styles.css

:root {
  color-scheme: light;
  --bg: #edf2f6;
  --panel: rgba(255, 255, 255, .84);
  --line: rgba(14, 26, 38, .13);
  --text: #0e1a26;
  --muted: #536171;
  --brand: #1e6ee8;
  --brand-dark: #0f4cad;
  --teal: #00a99a;
  --ok: #087f5b;
  --ok-soft: rgba(16, 185, 129, .16);
  --glass-stroke: rgba(255, 255, 255, .62);
  --shadow: 0 10px 28px rgba(8, 28, 61, .12);
  --radius-xl: 18px;
  --radius-md: 10px;
  --radius-sm: 8px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-width: 1720px;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

button, input, select {
  font: inherit;
}

button {
  min-height: 32px;
  padding: 0 11px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--brand), var(--teal));
  color: white;
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
}

button.secondary {
  background: rgba(255, 255, 255, .9);
  border-color: var(--line);
  color: var(--brand-dark);
}

button.danger {
  background: #b42318;
  border-color: rgba(180, 35, 24, .22);
}

button:disabled {
  cursor: not-allowed;
  opacity: .52;
}

input, select {
  min-height: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, .96);
  color: var(--text);
  padding: 0 10px;
}

a { color: inherit; text-decoration: none; }

.app-shell {
  width: 1720px;
  min-height: 100vh;
  margin: 0 auto;
  padding: 16px;
}

.top-header {
  min-height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 10px 14px;
}

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

.brand-logo {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--brand), var(--teal));
  color: white;
  font-weight: 900;
  box-shadow: 0 8px 18px rgba(30, 110, 232, .28);
}

.brand strong {
  display: block;
  font-size: 16px;
}

.brand span {
  display: block;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  margin-top: 2px;
}

.panel {
  min-width: 0;
  border: 1px solid var(--glass-stroke);
  border-radius: var(--radius-xl);
  background: var(--panel);
  backdrop-filter: blur(18px) saturate(180%);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.settings-strip {
  min-width: 0;
  display: grid;
  grid-template-columns: 132px 154px 132px;
  gap: 8px;
  align-items: end;
  margin-left: auto;
}

.settings-title {
  min-height: 34px;
  padding: 0 10px;
  background: rgba(255, 255, 255, .9);
  border-color: var(--line);
  color: var(--brand-dark);
  box-shadow: none;
}

.settings-strip label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.settings-strip label > span {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.info-button {
  width: 18px;
  min-height: 18px;
  padding: 0;
  border-radius: 50%;
  background: white;
  border-color: var(--line);
  color: var(--muted);
  box-shadow: none;
}

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

.workspace {
  display: grid;
  grid-template-columns: 740px minmax(0, 1fr);
  gap: 14px;
  height: calc(100vh - 118px);
  min-height: 820px;
  margin-top: 14px;
}

.preview-panel,
.formula-panel {
  display: flex;
  flex-direction: column;
}

.panel-header,
.formula-topbar {
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 0 14px;
  border-bottom: 1px solid var(--line);
  background: rgba(255,255,255,.54);
}

.formula-topbar.compact {
  min-height: 50px;
}

.panel-header h2,
.formula-topbar h2 {
  margin: 0;
  font-size: 15px;
}

.panel-header span,
.formula-topbar span {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.page-controls,
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-controls button {
  min-height: 30px;
  background: white;
  color: var(--brand-dark);
  border-color: var(--line);
}

.page-controls strong {
  min-width: 74px;
  text-align: center;
  font-size: 12px;
  color: var(--muted);
}

.preview-stage {
  position: relative;
  flex: 1;
  min-height: 0;
  overflow: auto;
  display: grid;
  justify-items: center;
  align-items: start;
  padding: 14px;
  background: #e4ebf2;
  border: 2px solid transparent;
}

.preview-stage.drag-active {
  border-color: rgba(30, 110, 232, .45);
  background: #eef6ff;
}

