:root {
  --bg: #edf3ff;
  --bg-accent: #f6f1e8;
  --surface: rgba(255, 255, 255, 0.88);
  --surface-strong: #ffffff;
  --line: rgba(28, 49, 87, 0.14);
  --line-strong: rgba(28, 49, 87, 0.22);
  --ink: #162033;
  --muted: #5a6578;
  --brand: #1f5eff;
  --brand-soft: rgba(31, 94, 255, 0.12);
  --success: #248a5c;
  --warning: #c87b16;
  --shadow: 0 10px 30px rgba(28, 49, 87, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  color: var(--ink);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: linear-gradient(180deg, #f7faff 0%, var(--bg) 42%, #eef4ff 100%);
}

button,
input,
select,
textarea {
  font: inherit;
}

.shell {
  max-width: 1500px;
  margin: 0 auto;
  padding: 28px 20px 40px;
}

.hero {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: flex-end;
  margin-bottom: 22px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--brand);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: clamp(34px, 4vw, 60px);
  line-height: 1.08;
}

.hero-text {
  max-width: 860px;
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: flex-end;
  align-self: center;
}

.hero-badges span,
.stat-pill,
.preview-chip {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: none;
}

.hero-badges span {
  padding: 10px 14px;
  font-size: 13px;
  color: var(--muted);
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(420px, 0.88fr);
  gap: 20px;
  align-items: start;
}

.editor-panel,
.preview-panel {
  min-width: 0;
}

.card {
  margin-bottom: 18px;
  border: 1px solid var(--line);
  border-radius: 26px;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: none;
  box-shadow: var(--shadow);
}

.config-card,
.share-card,
.editor-card,
.preview-card {
  padding: 22px;
}

.note-card {
  padding: 16px 18px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.note-card p {
  margin: 0;
}

.config-row {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 20px;
  align-items: end;
}

.field {
  display: block;
  flex: 1 1 220px;
}

.field span {
  display: block;
  margin-bottom: 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--muted);
}

.check {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.64);
  color: var(--muted);
}

.check input {
  width: 16px;
  height: 16px;
}

select,
input[type="url"],
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface-strong);
  padding: 12px 14px;
  color: var(--ink);
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease,
    transform 0.2s ease;
}

select:focus,
input[type="url"]:focus,
input[type="file"]:focus,
textarea:focus {
  outline: none;
  border-color: rgba(31, 94, 255, 0.48);
  box-shadow: 0 0 0 4px rgba(31, 94, 255, 0.1);
}

textarea {
  min-height: 420px;
  resize: vertical;
  line-height: 1.7;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 16px;
}

.section-head h2 {
  margin: 0;
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: 24px;
}

.section-head p {
  margin: 8px 0 0;
  color: var(--muted);
  line-height: 1.6;
  font-size: 14px;
}

.meta-inline {
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}

.share-row {
  display: flex;
  gap: 12px;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 16px;
}

button {
  border: 0;
  border-radius: 14px;
  padding: 12px 18px;
  font-weight: 700;
  cursor: pointer;
  transition:
    transform 0.18s ease,
    box-shadow 0.18s ease,
    opacity 0.18s ease;
}

button:hover {
  transform: translateY(-1px);
}

button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
}

#formatBtn,
#importShareBtn {
  background: var(--brand);
  color: #fff;
  box-shadow: 0 12px 28px rgba(31, 94, 255, 0.24);
}

.secondary-btn {
  background: rgba(255, 255, 255, 0.86);
  color: var(--ink);
  border: 1px solid var(--line);
}

.ghost-btn {
  background: transparent;
  color: var(--muted);
  border: 1px dashed var(--line-strong);
}

.stats-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 14px;
}

.stat-pill {
  padding: 10px 14px;
  color: var(--muted);
  font-size: 13px;
}

.preview-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.preview-chip {
  padding: 8px 12px;
  font-size: 12px;
  color: var(--muted);
}

.preview-card {
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: none;
}

.preview-body {
  min-height: 860px;
  padding: 26px;
  border: 1px solid rgba(34, 55, 88, 0.08);
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(243, 247, 255, 0.86), rgba(255, 255, 255, 0.96));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7);
  contain: layout paint style;
}

.preview-body > * {
  content-visibility: auto;
  contain-intrinsic-size: auto 160px;
}

.preview-body h1,
.preview-body h2,
.preview-body h3 {
  color: #101a2e;
  font-family: "Noto Serif SC", "Songti SC", serif;
}

.preview-body h1 {
  margin: 0 0 22px;
  font-size: 34px;
  line-height: 1.2;
  text-align: center;
}

.preview-body h2 {
  margin: 22px 0 10px;
  font-size: 24px;
}

.preview-body h3 {
  margin: 18px 0 8px;
  font-size: 18px;
}

.preview-body p {
  margin: 12px 0;
  font-size: 16px;
  line-height: 1.88;
  text-indent: 2em;
}

.preview-body .paragraph-no-indent {
  text-indent: 0;
}

.preview-body .preview-reference {
  text-indent: 0;
  padding-left: 2em;
  text-indent: -1.4em;
}

.preview-body .caption {
  margin: 18px 0 8px;
  text-align: center;
  text-indent: 0;
  color: #29364a;
  font-weight: 600;
}

