:root {
  --ink: #10213d;
  --ink-soft: #46536a;
  --muted: #778298;
  --accent: #d91f26;
  --accent-dark: #b9151c;
  --accent-soft: #fff6f6;
  --line: #cbd3df;
  --line-soft: #e6eaf0;
  --surface: #ffffff;
  --surface-subtle: #f7f9fc;
  --success: #176c45;
  --shadow: 0 12px 36px rgba(16, 33, 61, 0.08);
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", STSong, "AR PL UMing CN", SimSun, serif;
  --font-sans: Inter, "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  background: var(--surface);
  color: var(--ink);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

button,
textarea {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
}

svg {
  display: block;
}

.site-header {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 110px;
  padding: 0 clamp(28px, 3.45vw, 52px);
  border-bottom: 1px solid var(--line-soft);
  background: rgba(255, 255, 255, 0.97);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: clamp(30px, 3.3vw, 50px);
  font-weight: 800;
  letter-spacing: 0.08em;
  text-decoration: none;
}

.brand-mark {
  width: 136px;
  color: var(--accent);
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2.2;
}

.site-nav {
  display: flex;
  align-items: stretch;
  gap: clamp(24px, 3vw, 46px);
  height: 100%;
}

.site-nav a,
.nav-button {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 0;
  background: transparent;
  color: var(--ink);
  font-size: 16px;
  font-weight: 650;
  text-decoration: none;
  cursor: pointer;
}

.site-nav a svg {
  width: 17px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.7;
}

.site-nav .active::after {
  position: absolute;
  right: 0;
  bottom: 27px;
  left: 0;
  height: 2px;
  background: var(--accent);
  content: "";
}

main {
  width: min(1412px, calc(100% - 48px));
  margin: 0 auto;
  padding: 36px 0 34px;
}

.intro {
  margin: 0 auto 34px;
  text-align: center;
}

.intro h1 {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(34px, 3.2vw, 50px);
  font-weight: 800;
  letter-spacing: 0.045em;
  line-height: 1.22;
}

.intro p {
  max-width: 800px;
  margin: 16px auto 0;
  color: var(--ink-soft);
  font-size: clamp(15px, 1.45vw, 19px);
  line-height: 1.7;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(340px, 0.84fr) minmax(580px, 1.55fr);
  column-gap: 24px;
  row-gap: 12px;
  align-items: stretch;
}

.input-panel,
.result-panel {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
}

.input-panel {
  display: flex;
  flex-direction: column;
  padding: 18px;
}

.direction-switch {
  display: grid;
  grid-template-columns: 1fr 1fr;
  margin-bottom: 27px;
  border: 1px solid var(--line);
  border-radius: 7px;
  overflow: hidden;
}

.direction-button {
  min-height: 48px;
  padding: 10px 12px;
  border: 0;
  background: var(--surface);
  color: var(--ink);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
}

.direction-button + .direction-button {
  border-left: 1px solid var(--line);
}

.direction-button.active {
  position: relative;
  z-index: 1;
  background: var(--accent-soft);
  color: var(--accent);
  box-shadow: inset 0 0 0 1.5px var(--accent);
}

.field-label,
.result-label {
  display: block;
  margin-bottom: 11px;
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 800;
}

.textarea-wrap {
  position: relative;
}

textarea {
  display: block;
  width: 100%;
  height: 198px;
  min-height: 198px;
  resize: vertical;
  padding: 17px 18px 38px;
  border: 1px solid var(--line);
  border-radius: 7px;
  outline: none;
  background: var(--surface);
  color: var(--ink);
  font-size: 20px;
  line-height: 1.7;
  transition: border-color 160ms ease, box-shadow 160ms ease;
}

textarea::placeholder {
  color: #a0a9b8;
}

textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(217, 31, 38, 0.1);
}

.character-count {
  position: absolute;
  right: 14px;
  bottom: 12px;
  color: var(--muted);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

.input-hint {
  min-height: 22px;
  margin: 11px 0 15px;
  color: var(--muted);
  font-size: 14px;
}

.input-actions,
.result-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.result-actions {
  justify-content: flex-end;
  flex: 0 0 auto;
}

.secondary-button,
.example-button,
.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  padding: 9px 14px;
  border: 1px solid #aeb9c9;
  border-radius: 6px;
  background: var(--surface);
  color: var(--ink);
  font-size: 14px;
  font-weight: 650;
  cursor: pointer;
  transition: border-color 150ms ease, background 150ms ease, color 150ms ease, transform 150ms ease;
}

.secondary-button:hover,
.example-button:hover {
  border-color: var(--ink);
  background: var(--surface-subtle);
}

.secondary-button:active,
.example-button:active,
.primary-button:active {
  transform: translateY(1px);
}

.secondary-button svg,
.example-button svg,
.icon-button svg,
.primary-button svg,
.accuracy-note svg,
.explanation summary svg {
  width: 19px;
  height: 19px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.7;
}

