/* ============ 基础变量（浅色主题） ============ */
:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --border: #e4e9f2;
  --border-strong: #cfd8e6;
  --text: #1c2434;
  --text-2: #4a566b;
  --muted: #7b8798;
  --primary: #4f46e5;
  --primary-soft: #eef0ff;
  --primary-dark: #3f37c9;
  --ok: #16a34a;
  --ok-soft: #e9f8ee;
  --err: #dc2626;
  --err-soft: #fdecec;
  --warn: #d97706;
  --warn-soft: #fef4e6;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(20, 30, 60, .05), 0 6px 20px rgba(20, 30, 60, .06);
  --shadow-lg: 0 10px 40px rgba(20, 30, 60, .12);
  --sidebar-w: 216px;
}

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

html, body { height: 100%; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system,
               BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

button, input, select { font-family: inherit; font-size: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; }
a { color: var(--primary); text-decoration: none; }

::selection { background: var(--primary-soft); }

/* 滚动条 */
::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: #ccd4e3; border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: #b3bed2; }
::-webkit-scrollbar-track { background: transparent; }

/* ============ 布局 ============ */
.app { display: flex; min-height: 100vh; }

/* --- 侧边栏 --- */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: sticky;
  top: 0;
  height: 100vh;
}

.brand {
  padding: 20px 18px 16px;
  border-bottom: 1px solid var(--border);
}
.brand-logo {
  width: 38px; height: 38px;
  border-radius: 11px;
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: #fff;
  display: grid; place-items: center;
  font-weight: 700; font-size: 17px;
  margin-bottom: 10px;
  box-shadow: 0 4px 12px rgba(99, 102, 241, .3);
}
.brand-title { font-size: 14px; font-weight: 700; line-height: 1.4; }
.brand-sub { font-size: 11.5px; color: var(--muted); margin-top: 3px; }

.nav { padding: 12px 10px; flex: 1; overflow-y: auto; }
.nav-group-label {
  font-size: 11px; font-weight: 600; color: var(--muted);
  padding: 12px 10px 6px; letter-spacing: .5px;
}
.nav-item {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 11px;
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 14px; font-weight: 500;
  width: 100%; text-align: left;
  transition: background .15s, color .15s;
  position: relative;
}
.nav-item:hover { background: var(--surface-2); color: var(--text); }
.nav-item.active { background: var(--primary-soft); color: var(--primary); font-weight: 600; }
.nav-item .ico { width: 18px; text-align: center; font-size: 15px; flex-shrink: 0; }
.nav-item .badge {
  margin-left: auto;
  background: var(--err); color: #fff;
  font-size: 11px; font-weight: 700;
  padding: 1px 7px; border-radius: 20px;
  min-width: 20px; text-align: center;
}
.nav-item.active .badge { background: var(--primary); }
.badge.zero { display: none; }

.sidebar-foot {
  padding: 12px 14px;
  border-top: 1px solid var(--border);
  font-size: 11.5px; color: var(--muted);
}
.sidebar-foot button {
  color: var(--muted); font-size: 11.5px; text-decoration: underline;
  text-underline-offset: 2px;
}
.sidebar-foot button:hover { color: var(--err); }

/* --- 主区 --- */
.main { flex: 1; min-width: 0; display: flex; flex-direction: column; }

.topbar {
  height: 60px;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 14px;
  padding: 0 24px;
  position: sticky; top: 0; z-index: 20;
}
.topbar h1 { font-size: 16px; font-weight: 700; }
.topbar .crumb { font-size: 12.5px; color: var(--muted); }
.topbar-right { margin-left: auto; display: flex; align-items: center; gap: 10px; }

.content { padding: 24px; flex: 1; }
.wrap { max-width: 1080px; margin: 0 auto; }
.wrap-narrow { max-width: 820px; margin: 0 auto; }

/* 移动端菜单按钮 */
.menu-btn { display: none; font-size: 20px; padding: 4px 8px; border-radius: 8px; }
.menu-btn:hover { background: var(--surface-2); }

/* ============ 通用组件 ============ */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.card-pad { padding: 20px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 600;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text-2);
  transition: all .15s;
  white-space: nowrap;
}
.btn:hover { background: var(--surface-2); border-color: var(--muted); color: var(--text); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; transform: none; }

.btn-primary {
  background: var(--primary); border-color: var(--primary); color: #fff;
  box-shadow: 0 2px 8px rgba(79, 70, 229, .25);
}
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); color: #fff; }

