/* ============================================================
   公式识图 EqLens · 设计系统
   ============================================================ */

:root {
  /* 品牌色 */
  --brand-400: #7B93FF;
  --brand-500: #4C6FFF;
  --brand-600: #3B5BFF;
  --brand-700: #2F49E8;
  --brand-bg: rgba(76, 111, 255, 0.08);
  --brand-bg-2: rgba(76, 111, 255, 0.14);

  /* 中性色 */
  --bg: #F4F6FB;
  --surface: #FFFFFF;
  --surface-2: #F8FAFD;
  --text: #182033;
  --text-2: #475069;
  --text-3: #8A94A6;
  --line: #E4E9F2;
  --line-2: #EEF1F7;

  /* 语义色 */
  --ok: #12B76A;
  --ok-bg: rgba(18, 183, 106, 0.1);
  --warn: #F79009;
  --err: #F04438;
  --err-bg: rgba(240, 68, 56, 0.08);

  /* 形状与阴影 */
  --radius: 16px;
  --radius-sm: 10px;
  --shadow-lg: 0 12px 40px -12px rgba(23, 32, 64, 0.16), 0 2px 6px rgba(23, 32, 64, 0.04);
  --shadow-sm: 0 1px 2px rgba(23, 32, 64, 0.06);
  --shadow-brand: 0 8px 24px -8px rgba(76, 111, 255, 0.5);

  /* 字体 */
  --sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "JetBrains Mono", "Cascadia Code", Consolas, "Courier New", monospace;

  --grad: linear-gradient(135deg, var(--brand-600) 0%, var(--brand-400) 100%);
}

html[data-theme="dark"] {
  --bg: #0D1220;
  --surface: #161C2C;
  --surface-2: #1B2236;
  --text: #E8ECF6;
  --text-2: #A8B3C7;
  --text-3: #6B7690;
  --line: #262F47;
  --line-2: #1E2639;
  --brand-bg: rgba(123, 147, 255, 0.1);
  --brand-bg-2: rgba(123, 147, 255, 0.18);
  --shadow-lg: 0 12px 40px -12px rgba(0, 0, 0, 0.5), 0 2px 6px rgba(0, 0, 0, 0.3);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.35);
}

/* ---------- 基础 ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.65;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 背景点阵装饰 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: radial-gradient(circle, var(--line) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: linear-gradient(180deg, rgba(0,0,0,.5), transparent 55%);
  -webkit-mask-image: linear-gradient(180deg, rgba(0,0,0,.5), transparent 55%);
  z-index: 0;
}

main, header, footer { position: relative; z-index: 1; }

::selection { background: var(--brand-bg-2); }

a { color: var(--brand-500); text-decoration: none; }
a:hover { text-decoration: underline; }

kbd {
  display: inline-block;
  padding: 2px 7px;
  font-family: var(--sans);
  font-size: 0.82em;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 6px;
}

button { font-family: inherit; }

:focus-visible { outline: 2px solid var(--brand-500); outline-offset: 2px; border-radius: 4px; }

.hidden { display: none !important; }

/* ---------- 图标 ---------- */
.ico { width: 1.05em; height: 1.05em; flex-shrink: 0; vertical-align: -0.16em; }

/* ---------- 导航 ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line-2);
}

.nav-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
  height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand { display: flex; align-items: center; gap: 10px; }
.brand:hover { text-decoration: none; }

.brand-logo {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  font-family: Georgia, serif;
  font-style: italic;
  font-size: 20px;
  font-weight: 700;
  color: #fff;
  background: var(--grad);
  border-radius: 9px;
  box-shadow: var(--shadow-brand);
}

.brand-name { font-size: 17px; font-weight: 700; color: var(--text); letter-spacing: 0.2px; }
.brand-name em { font-style: normal; font-size: 12px; font-weight: 600; color: var(--text-3); margin-left: 7px; letter-spacing: 0.4px; }

.nav-actions { display: flex; align-items: center; gap: 10px; }

.engine-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  height: 34px;
  padding: 0 13px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.18s ease;
}

