:root{
  --bg:#F3F5FB;
  --card:#FFFFFF;
  --ink:#161B33;
  --ink-2:#3C4463;
  --muted:#8B92AA;
  --line:#E9ECF5;
  --primary:#4A5BF5;
  --primary-2:#6D7CFF;
  --primary-soft:#EEF0FF;
  --accent:#FF8A3D;
  --accent-soft:#FFF2E8;
  --green:#11A873;
  --green-soft:#E8F8F1;
  --red:#E5484D;
  --red-soft:#FDEDEE;
  --shadow:0 10px 30px rgba(22,27,51,.07);
  --shadow-sm:0 4px 14px rgba(22,27,51,.06);
  --r:22px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  font-family:-apple-system,BlinkMacSystemFont,"SF Pro SC","PingFang SC","HarmonyOS Sans SC","Noto Sans SC","Microsoft YaHei",sans-serif;
  background:#E9EDF6;color:var(--ink);
  -webkit-font-smoothing:antialiased;
  overscroll-behavior-y:none;
}
#app{
  position:relative;max-width:540px;margin:0 auto;min-height:100vh;min-height:100dvh;
  background:var(--bg);overflow-x:hidden;
  box-shadow:0 0 60px rgba(20,26,46,.10);
}
button{font-family:inherit;border:0;background:none;padding:0;color:inherit;cursor:pointer}
a{color:inherit;text-decoration:none}
svg{display:block;fill:none;stroke:currentColor;stroke-width:1.9;stroke-linecap:round;stroke-linejoin:round}

/* ---------- generic page ---------- */
.page{padding:calc(env(safe-area-inset-top) + 14px) 18px calc(96px + env(safe-area-inset-bottom));animation:pageIn .3s cubic-bezier(.2,.8,.2,1)}
.page.no-tab{padding-bottom:calc(120px + env(safe-area-inset-bottom))}
@keyframes pageIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
@keyframes pop{0%{transform:scale(.94);opacity:0}100%{transform:scale(1);opacity:1}}

/* ---------- top brand ---------- */
.brandbar{display:flex;align-items:center;gap:10px;margin-bottom:16px}
.brand-logo{width:34px;height:34px;border-radius:10px;object-fit:cover;box-shadow:0 4px 10px rgba(74,91,245,.28)}
.brand-name{font-size:15px;font-weight:700;letter-spacing:.2px}
.brand-sub{font-size:11px;color:var(--muted);margin-top:1px}
.brandbar .spacer{flex:1}
.icon-btn{width:38px;height:38px;border-radius:12px;background:#fff;display:flex;align-items:center;justify-content:center;color:var(--ink-2);box-shadow:var(--shadow-sm)}
.icon-btn svg{width:19px;height:19px}

/* ---------- hero ---------- */
.hero{
  position:relative;border-radius:26px;overflow:hidden;color:#fff;
  background:linear-gradient(135deg,#1B2450 0%,#2C3A8F 52%,#4A5BF5 100%);
  box-shadow:0 18px 40px rgba(44,58,143,.28);
  padding:22px 20px 20px;min-height:196px;isolation:isolate;
}
.hero:before{content:"";position:absolute;width:220px;height:220px;border-radius:50%;background:radial-gradient(circle,rgba(255,138,61,.42),transparent 68%);right:-70px;top:-80px;z-index:-1}
.hero:after{content:"";position:absolute;width:180px;height:180px;border-radius:50%;background:radial-gradient(circle,rgba(109,124,255,.55),transparent 70%);left:-60px;bottom:-90px;z-index:-1}
.hero-eyebrow{font-size:11.5px;letter-spacing:2.5px;opacity:.7;font-weight:600}
.hero-title{font-size:27px;font-weight:800;margin:7px 0 4px;letter-spacing:.5px}
.hero-desc{font-size:12.5px;opacity:.72;line-height:1.6;max-width:190px}
.hero-art{position:absolute;right:-6px;bottom:0;width:190px;height:150px;object-fit:cover;object-position:center;border-radius:22px 0 0 0;opacity:.96;mask-image:linear-gradient(to right,transparent 0,#000 18%,#000 100%)}
.hero-cta{
  position:relative;z-index:2;margin-top:18px;display:inline-flex;align-items:center;gap:8px;
  background:#fff;color:#243070;font-weight:700;font-size:14px;padding:11px 18px;border-radius:14px;
  box-shadow:0 8px 18px rgba(0,0,0,.18);transition:transform .15s;
}
.hero-cta:active{transform:scale(.96)}
.hero-cta svg{width:16px;height:16px;stroke-width:2.4}
.hero-progress{position:absolute;right:18px;top:20px;font-size:11px;background:rgba(255,255,255,.14);padding:5px 10px;border-radius:999px;backdrop-filter:blur(6px)}

