/* Pages outside the slide deck: lecturer panel, analytics, results, materials, landing and join pages.
   Every class here starts with "u-" so nothing collides with slide/animation CSS in app.css. */
body.u { background: var(--paper); color: var(--ink); min-height: 100vh; }
body.u a { color: var(--teal-d); }
.u-ico { width: 18px; height: 18px; flex: none; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.u-ico.lg { width: 24px; height: 24px; }
.u-sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* ---------------------------------------------------------------- top navigation */
.u-nav { background: var(--dark); color: #fff; position: sticky; top: 0; z-index: 30; box-shadow: 0 1px 0 rgba(255,255,255,.06); }
.u-nav-in { max-width: 1240px; margin: 0 auto; padding: 0 20px; height: 62px; display: flex; align-items: center; gap: 22px; }
.u-brand { display: flex; align-items: center; gap: 10px; color: #fff !important; text-decoration: none; font: 800 17px/1.1 var(--head); white-space: nowrap; }
.u-brand-mark { width: 32px; height: 32px; border-radius: 9px; background: var(--teal); display: grid; place-items: center; }
.u-brand-mark .u-ico { width: 20px; height: 20px; stroke: #fff; stroke-width: 2.4; }
.u-brand small { display: block; font: 600 11.5px var(--body); color: #7FA5A0; letter-spacing: .02em; margin-top: 2px; }
.u-tabs-nav { display: flex; gap: 4px; height: 100%; overflow-x: auto; scrollbar-width: none; }
.u-tabs-nav::-webkit-scrollbar { display: none; }
.u-tabs-nav a { display: flex; align-items: center; gap: 8px; padding: 0 14px; color: #A9C4C0 !important; text-decoration: none; font: 650 14.5px var(--body); border-bottom: 3px solid transparent; white-space: nowrap; }
.u-tabs-nav a:hover { color: #fff !important; }
.u-tabs-nav a.on { color: #fff !important; border-bottom-color: #6FE0CF; }
.u-tabs-nav a.adm { color: #F3C982 !important; }
.u-nav-right { margin-left: auto; display: flex; align-items: center; gap: 12px; }
.u-user { display: flex; align-items: center; gap: 8px; font: 600 13.5px var(--body); color: #CFE3E0; white-space: nowrap; }
.u-avatar { width: 30px; height: 30px; border-radius: 50%; background: #17403B; color: #6FE0CF; display: grid; place-items: center; font: 800 13px var(--head); }
.u-nav form { margin: 0; }
.u-icon-btn { display: inline-flex; align-items: center; gap: 6px; background: transparent; border: 1px solid rgba(255,255,255,.16); color: #DDEDEB; border-radius: 9px; padding: 7px 11px; font: 600 13.5px var(--body); cursor: pointer; text-decoration: none; }
.u-icon-btn:hover { background: rgba(255,255,255,.08); }
.u-lang { display: inline-flex; background: rgba(255,255,255,.08); border-radius: 10px; padding: 3px; }
.u-lang a { padding: 5px 11px; border-radius: 8px; color: #A9C4C0 !important; text-decoration: none; font: 700 13px var(--body); }
.u-lang a.on { background: #fff; color: var(--ink) !important; }
@media (max-width: 720px) {
  .u-nav-in { height: auto; flex-wrap: wrap; padding: 10px 14px 0; gap: 10px 14px; }
  .u-tabs-nav { order: 3; flex-basis: 100%; height: 44px; }
  .u-user span.name, .u-brand small { display: none; }
}

