:root {
  --ink: #17211f;
  --muted: #60706c;
  --line: #d8e1dd;
  --paper: #f7f8f5;
  --panel: #ffffff;
  --teal: #0b7d77;
  --teal-dark: #075e5a;
  --blue: #315c9a;
  --coral: #c95d45;
  --amber: #a56b12;
  --shadow: 0 16px 38px rgba(25, 38, 35, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background: var(--paper);
  font-family:
    Inter,
    "PingFang SC",
    "Microsoft YaHei",
    Arial,
    sans-serif;
}

button,
input {
  font: inherit;
}

.app-shell {
  display: grid;
  grid-template-columns: 288px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  border-right: 1px solid var(--line);
  background: #eef4f1;
  padding: 24px 18px;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 24px;
}

.brand-mark,
.avatar {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 8px;
  background: var(--teal);
  color: #fff;
  font-weight: 800;
}

.brand h1,
.brand p,
.topbar h2,
.topbar p,
.coach-header h3,
.coach-header p,
.profile-panel h3,
.profile-panel p {
  margin: 0;
}

.brand h1 {
  font-size: 20px;
}

.brand p,
.coach-header p,
.profile-panel p,
.label,
.eyebrow {
  color: var(--muted);
  font-size: 13px;
}

.lesson-list {
  display: grid;
  gap: 8px;
}

.lesson-button {
  width: 100%;
  border: 1px solid transparent;
  border-radius: 8px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  padding: 12px;
  text-align: left;
}

.lesson-button:hover,
.lesson-button.active {
  border-color: var(--line);
  background: #fff;
}

.lesson-button strong {
  display: block;
  font-size: 14px;
}

.lesson-button span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.workspace {
  min-width: 0;
  padding: 24px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
}

.topbar h2 {
  margin-top: 3px;
  font-size: 28px;
  letter-spacing: 0;
}

.status-pill {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: var(--teal-dark);
  padding: 8px 12px;
  font-size: 13px;
  white-space: nowrap;
}

.practice-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 18px;
  align-items: start;
}

.practice-panel,
.coach-panel,
.dashboard,
.profile-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.practice-panel {
  padding: 18px;
}

.target-row {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 14px;
}

.target-sound {
  margin-top: 4px;
  color: var(--teal-dark);
  font-size: 72px;
  font-weight: 800;
  line-height: 1;
}

.score-block {
  min-width: 128px;
  border-left: 1px solid var(--line);
  padding-left: 18px;
}

.score-block strong {
  display: block;
  margin-top: 10px;
  color: var(--blue);
  font-size: 32px;
}

.visualizer {
  position: relative;
  overflow: hidden;
  min-height: 270px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfa;
}

#waveCanvas {
  display: block;
  width: 100%;
  height: 270px;
}

.visualizer-copy {
  position: absolute;
  inset: 22px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  pointer-events: none;
}

.visualizer-copy p {
  max-width: 460px;
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.visualizer-copy strong {
  margin-top: 12px;
  color: var(--ink);
  font-size: 56px;
  letter-spacing: 0;
}

.controls,
.input-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.controls {
  margin-top: 14px;
}

.button {
  min-height: 42px;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  padding: 0 15px;
  font-weight: 700;
}

.button.primary {
  background: var(--teal);
  color: #fff;
}

.button.primary.recording {
  background: var(--coral);
}

.button.secondary {
  border-color: #9cc8c2;
  background: #e9f7f4;
  color: var(--teal-dark);
}

.button.ghost {
  border-color: var(--line);
  background: #fff;
  color: var(--ink);
}

.spoken-input {
  margin-top: 18px;
}

.spoken-input label,
.speed-control label,
.config-grid label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 13px;
}

.spoken-input input,
.config-grid input,
.config-grid select,
#videoInput {
  flex: 1 1 260px;
  min-height: 42px;
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  background: #fff;
  color: var(--ink);
}