/* ---------- stats strip ---------- */
.stat-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:14px}
.stat-cell{background:var(--card);border-radius:18px;padding:14px 10px;text-align:center;box-shadow:var(--shadow-sm)}
.stat-num{font-size:21px;font-weight:800;letter-spacing:-.5px}
.stat-num small{font-size:11px;font-weight:600;color:var(--muted);margin-left:1px}
.stat-label{font-size:11px;color:var(--muted);margin-top:3px}

/* ---------- section ---------- */
.section{margin-top:24px}
.section-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:11px;padding:0 2px}
.section-title{font-size:16.5px;font-weight:800;letter-spacing:.2px}
.section-more{font-size:12px;color:var(--muted);display:flex;align-items:center;gap:2px}
.section-more svg{width:13px;height:13px}

/* ---------- mode grid ---------- */
.mode-grid{display:grid;grid-template-columns:1fr 1fr;gap:11px}
.mode-card{
  position:relative;background:var(--card);border-radius:20px;padding:16px;min-height:104px;
  box-shadow:var(--shadow-sm);overflow:hidden;transition:transform .16s ease;
}
.mode-card:active{transform:scale(.975)}
.mode-ico{width:38px;height:38px;border-radius:12px;display:flex;align-items:center;justify-content:center;margin-bottom:11px}
.mode-ico svg{width:19px;height:19px;stroke-width:2}
.mode-title{font-size:14.5px;font-weight:700}
.mode-desc{font-size:11px;color:var(--muted);margin-top:3px;line-height:1.45}
.mode-card .deco{position:absolute;right:-16px;bottom:-18px;width:74px;height:74px;border-radius:50%;opacity:.5}
.bg-blue{background:var(--primary-soft);color:var(--primary)}
.bg-orange{background:var(--accent-soft);color:#E86A17}
.bg-green{background:var(--green-soft);color:var(--green)}
.bg-red{background:var(--red-soft);color:var(--red)}
.deco-blue{background:radial-gradient(circle,#C9D0FF,transparent 70%)}
.deco-orange{background:radial-gradient(circle,#FFD9BF,transparent 70%)}
.deco-green{background:radial-gradient(circle,#C6F0DF,transparent 70%)}
.deco-red{background:radial-gradient(circle,#FFD2D4,transparent 70%)}

/* ---------- list rows ---------- */
.row-list{background:var(--card);border-radius:20px;box-shadow:var(--shadow-sm);overflow:hidden}
.row{display:flex;align-items:center;gap:12px;padding:15px 16px;border-bottom:1px solid var(--line);transition:background .15s}
.row:last-child{border-bottom:0}
.row:active{background:#FAFBFF}
.row-ico{width:36px;height:36px;border-radius:11px;display:flex;align-items:center;justify-content:center;flex:0 0 auto}
.row-ico svg{width:17px;height:17px}
.row-main{flex:1;min-width:0}
.row-title{font-size:14.5px;font-weight:600}
.row-sub{font-size:11.5px;color:var(--muted);margin-top:2px}
.row-value{font-size:13px;font-weight:700;color:var(--muted)}
.chev{width:16px;height:16px;color:#C3C8D8}
.badge{min-width:22px;height:22px;padding:0 7px;border-radius:999px;background:var(--red-soft);color:var(--red);font-size:11.5px;font-weight:700;display:inline-flex;align-items:center;justify-content:center}