/* ---------------------------------------------------------------- page scaffolding */
.u-page { max-width: 1240px; margin: 0 auto; padding: 26px 20px 80px; }
.u-page.narrow { max-width: 880px; }
.u-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 16px; flex-wrap: wrap; margin-bottom: 20px; }
.u-head h1 { font: 800 30px/1.15 var(--head); letter-spacing: -0.01em; margin: 0; }
.u-head .u-sub { font: 500 15px/1.5 var(--body); color: var(--muted); margin-top: 6px; }
.u-kicker { font: 700 12px var(--body); letter-spacing: .12em; text-transform: uppercase; color: var(--teal); margin-bottom: 6px; }
.u-actions { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.u-card { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 20px 22px; box-shadow: 0 1px 2px rgba(11,31,30,.03); }
.u-card + .u-card { margin-top: 16px; }
.u-card h2 { font: 800 19px/1.25 var(--head); margin: 0 0 4px; display: flex; align-items: center; gap: 10px; }
.u-card h2 .u-ico { color: var(--teal); }
.u-card .u-card-sub { font: 500 13.5px/1.45 var(--body); color: var(--muted); margin: 0 0 14px; }
.u-cols { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 22px; align-items: start; }
.u-cols.even { grid-template-columns: 1fr 1fr; }
.u-stack { display: grid; gap: 16px; }
@media (max-width: 960px) { .u-cols, .u-cols.even { grid-template-columns: 1fr; } }
.u-muted { color: var(--muted); }
.u-empty { text-align: center; padding: 34px 20px; color: var(--muted); font: 500 15px/1.5 var(--body); }

/* ---------------------------------------------------------------- buttons, badges, forms */
.u-btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; border: 1.5px solid transparent; border-radius: 12px; padding: 11px 18px; background: var(--teal); color: #fff !important; font: 750 15px var(--head); text-decoration: none; cursor: pointer; white-space: nowrap; transition: background .15s, border-color .15s, transform .1s; }
.u-btn:hover { background: var(--teal-d); }
.u-btn:active { transform: translateY(1px); }
.u-btn.ghost { background: #fff; color: var(--ink) !important; border-color: var(--line); }
.u-btn.ghost:hover { border-color: var(--teal); background: var(--mint); }
.u-btn.dark { background: var(--ink); }
.u-btn.dark:hover { background: #000; }
.u-btn.danger { background: #fff; color: var(--red) !important; border-color: #F0C3BF; }
.u-btn.danger:hover { background: var(--red-l); }
.u-btn.sm { padding: 7px 12px; font-size: 13.5px; border-radius: 10px; }
.u-btn.lg { padding: 15px 24px; font-size: 17px; border-radius: 14px; }
.u-btn.block { width: 100%; }
.u-btn .u-ico { width: 17px; height: 17px; }
.u-badge { display: inline-flex; align-items: center; gap: 5px; font: 700 12px var(--body); padding: 3px 9px; border-radius: 999px; background: var(--mint); color: var(--teal-d); white-space: nowrap; }
.u-badge.off { background: #EEF1F0; color: #6E7E7B; }
.u-badge.warn { background: var(--amber-l); color: #8A5A0E; }
.u-badge.live { background: var(--green-l); color: #1F7A45; }
.u-badge.live::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--green); animation: u-pulse 1.6s infinite; }
@keyframes u-pulse { 0%, 100% { opacity: 1; } 50% { opacity: .3; } }
.u-input, .u-select { display: block; width: 100%; font: 500 16px var(--body); padding: 11px 14px; border-radius: 12px; border: 1.5px solid var(--line); background: #fff; color: var(--ink); }
.u-input:focus, .u-select:focus { outline: none; border-color: var(--teal); box-shadow: 0 0 0 4px rgba(15,139,126,.12); }
.u-label { display: block; font: 650 13.5px var(--body); color: var(--ink-2); margin: 14px 0 6px; }
.u-form-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.u-form-row .u-input { flex: 1; min-width: 200px; width: auto; }
.u-err { color: var(--red); font: 600 14px var(--body); margin-top: 10px; }
.u-msgs { position: fixed; right: 18px; bottom: 18px; z-index: 60; display: grid; gap: 8px; max-width: min(420px, calc(100vw - 36px)); }
.u-msg { background: var(--dark); color: #fff; border-radius: 14px; padding: 13px 16px; font: 600 14.5px/1.4 var(--body); box-shadow: 0 12px 34px rgba(0,0,0,.22); display: flex; gap: 10px; align-items: flex-start; animation: u-in .3s ease-out; }
.u-msg.error { background: #7A231E; }
.u-msg .u-ico { color: #6FE0CF; margin-top: 1px; }
@keyframes u-in { from { transform: translateY(10px); opacity: 0; } }
.u-warn { display: flex; gap: 12px; background: var(--amber-l); border: 1px solid #EBC98C; color: #6B4A10; border-radius: 14px; padding: 14px 18px; margin-bottom: 18px; font: 500 14.5px/1.5 var(--body); }
.u-warn .u-ico { color: #B5781A; margin-top: 2px; }