.speed-control {
  display: grid;
  gap: 8px;
  margin-top: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfa;
  padding: 12px;
}

.speed-control > div {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

.speed-control span {
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 800;
  white-space: nowrap;
}

.speed-control input {
  width: 100%;
}

.coach-panel {
  padding: 18px;
}

.coach-header {
  display: flex;
  gap: 12px;
  align-items: center;
}

.feedback {
  margin-top: 18px;
  border-left: 4px solid var(--teal);
  background: #eef8f6;
  border-radius: 6px;
  padding: 14px;
  line-height: 1.65;
}

.micro-check {
  margin-top: 18px;
  display: grid;
  gap: 10px;
}

.micro-check h4 {
  margin: 0 0 2px;
  font-size: 15px;
}

.micro-check label {
  display: flex;
  gap: 8px;
  align-items: center;
  color: var(--ink);
  font-size: 14px;
}

.support-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  gap: 18px;
  margin-top: 18px;
}

.video-panel,
.model-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: var(--shadow);
  padding: 18px;
}

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

.panel-heading h3,
.panel-heading p {
  margin: 0;
}

.panel-heading h3 {
  font-size: 18px;
}

.panel-heading p {
  margin-top: 4px;
  color: var(--muted);
  font-size: 13px;
}

.panel-heading a {
  border: 1px solid #9cc8c2;
  border-radius: 8px;
  color: var(--teal-dark);
  padding: 8px 10px;
  text-decoration: none;
  white-space: nowrap;
}

.video-frame {
  display: grid;
  place-items: center;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #17211f;
  color: #dce7e4;
  margin-bottom: 12px;
}

.video-frame iframe {
  width: 100%;
  height: 100%;
  border: 0;
}

.config-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 12px;
}

.config-grid label {
  margin-bottom: 0;
}

.config-grid input,
.config-grid select {
  width: 100%;
  margin-top: 8px;
}

.dashboard {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 18px;
  margin-top: 18px;
  padding: 16px;
}

.progress-strip {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 8px;
}

.step {
  min-height: 68px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfa;
  padding: 10px;
  font-size: 13px;
}

.step.active {
  border-color: var(--teal);
  background: #eaf7f5;
}

.step.done {
  border-color: #bfd3c5;
  background: #eff6ea;
}

.step strong {
  display: block;
  margin-bottom: 5px;
}

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

.records > div {
  border-left: 1px solid var(--line);
  padding-left: 12px;
}

.records strong {
  display: block;
  margin-top: 8px;
  font-size: 24px;
  color: var(--amber);
}

.profile-panel {
  margin-top: 18px;
  padding: 18px;
}

.profile-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  margin-top: 14px;
}

.profile-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfa;
  padding: 12px;
}

.profile-item strong {
  display: block;
  margin-bottom: 5px;
}

.profile-item span {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
}

@media (max-width: 1080px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .lesson-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .practice-layout,
  .support-layout,
  .dashboard {
    grid-template-columns: 1fr;
  }

  .config-grid {
    grid-template-columns: 1fr;
  }

  .profile-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 680px) {
  .workspace,
  .sidebar {
    padding: 16px;
  }

  .topbar,
  .target-row {
    align-items: flex-start;
    flex-direction: column;
  }

  .lesson-list,
  .support-layout,
  .config-grid,
  .progress-strip,
  .records,
  .profile-grid {
    grid-template-columns: 1fr;
  }

  .button,
  .input-row input,
  .input-row button {
    width: 100%;
  }

  .panel-heading,
  .speed-control > div {
    flex-direction: column;
  }

  .panel-heading a {
    width: 100%;
    text-align: center;
  }

  .score-block {
    width: 100%;
    border-left: 0;
    border-top: 1px solid var(--line);
    padding-top: 12px;
    padding-left: 0;
  }

  .target-sound {
    font-size: 58px;
  }

  .visualizer-copy strong {
    font-size: 38px;
  }
}