/* ---------- today card ---------- */
.today-card{background:linear-gradient(120deg,#FFFFFF,#F7F8FF);border-radius:20px;padding:16px;box-shadow:var(--shadow-sm);display:flex;align-items:center;gap:16px}
.ring{position:relative;width:70px;height:70px;flex:0 0 auto}
.ring svg{width:70px;height:70px;transform:rotate(-90deg)}
.ring .track{stroke:#E9ECF5;stroke-width:7}
.ring .bar{stroke:url(#ringGrad);stroke-width:7;stroke-linecap:round;transition:stroke-dashoffset .6s ease}
.ring-label{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.ring-label b{font-size:16px;line-height:1}
.ring-label span{font-size:9px;color:var(--muted);margin-top:2px}
.today-main{flex:1}
.today-title{font-size:14px;font-weight:700}
.today-desc{font-size:11.5px;color:var(--muted);margin-top:4px;line-height:1.5}

/* ---------- tabs ---------- */
.tabbar{
  position:fixed;bottom:0;left:50%;transform:translateX(-50%);width:100%;max-width:540px;z-index:50;
  display:flex;padding:8px 10px calc(8px + env(safe-area-inset-bottom));
  background:rgba(255,255,255,.88);backdrop-filter:blur(18px) saturate(160%);
  border-top:1px solid rgba(233,236,245,.9);
}
body.quiz-mode .tabbar,body.quiz-mode .fab{display:none}
.tab{flex:1;display:flex;flex-direction:column;align-items:center;gap:3px;padding:5px 0;color:#A6ABC0;font-size:10px;font-weight:600}
.tab svg{width:23px;height:23px;stroke-width:1.9}
.tab.active{color:var(--primary)}
.tab.active svg{stroke-width:2.2}

/* ---------- practice setup ---------- */
.headline{padding:6px 2px 2px}
.headline h1{font-size:25px;font-weight:800;margin:0;letter-spacing:.3px}
.headline p{font-size:12.5px;color:var(--muted);margin:6px 0 0;line-height:1.55}
.filter-group{margin-top:20px}
.filter-label{font-size:12.5px;font-weight:700;color:var(--ink-2);margin-bottom:9px;padding-left:2px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{padding:9px 15px;border-radius:13px;background:#fff;border:1.5px solid transparent;font-size:13px;color:var(--ink-2);box-shadow:var(--shadow-sm);transition:all .16s}
.chip.on{background:var(--primary);color:#fff;border-color:var(--primary);box-shadow:0 8px 18px rgba(74,91,245,.3)}
.chip:active{transform:scale(.96)}
.start-card{margin-top:26px;background:var(--card);border-radius:22px;padding:18px;box-shadow:var(--shadow)}
.start-info{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px}
.start-info b{font-size:15px}
.start-info span{font-size:12px;color:var(--muted)}
.btn-primary{
  width:100%;height:52px;border-radius:16px;background:linear-gradient(120deg,#4A5BF5,#6D7CFF);
  color:#fff;font-size:16px;font-weight:700;letter-spacing:.5px;display:flex;align-items:center;justify-content:center;gap:8px;
  box-shadow:0 12px 26px rgba(74,91,245,.32);transition:transform .15s;
}
.btn-primary:active{transform:scale(.98)}
.btn-primary svg{width:18px;height:18px;stroke-width:2.2}
.btn-ghost{width:100%;height:48px;border-radius:15px;background:#fff;color:var(--ink-2);font-size:14.5px;font-weight:600;box-shadow:var(--shadow-sm);display:flex;align-items:center;justify-content:center;gap:7px}
.btn-ghost:active{transform:scale(.98)}