/* ---------------------------------------------------------------- KPI tiles and bars */
.u-tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 12px; margin-bottom: 18px; }
.u-tile { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 14px 16px; position: relative; overflow: hidden; }
.u-tile .k { font: 650 12.5px var(--body); color: var(--muted); display: flex; align-items: center; gap: 7px; }
.u-tile .k .u-ico { width: 16px; height: 16px; color: var(--teal); }
.u-tile .v { font: 800 30px/1.1 var(--head); letter-spacing: -0.01em; margin-top: 6px; font-variant-numeric: tabular-nums; }
.u-tile .v small { font: 600 14px var(--body); color: var(--muted); margin-left: 4px; }
.u-tile .s { font: 500 12.5px var(--body); color: var(--faint); margin-top: 2px; }
.u-tile.accent { background: var(--dark); border-color: var(--dark); color: #fff; }
.u-tile.accent .k { color: #7FA5A0; } .u-tile.accent .k .u-ico { color: #6FE0CF; }
.u-tile.accent .v { color: #fff; letter-spacing: .12em; }
.u-bar { height: 8px; border-radius: 99px; background: var(--line-2); overflow: hidden; }
.u-bar > span { display: block; height: 100%; border-radius: 99px; background: var(--teal); }
.u-bar.thick { height: 12px; }
.u-bar.amber > span { background: var(--amber); }
.u-bar.red > span { background: var(--red); }
.u-bar.violet > span { background: var(--violet); }
.u-pct { font: 800 14px var(--head); font-variant-numeric: tabular-nums; }
.u-pct.good { color: var(--green); } .u-pct.mid { color: #B5781A; } .u-pct.bad { color: var(--red); }

/* ---------------------------------------------------------------- tables */
.u-table-wrap { overflow-x: auto; margin: 0 -4px; }
.u-table { width: 100%; border-collapse: collapse; font: 500 14px/1.4 var(--body); }
.u-table th { text-align: left; font: 700 11.5px var(--body); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); padding: 9px 10px; border-bottom: 1.5px solid var(--line); white-space: nowrap; }
.u-table td { padding: 10px; border-bottom: 1px solid var(--line-2); vertical-align: middle; }
.u-table tr:last-child td { border-bottom: 0; }
.u-table tr:hover td { background: #FAFCFB; }
.u-table td.num, .u-table th.num { text-align: right; font-variant-numeric: tabular-nums; }
.u-table .u-rank { width: 30px; height: 30px; border-radius: 9px; background: var(--line-2); display: grid; place-items: center; font: 800 13px var(--head); color: var(--ink-2); }
/* row 1 is the header row */
.u-table tr:nth-child(2) .u-rank.medal { background: #F6D77A; } .u-table tr:nth-child(3) .u-rank.medal { background: #DDE3E2; } .u-table tr:nth-child(4) .u-rank.medal { background: #EBC2A0; }
.u-table code { font: 600 12px ui-monospace, Consolas, monospace; color: var(--muted); }
.u-dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; background: #C9D4D2; margin-right: 6px; }
.u-dot.on { background: var(--green); }

