:root {
  color-scheme: light;
  --background: #f5f4ef;
  --surface: #ffffff;
  --surface-muted: #efeee8;
  --ink: #171714;
  --ink-muted: #6d6b63;
  --line: #d8d6cc;
  --accent: #d7ff59;
  --accent-hover: #c8f044;
  --danger: #a6382d;
  --shadow: 0 18px 50px rgba(27, 26, 21, 0.08);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--background);
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 50% -10%, rgba(215, 255, 89, 0.18), transparent 35rem),
    var(--background);
}

button,
textarea {
  font: inherit;
}

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

button:focus-visible,
a:focus-visible,
textarea:focus-visible,
.output:focus-visible {
  outline: 3px solid rgba(23, 23, 20, 0.22);
  outline-offset: 3px;
}

.shell {
  width: min(1180px, 100%);
  min-height: 100vh;
  margin: 0 auto;
  padding: 32px 20px 22px;
  display: flex;
  flex-direction: column;
}

.site-header {
  width: 100%;
  margin-bottom: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  color: inherit;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 1.15rem;
  font-weight: 760;
  letter-spacing: -0.03em;
}

.brand-mark {
  width: 34px;
  height: 34px;
  border: 1.5px solid var(--ink);
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--accent);
  font-size: 0.98rem;
}

.site-header p {
  margin: 0;
  color: var(--ink-muted);
  font-size: 0.93rem;
}

.workspace {
  flex: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 16px;
  align-items: stretch;
}

.panel {
  min-height: 400px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.input-panel,
.output-panel {
  display: flex;
  flex-direction: column;
}

.panel-heading {
  min-height: 58px;
  padding: 0 18px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  font-size: 0.88rem;
  font-weight: 680;
}

#character-count {
  color: var(--ink-muted);
  font-size: 0.78rem;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

textarea {
  width: 100%;
  flex: 1;
  min-height: 220px;
  padding: 22px;
  resize: none;
  border: 0;
  outline: 0;
  color: var(--ink);
  background: transparent;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.94rem;
  line-height: 1.65;
}

textarea::placeholder {
  color: #9b998f;
}

.input-actions {
  padding: 14px 16px 8px;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: auto minmax(140px, 1fr);
  gap: 10px;
}

.button {
  min-height: 48px;
  padding: 0 18px;
  border: 1px solid var(--ink);
  border-radius: 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  font-weight: 720;
  transition:
    transform 140ms ease,
    background-color 140ms ease,
    opacity 140ms ease;
}

.button:not(:disabled):active {
  transform: translateY(1px);
}

.button:disabled {
  cursor: not-allowed;
  opacity: 0.42;
}

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

.button-primary:not(:disabled):hover {
  background: var(--accent-hover);
}

.button-secondary {
  background: transparent;
}

.button-secondary:not(:disabled):hover {
  background: var(--surface-muted);
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(23, 23, 20, 0.28);
  border-top-color: var(--ink);
  border-radius: 50%;
  display: none;
  animation: spin 700ms linear infinite;
}

.is-loading .spinner {
  display: block;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.shortcut {
  margin: 0;
  padding: 0 16px 14px;
  color: var(--ink-muted);
  font-size: 0.72rem;
  text-align: right;
}

.shortcut span {
  margin: 0 2px;
}

kbd {
  padding: 1px 4px;
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
  background: var(--surface-muted);
  font: inherit;
}

.output-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.action-button,
.copy-button {
  min-height: 34px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 9px;
  color: var(--ink);
  background: var(--surface-muted);
  cursor: pointer;
  font-size: 0.78rem;
  font-weight: 700;
  transition: border-color 140ms ease, background-color 140ms ease;
}

.action-button:disabled,
.copy-button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.action-button:not(:disabled):hover,
.copy-button:not(:disabled):hover {
  border-color: var(--ink);
  background: var(--surface);
}

.output {
  flex: 1;
  min-height: 220px;
  padding: 22px;
  overflow-y: auto;
  overflow-wrap: break-word;
  word-break: break-word;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--ink);
}

.output p {
  margin: 0 0 1.1em 0;
}

.output p:last-child {
  margin-bottom: 0;
}

.output h1,
.output h2,
.output h3,
.output h4,
.output h5,
.output h6 {
  margin: 1.2em 0 0.5em 0;
  font-weight: 750;
  line-height: 1.35;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.output h1:first-child,
.output h2:first-child,
.output h3:first-child,
.output h4:first-child {
  margin-top: 0;
}