/* ---------- quiz ---------- */
.quiz-top{position:sticky;top:0;z-index:20;background:rgba(243,245,251,.92);backdrop-filter:blur(14px);padding:calc(env(safe-area-inset-top) + 10px) 16px 8px}
.quiz-top-row{display:flex;align-items:center;gap:12px}
.quiz-close{width:36px;height:36px;border-radius:12px;background:#fff;display:flex;align-items:center;justify-content:center;color:var(--ink-2);box-shadow:var(--shadow-sm)}
.quiz-close svg{width:18px;height:18px}
.quiz-counter{flex:1;font-size:13px;font-weight:700;color:var(--ink-2);text-align:center}
.quiz-counter span{color:var(--muted);font-weight:600}
.quiz-tools{display:flex;gap:8px}
.fav-btn{width:36px;height:36px;border-radius:12px;background:#fff;display:flex;align-items:center;justify-content:center;color:#C3C8D8;box-shadow:var(--shadow-sm)}
.fav-btn svg{width:18px;height:18px}
.fav-btn.on{color:var(--accent);background:var(--accent-soft)}
.fav-btn.on svg{fill:var(--accent);stroke:var(--accent)}
.progress-track{height:4px;border-radius:99px;background:#E3E7F2;margin-top:12px;overflow:hidden}
.progress-fill{height:100%;border-radius:99px;background:linear-gradient(90deg,#4A5BF5,#8B96FF);transition:width .3s ease}
.quiz-body{padding:16px 18px calc(140px + env(safe-area-inset-bottom))}
.quiz-meta{display:flex;align-items:center;gap:8px;margin-bottom:12px}
.tag{font-size:10.5px;font-weight:700;padding:4px 9px;border-radius:7px;letter-spacing:.4px}
.tag-single{background:var(--primary-soft);color:var(--primary)}
.tag-multi{background:var(--accent-soft);color:#E86A17}
.tag-judge{background:var(--green-soft);color:var(--green)}
.tag-cat{background:#F1F3F9;color:#7C849D}
.question{font-size:17.5px;line-height:1.72;font-weight:600;letter-spacing:.1px;margin:4px 0 22px;white-space:pre-wrap}
.options{display:flex;flex-direction:column;gap:10px}
.option{
  display:flex;align-items:flex-start;gap:11px;width:100%;text-align:left;
  background:#fff;border:1.5px solid #EAEDF6;border-radius:16px;padding:14px 14px;font-size:14.5px;line-height:1.55;
  color:var(--ink-2);transition:all .16s ease;box-shadow:0 2px 8px rgba(22,27,51,.03);
}
.option:active{transform:scale(.99)}
.option .k{
  flex:0 0 auto;width:26px;height:26px;border-radius:9px;background:#F2F4FA;color:#8B92AA;
  font-size:12.5px;font-weight:700;display:flex;align-items:center;justify-content:center;transition:all .16s;
}
.option.selected{border-color:var(--primary);background:#F3F5FF}
.option.selected .k{background:var(--primary);color:#fff}
.option.right{border-color:var(--green);background:var(--green-soft)}
.option.right .k{background:var(--green);color:#fff}
.option.wrong{border-color:var(--red);background:var(--red-soft)}
.option.wrong .k{background:var(--red);color:#fff}
.option.missed{border-color:var(--green);border-style:dashed}
.option.missed .k{background:var(--green-soft);color:var(--green)}
.option[disabled]{opacity:1}
.judge-wrap{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.judge-btn{height:76px;border-radius:18px;background:#fff;border:1.5px solid #EAEDF6;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:5px;font-size:15px;font-weight:700;color:var(--ink-2);box-shadow:0 2px 8px rgba(22,27,51,.03)}
.judge-btn svg{width:24px;height:24px}
.judge-btn:active{transform:scale(.98)}
.judge-btn.right{border-color:var(--green);background:var(--green-soft);color:var(--green)}
.judge-btn.wrong{border-color:var(--red);background:var(--red-soft);color:var(--red)}
.judge-btn.missed{border-color:var(--green);border-style:dashed;color:var(--green)}
.quiz-bar{
  position:fixed;bottom:0;left:50%;transform:translateX(-50%);width:100%;max-width:540px;z-index:30;
  padding:12px 18px calc(14px + env(safe-area-inset-bottom));
  background:linear-gradient(to top,#F3F5FB 70%,rgba(243,245,251,0));
}
.result-banner{display:flex;align-items:center;gap:10px;padding:12px 15px;border-radius:15px;margin-bottom:10px;font-size:13.5px;font-weight:600;animation:pop .25s ease}
.result-banner.ok{background:var(--green-soft);color:#0B7C55}
.result-banner.no{background:var(--red-soft);color:#B33136}
.result-banner svg{width:19px;height:19px;flex:0 0 auto}
.result-banner .ans{margin-left:auto;font-size:12px;font-weight:700;opacity:.85}
.btn-next{width:100%;height:52px;border-radius:16px;background:linear-gradient(120deg,#4A5BF5,#6D7CFF);color:#fff;font-size:15.5px;font-weight:700;box-shadow:0 12px 26px rgba(74,91,245,.3)}
.btn-next.submit{background:linear-gradient(120deg,#111A3A,#2C3A8F)}
.btn-next[disabled]{background:#C9CEDE;box-shadow:none}