.engine-badge:hover { border-color: var(--brand-400); color: var(--text); }

.engine-badge .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--warn);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--warn) 20%, transparent);
}
.engine-badge.live .dot { background: var(--ok); box-shadow: 0 0 0 3px var(--ok-bg); }
.engine-badge.pending { color: var(--warn); }
.engine-badge.pending:hover { color: var(--warn); }

/* 错误态中的令牌引导 */
.error-guide { margin-top: 4px; font-size: 12.5px; line-height: 1.7; color: var(--text-3); text-align: center; }
.error-guide a { color: var(--brand-500); text-decoration: none; border-bottom: 1px dashed var(--brand-400); }
.error-guide a:hover { color: var(--brand-600); }

/* 设置弹窗：识别模型选择 */
.model-options { display: flex; gap: 10px; margin-top: 8px; }
.model-option {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}
.model-option:hover { border-color: var(--brand-400); }
.model-option:has(input:checked) { border-color: var(--brand-500); background: var(--brand-bg); }
.model-option input { accent-color: var(--brand-500); margin: 0; }
.model-name { display: flex; flex-direction: column; gap: 2px; font-size: 13px; font-weight: 600; color: var(--text); }
.model-name small { font-size: 11.5px; font-weight: 400; color: var(--text-3); }
@media (max-width: 640px) { .model-options { flex-direction: column; } }

.icon-btn {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  font-size: 17px;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.18s ease;
}

.icon-btn:hover { color: var(--text); border-color: var(--brand-400); transform: translateY(-1px); }
.icon-btn .ico { width: 1em; height: 1em; }

.ico-moon { display: none; }
html[data-theme="dark"] .ico-sun { display: none; }
html[data-theme="dark"] .ico-moon { display: block; }

/* ---------- 页面骨架 ---------- */
.page {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 48px 24px 64px;
  flex: 1;
}

/* ---------- 英雄区 ---------- */
.hero { text-align: center; margin-bottom: 40px; }

.hero-title {
  font-size: clamp(30px, 4.4vw, 46px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.5px;
}

.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub {
  max-width: 620px;
  margin: 18px auto 0;
  font-size: 16px;
  color: var(--text-2);
}

.hero-chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 24px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
}

.chip .ico { color: var(--ok); width: 0.95em; height: 0.95em; }

/* ---------- 上传区 ---------- */
.dropzone {
  background:
    radial-gradient(600px 200px at 50% -40px, var(--brand-bg), transparent 70%),
    var(--surface);
  border: 2px dashed var(--line);
  border-radius: 20px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
  cursor: pointer;
}

.dropzone:hover, .dropzone:focus-visible {
  border-color: var(--brand-400);
  box-shadow: var(--shadow-lg);
}

.dropzone.dragover {
  border-color: var(--brand-500);
  background:
    radial-gradient(600px 220px at 50% -40px, var(--brand-bg-2), transparent 70%),
    var(--surface);
  box-shadow: var(--shadow-lg);
  transform: scale(1.006);
}

.dropzone-inner {
  padding: 64px 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.dropzone-icon {
  width: 72px;
  height: 72px;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--grad);
  border-radius: 22px;
  box-shadow: var(--shadow-brand);
  margin-bottom: 22px;
  animation: float 3.6s ease-in-out infinite;
}

.dropzone-icon svg { width: 34px; height: 34px; }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-7px); }
}

.dropzone-title { font-size: 18px; font-weight: 700; line-height: 1.6; }
.dropzone-sub { margin-top: 8px; font-size: 13px; color: var(--text-3); }

.dropzone-steps {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 12px;
  margin-top: 26px;
}

.step {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
}

.step i {
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  font-style: normal;
  font-size: 12px;
  font-weight: 700;
  color: var(--brand-500);
  background: var(--brand-bg);
  border-radius: 50%;
  flex-shrink: 0;
}