/* ---------------------------------------------------------------- tabs inside a page */
.u-tabs { display: flex; gap: 4px; border-bottom: 1.5px solid var(--line); margin-bottom: 18px; overflow-x: auto; }
.u-tabs a { padding: 10px 14px; color: var(--muted) !important; text-decoration: none; font: 700 14.5px var(--body); border-bottom: 3px solid transparent; margin-bottom: -1.5px; white-space: nowrap; }
.u-tabs a.on, .u-tabs a:hover { color: var(--ink) !important; border-bottom-color: var(--teal); }
.u-chips { display: flex; gap: 6px; flex-wrap: wrap; }
.u-chip { display: inline-flex; align-items: center; gap: 7px; padding: 7px 13px; border-radius: 999px; border: 1.5px solid var(--line); background: #fff; color: var(--ink) !important; text-decoration: none; font: 650 14px var(--body); }
.u-chip b { color: var(--muted); font-weight: 700; letter-spacing: .04em; }
.u-chip:hover { border-color: var(--teal); }
.u-chip.on { background: var(--teal); border-color: var(--teal); color: #fff !important; }
.u-chip.on b { color: #CDEFE9; }

/* ---------------------------------------------------------------- lecturer main panel */
.u-groupbar { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; margin-bottom: 18px; }
.u-groupbar .u-select { width: auto; min-width: 280px; font-weight: 650; }
.u-mods { display: grid; gap: 12px; }
.u-mod { display: grid; grid-template-columns: 62px minmax(0, 1fr) auto; gap: 18px; align-items: center; background: #fff; border: 1.5px solid var(--line); border-radius: 18px; padding: 16px 18px; transition: border-color .15s, box-shadow .15s; }
.u-mod:hover { border-color: #9FD6CE; box-shadow: 0 10px 28px rgba(11,31,30,.07); }
.u-mod.current { border-color: var(--teal); box-shadow: 0 0 0 3px rgba(15,139,126,.1); }
.u-mod-n { width: 62px; height: 62px; border-radius: 16px; background: var(--dark); color: #6FE0CF; display: grid; place-items: center; font: 800 28px var(--head); }
.u-mod-t { font: 750 18px/1.25 var(--head); }
.u-mod-uz { font: 500 13.5px var(--body); color: var(--muted); margin-top: 2px; }
.u-mod-meta { display: flex; gap: 6px 14px; flex-wrap: wrap; font: 500 13px var(--body); color: var(--muted); margin-top: 8px; }
.u-mod-meta b { color: var(--ink-2); font-weight: 700; }
.u-mod-prog { display: grid; grid-template-columns: 1fr auto; gap: 10px; align-items: center; margin-top: 10px; max-width: 420px; font: 600 12.5px var(--body); color: var(--muted); }
.u-mod-go { display: flex; flex-direction: column; gap: 6px; align-items: stretch; min-width: 190px; }
.u-mod-links { display: flex; gap: 6px; justify-content: flex-end; }
@media (max-width: 760px) {
  .u-mod { grid-template-columns: 52px minmax(0, 1fr); }
  .u-mod-n { width: 52px; height: 52px; font-size: 24px; }
  .u-mod-go { grid-column: 1 / -1; min-width: 0; }
}
.u-join { text-align: center; position: sticky; top: 80px; }
.u-join img { width: 210px; height: 210px; margin: 6px auto 0; display: block; border-radius: 12px; }
.u-join .host { font: 600 14px var(--body); color: var(--teal-d); margin-top: 8px; word-break: break-all; }
.u-join .code { font: 800 44px/1.05 var(--head); letter-spacing: .14em; margin: 2px 0 4px; }
.u-join .note { font: 500 12.5px/1.45 var(--body); color: var(--muted); margin: 6px 0 12px; }
.u-join .u-actions { justify-content: center; }
.u-join .u-btn { flex: 1; }
.u-keys { display: grid; grid-template-columns: auto 1fr; gap: 7px 12px; font: 500 13.5px var(--body); color: var(--ink-2); align-items: center; }
body.u kbd { display: inline-block; min-width: 24px; padding: 2px 7px; border-radius: 7px; background: #fff; border: 1px solid var(--line); border-bottom-width: 2px; font: 700 12.5px var(--body); text-align: center; color: var(--ink); }
.u-check { list-style: none; margin: 0; padding: 0; display: grid; gap: 9px; font: 500 14px/1.4 var(--body); color: var(--ink-2); }
.u-check li { display: grid; grid-template-columns: 22px 1fr; gap: 8px; }
.u-check .u-ico { color: var(--teal); margin-top: 1px; }
details.u-more > summary { cursor: pointer; list-style: none; font: 700 14px var(--body); color: var(--ink-2); display: flex; align-items: center; gap: 8px; }
details.u-more > summary::-webkit-details-marker { display: none; }
details.u-more > summary::after { content: "▾"; margin-left: auto; color: var(--muted); transition: transform .2s; }
details.u-more[open] > summary::after { transform: rotate(180deg); }
details.u-more[open] > summary { margin-bottom: 12px; }

