/* 学习相关页面：顶部导航、今日计划和打卡、复习、表达库、学习记录（图表）、复盘数据 */
:root {
  /* 图表：两条折线（很自然 / 夹中文，已跑色盲和区分度校验）、柱子、日历深浅（单色由浅到深） */
  --c1: #2f7d4f; --c2: #3a5ba8; --bar: #5b6270;
  --s0: #e6e8ec; --s1: #c4e3cf; --s2: #86c49c; --s3: #4a9c69; --s4: #2f7d4f;
}
@media (prefers-color-scheme: dark) {
  :root {
    --c1: #4ea874; --c2: #6f8fdb; --bar: #8b919c;
    --s0: #25282e; --s1: #1f4631; --s2: #2c6a45; --s3: #3f935d; --s4: #62bb85;
  }
}
.muted { color: var(--muted); }
kbd { font: 11px ui-monospace, Menlo, monospace; border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 4px; padding: 0 4px; margin-left: 4px; color: var(--muted); background: var(--panel); }
.btn.primary kbd { color: inherit; border-color: color-mix(in srgb, currentColor 40%, transparent); background: none; }
.acts-row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 14px 0 0; }
a.btn { text-decoration: none; display: inline-flex; align-items: center; gap: 4px; }
select { font: inherit; }

/* 顶部导航 */
#nav { display: flex; gap: 2px; }
#nav a { color: var(--muted); text-decoration: none; padding: 5px 10px; border-radius: 8px; font-size: 14px; white-space: nowrap; }
#nav a:hover { color: var(--ink); background: var(--bg); }
#nav a.on { color: var(--ink); background: var(--bg); font-weight: 600; }
.badge { display: inline-block; min-width: 18px; padding: 0 5px; border-radius: 99px; background: var(--accent); color: #fff; font-size: 11px; line-height: 18px; text-align: center; font-weight: 600; }

/* 今日计划 + 打卡 */
.plan { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 14px; margin-bottom: 14px; }
.plan-main, .streak { background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 14px 18px; }
.plan-h { display: flex; align-items: baseline; gap: 10px; margin-bottom: 4px; }
.plan-h h2 { margin: 0; font-size: 20px; }
.plan-h small { color: var(--muted); }
.step { display: flex; align-items: center; gap: 12px; padding: 9px 0; border-top: 1px solid var(--line); }
.step:first-of-type { border-top: none; }
.step .st { color: var(--muted); font-size: 20px; line-height: 1; }
.step.done .st { color: var(--good); }
.step .sb { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.step .sb small { color: var(--muted); }
.step.done .sb b { color: var(--muted); }
.step.skip { opacity: .6; }
.step .btn { white-space: nowrap; padding: 6px 12px; font-size: 14px; }
.pbar { display: block; height: 6px; background: var(--line); border-radius: 3px; overflow: hidden; margin-top: 5px; max-width: 260px; }
.pbar i { display: block; height: 100%; background: var(--good); border-radius: 3px; }
.streak { display: flex; flex-direction: column; gap: 14px; }
.streak-side { display: flex; flex-direction: column; gap: 6px; }
.streak-n { display: flex; align-items: baseline; gap: 6px; color: var(--accent); }
.streak-n .ic { width: 26px; height: 26px; align-self: center; }
.streak-n b { font: 700 34px/1 Fraunces, serif; }
.streak-n span { color: var(--muted); font-size: 14px; }
.streak-meta { font-size: 13px; color: var(--muted); }
.cal-legend { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 12px; 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: 3px; }
.cal-legend i.act { background: var(--s2); } .cal-legend i.goal { background: var(--s4); }
.cal-legend a { color: var(--ink); margin-left: auto; text-decoration: none; }
.cal-legend a:hover { text-decoration: underline; }
/* 打卡月历 */
.mcal { border-top: 1px solid var(--line); padding-top: 10px; }
.cal-h { display: flex; align-items: center; justify-content: space-between; margin-bottom: 6px; }