.preview-body .equation-block {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  align-items: center;
  margin: 18px 0;
  padding: 14px 18px;
  border: 1px solid rgba(31, 94, 255, 0.18);
  border-radius: 16px;
  background: linear-gradient(180deg, rgba(248, 251, 255, 0.96), rgba(240, 246, 255, 0.92));
  contain: layout paint;
}

.preview-body .equation-text {
  font-family: "Cambria Math", "Times New Roman", serif;
  font-size: 17px;
  text-align: center;
  text-indent: 0;
  line-height: 1.9;
}

.preview-body .equation-no {
  color: var(--muted);
  font-size: 14px;
}

.preview-body .equation-formula {
  display: inline-block;
  white-space: normal;
  word-break: keep-all;
}

.preview-body .equation-formula sub,
.preview-body .equation-formula sup {
  font-size: 0.68em;
  line-height: 0;
}

.preview-body .math-frac {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0 0.16em;
  vertical-align: middle;
  line-height: 1.08;
}

.preview-body .math-frac > span:first-child {
  min-width: 1.1em;
  padding: 0 0.18em 0.12em;
  border-bottom: 1px solid currentColor;
}

.preview-body .math-frac > span:last-child {
  padding: 0.12em 0.18em 0;
}

.preview-body .math-radical {
  display: inline-flex;
  align-items: baseline;
  gap: 0.06em;
}

.preview-limit-notice {
  margin: 22px 0 0;
  padding: 14px 16px;
  border: 1px dashed rgba(31, 94, 255, 0.32);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.78);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.inline-preview-action {
  margin-left: 10px;
  padding: 6px 10px;
  border-radius: 10px;
  background: rgba(31, 94, 255, 0.1);
  color: var(--brand);
  font-size: 13px;
  box-shadow: none;
}

.preview-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  background: rgba(255, 255, 255, 0.88);
}

.preview-body th,
.preview-body td {
  padding: 10px 12px;
  border-bottom: 1px solid rgba(22, 32, 51, 0.12);
  font-size: 14px;
  line-height: 1.6;
  text-align: center;
}

.preview-body th {
  border-top: 2px solid rgba(22, 32, 51, 0.7);
  border-bottom: 1px solid rgba(22, 32, 51, 0.35);
  background: rgba(246, 249, 255, 0.95);
}

.preview-body tr:last-child td {
  border-bottom: 2px solid rgba(22, 32, 51, 0.7);
}

.preview-body .inline-math,
.preview-body .inline-code {
  display: inline-block;
  padding: 0.05em 0.4em;
  border-radius: 8px;
  background: rgba(31, 94, 255, 0.08);
  color: #14336d;
  text-indent: 0;
  font-family: "Cambria Math", "JetBrains Mono", monospace;
}

.preview-body .citation {
  vertical-align: super;
  font-size: 0.8em;
  color: var(--brand);
}

.preview-body .code-block {
  margin: 16px 0;
  padding: 14px 16px;
  border-radius: 16px;
  background: #192130;
  color: #f2f6ff;
  font-family: "JetBrains Mono", "Cascadia Code", monospace;
  font-size: 13px;
  line-height: 1.7;
  overflow-x: auto;
}

.empty-state {
  display: grid;
  place-items: center;
  min-height: 760px;
  text-align: center;
  color: var(--muted);
}

.empty-state h3 {
  margin: 0 0 10px;
  font-size: 28px;
}

.empty-state p {
  max-width: 420px;
  margin: 0;
  text-indent: 0;
}

input[type="file"] {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface-strong);
  padding: 12px 14px;
  color: var(--ink);
  cursor: pointer;
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

.image-preview-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 12px;
}

.image-preview-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.88);
}

.image-preview-item img {
  width: 48px;
  height: 48px;
  object-fit: cover;
  border-radius: 6px;
}

.image-preview-name {
  font-size: 13px;
  color: var(--muted);
  max-width: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.image-remove-btn {
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(220, 50, 50, 0.1);
  color: #c0392b;
  font-size: 12px;
  font-weight: 600;
  border: none;
  cursor: pointer;
}

.image-remove-btn:hover {
  background: rgba(220, 50, 50, 0.2);
  transform: none;
}

.preview-body .figure-image {
  text-align: center;
  margin: 18px 0 6px;
  text-indent: 0;
}

.preview-body .figure-image img {
  max-width: 100%;
  max-height: 480px;
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(28, 49, 87, 0.1);
}

@media (max-width: 1180px) {
  .workspace {
    grid-template-columns: 1fr;
  }

  .preview-card {
    position: static;
  }

  .preview-body {
    min-height: 520px;
  }
}

.image-size-warning {
  padding: 10px 14px;
  margin-bottom: 12px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.5;
}

.image-size-warning--warn {
  background: #fff8e1;
  color: #8a6d00;
  border: 1px solid #ffe082;
}

.image-size-warning--error {
  background: #fff0f0;
  color: #c62828;
  border: 1px solid #ef9a9a;
}

@media (max-width: 720px) {
  .shell {
    padding: 18px 14px 30px;
  }

  .hero {
    display: block;
  }

  .hero-badges {
    justify-content: flex-start;
    margin-top: 16px;
  }

  .config-row,
  .share-row,
  .toolbar,
  .section-head {
    display: grid;
  }

  .preview-body {
    padding: 18px;
  }

  textarea {
    min-height: 320px;
  }
}