.btn-ok { background: var(--ok); border-color: var(--ok); color: #fff; }
.btn-ok:hover { background: #15803d; border-color: #15803d; color: #fff; }

.btn-danger { background: var(--surface); border-color: #f2c4c4; color: var(--err); }
.btn-danger:hover { background: var(--err-soft); border-color: var(--err); color: var(--err); }

.btn-sm { padding: 5px 12px; font-size: 13px; border-radius: 7px; }
.btn-lg { padding: 12px 26px; font-size: 15px; border-radius: 11px; }
.btn-block { width: 100%; }

/* 标签 */
.tag {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 2px 9px; border-radius: 20px;
  font-size: 12px; font-weight: 600;
  background: var(--surface-2); color: var(--text-2);
  border: 1px solid var(--border);
}
.tag-single { background: var(--primary-soft); color: var(--primary); border-color: #d5d8fb; }
.tag-multi  { background: var(--warn-soft); color: var(--warn); border-color: #f6dfb8; }
.tag-judge  { background: #e8f4fd; color: #0369a1; border-color: #c5e3f6; }
.tag-ok     { background: var(--ok-soft); color: var(--ok); border-color: #bfe8cd; }
.tag-err    { background: var(--err-soft); color: var(--err); border-color: #f6c9c9; }

/* 统计卡 */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.stat {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 18px; box-shadow: var(--shadow);
}
.stat-label { font-size: 12.5px; color: var(--muted); display: flex; align-items: center; gap: 5px; }
.stat-val { font-size: 27px; font-weight: 700; margin-top: 6px; letter-spacing: -.5px; }
.stat-sub { font-size: 11.5px; color: var(--muted); margin-top: 2px; }
.stat.ok .stat-val { color: var(--ok); }
.stat.err .stat-val { color: var(--err); }
.stat.pri .stat-val { color: var(--primary); }

/* 分区标题 */
.sec-head {
  display: flex; align-items: center; gap: 10px;
  margin: 26px 0 12px;
}
.sec-head h2 { font-size: 15px; font-weight: 700; }
.sec-head .line { flex: 1; height: 1px; background: var(--border); }
.sec-head .more { font-size: 13px; font-weight: 500; }

/* 进度条 */
.bar { height: 7px; background: #eaeef5; border-radius: 20px; overflow: hidden; }
.bar > i { display: block; height: 100%; border-radius: 20px; background: var(--primary); transition: width .4s ease; }
.bar.ok > i { background: var(--ok); }
.bar.warn > i { background: var(--warn); }

/* 空状态 */
.empty { text-align: center; padding: 56px 20px; color: var(--muted); }
.empty .ico { font-size: 44px; opacity: .35; margin-bottom: 12px; }
.empty p { font-size: 14px; }

/* ============ 仪表盘 ============ */
.hero {
  background: linear-gradient(120deg, #5b54e8 0%, #7c4ddd 55%, #9a4ecf 100%);
  border-radius: var(--radius);
  padding: 26px 28px;
  color: #fff;
  box-shadow: 0 8px 28px rgba(91, 84, 232, .28);
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: '';
  position: absolute; right: -60px; top: -70px;
  width: 230px; height: 230px; border-radius: 50%;
  background: rgba(255, 255, 255, .09);
}
.hero::before {
  content: '';
  position: absolute; right: 40px; bottom: -90px;
  width: 160px; height: 160px; border-radius: 50%;
  background: rgba(255, 255, 255, .07);
}
.hero h2 { font-size: 21px; font-weight: 700; position: relative; }
.hero p { font-size: 13.5px; opacity: .88; margin-top: 6px; position: relative; }
.hero-meta { display: flex; gap: 26px; margin-top: 18px; position: relative; flex-wrap: wrap; }
.hero-meta div { font-size: 12.5px; opacity: .85; }
.hero-meta b { display: block; font-size: 20px; font-weight: 700; opacity: 1; }

.quick { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 20px; }
.qcard {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 18px;
  text-align: left; box-shadow: var(--shadow);
  transition: transform .16s, box-shadow .16s, border-color .16s;
}
.qcard:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.qcard .ico {
  width: 40px; height: 40px; border-radius: 11px;
  display: grid; place-items: center; font-size: 19px; margin-bottom: 11px;
}
.qcard h3 { font-size: 14.5px; font-weight: 700; }
.qcard p { font-size: 12.5px; color: var(--muted); margin-top: 4px; line-height: 1.55; }

