:root {
  --bg: #f4f6f9;
  --card: #ffffff;
  --text: #2c3e50;
  --muted: #7f8c9a;
  --primary: #2e86de;
  --primary-d: #1e6fc0;
  --border: #e3e8ef;
  --c-kcal: #e67e22;
  --c-protein: #e74c3c;
  --c-fat: #f1c40f;
  --c-carb: #3498db;
  --danger: #e74c3c;
  --ok: #27ae60;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 15px;
}
.hidden { display: none !important; }
h1, h2, h3 { margin: 0 0 0.5em; }
h2 { font-size: 20px; }
h3 { font-size: 16px; color: var(--muted); margin-top: 1.2em; }

/* 登录 / 注册 */
.auth-screen { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 16px; }
.auth-card {
  background: var(--card); border-radius: 16px; box-shadow: var(--shadow);
  width: 100%; max-width: 380px; padding: 32px 28px;
}
.auth-card h1 { text-align: center; font-size: 26px; color: var(--primary); }
.subtitle { text-align: center; color: var(--muted); margin-top: -6px; font-size: 13px; }
.auth-tabs { display: flex; gap: 8px; margin: 20px 0 14px; }
.auth-tabs button {
  flex: 1; padding: 10px; border: 1px solid var(--border); background: #fff; border-radius: 10px; cursor: pointer; color: var(--muted);
}
.auth-tabs button.active { background: var(--primary); color: #fff; border-color: var(--primary); }
#auth-form { display: flex; flex-direction: column; gap: 10px; }
#auth-form input { padding: 11px 12px; border: 1px solid var(--border); border-radius: 10px; font-size: 15px; }
#auth-form button { padding: 11px; border: none; background: var(--primary); color: #fff; border-radius: 10px; font-size: 15px; cursor: pointer; }
#auth-form button:hover { background: var(--primary-d); }
.auth-tip { font-size: 12px; color: var(--muted); text-align: center; margin-top: 14px; }

/* 主应用 */
.topbar {
  position: sticky; top: 0; z-index: 10; background: var(--card); border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between; padding: 10px 16px; flex-wrap: wrap; gap: 8px;
}
.brand { font-weight: 700; color: var(--primary); font-size: 18px; display: flex; align-items: center; gap: 8px; }
.mode-badge { font-size: 11px; font-weight: 600; color: #8a6d3b; background: #fdf3e1; border: 1px solid #f3d9a8; padding: 2px 8px; border-radius: 999px; }
.backup-group { display: inline-flex; gap: 6px; align-items: center; }
button.ghost { background: #eef2f7; color: var(--text); border: 1px solid var(--border); padding: 7px 12px; border-radius: 9px; cursor: pointer; font-size: 13px; }
button.ghost:hover { background: #e3e9f1; }
.nav { display: flex; gap: 6px; flex-wrap: wrap; align-items: center; }
.nav button {
  border: none; background: transparent; color: var(--muted); padding: 8px 12px; border-radius: 8px; cursor: pointer; font-size: 14px;
}
.nav button.active { background: var(--primary); color: #fff; }
.nav button.logout { color: var(--danger); }
main { max-width: 880px; margin: 0 auto; padding: 18px 16px 60px; }

/* 卡片 */
.card { background: var(--card); border-radius: 14px; box-shadow: var(--shadow); padding: 20px; margin-bottom: 18px; }
.hint { color: var(--muted); font-size: 13px; margin: 4px 0 14px; }

/* 表单 */
.form-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
label { display: flex; flex-direction: column; font-size: 13px; color: var(--muted); gap: 4px; }
label.full { grid-column: 1 / -1; }
input, select {
  padding: 9px 10px; border: 1px solid var(--border); border-radius: 9px; font-size: 14px; color: var(--text); background: #fff;
}
input:focus, select:focus { outline: none; border-color: var(--primary); }
.row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin: 12px 0; }
.date-row { align-items: flex-end; }
.field-date { display: flex; flex-direction: column; gap: 4px; flex: 0 0 auto; max-width: 240px; }
.field-date input { width: 100%; box-sizing: border-box; }