.step-arrow { color: var(--text-3); font-size: 12px; }

.dropzone .btn { margin-top: 26px; }

/* ---------- 卡片 ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--line-2);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--line-2);
}

.card-head h3 { font-size: 15px; font-weight: 700; }

.card-head-actions { display: flex; gap: 8px; }

/* ---------- 工作区 ---------- */
.ws-grid {
  display: grid;
  grid-template-columns: minmax(280px, 2fr) 3fr;
  gap: 20px;
  align-items: start;
}

.img-card { overflow: hidden; }

.img-box {
  background:
    repeating-conic-gradient(var(--line-2) 0% 25%, transparent 0% 50%) 0 0 / 18px 18px,
    var(--surface-2);
  display: grid;
  place-items: center;
  padding: 20px;
  min-height: 220px;
}

.img-box img {
  max-width: 100%;
  max-height: 360px;
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
}

.img-meta {
  padding: 10px 20px 14px;
  font-size: 12px;
  color: var(--text-3);
  border-top: 1px solid var(--line-2);
}

/* ---------- 结果区 ---------- */
.result-card { position: relative; }

.status-tags { display: flex; gap: 8px; flex-wrap: wrap; }

.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-3);
  background: var(--surface-2);
  border: 1px solid var(--line-2);
  border-radius: 999px;
  white-space: nowrap;
}

.tag-ok { color: var(--ok); background: var(--ok-bg); border-color: transparent; }
.tag-live { color: var(--brand-500); background: var(--brand-bg); border-color: transparent; }

/* 加载态 */
.result-loading { padding: 24px 20px; }

.stage-row {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  margin-bottom: 22px;
}

.spinner {
  width: 18px;
  height: 18px;
  border: 2.5px solid var(--line);
  border-top-color: var(--brand-500);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex-shrink: 0;
}

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

.skeleton {
  border-radius: 8px;
  background: linear-gradient(90deg, var(--line-2) 25%, var(--line) 45%, var(--line-2) 65%);
  background-size: 200% 100%;
  animation: shimmer 1.4s ease infinite;
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.sk-preview { height: 110px; margin-bottom: 18px; }
.sk-line { height: 14px; margin-bottom: 10px; }
.sk-line.short { width: 55%; }

/* 错误态 */
.result-error {
  padding: 44px 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  color: var(--text-2);
}

.result-error svg { width: 44px; height: 44px; color: var(--err); margin-bottom: 14px; }
.result-error p { font-size: 14px; max-width: 380px; white-space: pre-line; }
.error-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 18px; }
.error-actions a.btn { text-decoration: none; }

/* 成功态 */
.result-body { padding: 20px; display: flex; flex-direction: column; }

.math-preview {
  background: var(--surface-2);
  border: 1px solid var(--line-2);
  border-radius: var(--radius-sm);
  padding: 26px 18px;
  overflow-x: auto;
  overflow-y: hidden;
  text-align: center;
  font-size: 1.12rem;
  min-height: 60px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 14px;
}

.math-preview .katex-display { margin: 0; }
.math-preview .render-fallback {
  font-family: var(--mono);
  font-size: 14px;
  color: var(--text-3);
  white-space: pre-wrap;
  word-break: break-all;
  text-align: left;
}
.math-preview .render-error { color: var(--err); font-size: 13px; }

.field-label {
  display: block;
  margin: 18px 2px 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
}

.latex-input {
  width: 100%;
  min-height: 92px;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  resize: vertical;
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.latex-input:focus {
  outline: none;
  border-color: var(--brand-500);
  box-shadow: 0 0 0 3px var(--brand-bg);
}

/* Tabs */
.tabs {
  display: flex;
  gap: 4px;
  margin-top: 18px;
  padding: 4px;
  background: var(--surface-2);
  border: 1px solid var(--line-2);
  border-radius: var(--radius-sm);
}

.tab {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 38px;
  padding: 0 10px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-3);
  background: transparent;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.18s ease;
  white-space: nowrap;
}

.tab small { font-size: 11px; font-weight: 500; opacity: 0.75; }
.tab:hover { color: var(--text-2); }