/* dialogs and the big QR overlay */
dialog.u-dialog { border: 0; border-radius: 20px; padding: 24px; width: min(480px, calc(100vw - 32px)); box-shadow: 0 30px 80px rgba(0,0,0,.3); }
dialog.u-dialog::backdrop { background: rgba(6,21,20,.55); backdrop-filter: blur(2px); }
dialog.u-dialog h2 { font: 800 22px var(--head); margin: 0 0 4px; }
.u-dialog-actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 20px; }
.u-qrfull { position: fixed; inset: 0; z-index: 80; background: var(--dark); color: #fff; display: none; place-items: center; text-align: center; cursor: zoom-out; }
.u-qrfull.on { display: grid; }
.u-qrfull img { width: min(62vh, 80vw); height: auto; border-radius: 22px; background: #fff; padding: 18px; }
.u-qrfull .host { font: 700 clamp(18px, 3vw, 30px) var(--body); color: #6FE0CF; margin-top: 18px; }
.u-qrfull .code { font: 800 clamp(40px, 9vw, 96px)/1 var(--head); letter-spacing: .14em; margin-top: 8px; }
.u-qrfull .hint { font: 500 14px var(--body); color: #7FA5A0; margin-top: 14px; }

/* ---------------------------------------------------------------- analytics */
.u-hbars { display: grid; gap: 10px; }
.u-hbar { display: grid; grid-template-columns: minmax(0, 1fr) 160px 54px; gap: 12px; align-items: center; font: 500 14px/1.35 var(--body); }
.u-hbar .t { min-width: 0; }
.u-hbar .t small { display: block; color: var(--faint); font-size: 12px; }
.u-hbar .n { text-align: right; font: 800 14px var(--head); font-variant-numeric: tabular-nums; }
@media (max-width: 600px) { .u-hbar { grid-template-columns: minmax(0, 1fr) 90px 46px; } }
.u-poll { padding: 14px 0; border-top: 1px solid var(--line-2); }
.u-poll:first-child { border-top: 0; padding-top: 0; }
.u-poll .q { font: 700 15px/1.4 var(--body); margin-bottom: 10px; }
.u-poll .q small { color: var(--muted); font-weight: 500; margin-left: 6px; }
.u-qtag { display: inline-block; font: 700 11px var(--body); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); background: var(--line-2); border-radius: 6px; padding: 2px 7px; margin-right: 6px; }