/* 按钮 */
button.primary { background: var(--primary); color: #fff; border: none; padding: 10px 16px; border-radius: 9px; cursor: pointer; font-size: 14px; }
button.primary:hover { background: var(--primary-d); }
button:not(.primary):not(.active) { background: #eef2f7; color: var(--text); border: 1px solid var(--border); padding: 9px 14px; border-radius: 9px; cursor: pointer; }

/* 消息 */
.msg { font-size: 13px; color: var(--muted); }
.msg.err { color: var(--danger); }
.msg.ok { color: var(--ok); }

/* 轻量弹窗提示（登录成功 / 保存成功 等） */
.toast {
  position: fixed; left: 50%; top: 22%;
  transform: translate(-50%, -12px);
  background: rgba(33, 45, 60, .96); color: #fff;
  padding: 12px 24px; border-radius: 12px;
  font-size: 15px; font-weight: 600; letter-spacing: .5px;
  z-index: 9999; opacity: 0; transition: opacity .25s, transform .25s;
  pointer-events: none; box-shadow: 0 10px 30px rgba(0, 0, 0, .22);
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.toast-err { background: rgba(200, 50, 50, .96); }

/* 保存提示小字 */
.save-tip {
  color: var(--primary); background: #f3f8ff;
  border: 1px dashed #bcd5f5; border-radius: 10px;
  padding: 8px 12px; margin: 10px 0 14px; font-size: 12.5px;
}

/* 食物搜索 */
.food-search { position: relative; }
.food-search input { width: 100%; }
.results { margin-top: 8px; display: flex; flex-direction: column; gap: 8px; max-height: 320px; overflow: auto; }
.food-item { border: 1px solid var(--border); border-radius: 10px; padding: 10px 12px; background: #fbfcfe; }
.fi-main { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.fi-main b { font-size: 15px; }
.tag { background: #eaf2fb; color: var(--primary); font-size: 11px; padding: 2px 7px; border-radius: 20px; }
.serv { color: var(--muted); font-size: 12px; }
.fi-nut { color: var(--muted); font-size: 12px; margin: 4px 0 8px; }
.fi-add { display: flex; align-items: center; gap: 8px; }
.fi-add .qty { width: 80px; }
.tag.custom { background: #fff3e0; color: #c8741b; }
.del-custom { background: #f1f3f6; color: var(--muted); border: 1px solid var(--border); padding: 6px 10px; border-radius: 8px; cursor: pointer; font-size: 12px; }
.del-custom:hover { color: var(--danger); border-color: var(--danger); }

/* 自定义食物添加表单 */
.custom-add { border: 1px dashed var(--primary); border-radius: 12px; padding: 14px; background: #f7fbff; }
.custom-add .ca-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin: 10px 0; }
.custom-add .ca-grid label { display: flex; flex-direction: column; gap: 4px; font-size: 13px; color: var(--muted); }
.custom-add .ca-grid input, .custom-add .ca-grid select { width: 100%; box-sizing: border-box; }
@media (max-width: 560px) { .custom-add .ca-grid { grid-template-columns: repeat(2, 1fr); } }

/* 表格 */
.nutri-table { width: 100%; border-collapse: collapse; font-size: 13px; margin-top: 6px; }
.nutri-table th, .nutri-table td { text-align: right; padding: 8px 6px; border-bottom: 1px solid var(--border); }
.nutri-table th:first-child, .nutri-table td:first-child { text-align: left; }
.nutri-table th { color: var(--muted); font-weight: 600; }
button.del { background: #fdecea; color: var(--danger); border: none; width: 26px; height: 26px; border-radius: 6px; cursor: pointer; line-height: 1; }