.output h1 { font-size: 1.45rem; }
.output h2 { font-size: 1.25rem; }
.output h3 { font-size: 1.1rem; }

.output ul,
.output ol {
  margin: 0 0 1.1em 0;
  padding-left: 1.4em;
}

.output li {
  margin-bottom: 0.35em;
}

.output blockquote {
  margin: 1em 0;
  padding: 10px 16px;
  border-left: 4px solid var(--accent);
  background: var(--surface-muted);
  border-radius: 0 8px 8px 0;
  color: var(--ink-muted);
}

.output code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.88em;
  background: var(--surface-muted);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--line);
}

.output pre {
  margin: 1em 0;
  padding: 14px 16px;
  background: #1a1a18;
  color: #e6e5df;
  border-radius: 10px;
  overflow-x: auto;
}

.output pre code {
  background: transparent;
  padding: 0;
  border: none;
  color: inherit;
}

.output a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.status {
  min-height: 37px;
  padding: 0 18px 14px;
  color: var(--ink-muted);
  font-size: 0.78rem;
}

.status.error {
  color: var(--danger);
}

footer {
  min-height: 52px;
  padding-top: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  flex-wrap: wrap;
  color: var(--ink-muted);
  font-size: 0.76rem;
  text-align: center;
}

footer a {
  color: inherit;
  text-underline-offset: 3px;
}

@media (max-width: 760px) {
  .shell {
    padding: 18px 12px 14px;
  }

  .site-header {
    margin-bottom: 18px;
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .site-header p {
    padding-left: 44px;
    margin-top: -8px;
  }

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

  .panel {
    min-height: auto;
    border-radius: 16px;
  }

  textarea {
    min-height: 42vh;
    padding: 18px;
    font-size: 16px;
  }

  .output-panel {
    min-height: 330px;
  }

  .empty-output,
  .output {
    min-height: 270px;
    padding: 18px;
    font-size: 0.92rem;
  }

  .input-actions {
    grid-template-columns: 1fr 2fr;
  }

  .shortcut {
    display: none;
  }

  footer {
    padding-top: 14px;
  }
}

.panel-title {
  display: flex;
  align-items: center;
  gap: 10px;
}

.rules-link {
  background: none;
  border: none;
  padding: 0;
  color: var(--ink-muted);
  font-size: 0.78rem;
  font-weight: 500;
  text-decoration: underline;
  text-underline-offset: 3px;
  cursor: pointer;
  transition: color 140ms ease;
}

.rules-link:hover {
  color: var(--ink);
}

/* Rules Modal */
.rules-modal {
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.18);
  max-width: 540px;
  width: calc(100% - 32px);
  color: var(--ink);
  overflow: hidden;
}

.rules-modal::backdrop {
  background: rgba(23, 23, 20, 0.45);
  backdrop-filter: blur(4px);
}

.modal-content {
  display: flex;
  flex-direction: column;
  max-height: 85vh;
}

.modal-header {
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface-muted);
}

.modal-header h2 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
}

.modal-close {
  background: none;
  border: none;
  font-size: 1.4rem;
  line-height: 1;
  color: var(--ink-muted);
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 6px;
  transition: color 140ms ease, background-color 140ms ease;
}

.modal-close:hover {
  color: var(--ink);
  background: rgba(0, 0, 0, 0.06);
}

.modal-body {
  padding: 22px;
  overflow-y: auto;
  font-size: 0.9rem;
  line-height: 1.6;
}

.modal-body section + section {
  margin-top: 20px;
}

.modal-changes-section {
  background: var(--surface-muted);
  padding: 16px;
  border-radius: 12px;
  border: 1px solid var(--line);
}

.modal-changes-list ul {
  margin: 0;
  padding-left: 18px;
}

.modal-changes-list li {
  margin-bottom: 6px;
}

.modal-body h3 {
  margin: 0 0 10px;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-muted);
}

.modal-body ul {
  margin: 0;
  padding-left: 20px;
}

.modal-body li {
  margin-bottom: 8px;
}

.modal-body li:last-child {
  margin-bottom: 0;
}

@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;
  }
}