/* ---------------------------------------------------------------- landing (home for visitors) */
.u-hero { max-width: 1040px; margin: 0 auto; padding: 44px 20px 70px; display: grid; grid-template-columns: 1.25fr 1fr; gap: 22px; align-items: stretch; }
.u-part { display: flex; flex-direction: column; justify-content: space-between; gap: 22px; padding: 34px 32px; border-radius: 24px; min-height: 360px;
  background: radial-gradient(620px 380px at 92% 0%, rgba(111,224,207,.28), transparent 62%), var(--dark); color: #fff !important; text-decoration: none; transition: transform .15s, box-shadow .15s; }
.u-part:hover { transform: translateY(-2px); box-shadow: 0 20px 50px rgba(6,21,20,.25); }
.u-part-ico { width: 66px; height: 66px; border-radius: 18px; background: var(--teal); display: grid; place-items: center; }
.u-part-ico .u-ico { width: 34px; height: 34px; stroke: #fff; }
.u-part h1 { font: 800 40px/1.05 var(--head); margin: 18px 0 4px; letter-spacing: -0.02em; }
.u-part .uz { font: 700 22px var(--head); color: #9FE9DE; }
.u-part p { font: 500 16px/1.5 var(--body); color: #A9C4C0; margin: 12px 0 0; max-width: 460px; }
.u-part .go { display: flex; align-items: center; justify-content: center; gap: 10px; height: 58px; border-radius: 16px; background: #fff; color: var(--ink); font: 800 18px var(--head); }
.u-side { display: grid; gap: 16px; align-content: start; }
.u-mine { display: flex; align-items: center; gap: 14px; padding: 16px 18px; border-radius: 18px; background: var(--mint); border: 1.5px solid var(--teal-l); color: var(--ink) !important; text-decoration: none; }
.u-mine:hover { border-color: var(--teal); }
.u-mine b { display: block; font: 800 16px var(--head); }
.u-mine small { font: 500 13px var(--body); color: var(--muted); }
.u-mine .u-ico { color: var(--teal); margin-left: auto; }
.u-login h2 { font: 800 21px var(--head); margin: 0; }
.u-foot-links { grid-column: 1 / -1; display: flex; gap: 18px; justify-content: center; flex-wrap: wrap; font: 600 15px var(--body); }
.u-foot-links a { display: inline-flex; align-items: center; gap: 7px; text-decoration: none; }
@media (max-width: 820px) {
  .u-hero { grid-template-columns: 1fr; padding-top: 18px; }
  .u-part { min-height: 0; padding: 26px 22px; }
  .u-part h1 { font-size: 32px; }
}

/* participant code / name pages */
.u-joinbox { max-width: 460px; margin: 7vh auto 0; padding: 0 18px 60px; text-align: center; }
.u-joinbox h1 { font: 800 30px/1.2 var(--head); margin: 0 0 6px; }
.u-joinbox .uz { font: 700 19px var(--head); color: var(--muted); }
.u-joinbox p { color: var(--muted); font: 500 15.5px/1.5 var(--body); margin: 10px 0 22px; }
.u-code { display: block; width: 100%; font: 800 44px var(--head); letter-spacing: .4em; text-indent: .4em; text-align: center; padding: 16px 10px; border-radius: 18px; border: 2px solid var(--line); background: #fff; color: var(--ink); }
.u-code:focus { outline: none; border-color: var(--teal); box-shadow: 0 0 0 5px rgba(15,139,126,.14); }
.u-name { display: block; width: 100%; font: 700 22px var(--body); text-align: center; padding: 15px; border-radius: 16px; border: 2px solid var(--line); background: #fff; }
.u-name:focus { outline: none; border-color: var(--teal); box-shadow: 0 0 0 5px rgba(15,139,126,.14); }
.u-joinbox .u-btn.block { margin-top: 14px; padding: 17px; font-size: 18px; border-radius: 16px; }
.u-joinbox .u-mine { text-align: left; margin-bottom: 16px; }
.u-steps3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-top: 26px; text-align: left; }
.u-steps3 div { background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 12px; font: 500 12.5px/1.4 var(--body); color: var(--muted); }
.u-steps3 b { display: block; font: 800 18px var(--head); color: var(--teal); }
.u-grouphead { display: inline-flex; align-items: center; gap: 8px; padding: 6px 14px; border-radius: 999px; background: var(--mint); color: var(--teal-d); font: 800 14px var(--body); letter-spacing: .06em; margin-bottom: 14px; }