/* 知识点列表 */
.topic-row {
  display: flex; align-items: center; gap: 12px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--border);
}
.topic-row:last-child { border-bottom: none; }
.topic-name { font-size: 13.5px; font-weight: 500; width: 150px; flex-shrink: 0; }
.topic-row .bar { flex: 1; }
.topic-num { font-size: 12.5px; color: var(--muted); width: 76px; text-align: right; flex-shrink: 0; }
.topic-row button { font-size: 12.5px; color: var(--primary); font-weight: 500; flex-shrink: 0; }
.topic-row button:hover { text-decoration: underline; }

/* 考试历史 */
.hist-row {
  display: flex; align-items: center; gap: 12px;
  padding: 11px 14px; border-radius: var(--radius-sm);
  background: var(--surface-2); margin-bottom: 8px;
  font-size: 13.5px;
}
.hist-score { font-size: 19px; font-weight: 700; width: 62px; flex-shrink: 0; }
.hist-row .muted { color: var(--muted); font-size: 12.5px; }

/* ============ 答题区 ============ */
.qbar {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 12px 18px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); margin-bottom: 16px; box-shadow: var(--shadow);
}
.qbar .grow { flex: 1; }
.qbar select, .qbar input[type=text] {
  padding: 6px 10px; border: 1px solid var(--border-strong);
  border-radius: 8px; background: var(--surface); font-size: 13.5px;
  outline: none; transition: border-color .15s;
}
.qbar select:focus, .qbar input:focus { border-color: var(--primary); }
.qbar label { font-size: 13px; color: var(--muted); }
.counter { font-size: 13.5px; color: var(--text-2); font-weight: 600; }
.counter b { color: var(--primary); font-size: 16px; }

.qcard-main {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
  overflow: hidden;
}
.qhead {
  display: flex; align-items: center; gap: 9px; flex-wrap: wrap;
  padding: 13px 20px; border-bottom: 1px solid var(--border);
  background: var(--surface-2);
}
.qhead .no { font-size: 14px; font-weight: 700; color: var(--text-2); }
.qhead .grow { flex: 1; }
.star-btn {
  font-size: 17px; line-height: 1; padding: 3px;
  filter: grayscale(1); opacity: .35; transition: all .15s;
}
.star-btn:hover { opacity: .7; }
.star-btn.on { filter: none; opacity: 1; }

.qbody { padding: 22px 24px; }
.qstem { font-size: 16px; line-height: 1.75; font-weight: 500; }
.qstem .blank { color: var(--primary); font-weight: 700; }

.opts { margin-top: 18px; display: flex; flex-direction: column; gap: 10px; }
.opt {
  display: flex; align-items: flex-start; gap: 11px;
  padding: 12px 15px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  background: var(--surface);
  text-align: left; width: 100%;
  font-size: 14.5px; line-height: 1.6;
  transition: all .14s;
}
.opt:hover:not(.locked) { border-color: var(--primary); background: var(--primary-soft); }
.opt .k {
  width: 25px; height: 25px; flex-shrink: 0;
  border-radius: 7px;
  border: 1px solid var(--border-strong);
  display: grid; place-items: center;
  font-size: 13px; font-weight: 700; color: var(--text-2);
  background: var(--surface-2);
  transition: all .14s;
}
.opt .v { padding-top: 1px; }

.opt.picked { border-color: var(--primary); background: var(--primary-soft); }
.opt.picked .k { background: var(--primary); border-color: var(--primary); color: #fff; }

.opt.correct { border-color: #86dcaa; background: var(--ok-soft); }
.opt.correct .k { background: var(--ok); border-color: var(--ok); color: #fff; }

.opt.wrong { border-color: #f0a9a9; background: var(--err-soft); }
.opt.wrong .k { background: var(--err); border-color: var(--err); color: #fff; }

.opt.locked { cursor: default; }

.multi-tip { font-size: 12.5px; color: var(--muted); margin-top: 12px; }

/* 结果反馈 */
.fb {
  margin-top: 18px; padding: 15px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid;
  animation: slideIn .22s ease;
}
@keyframes slideIn { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }
.fb.ok { background: var(--ok-soft); border-color: #bfe8cd; }
.fb.no { background: var(--err-soft); border-color: #f6c9c9; }
.fb-title { font-size: 14.5px; font-weight: 700; display: flex; align-items: center; gap: 7px; }
.fb.ok .fb-title { color: var(--ok); }
.fb.no .fb-title { color: var(--err); }
.fb-ans { font-size: 13.5px; margin-top: 7px; line-height: 1.7; }
.fb-ans b { font-weight: 700; }
.fb-hint { font-size: 12.5px; color: var(--text-2); margin-top: 6px; }

