:root {
  --bg: #f4f5fb;
  --bg-grad: linear-gradient(180deg, #f7f8fd 0%, #eef1f8 100%);
  --card: #ffffff;
  --border: #e6e8f0;
  --border-strong: #d8dce8;
  --text: #232838;
  --text-soft: #5a6178;
  --muted: #8d93a8;
  --primary: #4a6cf7;
  --primary-dark: #3a55d6;
  --primary-soft: #eef1ff;
  --danger: #e5484d;
  --danger-soft: #fdeeee;
  --warn: #e08f2c;
  --warn-soft: #fff4e2;
  --ok: #2e9e5b;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(23, 30, 54, 0.03), 0 1px 4px rgba(23, 30, 54, 0.05);
  --shadow-hover: 0 2px 6px rgba(23, 30, 54, 0.08), 0 6px 18px rgba(74, 108, 247, 0.08);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg-grad);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* ---------- 顶栏 ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 26px;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 50;
}
.logo { font-weight: 800; font-size: 17px; letter-spacing: 0.2px; color: var(--primary); }
.logo::before { content: "✦"; margin-right: 6px; font-size: 14px; }
.topbar nav a {
  margin-left: 6px;
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  padding: 7px 13px;
  border-radius: 999px;
  transition: all 0.18s;
}
.topbar nav a:hover { color: var(--text); background: var(--primary-soft); }
.topbar nav a.active { color: var(--primary); background: var(--primary-soft); font-weight: 600; }

/* ---------- 布局 ---------- */
main { max-width: 880px; margin: 26px auto 60px; padding: 0 18px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 26px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.card h2 { margin: 0 0 16px; font-size: 18px; font-weight: 700; }
.card h3 { font-size: 15px; margin: 20px 0 10px; color: var(--text-soft); }

/* ---------- 表单 ---------- */
label { display: block; font-size: 12.5px; color: var(--muted); margin: 14px 0 6px; font-weight: 600; letter-spacing: 0.2px; }
input[type="text"], input[type="search"], select, textarea {
  width: 100%;
  padding: 9px 12px;
  border: 1px solid var(--border-strong);
  border-radius: 9px;
  font-size: 14px;
  font-family: inherit;
  background: #fff;
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
}
textarea { resize: vertical; }
input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.14);
}
.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 0 14px;
}

/* ---------- 按钮 ---------- */
button {
  font-family: inherit;
  font-size: 14px;
  padding: 8px 16px;
  border: 1px solid var(--border-strong);
  background: #fff;
  color: var(--text-soft);
  border-radius: 9px;
  cursor: pointer;
  transition: all 0.15s;
}
button:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); }
button.primary {
  background: linear-gradient(135deg, #4a6cf7, #3a55d6);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 1px 4px rgba(74, 108, 247, 0.35);
}
button.primary:hover { background: linear-gradient(135deg, #5b7bf8, #425fd8); color: #fff; }
button.danger { color: var(--danger); border-color: #f0c9cb; }
button.danger:hover { background: var(--danger-soft); color: var(--danger); }
button:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-row { display: flex; gap: 10px; margin-top: 16px; flex-wrap: wrap; }

/* ---------- 上传 / 裁剪 ---------- */
.drop-zone {
  border: 2px dashed var(--border-strong);
  border-radius: var(--radius);
  padding: 40px 16px;
  text-align: center;
  color: var(--muted);
  cursor: pointer;
  margin-top: 14px;
  transition: all 0.2s;
  background: #fbfcff;
  font-size: 14px;
}
.drop-zone:hover, .drop-zone.drag { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); }
.crop-wrap { margin-top: 14px; }
.crop-box {
  position: relative;
  display: inline-block;
  max-width: 100%;
  background: #111;
  border-radius: 10px;
  overflow: hidden;
  line-height: 0;
  box-shadow: var(--shadow-hover);
}
.crop-box img { max-width: 100%; display: block; }
.crop-frame {
  position: absolute;
  border: 2px solid #4a9eff;
  background: rgba(74, 158, 255, 0.10);
  cursor: move;
  touch-action: none;
}
.crop-handle { position: absolute; right: 0; bottom: 0; width: 18px; height: 18px; }
.crop-handle::after {
  content: "";
  position: absolute;
  right: 3px; bottom: 3px;
  width: 10px; height: 10px;
  border-right: 2px solid #4a9eff;
  border-bottom: 2px solid #4a9eff;
}
.img-preview { margin-top: 14px; }
.img-preview img { max-width: 100%; border-radius: 10px; box-shadow: var(--shadow); }

