:root {
  color-scheme: light;
  --desk: oklch(95.5% 0.018 82);
  --desk-deep: oklch(90% 0.028 82);
  --paper: oklch(99% 0.008 86);
  --paper-warm: oklch(97% 0.018 86);
  --tray: oklch(93.5% 0.025 78);
  --ink: oklch(22% 0.018 70);
  --muted: oklch(47% 0.022 72);
  --soft: oklch(65% 0.018 74);
  --line: oklch(83% 0.025 78);
  --line-strong: oklch(73% 0.035 76);
  --accent: oklch(46% 0.095 150);
  --accent-soft: oklch(89% 0.05 150);
  --action: oklch(55% 0.12 48);
  --success: oklch(48% 0.12 150);
  --danger: oklch(54% 0.16 28);
  --shadow: 0 24px 54px oklch(42% 0.04 72 / 0.16);
  --paper-shadow: 0 18px 36px oklch(42% 0.035 72 / 0.13);
  font-family: Georgia, "Times New Roman", "Noto Serif SC", serif;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--desk);
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(90deg, oklch(66% 0.018 78 / 0.12) 1px, transparent 1px) 0 0 / 34px 34px,
    linear-gradient(180deg, var(--desk), oklch(97% 0.012 86));
  color: var(--ink);
}

body::before {
  position: fixed;
  inset: 0;
  pointer-events: none;
  content: "";
  opacity: 0.28;
  background-image:
    radial-gradient(oklch(48% 0.02 72 / 0.12) 0.7px, transparent 0.8px);
  background-size: 6px 6px;
}

button,
input,
textarea {
  font: inherit;
}

button {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
}

button:focus,
input:focus,
textarea:focus {
  outline: none;
}

button:focus-visible,
.dropzone:focus-within,
textarea:focus-visible {
  outline: 3px solid oklch(70% 0.09 150);
  outline-offset: 3px;
}

.shell {
  position: relative;
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  min-height: 100vh;
  padding: 20px 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  gap: 16px;
}

.dropzone-icon svg {
  width: 100%;
  height: 100%;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.intro {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  max-width: 790px;
}

.eyebrow,
.panel-label,
.result-meta,
.status,
.summary,
.panel-caption {
  margin: 0;
}

.eyebrow,
.panel-label {
  color: var(--accent);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 0.78rem;
  font-weight: 760;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin: 4px 0 0;
  color: var(--ink);
  font-size: 2.3rem;
  font-weight: 650;
  line-height: 1.02;
  letter-spacing: 0;
}

.summary {
  max-width: 65ch;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.55;
}

.format-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 2px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
}

.format-strip span {
  min-height: 28px;
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: oklch(99% 0.008 86 / 0.78);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 650;
}

.workspace {
  display: grid;
  grid-template-columns: 360px minmax(0, 1fr);
  gap: 22px;
  align-items: stretch;
  min-height: 0;
}

.upload-panel,
.output-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.upload-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 18px;
  background:
    linear-gradient(180deg, oklch(99% 0.008 86), oklch(96% 0.018 82));
}

.panel-heading {
  display: grid;
  gap: 4px;
  padding: 2px 2px 0;
}

.panel-caption,
.dropzone-help,
.status,
.result-meta {
  color: var(--muted);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 0.92rem;
  line-height: 1.45;
}

.dropzone {
  display: grid;
  min-height: 210px;
  place-items: center;
  gap: 10px;
  padding: 28px;
  border: 1px dashed var(--line-strong);
  border-radius: 8px;
  background:
    linear-gradient(180deg, oklch(98% 0.01 86), var(--tray));
  box-shadow: inset 0 0 0 5px oklch(99% 0.008 86 / 0.5);
  cursor: pointer;
  text-align: center;
  transition: border-color 160ms ease-out, background 160ms ease-out, box-shadow 160ms ease-out, transform 160ms ease-out;
}

.dropzone:hover,
.dropzone.is-dragging {
  border-color: var(--accent);
  background: linear-gradient(180deg, oklch(99% 0.012 86), oklch(92% 0.042 150));
  box-shadow: inset 0 0 0 5px oklch(99% 0.008 86 / 0.56), 0 10px 24px oklch(42% 0.04 72 / 0.1);
}

.dropzone:active {
  transform: translateY(1px);
}

.dropzone input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.dropzone-icon {
  display: grid;
  width: 56px;
  height: 56px;
  place-items: center;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  color: var(--accent);
  box-shadow: var(--paper-shadow);
}