/* 宏量进度条 */
.macros { display: flex; flex-direction: column; gap: 14px; margin-top: 8px; }
.macro-head { display: flex; justify-content: space-between; align-items: baseline; font-size: 14px; gap: 8px; flex-wrap: wrap; }
.macro-head b { font-size: 15px; }
.macro-head i { color: var(--muted); font-style: normal; font-size: 12px; }
.bar { height: 12px; background: #eef2f7; border-radius: 20px; overflow: hidden; margin-top: 5px; }
.bar-fill { height: 100%; border-radius: 20px; transition: width 0.3s; }

/* 结果统计 */
.result-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 8px 0 12px; }
.stat { background: #f7f9fc; border: 1px solid var(--border); border-radius: 12px; padding: 14px; text-align: center; }
.stat span { display: block; color: var(--muted); font-size: 12px; }
.stat b { display: block; font-size: 24px; margin: 4px 0; }
.stat i { font-style: normal; color: var(--muted); font-size: 11px; }
.stat.highlight { background: #eaf2fb; border-color: var(--primary); }
.stat.over b { color: var(--c-kcal); }
.stat.under b { color: var(--ok); }

/* 知识课堂 */
.lv { margin-top: 22px; color: var(--text) !important; border-left: 4px solid var(--primary); padding-left: 10px; }
.articles { display: flex; flex-direction: column; gap: 8px; }
.article { border: 1px solid var(--border); border-radius: 10px; background: #fbfcfe; overflow: hidden; }
.article summary { cursor: pointer; padding: 12px 14px; display: flex; align-items: center; gap: 10px; }
.article summary b { flex: 1; font-size: 14px; }
.article-body { padding: 0 16px 14px; font-size: 14px; color: #3a4a5a; }
.article-body ul { padding-left: 20px; margin: 6px 0; }
.article-body li { margin: 4px 0; }

/* 知识来源引用块 */
.article-source {
  margin-top: 12px; padding: 10px 12px; background: #f3f7fb; border-left: 3px solid var(--primary);
  border-radius: 0 8px 8px 0; font-size: 12px; line-height: 1.7; color: #5a6b7b;
}
.article-source .src-label { display: block; font-weight: 700; color: var(--primary); margin-bottom: 3px; }
.article-source i { color: #7a8a9a; }

/* 营养计算器：公式与来源折叠块 */
.formula-note { margin-top: 14px; border: 1px solid var(--border); border-radius: 10px; background: #fbfcfe; overflow: hidden; }
.formula-note summary { cursor: pointer; padding: 11px 14px; font-size: 13px; font-weight: 600; color: var(--primary); }
.formula-body { padding: 0 16px 14px; font-size: 13px; color: #3a4a5a; }
.formula-body p { margin: 10px 0 4px; }
.formula-body ul { padding-left: 20px; margin: 4px 0; }
.formula-body li { margin: 3px 0; }

/* 知识联动跳转按钮 */
.link-row { margin-top: 14px; display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.link-label { font-size: 13px; color: var(--muted); }
.link-chip {
  border: 1px solid var(--primary); color: var(--primary); background: #fff; padding: 6px 12px;
  border-radius: 20px; cursor: pointer; font-size: 13px; transition: all .15s;
}
.link-chip:hover { background: var(--primary); color: #fff; }

/* 联动打开文章时的高亮闪烁 */
.article.flash { box-shadow: 0 0 0 3px rgba(46,134,222,.5); transition: box-shadow .3s; }