.qfoot {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 14px 20px; border-top: 1px solid var(--border); background: var(--surface-2);
}
.qfoot .grow { flex: 1; }
.kbd-hint { font-size: 11.5px; color: var(--muted); }
kbd {
  background: var(--surface); border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 5px; padding: 1px 5px;
  font-size: 11px; font-family: ui-monospace, Consolas, monospace;
  color: var(--text-2);
}

/* ============ 考试 ============ */
.exam-layout { display: grid; grid-template-columns: 1fr 250px; gap: 18px; align-items: start; }

.sheet {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 16px;
  position: sticky; top: 78px;
}
.sheet h4 { font-size: 13.5px; font-weight: 700; margin-bottom: 4px; }
.sheet .sheet-sub { font-size: 11.5px; color: var(--muted); margin-bottom: 12px; }
.sheet-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; }
.sheet-cell {
  aspect-ratio: 1; border-radius: 7px;
  border: 1px solid var(--border-strong);
  background: var(--surface-2);
  font-size: 12.5px; font-weight: 600; color: var(--text-2);
  display: grid; place-items: center;
  transition: all .13s;
}
.sheet-cell:hover { border-color: var(--primary); }
.sheet-cell.done { background: var(--primary); border-color: var(--primary); color: #fff; }
.sheet-cell.cur { outline: 2px solid var(--primary); outline-offset: 1px; }
.sheet-legend { display: flex; gap: 12px; margin-top: 12px; font-size: 11.5px; color: var(--muted); flex-wrap: wrap; }
.sheet-legend i { display: inline-block; width: 9px; height: 9px; border-radius: 3px; margin-right: 4px; vertical-align: -1px; }

.timer {
  display: flex; align-items: center; gap: 7px;
  padding: 6px 13px; border-radius: 20px;
  background: var(--surface-2); border: 1px solid var(--border);
  font-size: 14px; font-weight: 700;
  font-variant-numeric: tabular-nums;
}
.timer.warn { background: var(--warn-soft); border-color: #f6dfb8; color: var(--warn); }
.timer.danger { background: var(--err-soft); border-color: #f6c9c9; color: var(--err); animation: pulse 1s infinite; }
@keyframes pulse { 50% { opacity: .55; } }

/* 配置区 */
.cfg-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.cfg-item label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 7px; }
.cfg-item .desc { font-size: 12px; color: var(--muted); font-weight: 400; }
.chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  padding: 7px 15px; border-radius: 20px;
  border: 1px solid var(--border-strong);
  background: var(--surface); font-size: 13.5px; font-weight: 500;
  transition: all .14s;
}
.chip:hover { border-color: var(--primary); color: var(--primary); }
.chip.on { background: var(--primary); border-color: var(--primary); color: #fff; }
.chip:disabled { opacity: .4; cursor: not-allowed; }

/* 成绩报告 */
.score-hero {
  text-align: center; padding: 30px 20px;
  background: linear-gradient(135deg, #f8f9ff, #f2effe);
  border-radius: var(--radius); border: 1px solid var(--border);
}
.score-ring {
  width: 132px; height: 132px; margin: 0 auto 14px;
  border-radius: 50%;
  display: grid; place-items: center;
  font-size: 34px; font-weight: 700;
  background: conic-gradient(var(--primary) var(--p, 0%), #e6e9f2 0);
  position: relative;
}
.score-ring::after {
  content: ''; position: absolute; inset: 11px;
  background: var(--surface); border-radius: 50%;
}
.score-ring span { position: relative; z-index: 1; }
.score-hero h2 { font-size: 19px; font-weight: 700; margin-top: 4px; }
.score-hero p { font-size: 13.5px; color: var(--text-2); margin-top: 5px; }

.breakdown { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 18px; }
.bd {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 13px; text-align: center;
}
.bd .n { font-size: 22px; font-weight: 700; }
.bd .l { font-size: 12px; color: var(--muted); margin-top: 2px; }