.form-error {
  margin: 13px 0 0;
  color: var(--accent);
  font-size: 13px;
  line-height: 1.5;
}

.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  width: 100%;
  min-height: 58px;
  margin-top: auto;
  padding: 13px 20px;
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font-size: 18px;
  font-weight: 750;
  cursor: pointer;
  transition: background 150ms ease, transform 150ms ease;
}

.primary-button:hover {
  background: var(--accent-dark);
}

.primary-button svg {
  width: 20px;
}

.input-panel > .primary-button {
  margin-top: 24px;
}

.result-panel {
  min-width: 0;
  padding: 20px 16px 12px;
}

.result-panel.result-updated .result-summary {
  animation: result-in 260ms ease-out both;
}

.result-heading-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin: 0 5px 16px;
}

.result-heading-row > div:first-child {
  min-width: 0;
}

.result-label {
  margin: 0 0 10px;
}

.result-summary {
  margin: 0;
  color: var(--accent);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(26px, 2.25vw, 37px);
  font-weight: 700;
  line-height: 1.24;
  overflow-wrap: anywhere;
}

.result-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
}

.result-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  table-layout: fixed;
}

.result-table th,
.result-table td {
  padding: 6px 10px;
  border-right: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  text-align: center;
  vertical-align: middle;
}

.result-table th:last-child,
.result-table td:last-child {
  border-right: 0;
}

.result-table tbody tr:last-child td {
  border-bottom: 0;
}

.result-table th {
  background: #fbfcfe;
  color: var(--ink);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.03em;
}

.result-table th:nth-child(1) {
  width: 12%;
}

.result-table th:nth-child(2) {
  width: 23%;
}

.result-table th:nth-child(3),
.result-table th:nth-child(4) {
  width: 19%;
}

.result-table th:nth-child(5) {
  width: 27%;
}

.result-table td {
  height: 46px;
  color: var(--ink-soft);
  font-size: 15px;
}

.result-table tbody tr {
  cursor: pointer;
  transition: background 130ms ease;
}

.result-table tbody tr:hover,
.result-table tbody tr:focus-within {
  background: var(--accent-soft);
}

.source-token {
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 700;
}

.match-token {
  color: var(--accent);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 18px;
  font-weight: 700;
}

.match-kind {
  display: block;
  margin-top: 1px;
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 9px;
  font-weight: 600;
}

.ipa-token {
  color: var(--ink);
  font-family: "DejaVu Sans", "Noto Sans", "Arial Unicode MS", sans-serif;
  font-size: 15px;
  letter-spacing: 0.02em;
}

.ipa-display {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: center;
  gap: 3px 7px;
  white-space: nowrap;
}

.tone-label {
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0;
}

.score-cell {
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 8px;
  align-items: center;
  font-variant-numeric: tabular-nums;
}

.score-bar {
  height: 7px;
  overflow: hidden;
  border-radius: 999px;
  background: #e7ebf1;
}

.score-bar span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--accent);
  animation: grow-bar 480ms ease-out both;
  transform-origin: left center;
}

.accuracy-note {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 11px 4px 8px;
  color: var(--ink-soft);
  font-size: 13px;
  line-height: 1.5;
}

.accuracy-note svg {
  width: 17px;
  flex: 0 0 auto;
}

.explanation {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.explanation summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 48px;
  padding: 0 4px;
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 750;
  cursor: pointer;
  list-style: none;
}

.explanation summary::-webkit-details-marker {
  display: none;
}

.explanation summary svg {
  transition: transform 180ms ease;
}

.explanation[open] summary svg {
  transform: rotate(180deg);
}

.explanation-content {
  padding: 0 8px 16px;
  color: var(--ink-soft);
  font-size: 13px;
  line-height: 1.75;
}

.explanation-content p,
.explanation-content ul {
  margin: 0;
}

.explanation-content ul {
  padding: 8px 0 0 20px;
}

.result-footer {
  display: flex;
  grid-column: 2;
  grid-row: 2;
  justify-content: center;
  padding-top: 0;
}

.example-button {
  min-width: 172px;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 13px;
  min-height: 68px;
  border-top: 1px solid var(--line-soft);
  color: var(--muted);
  font-size: 14px;
}

.site-footer i {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--muted);
}

.help-dialog {
  width: min(560px, calc(100% - 30px));
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: var(--shadow);
  color: var(--ink);
}

.help-dialog::backdrop {
  background: rgba(16, 33, 61, 0.38);
  backdrop-filter: blur(2px);
}

.dialog-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 25px 26px 18px;
  border-bottom: 1px solid var(--line-soft);
}

.dialog-header h2 {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 25px;
}

.dialog-header p {
  margin: 5px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.icon-button {
  width: 38px;
  min-height: 38px;
  padding: 0;
  border-color: transparent;
}

.dialog-body {
  padding: 21px 28px 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