/* ---------- exam ---------- */
.exam-head{display:flex;align-items:center;gap:10px}
.timer{display:flex;align-items:center;gap:6px;font-size:14px;font-weight:800;color:var(--primary);background:#fff;padding:8px 12px;border-radius:12px;box-shadow:var(--shadow-sm)}
.timer svg{width:15px;height:15px}
.timer.warn{color:var(--red)}
.exam-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:9px;margin-top:18px}
.exam-dot{aspect-ratio:1;border-radius:12px;background:#fff;display:flex;align-items:center;justify-content:center;font-size:12.5px;font-weight:700;color:#8B92AA;box-shadow:var(--shadow-sm);border:1.5px solid transparent}
.exam-dot.done{background:var(--primary-soft);color:var(--primary)}
.exam-dot.cur{border-color:var(--primary);color:var(--primary);background:#fff}

/* ---------- result ---------- */
.score-hero{text-align:center;padding:26px 0 8px}
.score-ring{position:relative;width:170px;height:170px;margin:0 auto}
.score-ring svg{width:170px;height:170px;transform:rotate(-90deg)}
.score-ring .track{stroke:#E9ECF5;stroke-width:12}
.score-ring .bar{stroke:url(#scoreGrad);stroke-width:12;stroke-linecap:round;stroke-dasharray:440;transition:stroke-dashoffset 1s ease}
.score-inner{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.score-inner b{font-size:48px;font-weight:800;line-height:1;letter-spacing:-2px}
.score-inner span{font-size:12px;color:var(--muted);margin-top:5px}
.score-title{font-size:20px;font-weight:800;margin-top:14px}
.score-sub{font-size:13px;color:var(--muted);margin-top:5px}
.result-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:22px}
.result-cell{background:#fff;border-radius:16px;padding:14px 8px;text-align:center;box-shadow:var(--shadow-sm)}
.result-cell b{display:block;font-size:18px;font-weight:800}
.result-cell span{font-size:11px;color:var(--muted)}

/* ---------- wrong list ---------- */
.q-item{background:#fff;border-radius:18px;padding:15px 16px;margin-bottom:10px;box-shadow:var(--shadow-sm);display:flex;gap:12px;align-items:flex-start}
.q-item:active{transform:scale(.99)}
.q-badge{flex:0 0 auto;width:30px;height:30px;border-radius:10px;background:var(--red-soft);color:var(--red);font-size:12px;font-weight:800;display:flex;align-items:center;justify-content:center}
.q-badge.fav{background:var(--accent-soft);color:var(--accent)}
.q-text{flex:1;font-size:13.8px;line-height:1.55;font-weight:500;color:var(--ink-2);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.q-sub{font-size:11px;color:var(--muted);margin-top:6px}
.empty{text-align:center;padding:48px 20px}
.empty img{width:150px;height:150px;object-fit:contain;opacity:.95}
.empty h3{font-size:16px;margin:6px 0 4px}
.empty p{font-size:12.5px;color:var(--muted);margin:0;line-height:1.6}

/* ---------- stats / me ---------- */
.profile-head{display:flex;align-items:center;gap:14px;background:linear-gradient(135deg,#1B2450,#39479E);color:#fff;border-radius:24px;padding:22px;box-shadow:0 16px 34px rgba(37,48,120,.28)}
.profile-ava{width:56px;height:56px;border-radius:18px;background:linear-gradient(135deg,#FF8A3D,#FFB37E);display:flex;align-items:center;justify-content:center;font-size:22px;font-weight:800;box-shadow:0 8px 16px rgba(0,0,0,.18)}
.profile-name{font-size:18px;font-weight:800}
.profile-sub{font-size:11.5px;opacity:.7;margin-top:4px}
.profile-head .spacer{flex:1}
.week-card{background:#fff;border-radius:20px;padding:18px 16px 12px;box-shadow:var(--shadow-sm);margin-top:14px}
.week-bars{display:flex;align-items:flex-end;justify-content:space-between;height:110px;gap:8px;margin-top:10px}
.week-col{flex:1;display:flex;flex-direction:column;align-items:center;gap:6px;height:100%;justify-content:flex-end}
.week-bar{width:100%;max-width:26px;border-radius:8px 8px 4px 4px;background:linear-gradient(180deg,#8B96FF,#4A5BF5);min-height:4px;transition:height .5s ease}
.week-bar.zero{background:#EDF0F7}
.week-day{font-size:10px;color:var(--muted)}
.setting-row{display:flex;align-items:center;gap:12px;padding:15px 16px;border-bottom:1px solid var(--line)}
.setting-row:last-child{border-bottom:0}
.setting-title{flex:1;font-size:14px;font-weight:600}
.switch{width:46px;height:27px;border-radius:99px;background:#DDE1EC;position:relative;transition:background .2s;flex:0 0 auto}
.switch:after{content:"";position:absolute;width:21px;height:21px;border-radius:50%;background:#fff;top:3px;left:3px;transition:transform .2s;box-shadow:0 2px 5px rgba(0,0,0,.15)}
.switch.on{background:var(--primary)}
.switch.on:after{transform:translateX(19px)}