.dropzone-title {
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 1.02rem;
  font-weight: 760;
}

.file-meta {
  display: grid;
  gap: 4px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: oklch(98% 0.012 86);
  color: var(--muted);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 0.92rem;
}

#file-name {
  color: var(--ink);
  font-weight: 730;
  word-break: break-word;
}

.primary-button,
.copy-button,
.secondary-button {
  min-height: 44px;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 740;
  transition: background 150ms ease-out, border-color 150ms ease-out, box-shadow 150ms ease-out, transform 150ms ease-out;
}

.primary-button {
  width: 100%;
  background: var(--ink);
  color: var(--paper);
  box-shadow: 0 12px 24px oklch(24% 0.018 70 / 0.18);
}

.primary-button:hover:not(:disabled),
.copy-button:hover:not(:disabled),
.secondary-button:hover:not(:disabled) {
  transform: translateY(-1px);
}

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

.primary-button:active:not(:disabled),
.copy-button:active:not(:disabled),
.secondary-button:active:not(:disabled) {
  transform: translateY(1px);
}

.primary-button:disabled,
.copy-button:disabled,
.secondary-button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.status {
  min-height: 2.6em;
}

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

.status.is-success {
  color: var(--success);
}

.output-panel {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  background: var(--paper);
}

.output-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
  background: oklch(97.5% 0.014 86);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
}

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

.copy-button,
.secondary-button {
  min-width: 92px;
  border-color: var(--line);
  background: var(--paper);
  color: var(--ink);
}

.copy-button:hover:not(:disabled),
.secondary-button:hover:not(:disabled) {
  border-color: var(--line-strong);
  background: oklch(96% 0.018 82);
}

#markdown-output {
  width: 100%;
  min-height: 0;
  height: 100%;
  resize: none;
  border: 0;
  padding: 24px 28px;
  background:
    linear-gradient(transparent 31px, oklch(83% 0.018 80 / 0.42) 32px) 0 0 / 100% 32px,
    var(--paper);
  color: var(--ink);
  font-family: "Cascadia Mono", "SFMono-Regular", Consolas, monospace;
  font-size: 0.94rem;
  line-height: 1.7;
  caret-color: var(--accent);
}

#markdown-output::placeholder {
  color: var(--soft);
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px 10px;
  color: var(--muted);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 0.86rem;
  flex-wrap: wrap;
}

.site-footer a {
  color: var(--accent);
  font-weight: 700;
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

.footer-divider {
  color: var(--soft);
}

.api-link-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
}

.api-link {
  display: inline-flex;
  min-height: 28px;
  align-items: center;
  padding: 2px 9px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: oklch(99% 0.008 86 / 0.72);
}

.api-link:hover,
.api-link:focus-visible {
  border-color: var(--line-strong);
  background: oklch(96% 0.018 82);
  text-decoration: none;
}

.api-hint {
  position: absolute;
  left: 50%;
  bottom: calc(100% + 10px);
  z-index: 2;
  width: min(260px, calc(100vw - 40px));
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--paper-shadow);
  color: var(--ink);
  font-size: 0.82rem;
  line-height: 1.45;
  text-align: left;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 4px);
  transition: opacity 150ms ease-out, transform 150ms ease-out;
}

.api-hint::after {
  position: absolute;
  left: 50%;
  top: 100%;
  width: 10px;
  height: 10px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  content: "";
  transform: translate(-50%, -5px) rotate(45deg);
}

.api-link-wrap:hover .api-hint,
.api-link:focus-visible + .api-hint {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (max-width: 820px) {
  .shell {
    width: min(100% - 24px, 680px);
    min-height: auto;
    padding: 20px 0 28px;
    display: block;
  }

  .site-footer {
    flex-wrap: wrap;
    margin-top: 18px;
  }

  h1 {
    font-size: 2.25rem;
  }

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

  .dropzone {
    min-height: 218px;
  }

  .output-panel {
    grid-template-rows: auto minmax(340px, 1fr);
  }

  #markdown-output {
    min-height: 340px;
    padding: 20px;
    background:
      linear-gradient(transparent 31px, oklch(83% 0.018 80 / 0.42) 32px) 0 0 / 100% 32px,
      var(--paper);
  }
}

@media (pointer: coarse) {
  .primary-button,
  .copy-button,
  .secondary-button {
    min-height: 48px;
  }
}