.dialog-body ol {
  margin: 0;
  padding-left: 22px;
}

.dialog-note {
  margin: 17px 0 0;
  padding: 13px 15px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
}

.dialog-close {
  width: calc(100% - 56px);
  min-height: 48px;
  margin: 20px 28px 26px;
  font-size: 15px;
}

.toast {
  position: fixed;
  z-index: 50;
  right: 24px;
  bottom: 24px;
  padding: 11px 16px;
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 160ms ease, transform 160ms ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

button:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 3px solid rgba(217, 31, 38, 0.24);
  outline-offset: 3px;
}

@keyframes grow-bar {
  from {
    transform: scaleX(0);
  }
}

@keyframes result-in {
  from {
    opacity: 0;
    transform: translateY(4px);
  }
}

@media (max-width: 1040px) {
  .site-header {
    height: 78px;
  }

  .brand-mark {
    width: 62px;
  }

  .brand {
    font-size: 34px;
  }

  main {
    padding-top: 42px;
  }

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

  .input-panel,
  .result-panel,
  .result-footer {
    grid-column: 1;
    grid-row: auto;
  }

  .input-panel {
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: 22px;
  }

  .direction-switch,
  .field-label,
  .input-panel > .primary-button,
  .form-error {
    grid-column: 1 / -1;
  }

  .textarea-wrap {
    grid-column: 1 / -1;
  }

  .input-hint {
    align-self: center;
  }

  .input-actions {
    justify-content: flex-end;
  }

  .input-panel > .primary-button {
    margin-top: 18px;
  }
}

@media (max-width: 720px) {
  .site-header {
    height: 68px;
    padding: 0 18px;
  }

  .brand {
    gap: 8px;
    font-size: 24px;
  }

  .brand-mark {
    width: 48px;
  }

  .site-nav {
    gap: 17px;
  }

  .site-nav .active,
  .site-nav .active::after {
    display: none;
  }

  .site-nav a,
  .nav-button {
    font-size: 13px;
  }

  .site-nav a svg {
    display: none;
  }

  main {
    width: min(100% - 24px, 620px);
    padding: 32px 0 28px;
  }

  .intro {
    margin-bottom: 25px;
    text-align: left;
  }

  .intro h1 {
    font-size: clamp(30px, 9vw, 42px);
    letter-spacing: 0.02em;
  }

  .intro p {
    margin-top: 12px;
    font-size: 14px;
  }

  .workspace {
    gap: 14px;
  }

  .input-panel {
    display: flex;
    padding: 12px;
  }

  .direction-switch {
    margin-bottom: 22px;
  }

  .direction-button {
    min-height: 46px;
    padding: 8px;
    font-size: 13px;
  }

  textarea {
    height: 154px;
    min-height: 154px;
    font-size: 18px;
  }

  .input-actions {
    justify-content: space-between;
  }

  .result-panel {
    padding: 20px 12px 12px;
  }

  .result-heading-row {
    display: block;
    margin: 0 2px 18px;
  }

  .result-actions {
    justify-content: flex-start;
    margin-top: 15px;
  }

  .result-summary {
    font-size: 28px;
  }

  .result-table-wrap {
    border: 0;
    overflow: visible;
  }

  .result-table,
  .result-table tbody,
  .result-table tr,
  .result-table td {
    display: block;
    width: 100%;
    min-width: 0;
  }

  .result-table thead {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
  }

  .result-table tbody {
    display: grid;
    gap: 9px;
  }

  .result-table tbody tr {
    display: grid;
    grid-template-columns: 55px 1fr;
    border: 1px solid var(--line);
    border-radius: 7px;
    overflow: hidden;
  }

  .result-table td {
    display: grid;
    grid-template-columns: minmax(95px, 38%) 1fr;
    align-items: center;
    min-height: 43px;
    height: auto;
    padding: 8px 10px;
    border: 0;
    border-bottom: 1px solid var(--line-soft);
    text-align: left;
  }

  .result-table td::before {
    color: var(--muted);
    font-size: 11px;
    font-weight: 700;
    content: attr(data-label);
  }

  .result-table td:first-child {
    grid-row: 1 / span 4;
    grid-column: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    border-right: 1px solid var(--line-soft);
    border-bottom: 0;
    background: #fbfcfe;
  }

  .result-table td:first-child::before {
    display: none;
  }

  .result-table td:not(:first-child) {
    grid-column: 2;
  }

  .ipa-display {
    justify-content: flex-start;
  }

  .result-table td:last-child {
    border-bottom: 0;
  }

  .score-cell {
    grid-template-columns: 36px 1fr;
  }

  .accuracy-note {
    align-items: flex-start;
  }

  .site-footer {
    min-height: 60px;
  }
}

@media (max-width: 460px) {
  .site-nav {
    gap: 12px;
  }

  .site-nav #github-link {
    display: none;
  }

  .result-table tbody tr {
    grid-template-columns: 46px 1fr;
  }

  .result-table td {
    grid-template-columns: 94px 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}