/* ---------------------------------------------------------------- materials */
.u-res-hero { background: radial-gradient(700px 300px at 95% 0%, rgba(111,224,207,.22), transparent 60%), var(--dark); color: #fff; }
.u-res-hero .in { max-width: 1240px; margin: 0 auto; padding: 34px 20px 38px; display: flex; gap: 20px; align-items: flex-end; justify-content: space-between; flex-wrap: wrap; }
.u-res-hero h1 { font: 800 34px/1.12 var(--head); margin: 0; letter-spacing: -0.01em; }
.u-res-hero p { font: 500 16px/1.5 var(--body); color: #A9C4C0; margin: 8px 0 0; max-width: 640px; }
.u-res-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
.u-res { background: #fff; border: 1px solid var(--line); border-radius: 20px; padding: 20px; display: flex; flex-direction: column; gap: 12px; }
.u-res-top { display: flex; gap: 14px; align-items: flex-start; }
.u-res-n { flex: none; width: 52px; height: 52px; border-radius: 15px; background: var(--dark); color: #6FE0CF; display: grid; place-items: center; font: 800 24px var(--head); }
.u-res-t { font: 800 17.5px/1.25 var(--head); }
.u-res-s { font: 500 13.5px/1.45 var(--body); color: var(--muted); margin-top: 4px; }
.u-res-meta { display: flex; gap: 6px; flex-wrap: wrap; }
.u-res ol { margin: 0; padding-left: 20px; font: 500 13.5px/1.55 var(--body); color: var(--ink-2); }
.u-res .u-actions { margin-top: auto; }
.u-res .u-actions .u-btn { flex: 1; }
.u-banner { display: flex; gap: 12px; align-items: center; justify-content: space-between; flex-wrap: wrap; background: var(--mint); border: 1.5px solid var(--teal-l); border-radius: 16px; padding: 12px 16px; margin-bottom: 18px; font: 600 14.5px var(--body); }

/* handout reader */
.u-reader-bar { position: sticky; top: 62px; z-index: 20; background: rgba(245,248,247,.94); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.u-reader-bar .in { max-width: 860px; margin: 0 auto; padding: 8px 18px; display: flex; gap: 10px; align-items: center; }
.u-reader-bar select { max-width: 360px; flex: 1; padding: 8px 10px; font-size: 14px; }
.u-progress { position: absolute; left: 0; bottom: -1px; height: 3px; background: var(--teal); width: 0; }
.u-totop { position: fixed; right: 16px; bottom: 16px; width: 46px; height: 46px; border-radius: 50%; background: var(--dark); color: #fff; border: 0; display: grid; place-items: center; box-shadow: 0 8px 22px rgba(0,0,0,.25); opacity: 0; pointer-events: none; transition: opacity .2s; cursor: pointer; }
.u-totop.on { opacity: 1; pointer-events: auto; }
@media (max-width: 720px) { .u-reader-bar { top: 106px; } }
.read .sec { scroll-margin-top: 130px; }
.u-mod-meta span { display: inline-flex; align-items: center; gap: 5px; }
.u-mod-meta .u-ico, .u-badge .u-ico { width: 14px; height: 14px; }
.u-banner .u-ico { color: var(--teal); vertical-align: -3px; }
.u-login summary .u-avatar .u-ico { width: 16px; height: 16px; }
.u-login summary h2 { margin: 0; }

/* phone: waiting screen */
.ph-rankcard { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; max-width: 320px; margin: 26px auto 0; }
.ph-rankcard div { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 12px 10px; }
.ph-rankcard b { display: block; font: 800 30px/1.1 var(--head); color: var(--teal-d); }
.ph-rankcard small { font: 600 12.5px var(--body); color: var(--muted); }
.ph-matlink { display: inline-flex; align-items: center; gap: 8px; margin-top: 22px; padding: 11px 16px; border-radius: 12px; background: var(--mint); color: var(--teal-d); font: 700 15px var(--body); text-decoration: none; }
.ph-matlink .ico { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; }
.u-stack > .u-card + .u-card { margin-top: 0; }
.u-nav a.u-icon-btn { color: #DDEDEB !important; }
@media (max-width: 720px) { .u-nav { position: static; } .u-reader-bar { top: 0; } }
.u-cols > .u-card + .u-card { margin-top: 0; }
@media (max-width: 720px) { .u-brand { white-space: normal; font-size: 14.5px; line-height: 1.15; } .u-brand small { display: none; } }