.tab.active {
  color: var(--brand-600);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

html[data-theme="dark"] .tab.active { color: var(--brand-400); }

.code-box {
  margin-top: 12px;
  padding: 14px 16px;
  max-height: 180px;
  overflow: auto;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.65;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--line-2);
  border-radius: var(--radius-sm);
  white-space: pre-wrap;
  word-break: break-all;
}

/* 操作按钮区 */
.actions-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

/* Word 提示 */
.word-tips {
  margin-top: 16px;
  border: 1px solid var(--line-2);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  font-size: 13px;
  color: var(--text-2);
}

.word-tips summary {
  padding: 11px 16px;
  font-weight: 600;
  color: var(--text-2);
  cursor: pointer;
  user-select: none;
  list-style: revert;
}

.word-tips summary:hover { color: var(--text); }
.word-tips ul { padding: 0 16px 14px 34px; }
.word-tips li { margin-top: 6px; }
.word-tips code { font-family: var(--mono); font-size: 12px; background: var(--brand-bg); color: var(--brand-600); padding: 1px 6px; border-radius: 5px; }
html[data-theme="dark"] .word-tips code { color: var(--brand-400); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 42px;
  padding: 0 20px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.18s ease;
  white-space: nowrap;
}

.btn:active { transform: scale(0.97); }

.btn-primary {
  color: #fff;
  background: var(--grad);
  box-shadow: var(--shadow-brand);
}
.btn-primary:hover { filter: brightness(1.06); }

.btn-secondary {
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
}
.btn-secondary:hover { border-color: var(--brand-400); color: var(--brand-600); }
html[data-theme="dark"] .btn-secondary:hover { color: var(--brand-400); }

.btn-ghost {
  color: var(--text-2);
  background: transparent;
  border: 1px dashed var(--line);
}
.btn-ghost:hover { color: var(--brand-600); border-color: var(--brand-400); }
html[data-theme="dark"] .btn-ghost:hover { color: var(--brand-400); }

.btn-sm { height: 34px; padding: 0 14px; font-size: 13px; }
.btn-sm .ico { width: 0.95em; height: 0.95em; }

/* ---------- 历史 ---------- */
.history { margin-top: 56px; }

.history-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.history-head h2 { font-size: 18px; font-weight: 700; }

.history-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 14px;
}

.history-item {
  position: relative;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--line-2);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: all 0.18s ease;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.history-item:hover { border-color: var(--brand-400); box-shadow: var(--shadow-lg); transform: translateY(-2px); }

.history-thumb {
  background:
    repeating-conic-gradient(var(--line-2) 0% 25%, transparent 0% 50%) 0 0 / 14px 14px,
    var(--surface-2);
  border-radius: 8px;
  overflow: hidden;
  height: 84px;
  display: grid;
  place-items: center;
}

.history-thumb img { max-width: 100%; max-height: 84px; }

.history-latex {
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-2);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  word-break: break-all;
}

.history-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-3);
}

.history-meta .engine-mini { padding: 1px 8px; border-radius: 999px; background: var(--surface-2); border: 1px solid var(--line-2); }

.history-del {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  font-size: 14px;
  color: var(--text-3);
  background: color-mix(in srgb, var(--surface) 80%, transparent);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  transition: all 0.15s ease;
}

.history-item:hover .history-del { opacity: 1; }
.history-del:hover { color: var(--err); background: var(--err-bg); }

.history-empty {
  padding: 32px;
  text-align: center;
  font-size: 14px;
  color: var(--text-3);
  background: var(--surface);
  border: 1px dashed var(--line);
  border-radius: var(--radius-sm);
}

/* ---------- 弹窗 ---------- */
.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 24px;
  background: rgba(13, 18, 32, 0.45);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn { from { opacity: 0; } }