.cal-title { border: none; background: none; color: var(--ink); font-weight: 600; font-size: 14px; padding: 3px 8px; border-radius: 7px; display: inline-flex; align-items: center; gap: 4px; }
.cal-title .ic { color: var(--muted); }
.cal-nav { border: none; background: none; color: var(--muted); width: 28px; height: 28px; border-radius: 7px; display: grid; place-items: center; }
.cal-title:hover, .cal-nav:hover:not(:disabled) { background: var(--bg); color: var(--ink); }
.cal-nav:disabled { opacity: .3; cursor: default; }
.cal-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; text-align: center; }
.cal-grid small { font-size: 11px; color: var(--muted); padding-bottom: 2px; }
.cd { aspect-ratio: 1; display: grid; place-items: center; border-radius: 8px; font-size: 12.5px; font-variant-numeric: tabular-nums; color: var(--ink); }
.cd.act { background: var(--s2); color: var(--ink); }
.cd.goal { background: var(--s4); color: var(--panel); font-weight: 600; }
.cd.today { box-shadow: inset 0 0 0 2px var(--ink); font-weight: 600; }
.cd.future { color: var(--muted); opacity: .45; }
.cal-foot { font-size: 12px; color: var(--muted); margin-top: 8px; text-align: center; }
.linkish { border: none; background: none; padding: 0; color: var(--ink); font-size: inherit; text-decoration: underline; }
.cal-months { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; }
.cal-months button { border: 1px solid var(--line); background: var(--panel); color: var(--ink); border-radius: 8px; padding: 8px 0 4px; font-size: 13px; display: flex; flex-direction: column; align-items: center; }
.cal-months button small { font-size: 11px; color: var(--good); }
.cal-months button:hover:not(:disabled) { border-color: var(--muted); }
.cal-months button.on { border-color: var(--accent); color: var(--accent); font-weight: 600; }
.cal-months button:disabled { opacity: .35; cursor: default; }
.hint { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; background: var(--good-soft); border-radius: 12px; padding: 10px 14px; margin-bottom: 14px; font-size: 14px; }
.hint.down { background: var(--warn-soft); }
.hint span { flex: 1; min-width: 200px; }
.hint .btn { padding: 4px 12px; }

/* 复盘页的本场数据、复习小结 */
.sstats { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.sstats > div { flex: 1; min-width: 80px; background: var(--bg); border-radius: 10px; padding: 8px 12px; border-top: 3px solid var(--line); }
.sstats b { display: block; font: 700 22px Fraunces, serif; }
.sstats small { color: var(--muted); }
.sstats .v-good, .sstats .g-good { border-color: var(--good); } .sstats .v-improve, .sstats .g-hard { border-color: var(--warn); }
.sstats .v-error, .sstats .g-again { border-color: var(--bad); } .sstats .v-chinese, .sstats .g-easy { border-color: var(--info); }
.cn.fold .fixkeep { display: none; }
.cn .fixkeep { margin: 6px 0 0; border: 1px solid var(--line); background: var(--panel); color: var(--muted); border-radius: 99px; font-size: 12px; padding: 1px 10px; }
.cn .fixkeep:hover { color: var(--ink); border-color: var(--muted); }
.cn .fixkeep.kept { color: var(--good); border-color: var(--good); cursor: default; }

/* 复习 */
.modes { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 16px; }
.mode { text-align: left; background: var(--bg); border: 1px solid var(--line); border-radius: 14px; padding: 16px; color: var(--ink); display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.mode:hover { border-color: var(--accent); }
.mode b { font: 700 18px Fraunces, "Songti SC", serif; }