.preview-stage img {
  width: 100%;
  max-width: 712px;
  height: auto;
  background: white;
  box-shadow: 0 12px 28px rgba(8, 28, 61, .16);
}

.preview-upload,
.preview-empty {
  align-self: center;
  justify-self: center;
  width: 360px;
  min-height: 170px;
  display: grid;
  place-items: center;
  gap: 8px;
  padding: 22px;
  color: var(--brand-dark);
  text-align: center;
  border: 1px dashed rgba(30, 110, 232, .5);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, .7);
  cursor: pointer;
}

.preview-upload strong,
.preview-empty strong {
  font-size: 16px;
}

.preview-upload span,
.preview-empty p {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}

.preview-upload input {
  display: none;
}

.preview-empty.processing {
  cursor: default;
}

.preview-empty.processing svg,
.modal-actions svg {
  animation: spin 1s linear infinite;
}

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

.candidate-head {
  display: grid;
  grid-template-columns: 1.05fr 1.15fr 1.15fr;
  gap: 7px;
  padding: 7px 12px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
  font-weight: 900;
}

.candidate-list {
  flex: 1;
  min-height: 0;
  overflow: auto;
  padding: 8px 12px 12px;
}

.candidate-card {
  display: grid;
  grid-template-columns: 1.05fr 1.15fr 1.15fr;
  gap: 7px;
  margin-bottom: 7px;
  padding: 7px;
  border: 1px solid rgba(14, 26, 38, .08);
  border-radius: var(--radius-md);
  background: rgba(255,255,255,.62);
}

.candidate-card.active {
  outline: 2px solid rgba(30, 110, 232, .34);
  background: #eef6ff;
}

.candidate-option {
  position: relative;
  min-height: 78px;
  display: block;
  padding: 7px 9px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,.92);
  color: var(--text);
  text-align: left;
  overflow: hidden;
  box-shadow: none;
}

.candidate-option.selected {
  border-color: rgba(8, 127, 91, .58);
  background: var(--ok-soft);
}

.candidate-option.disabled {
  color: var(--muted);
  background: rgba(245, 247, 250, .88);
}

.option-title {
  display: flex;
  justify-content: space-between;
  gap: 6px;
  margin-bottom: 4px;
}

.option-title strong {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 12px;
}

.option-title em {
  padding: 1px 6px;
  border-radius: 999px;
  background: rgba(83, 97, 113, .12);
  color: var(--muted);
  font-size: 11px;
  font-style: normal;
  font-weight: 900;
}

.formula-value {
  display: block;
  max-height: 46px;
  overflow: auto;
  font-size: 12px;
  line-height: 1.35;
  word-break: break-word;
  overflow-wrap: anywhere;
}

.formula-value .katex {
  white-space: normal;
}

.math-render {
  font-size: 13px;
}

.checkmark {
  position: absolute;
  right: 7px;
  bottom: 6px;
  color: var(--ok);
}

.empty-state {
  padding: 16px 8px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  background: rgba(8, 28, 61, .22);
  backdrop-filter: blur(8px);
}

.ai-modal {
  width: 560px;
  border-radius: var(--radius-xl);
  background: white;
  border: 1px solid var(--line);
  box-shadow: 0 22px 70px rgba(8, 28, 61, .22);
  overflow: hidden;
}

.modal-header {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
}

.modal-header h2,
.modal-header p {
  margin: 0;
}

.modal-header h2 {
  font-size: 17px;
}

.modal-header p {
  margin-top: 4px;
  color: var(--muted);
  font-size: 12px;
}

.icon-only {
  width: 34px;
  padding: 0;
}

.modal-body {
  display: grid;
  gap: 12px;
  padding: 16px;
}

.modal-body label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.modal-body input,
.modal-body select {
  width: 100%;
}

.modal-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding: 12px 16px 16px;
}

.test-message {
  margin: 2px 0 0;
  font-size: 12px;
  font-weight: 750;
}

.test-message.ok {
  color: var(--ok);
}

.test-message.failed {
  color: #b42318;
}