px;
}

.chord-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.chord-pill {
  min-height: 44px;
  border-radius: var(--radius);
  color: #fff;
  background: var(--red);
  font-weight: 800;
}

.session-grid {
  grid-template-columns: minmax(300px, 0.9fr) minmax(0, 1.1fr);
  align-items: stretch;
  margin-bottom: 18px;
}

.timer-panel {
  display: grid;
  gap: 18px;
  place-items: center;
  padding: 24px;
}

.timer-ring {
  position: relative;
  width: min(330px, 80vw);
  aspect-ratio: 1;
  display: grid;
  place-items: center;
}

.timer-ring svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.timer-ring circle {
  fill: none;
  stroke-width: 12;
  stroke-linecap: round;
}

.timer-ring circle:first-child {
  stroke: #e4d6bf;
}

#timerCircle {
  stroke: var(--green);
  stroke-dasharray: 440;
  stroke-dashoffset: 440;
  transition: stroke-dashoffset 0.25s ease;
}

.timer-ring div {
  position: relative;
  display: grid;
  place-items: center;
  gap: 8px;
}

.timer-ring strong {
  font-size: clamp(42px, 7vw, 72px);
  line-height: 1;
}

.timer-ring span {
  color: var(--muted);
}

.task-detail-panel {
  min-height: 100%;
}

.task-detail-panel p {
  margin: 0 0 18px;
  color: var(--muted);
  line-height: 1.6;
}

.large-chord-area {
  min-height: 248px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 12px;
  place-items: center;
}

.scale-practice {
  display: grid;
  grid-column: 1 / -1;
  gap: 14px;
  width: 100%;
}

.scale-header {
  display: grid;
  grid-template-columns: minmax(140px, 0.7fr) minmax(0, 1.3fr);
  gap: 12px;
  align-items: center;
}

.scale-header > div:first-child {
  display: grid;
  gap: 4px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fffdf8;
}

.scale-header span,
.scale-sequence > span,
.scale-note small {
  color: var(--muted);
  font-size: 12px;
}

.scale-header strong {
  font-size: 18px;
}

.scale-path,
.scale-sequence div {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.scale-path span,
.scale-sequence code {
  display: inline-grid;
  min-height: 34px;
  place-items: center;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fffdf8;
  color: var(--ink);
  font-family: inherit;
  font-weight: 800;
}

.scale-note-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.scale-note {
  display: grid;
  gap: 4px;
  min-height: 88px;
  align-content: center;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fffdf8;
}

.scale-note strong {
  color: var(--green-dark);
  font-size: 24px;
  line-height: 1;
}

.scale-note span {
  color: var(--ink);
  font-size: 13px;
}

.scale-sequence {
  display: grid;
  gap: 8px;
  padding: 14px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.46);
}

.next-task {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.switch-controls {
  display: grid;
  grid-template-columns: 1.4fr 0.7fr 0.7fr;
  gap: 12px;
  margin-bottom: 16px;
}

.switch-controls label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
}

.switch-stage {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.switch-stage div {
  min-height: 102px;
  display: grid;
  align-content: center;
  gap: 6px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fffdf8;
}

.switch-stage strong {
  font-size: clamp(28px, 5vw, 52px);
  line-height: 1;
}

.rhythm-patterns {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.rhythm-patterns .panel-heading {
  margin-bottom: 0;
}

.demo-bpm-control {
  display: grid;
  grid-template-columns: auto minmax(150px, 220px) minmax(160px, 1fr);
  gap: 12px;
  align-items: center;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 248, 0.78);
}

.demo-bpm-control > span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.demo-bpm-stepper {
  display: grid;
  grid-template-columns: 42px minmax(54px, 1fr) 42px;
  gap: 8px;
  align-items: center;
}

.demo-bpm-stepper strong {
  text-align: center;
  font-size: 24px;
}

.pattern-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.pattern-card {
  display: grid;
  gap: 5px;
  min-height: 78px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fffdf8;
  color: var(--ink);
  text-align: left;
}

.pattern-card.active {
  border-color: var(--green);
  box-shadow: inset 0 0 0 2px rgba(47, 111, 88, 0.16);
}

.pattern-card strong {
  font-size: 15px;
}

.pattern-card span {
  color: var(--muted);
  font-size: 12px;
}

.search-box {
  width: min(280px, 100%);
}

.chord-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 16px;
}

.chord-card {
  display: grid;
  gap: 14px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 250, 241, 0.95);
  box-shadow: var(--shadow);
}

.chord-card h3 {
  margin: 0;
  font-size: 24px;
}

.chord-card p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.fretboard {
  width: 100%;
  max-width: 220px;
  justify-self: center;
}

.records-layout {
  grid-template-columns: 0.8fr 1.2fr;
  align-items: start;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  grid-column: 1 / -1;
}

.chart-panel,
.history-panel {
  min-height: 290px;
}

.bar-chart {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  align-items: end;
  gap: 10px;
  min-height: 210px;
}

.bar {
  display: grid;
  gap: 8px;
  align-items: end;
  min-width: 0;
}

.bar-fill {
  min-height: 4px;
  border-radius: 6px 6px 0 0;
  background: var(--blue);
}

.bar label {
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

.history-list {
  display: grid;
  gap: 10px;
  max-height: 360px;
  overflow: auto;
}

.history-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fffdf8;
}

.history-item strong,
.history-item span {
  min-width: 0;
}

.history-item span {
  color: var(--muted);
  font-size: 13px;
}

.empty-state {
  padding: 20px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  color: var(--muted);
  background: rgba(255, 255, 255, 0.42);
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    height: auto;
    padding: max(16px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right)) 16px max(16px, env(safe-area-inset-left));
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .tabs {
    grid-template-columns: repeat(4, 1fr);
  }

  .tab-button {
    justify-content: center;
    min-height: 46px;
    padding: 0 8px;
  }

  .mini-stats {
    display: none;
  }

  main {
    padding: 18px max(15px, env(safe-area-inset-right)) max(18px, env(safe-area-inset-bottom)) max(15px, env(safe-area-inset-left));
  }

  .today-layout,
  .session-grid,
  .records-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .brand h1 {
    font-size: 17px;
  }

  .section-head {
    align-items: flex-start;
    flex-direction: column;
  }

  .segmented {
    width: 100%;
    grid-template-columns: repeat(3, 1fr);
  }

  .task-item {
    grid-template-columns: 36px minmax(0, 1fr);
  }

  .task-minutes {
    grid-column: 2;
  }

  .switch-controls,
  .switch-stage,
  .stats-grid,
  .demo-bpm-control,
  .pattern-grid {
    grid-template-columns: 1fr;
  }

  .scale-header,
  .scale-note-grid {
    grid-template-columns: 1fr 1fr;
  }

  .session-actions,
  .action-row {
    width: 100%;
  }

  .primary-action,
  .secondary-action,
  .ghost-action {
    flex: 1;
    min-width: 0;
  }

  .tabs {
    gap: 6px;
  }

  .tab-button {
    font-size: 13px;
    gap: 4px;
  }
}

@media (max-width: 430px) {
  .scale-header,
  .scale-note-grid {
    grid-template-columns: 1fr;
  }
}