/* ---------- 左右分栏(识别对比) ---------- */
.split {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 3fr);
  gap: 22px;
  align-items: start;
}
.split-left { position: sticky; top: 74px; }
.split-left img {
  width: 100%;
  border-radius: 10px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
@media (max-width: 700px) {
  .split { grid-template-columns: 1fr; }
  .split-left { position: static; }
}

/* ---------- 题干/选项 自动撑高、全宽、自动换行 ---------- */
.auto-grow { overflow: hidden; resize: none; min-height: 44px; }
.option-rows { display: flex; flex-direction: column; gap: 7px; margin-top: 4px; }
.option-row { display: flex; align-items: flex-start; gap: 9px; }
.option-key {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  margin-top: 9px;
  border-radius: 50%;
  background: linear-gradient(135deg, #4a6cf7, #3a55d6);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  box-shadow: 0 1px 3px rgba(74, 108, 247, 0.35);
}
.option-row textarea { flex: 1; }

/* ---------- AI 解析可视化 ---------- */
.muted { color: var(--muted); }
.link-btn { border: none; background: none; color: var(--primary); font-size: 12.5px; padding: 0 4px; cursor: pointer; text-decoration: underline; }
.link-btn:hover { color: var(--primary-dark); background: none; }
.analysis-view { font-size: 14.5px; line-height: 1.85; color: var(--text); }
.analysis-view .md-h {
  font-weight: 700;
  margin: 16px 0 7px;
  color: var(--primary-dark);
  font-size: 15px;
}
.analysis-view p { margin: 7px 0; }
.analysis-view ul { margin: 7px 0; padding-left: 22px; }
.analysis-view li { margin: 3px 0; }
.analysis-view strong { color: var(--primary-dark); }
.analysis-view code {
  background: var(--primary-soft);
  color: var(--primary-dark);
  padding: 1px 6px;
  border-radius: 5px;
  font-size: 12.5px;
}
.analysis-edit { width: 100%; min-height: 230px; font-size: 13px; line-height: 1.75; }

/* ---------- 追问聊天 ---------- */
.chat-box { margin-top: 20px; border-top: 1px solid var(--border); padding-top: 14px; }
.chat-tag { font-size: 12.5px; color: var(--muted); margin-bottom: 10px; }
#chat-thread { max-height: 340px; overflow-y: auto; }
.chat-msg {
  font-size: 14px;
  line-height: 1.75;
  margin-bottom: 9px;
  padding: 9px 13px;
  border-radius: 10px;
  white-space: pre-wrap;
  overflow-wrap: break-word;
}
.chat-msg.user { background: var(--primary-soft); color: var(--text); }
.chat-msg.assistant { background: #f6f7fb; border: 1px solid var(--border); }
.chat-msg.loading-msg { color: var(--muted); }
.chat-msg .md-h { font-weight: 700; margin: 6px 0 2px; color: var(--primary-dark); }
.chat-msg ul { margin: 4px 0; padding-left: 20px; }
.chat-input-row { display: flex; gap: 8px; }
.chat-input-row input { flex: 1; }

/* ---------- 详情页左右布局 ---------- */
.detail-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}
.detail-left h2, .detail-right h2 { margin-top: 0; }
@media (max-width: 800px) {
  .detail-split { grid-template-columns: 1fr; }
}

/* ---------- 错题群 ---------- */
.clu-banner {
  background: var(--primary-soft);
  border: 1px solid var(--border);
  border-radius: 9px;
  padding: 10px 16px;
  font-size: 14px;
  margin-bottom: 14px;
}
.clu-banner.ok { background: #eafff0; color: var(--ok); }
.clu-banner strong { color: var(--primary-dark); }
.clu-detail label { margin-top: 12px; }
.batch-card { border: 1px dashed var(--border-strong); padding: 16px 18px; margin-bottom: 12px; background: #fbfcff; }
.batch-card .q-top { margin-bottom: 6px; }