/* ============ 知识课堂：书籍式阅读 ============ */
.book { display: flex; flex-direction: column; height: calc(100vh - 150px); min-height: 480px; border: 1px solid var(--border); border-radius: 14px; overflow: hidden; background: #fff; }
.book-top { display: flex; align-items: center; gap: 12px; padding: 10px 14px; border-bottom: 1px solid var(--border); background: #f7f9fc; }
.book-title { font-weight: 700; color: var(--text); font-size: 15px; flex: 1; }
.toc-toggle { display: none; border: 1px solid var(--border); background: #fff; border-radius: 8px; padding: 6px 10px; cursor: pointer; font-size: 13px; }
.book-progress { display: flex; align-items: center; gap: 8px; min-width: 160px; }
.bp-bar { flex: 1; height: 8px; background: #e3e9f1; border-radius: 99px; overflow: hidden; position: relative; }
.bp-bar::after { content: ''; position: absolute; left: 0; top: 0; height: 100%; width: var(--w, 0%); background: linear-gradient(90deg, var(--primary), #6db8ff); transition: width .3s; }
#bp-pct { font-size: 12px; color: var(--muted); min-width: 34px; text-align: right; }

.book-main { display: flex; flex: 1; min-height: 0; }
.book-toc { width: 230px; flex-shrink: 0; border-right: 1px solid var(--border); overflow-y: auto; padding: 10px 8px; background: #fbfcfe; }
.toc-ch { margin-bottom: 14px; }
.toc-ch-title { font-size: 12px; font-weight: 700; color: var(--primary); padding: 4px 8px; letter-spacing: .3px; }
.toc-sec { display: block; width: 100%; text-align: left; border: none; background: transparent; padding: 7px 10px; border-radius: 7px; cursor: pointer; font-size: 13px; color: #45566a; line-height: 1.35; }
.toc-sec:hover { background: #eaf2fc; }
.toc-sec.active { background: var(--primary); color: #fff; font-weight: 600; }

.book-read { flex: 1; min-width: 0; overflow-y: auto; padding: 22px 28px 40px; }
.book-sec { max-width: 720px; margin: 0 auto; }
.sec-crumb { font-size: 12px; color: var(--muted); margin-bottom: 4px; }
.sec-title { font-size: 22px; color: var(--text); margin: 0 0 14px; }
.book-body { font-size: 15px; line-height: 1.85; color: #34465a; }
.book-body p { margin: 12px 0; }
.book-body ul { padding-left: 22px; margin: 10px 0; }
.book-body li { margin: 6px 0; }
.book-body .note { background: #fff8e6; border-left: 4px solid #f0b429; padding: 10px 12px; border-radius: 8px; font-size: 14px; color: #6b5310; }
.book-body b { color: var(--text); }
.article-source { margin-top: 18px; padding: 10px 12px; background: #f5f8fc; border: 1px solid var(--border); border-radius: 10px; font-size: 12px; color: #5a6b7d; }
.article-source .src-label { display: block; font-weight: 700; color: var(--primary); margin-bottom: 4px; }
.article-source i { color: #7a8a9a; }

mark.hl { background: #fff1a8; color: inherit; border-radius: 3px; padding: 0 1px; cursor: pointer; box-shadow: 0 0 0 1px rgba(240,180,40,.5); }
.hl-btn { position: fixed; z-index: 9999; background: #2e86de; color: #fff; border: none; border-radius: 8px; padding: 7px 12px; font-size: 13px; cursor: pointer; box-shadow: 0 4px 14px rgba(0,0,0,.2); }

.book-nav { display: flex; align-items: center; justify-content: space-between; gap: 12px; max-width: 720px; margin: 28px auto 0; padding-top: 16px; border-top: 1px dashed var(--border); }
.book-nav .ghost { padding: 8px 16px; }
.book-nav .ghost:disabled { opacity: .4; cursor: not-allowed; }
.read-flag { font-size: 13px; color: var(--ok); font-weight: 600; }

/* 移动端：目录改为可折叠抽屉 */
@media (max-width: 760px) {
  .book { height: calc(100vh - 130px); }
  .toc-toggle { display: inline-block; }
  .book-toc { position: absolute; z-index: 50; top: 0; left: 0; bottom: 0; width: 78%; max-width: 280px; box-shadow: 4px 0 18px rgba(0,0,0,.12); transform: translateX(-105%); transition: transform .25s; }
  .book-toc.open { transform: translateX(0); }
  .book-main { position: relative; }
  .book-read { padding: 16px 14px 36px; }
  .sec-title { font-size: 19px; }
  .book-body { font-size: 15px; line-height: 1.8; }
}