.review-item {
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 15px 17px; margin-bottom: 10px; background: var(--surface);
}
.review-item .rh { display: flex; align-items: center; gap: 9px; margin-bottom: 8px; flex-wrap: wrap; }
.review-item .rh .no { font-weight: 700; font-size: 13.5px; }
.review-item .rstem { font-size: 14.5px; line-height: 1.7; }
.review-item .rans { font-size: 13.5px; margin-top: 9px; padding-top: 9px; border-top: 1px dashed var(--border); line-height: 1.7; }
.review-item .rans .mine { color: var(--err); font-weight: 600; }
.review-item .rans .right { color: var(--ok); font-weight: 600; }

/* ============ 列表（错题/收藏/检索） ============ */
.qlist { display: flex; flex-direction: column; gap: 10px; }
.qitem {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 15px 17px;
  box-shadow: var(--shadow);
  transition: border-color .15s;
}
.qitem:hover { border-color: var(--border-strong); }
.qitem .qih { display: flex; align-items: center; gap: 9px; margin-bottom: 8px; flex-wrap: wrap; }
.qitem .qih .no { font-size: 12.5px; font-weight: 700; color: var(--muted); }
.qitem .qih .grow { flex: 1; }
.qitem .qstem-s { font-size: 14.5px; line-height: 1.7; }
.qitem .qmeta { font-size: 12.5px; color: var(--muted); margin-top: 9px; display: flex; gap: 14px; flex-wrap: wrap; align-items: center; }
.qitem .qmeta .ans { color: var(--ok); font-weight: 600; }
.qitem .acts { display: flex; gap: 7px; margin-top: 10px; }

mark { background: #fff2a8; color: inherit; border-radius: 3px; padding: 0 1px; }

.search-box { position: relative; }
.search-box input {
  width: 100%; padding: 11px 15px 11px 40px;
  border: 1px solid var(--border-strong); border-radius: var(--radius-sm);
  font-size: 14.5px; outline: none; background: var(--surface);
  transition: border-color .15s, box-shadow .15s;
}
.search-box input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }
.search-box .ico { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); opacity: .4; }

/* ============ 弹窗 / Toast ============ */
.modal-mask {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(20, 26, 45, .45);
  backdrop-filter: blur(3px);
  display: grid; place-items: center; padding: 20px;
  animation: fade .18s ease;
}
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
.modal {
  background: var(--surface); border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  max-width: 440px; width: 100%; padding: 24px;
  animation: pop .2s ease;
}
@keyframes pop { from { opacity: 0; transform: scale(.95) translateY(8px); } to { opacity: 1; transform: none; } }
.modal h3 { font-size: 16.5px; font-weight: 700; margin-bottom: 8px; }
.modal p { font-size: 14px; color: var(--text-2); line-height: 1.7; }
.modal .mfoot { display: flex; gap: 10px; justify-content: flex-end; margin-top: 20px; }

#toast {
  position: fixed; bottom: 28px; left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: #1c2434; color: #fff;
  padding: 11px 22px; border-radius: 22px;
  font-size: 14px; font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 200; opacity: 0;
  transition: all .28s cubic-bezier(.2, .9, .3, 1.4);
  pointer-events: none;
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ============ 响应式 ============ */
@media (max-width: 1100px) {
  .exam-layout { grid-template-columns: 1fr; }
  .sheet { position: static; order: -1; }
  .sheet-grid { grid-template-columns: repeat(10, 1fr); }
}

@media (max-width: 860px) {
  .sidebar {
    position: fixed; left: 0; top: 0; z-index: 60;
    transform: translateX(-100%);
    transition: transform .24s ease;
    box-shadow: var(--shadow-lg);
  }
  .sidebar.open { transform: none; }
  .menu-btn { display: block; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .quick { grid-template-columns: 1fr; }
  .cfg-grid { grid-template-columns: 1fr; }
  .breakdown { grid-template-columns: repeat(2, 1fr); }
  .content { padding: 16px; }
  .topbar { padding: 0 14px; }
  .qbody { padding: 18px 16px; }
  .topic-name { width: 108px; font-size: 12.5px; }
  .sheet-grid { grid-template-columns: repeat(8, 1fr); }
}

@media (max-width: 520px) {
  .stats { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .stat-val { font-size: 22px; }
  .hero { padding: 20px; }
  .hero h2 { font-size: 18px; }
  .topbar h1 { font-size: 14.5px; }
  .breakdown { grid-template-columns: repeat(2, 1fr); }
  .qfoot .kbd-hint { display: none; }
}

@media print {
  .sidebar, .topbar, .qfoot, .qbar, .no-print { display: none !important; }
  body { background: #fff; }
  .content { padding: 0; }
  .card, .qcard-main { box-shadow: none; }
}