.toast{position:fixed;left:50%;bottom:110px;transform:translate(-50%,20px);background:rgba(22,27,51,.92);color:#fff;font-size:13px;padding:11px 18px;border-radius:12px;opacity:0;pointer-events:none;transition:all .28s;z-index:99;max-width:80%;text-align:center}
.toast.show{opacity:1;transform:translate(-50%,0)}

/* safe area for iphone */
@supports(padding:max(0px)){.page{padding-top:max(calc(env(safe-area-inset-top) + 14px),20px)}}

/* ---------- explanation ---------- */
.quiz-actions{display:flex;gap:10px}
.quiz-actions .btn-next{flex:1}
.btn-explain{flex:0 0 38%;height:52px;border-radius:16px;background:#fff;color:var(--primary);font-size:14.5px;font-weight:700;border:1.5px solid #C9D0FF;display:flex;align-items:center;justify-content:center;transition:transform .15s}
.btn-explain:active{transform:scale(.98)}
.explain-card{margin-top:18px;background:#fff;border-radius:18px;padding:16px 16px 15px;box-shadow:var(--shadow);border-left:4px solid var(--accent);animation:pageIn .25s ease}
.explain-title{display:flex;align-items:center;gap:6px;font-size:12px;font-weight:800;color:#E86A17;letter-spacing:1px;margin-bottom:9px}
.explain-title svg{width:15px;height:15px;stroke-width:2}
.explain-text{font-size:14px;line-height:1.72;color:var(--ink-2)}
.explain-text mark{background:#FFE1E2;color:#C92A2A;font-weight:700;padding:0 2px;border-radius:4px}
.explain-answer{margin-top:11px;font-size:13px;color:var(--muted);line-height:1.7}
.explain-answer b{color:var(--red);font-weight:800}
.explain-memory{margin-top:11px;background:var(--accent-soft);border-radius:11px;padding:10px 12px;font-size:12.8px;line-height:1.65;color:#A9531A;display:flex;gap:7px;align-items:flex-start}
.explain-memory .mem-ico{flex:0 0 auto}

/* ---------- sprint card ---------- */
.sprint-card{position:relative;margin-top:14px;width:100%;display:flex;align-items:center;gap:13px;background:linear-gradient(120deg,#FF6A2B 0%,#FF9A4D 100%);color:#fff;border-radius:20px;padding:16px;box-shadow:0 14px 28px rgba(255,106,43,.30);overflow:hidden;text-align:left;transition:transform .15s}
.sprint-card:active{transform:scale(.985)}
.sprint-ico{width:44px;height:44px;border-radius:14px;background:rgba(255,255,255,.24);display:flex;align-items:center;justify-content:center;font-size:22px;flex:0 0 auto}
.sprint-main{flex:1;min-width:0}
.sprint-title{font-size:16px;font-weight:800;letter-spacing:.3px}
.sprint-desc{font-size:11.5px;opacity:.9;margin-top:3px}
.sprint-card .chev{color:rgba(255,255,255,.8);width:18px;height:18px;flex:0 0 auto}

/* emphasis for the answer line inside explanation */
.explain-answer{font-size:13px;color:var(--muted);line-height:1.8;margin-bottom:4px}
.explain-answer b{color:#D92D2D;font-size:15.5px;font-weight:800;background:#FFF0F0;padding:1px 6px;border-radius:6px}