.mode small { flex-basis: 100%; color: var(--muted); }
.mode > .ic { width: 22px; height: 22px; color: var(--accent); }
.rv-top { display: flex; align-items: center; gap: 10px; }
.rv-top .pbar { flex: 1; margin: 0; max-width: none; }
.rv-top .pbar i { background: var(--accent); }
.tag.fix { background: var(--warn-soft); color: var(--warn); }
.rv-front { text-align: center; padding: 30px 0 10px; display: flex; flex-direction: column; gap: 10px; align-items: center; }
.rv-front small { color: var(--muted); }
.rv-expr { font: 700 30px/1.3 Fraunces, Georgia, serif; }
.rv-expr.sm { font-size: 22px; }
.rv-orig { font-size: 18px; padding: 10px 14px; background: var(--bad-soft); border-radius: 10px; margin: 8px 0; }
.rv-hint { margin-top: 10px; padding: 8px 12px; border-radius: 8px; background: var(--info-soft); }
.rv-hint small { color: var(--muted); display: block; }
.mono { font-family: ui-monospace, Menlo, monospace; letter-spacing: .05em; }
.result .better { margin-top: 6px; font-weight: 500; }
.card small { display: block; color: var(--muted); }
.card .src { font-size: 12px; color: var(--muted); margin-top: 4px; }
.btn.grade { min-width: 96px; }
.btn.grade small { color: inherit; opacity: .7; }

/* 表达库 */
#cardsBody { max-width: 900px; margin: 0 auto; }
.cards-top { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.cards-top h2 { margin: 0 8px 0 0; }
.cards-top input, .addcard input { flex: 1; min-width: 160px; padding: 8px 12px; border-radius: 8px; border: 1px solid var(--line); background: var(--panel); color: var(--ink); font: inherit; }
.addcard { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 12px; margin-top: 12px; display: flex; flex-direction: column; gap: 8px; }
.addcard .row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.filters { margin: 14px 0 8px; }
.filters .chip { background: var(--panel); cursor: pointer; font-size: 13px; }
.crow { display: flex; gap: 10px; background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 10px 14px; margin: 8px 0; }
.crow .addcard { flex: 1; margin: 0; border: none; padding: 0; }
.cmain { flex: 1; min-width: 0; }
.cmain b { font-size: 16px; }
.cmain .ex { color: var(--muted); font-style: italic; }
.cmain small { display: block; color: var(--muted); }
.corig { font-size: 14px; color: var(--muted); }
.cmeta { font-size: 12.5px; color: var(--muted); margin-top: 4px; }
.cmeta a { color: var(--muted); }
.cmeta span[class^="st-"] { font-weight: 600; }
.st-new { color: var(--info); } .st-learning { color: var(--warn); } .st-familiar { color: var(--c1); } .st-mastered { color: var(--good); }
.cacts { display: flex; flex-direction: column; gap: 4px; }
.cacts .say { font-size: 15px; padding: 2px; }

/* 学习记录 */
#statsBody { max-width: 1100px; margin: 0 auto; }
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin-bottom: 14px; }
.tile { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 12px 16px; }
.tile b { display: block; font: 700 26px Fraunces, serif; }
.tile b span { font: 400 13px Inter, sans-serif; color: var(--muted); margin: 0 4px 0 2px; }
.tile b .ic { color: var(--accent); width: 22px; height: 22px; }
.tile small { color: var(--muted); }
.tiles.sm { grid-template-columns: repeat(4, 1fr); }
.tiles.sm .tile { background: var(--bg); padding: 8px 12px; }
.tiles.sm .tile b { font-size: 20px; }
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 14px 18px; margin-bottom: 14px; min-width: 0; }
.panel-h { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; margin: 4px 0 8px; }
.panel-h h3 { margin: 0; font-size: 16px; }