.modal {
  width: 100%;
  max-width: 520px;
  background: var(--surface);
  border: 1px solid var(--line-2);
  border-radius: 20px;
  box-shadow: 0 24px 80px -16px rgba(0, 0, 0, 0.4);
  animation: pop 0.24s cubic-bezier(0.34, 1.4, 0.64, 1);
  max-height: 90vh;
  overflow: auto;
}

@keyframes pop { from { opacity: 0; transform: scale(0.94) translateY(8px); } }

.modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line-2);
}

.modal-head h3 { font-size: 16px; font-weight: 700; }

.modal-body { padding: 20px 22px; }

.modal-tip {
  font-size: 13px;
  color: var(--text-2);
  background: var(--brand-bg);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin-bottom: 18px;
}

.engine-options { display: flex; flex-direction: column; gap: 10px; }

.engine-option {
  display: flex;
  gap: 12px;
  padding: 14px 16px;
  background: var(--surface-2);
  border: 1.5px solid var(--line);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.18s ease;
}

.engine-option:hover { border-color: var(--brand-400); }

.engine-option:has(input:checked) {
  border-color: var(--brand-500);
  background: var(--brand-bg);
  box-shadow: 0 0 0 3px var(--brand-bg);
}

.engine-option input { margin-top: 3px; accent-color: var(--brand-500); }
.engine-option-title { display: flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 700; }
.engine-option-desc { margin-top: 3px; font-size: 12.5px; color: var(--text-3); line-height: 1.55; }

.token-wrap { margin-top: 16px; }

.input {
  width: 100%;
  height: 42px;
  padding: 0 14px;
  font-size: 14px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.input:focus { outline: none; border-color: var(--brand-500); box-shadow: 0 0 0 3px var(--brand-bg); }

.field-help { margin-top: 8px; font-size: 12.5px; color: var(--text-3); line-height: 1.6; }
.field-warn { color: var(--warn); }

.modal-foot {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding: 16px 22px 20px;
  border-top: 1px solid var(--line-2);
}

/* ---------- Toast ---------- */
.toast-wrap {
  position: fixed;
  top: 18px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 200;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  pointer-events: none;
}

.toast {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  max-width: min(92vw, 460px);
  padding: 11px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.25s cubic-bezier(0.34, 1.3, 0.64, 1);
}

.toast.out { animation: toastOut 0.25s ease forwards; }

.toast.ok .ico { color: var(--ok); }
.toast.err .ico { color: var(--err); }
.toast.info .ico { color: var(--brand-500); }
.toast .sub { font-weight: 500; font-size: 12.5px; color: var(--text-3); }

@keyframes toastIn { from { opacity: 0; transform: translateY(-12px) scale(0.94); } }
@keyframes toastOut { to { opacity: 0; transform: translateY(-8px) scale(0.96); } }

/* ---------- 页脚 ---------- */
.footer {
  border-top: 1px solid var(--line-2);
  padding: 28px 24px 36px;
  text-align: center;
  font-size: 13px;
  color: var(--text-3);
}

.footer-privacy { max-width: 640px; margin: 0 auto 8px; line-height: 1.7; }

/* ---------- 响应式 ---------- */
@media (max-width: 920px) {
  .ws-grid { grid-template-columns: 1fr; }
  .brand-name em { display: none; }
}

@media (max-width: 640px) {
  .page { padding: 32px 16px 48px; }
  .hero-sub { font-size: 14.5px; }
  .dropzone-inner { padding: 44px 18px; }
  .nav-inner { padding: 0 16px; }
  .engine-badge span:last-child { max-width: 90px; overflow: hidden; text-overflow: ellipsis; }
  .actions-row .btn { flex: 1; }
  .dropzone-steps { flex-direction: column; align-items: flex-start; gap: 8px; }
  .step-arrow { transform: rotate(90deg); }
  .history-grid { grid-template-columns: 1fr 1fr; }
}

/* KaTeX 暗色适配 */
html[data-theme="dark"] .math-preview .katex { color: var(--text); }

/* 滚动条 */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-thumb { background: var(--line); border-radius: 999px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-3); }
::-webkit-scrollbar-track { background: transparent; }