/* 训练计划日历 */
.cal-head { display: flex; align-items: center; justify-content: space-between; margin: 6px 0 8px; }
.cal-title { font-weight: 700; color: var(--text); font-size: 15px; }
.cal-legend { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 10px; font-size: 12px; color: var(--muted); }
.cal-legend span { display: inline-flex; align-items: center; gap: 4px; }
.cal-legend i { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }
.cal-week { display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; margin-bottom: 4px; }
.cal-week span { text-align: center; font-size: 12px; color: var(--muted); padding: 4px 0; }
.cal-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; }
.cal-cell {
  position: relative; min-height: 52px; border: 1px solid var(--border); border-radius: 8px;
  background: #fbfcfe; padding: 4px 5px; cursor: pointer; display: flex; flex-direction: column;
  font-size: 13px; color: var(--text); transition: all .12s;
}
.cal-cell:hover { border-color: var(--primary); background: #f0f6fd; }
.cal-cell.empty { background: transparent; border: none; cursor: default; }
.cal-cell.has { background: #f3f8ff; }
.cal-cell.selected { border-color: var(--primary); box-shadow: 0 0 0 2px rgba(46,134,222,.35); background: #eaf2fb; }
.cal-day { font-weight: 600; }
.cal-dot { position: absolute; top: 6px; right: 6px; width: 9px; height: 9px; border-radius: 50%; }
.cal-plan { font-size: 11px; color: var(--muted); margin-top: auto; }

/* AI 达标助手 */
.ai-card { background: linear-gradient(180deg, #fbfdff, #f4f8fd); }
.ai-settings { border: 1px solid var(--border); border-radius: 10px; background: #fff; overflow: hidden; margin-bottom: 10px; }
.ai-settings summary { cursor: pointer; padding: 11px 14px; font-size: 13px; font-weight: 600; color: var(--primary); }
.ai-settings .form-grid { padding: 0 14px 6px; }
.ai-out { margin-top: 12px; }
.ai-reply { background: #fff; border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px; font-size: 14px; color: #34465a; line-height: 1.7; }
.ai-reply p { margin: 6px 0; }
.ai-reply ul { padding-left: 20px; margin: 6px 0; }
.ai-reply li { margin: 4px 0; }

/* 反馈与建议 */
.fb-form { margin-top: 6px; }
.fb-form textarea {
  width: 100%; box-sizing: border-box; resize: vertical; font-family: inherit;
  border: 1px solid var(--border); border-radius: 9px; padding: 10px; font-size: 14px; color: var(--text);
}
.fb-form textarea:focus { outline: none; border-color: var(--primary); }
.fb-list { display: flex; flex-direction: column; gap: 12px; margin-top: 6px; }
.fb-item { border: 1px solid var(--border); border-radius: 12px; padding: 14px 16px; background: #fbfcfe; }
.fb-meta { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; margin-bottom: 6px; }
.fb-meta b { font-size: 14px; color: var(--primary); }
.fb-meta span { font-size: 12px; color: var(--muted); }
.fb-content { font-size: 14px; color: #34465a; line-height: 1.7; white-space: pre-wrap; word-break: break-word; }


/* 移动端 */
@media (max-width: 600px) {
  .form-grid { grid-template-columns: 1fr; }
  .result-grid { grid-template-columns: 1fr; }
  .nav button { padding: 7px 9px; font-size: 13px; }
  main { padding: 14px 12px 50px; }
  .card { padding: 16px; }
  /* 训练记录：日期行纵向排列，避免「回到今天」按钮在手机上盖住日期选择 */
  .date-row { flex-direction: column; align-items: stretch; }
  .field-date { max-width: 100%; }
  .date-row .ghost { width: 100%; margin-top: 8px; }
}