.panel-h small { color: var(--muted); }
.panel-h a { margin-left: auto; font-size: 13px; color: var(--muted); }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.chart { width: 100%; height: auto; display: block; overflow: visible; }
.chart .grid { stroke: var(--line); stroke-width: 1; }
.chart .axis { stroke: var(--muted); stroke-width: 1; opacity: .5; }
.chart .ax { fill: var(--muted); font-size: 11px; font-family: Inter, sans-serif; }
.chart .lbl { fill: var(--ink); font-size: 12px; font-family: Inter, sans-serif; }
.chart .bar { fill: var(--bar); }
.chart g:hover .bar { fill: var(--ink); }
.chart .hit { fill: transparent; }
.chart .line { fill: none; stroke-width: 2; stroke-linejoin: round; stroke-linecap: round; }
.chart .line.c1 { stroke: var(--c1); } .chart .line.c2 { stroke: var(--c2); }
.chart .dot { stroke: var(--panel); stroke-width: 2; }
.chart .dot.c1 { fill: var(--c1); } .chart .dot.c2 { fill: var(--c2); }
.chart .cross { stroke: var(--muted); stroke-width: 1; opacity: 0; }
.chart .col:hover .cross { opacity: .6; }
.heat-wrap { overflow-x: auto; }
.heat .cell { cursor: pointer; }
.heat .cell:hover, .heat .cell.pick { stroke: var(--ink); stroke-width: 1.5; }
.heat .cell.now { stroke: var(--accent); stroke-width: 1.5; }
.s0 { fill: var(--s0); } .s1 { fill: var(--s1); } .s2 { fill: var(--s2); } .s3 { fill: var(--s3); } .s4 { fill: var(--s4); }
.legend-seq { display: flex; gap: 3px; align-items: center; font-size: 12px; color: var(--muted); justify-content: flex-end; margin-top: 4px; }
.legend-seq i { width: 12px; height: 12px; border-radius: 3px; display: inline-block; }
.legend-seq i.s0 { background: var(--s0); } .legend-seq i.s1 { background: var(--s1); } .legend-seq i.s2 { background: var(--s2); }
.legend-seq i.s3 { background: var(--s3); } .legend-seq i.s4 { background: var(--s4); }
.legend { display: flex; gap: 14px; font-size: 13px; color: var(--muted); margin-bottom: 4px; }
.key { display: inline-block; width: 14px; height: 3px; border-radius: 2px; vertical-align: middle; margin-right: 5px; }
.key.c1 { background: var(--c1); } .key.c2 { background: var(--c2); }
.charttip { position: fixed; z-index: 30; pointer-events: none; background: var(--ink); color: var(--bg); font-size: 12.5px; line-height: 1.5; padding: 6px 10px; border-radius: 8px; max-width: 260px; }
.charttip .key { height: 8px; width: 8px; border-radius: 50%; }
.hbars { display: flex; flex-direction: column; gap: 6px; margin-bottom: 10px; }
.hb { display: grid; grid-template-columns: minmax(0, 40%) 1fr; gap: 10px; align-items: center; font-size: 13px; }
.hb span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.hb div { display: flex; align-items: center; gap: 6px; }
.hb i { display: block; height: 12px; background: var(--bar); border-radius: 0 4px 4px 0; min-width: 2px; }
.hb b { font-weight: 500; font-size: 12px; color: var(--muted); }
.dtable summary { font-size: 12.5px; color: var(--muted); cursor: pointer; margin-top: 6px; }
.dtable table { border-collapse: collapse; font-size: 12.5px; margin-top: 6px; width: 100%; }
.dtable th, .dtable td { border-bottom: 1px solid var(--line); padding: 3px 6px; text-align: right; }
.dtable th:first-child, .dtable td:first-child { text-align: left; }
.daybox { background: var(--bg); border-radius: 10px; padding: 10px 14px; margin-top: 10px; }
.daybox h4 { margin: 0 0 6px; }
.dayrow { display: block; padding: 4px 0; color: var(--ink); text-decoration: none; font-size: 14px; }
a.dayrow:hover { color: var(--accent); }
.dayrow small { color: var(--muted); }