/* ---------- 多图上传 ---------- */
.img-card-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 12px;
  background: #fbfcff;
}
.img-card-top {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 8px;
}
.img-card-top img {
  max-height: 150px;
  border-radius: 8px;
  border: 1px solid var(--border);
}
.img-card-remove {
  padding: 4px 10px;
  font-size: 13px;
  flex-shrink: 0;
}
.img-card-item label { margin-top: 6px; }
.img-card-item input[type="text"] { width: 100%; }
.img-card-status { font-size: 13px; margin-left: 8px; }
.img-card-result { margin-top: 8px; }

/* ---------- 列表 ---------- */
.toolbar { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.toolbar select, .toolbar input { width: auto; }
.toolbar input[type="search"] { flex: 1; min-width: 180px; }
.q-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 18px;
  margin-top: 12px;
  cursor: pointer;
  background: #fff;
  transition: all 0.16s;
}
.q-item:hover { border-color: var(--primary); box-shadow: var(--shadow-hover); transform: translateY(-1px); }
.q-item .q-top { display: flex; gap: 8px; align-items: center; margin-bottom: 7px; flex-wrap: wrap; }
.badge {
  font-size: 12px;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  white-space: nowrap;
  font-weight: 600;
}
.badge.wrong { background: var(--danger-soft); color: var(--danger); }
.badge.unknown { background: var(--warn-soft); color: var(--warn); }
.q-item .q-content { font-size: 14px; color: var(--text); line-height: 1.7; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.q-item .q-meta { font-size: 12.5px; color: var(--muted); margin-top: 7px; }
.pager { display: flex; gap: 12px; align-items: center; justify-content: center; margin-top: 18px; color: var(--muted); font-size: 13px; }
.empty { text-align: center; color: var(--muted); padding: 44px 0; }

/* ---------- 统计 / 账单 ---------- */
.chart { width: 100%; height: 360px; }
.chart.small { height: 280px; }
.stat-summary { font-size: 14px; color: var(--muted); margin-bottom: 10px; }
.chart-holder { margin-top: 20px; }

.bill-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 12px;
  margin-bottom: 22px;
}
.bill-card {
  background: linear-gradient(160deg, #ffffff, #f6f8ff);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  box-shadow: var(--shadow);
}
.bill-num { font-size: 24px; font-weight: 800; color: var(--primary-dark); }
.bill-label { font-size: 12.5px; color: var(--muted); margin-top: 4px; }
.bill-note { font-size: 12px; color: var(--muted); margin: 12px 0 4px; }
.bill-table-wrap { overflow-x: auto; }
.bill-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.bill-table th { text-align: left; font-size: 12px; color: var(--muted); font-weight: 600; padding: 8px 10px; border-bottom: 1px solid var(--border); }
.bill-table td { padding: 8px 10px; border-bottom: 1px solid var(--border); color: var(--text); }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 34px;
  transform: translateX(-50%) translateY(20px);
  background: #2b3050;
  color: #fff;
  padding: 11px 20px;
  border-radius: 10px;
  font-size: 14px;
  opacity: 0;
  pointer-events: none;
  transition: all 0.25s;
  z-index: 100;
  max-width: 80vw;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.18);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast.error { background: var(--danger); }
.toast.warn { background: var(--warn); }
.toast.ok { background: var(--ok); }

/* ---------- 加载 ---------- */
.loading { text-align: center; color: var(--muted); padding: 32px 0; }
.spinner {
  display: inline-block;
  width: 18px; height: 18px;
  border: 2px solid rgba(74, 108, 247, 0.22);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  vertical-align: -4px;
  margin-right: 8px;
}
@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 600px) {
  main { margin: 14px auto 50px; }
  .topbar { padding: 10px 14px; }
  .logo { font-size: 15px; }
  .topbar nav a { padding: 6px 9px; font-size: 13px; }
}