/* =====================================================================================================================
   CPLP — Design System 80–20 (UX MVP 18/10/2026)
   80 % chuyên nghiệp: tối giản, dễ quan sát, ít thao tác · 20 % sinh động: màu trạng thái, phản hồi, điểm nhấn nhỏ.
   Dựng TRÊN các token sẵn có của app.css (--brand, --surface, --ok, --bad… sáng / tối) — chỉ thêm token ngữ nghĩa và
   component tiền tố .ux-*. Dùng chung cho Landing, Contest, bảng xếp hạng (IN / OUT) và về sau cho Chấm thi.
   Không có hoạt ảnh nặng; mọi chuyển động tắt khi người dùng chọn "giảm chuyển động".
   ===================================================================================================================== */
:root {
  /* ---- màu ngữ nghĩa (20 %: một màu nhấn trẻ trung, dùng tiết kiệm) ---- */
  --ux-accent: #f2672e;           /* cam san hô: điểm nhấn, nút hành động phụ nổi bật */
  --ux-accent-bg: #fff1ea;
  --ux-live: #d92d20;             /* đang diễn ra */
  --ux-live-bg: #fef0ee;
  --ux-up: var(--brand);          /* sắp diễn ra */
  --ux-up-bg: var(--brand-50);
  --ux-ended: var(--neutral);     /* đã kết thúc */
  --ux-ended-bg: var(--neutral-bg);
  --ux-partial: #9a6700;          /* có điểm, chưa trọn */
  --ux-partial-bg: #fff6d6;
  --ux-gold: #c99400; --ux-silver: #8a94a6; --ux-bronze: #b0652b;
  --ux-hero-a: #0060af; --ux-hero-b: #1b7fd1; --ux-hero-c: #3aa0e8;
  /* ---- khoảng cách (lưới 4 px) ---- */
  --ux-1: 4px; --ux-2: 8px; --ux-3: 12px; --ux-4: 16px; --ux-5: 20px; --ux-6: 24px; --ux-8: 32px; --ux-10: 40px; --ux-12: 48px;
  /* ---- chữ ---- */
  --ux-fs-xs: .78rem; --ux-fs-sm: .875rem; --ux-fs-md: 1rem; --ux-fs-lg: 1.15rem; --ux-fs-xl: 1.45rem;
  --ux-fs-2xl: clamp(1.6rem, 1.2rem + 1.6vw, 2.35rem); --ux-fs-3xl: clamp(1.9rem, 1.3rem + 2.6vw, 3rem);
  --ux-focus: 0 0 0 3px var(--ring-focus), 0 0 0 1px var(--brand);
  --ux-ease: cubic-bezier(.2, .7, .2, 1);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ux-accent: #ff8d5c; --ux-accent-bg: #3a2014; --ux-live: #ff6b5e; --ux-live-bg: #3a1714;
    --ux-partial: #f2c14e; --ux-partial-bg: #33290c; --ux-hero-a: #0b3d6b; --ux-hero-b: #11538f; --ux-hero-c: #1a6db3;
  }
}
:root[data-theme="dark"] {
  --ux-accent: #ff8d5c; --ux-accent-bg: #3a2014; --ux-live: #ff6b5e; --ux-live-bg: #3a1714;
  --ux-partial: #f2c14e; --ux-partial-bg: #33290c; --ux-hero-a: #0b3d6b; --ux-hero-b: #11538f; --ux-hero-c: #1a6db3;
}

/* ---- phông Arena (OFL, tự lưu trữ, cắt Latin / Latin mở rộng / tiếng Việt) — trình duyệt chỉ tải khi trang dùng tới ---- */
@font-face { font-family: "CVP Chakra Petch"; font-style: normal; font-weight: 600; font-display: swap;
  src: url("../fonts/arena/chakra-petch-vietnamese-600-normal.woff2") format("woff2");
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB; }
@font-face { font-family: "CVP Chakra Petch"; font-style: normal; font-weight: 600; font-display: swap;
  src: url("../fonts/arena/chakra-petch-latin-ext-600-normal.woff2") format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "CVP Chakra Petch"; font-style: normal; font-weight: 600; font-display: swap;
  src: url("../fonts/arena/chakra-petch-latin-600-normal.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "CVP Chakra Petch"; font-style: normal; font-weight: 700; font-display: swap;
  src: url("../fonts/arena/chakra-petch-vietnamese-700-normal.woff2") format("woff2");
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB; }
@font-face { font-family: "CVP Chakra Petch"; font-style: normal; font-weight: 700; font-display: swap;
  src: url("../fonts/arena/chakra-petch-latin-ext-700-normal.woff2") format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "CVP Chakra Petch"; font-style: normal; font-weight: 700; font-display: swap;
  src: url("../fonts/arena/chakra-petch-latin-700-normal.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "CVP JetBrains Mono"; font-style: normal; font-weight: 400 700; font-display: swap;
  src: url("../fonts/arena/jetbrains-mono-latin-600-normal.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }

/* ---- truy cập: viền focus rõ, giảm chuyển động ---- */
.ux :focus-visible, .ux-focus:focus-visible, .ux-card-link:focus-visible, .ux-ptab:focus-visible,
.ux-btn:focus-visible { outline: none; box-shadow: var(--ux-focus); border-radius: var(--radius-sm); }
@media (prefers-reduced-motion: reduce) {
  .ux *, .ux-toast, .ux-card-link, .ux-pulse { animation: none !important; transition: none !important; }
}
.ux-sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* ---- chip trạng thái (Contest / bài / kết quả) ---- */
.ux-chip { display: inline-flex; align-items: center; gap: 6px; padding: 3px 10px; border-radius: 999px;
  font-size: var(--ux-fs-xs); font-weight: 700; letter-spacing: .02em; line-height: 1.5; white-space: nowrap;
  background: var(--neutral-bg); color: var(--neutral); }
.ux-chip.is-live { background: var(--ux-live-bg); color: var(--ux-live); }
.ux-chip.is-upcoming { background: var(--ux-up-bg); color: var(--ux-up); }
.ux-chip.is-ended { background: var(--ux-ended-bg); color: var(--ux-ended); }
.ux-chip.is-ac { background: var(--ok-bg); color: var(--ok); }
.ux-chip.is-partial { background: var(--ux-partial-bg); color: var(--ux-partial); }
.ux-chip.is-tried { background: var(--bad-bg); color: var(--bad); }
.ux-chip.is-pending { background: var(--info-bg); color: var(--brand); }
.ux-chip.is-accent { background: var(--ux-accent-bg); color: var(--ux-accent); }
.ux-pulse { width: 8px; height: 8px; border-radius: 50%; background: currentColor; box-shadow: 0 0 0 0 currentColor;
  animation: ux-pulse 1.6s infinite; }
@keyframes ux-pulse { 0% { box-shadow: 0 0 0 0 color-mix(in srgb, currentColor 50%, transparent); }
  70% { box-shadow: 0 0 0 7px transparent; } 100% { box-shadow: 0 0 0 0 transparent; } }

/* ---- nút ---- */
.ux-btn { display: inline-flex; flex: none; white-space: nowrap; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 0 18px;
  border-radius: var(--radius); border: 1px solid var(--border); background: var(--surface); color: var(--text);
  font-weight: 650; text-decoration: none; cursor: pointer; transition: transform .15s var(--ux-ease), background .15s; }
.ux-btn:hover { background: var(--button-hover-surface); text-decoration: none; }
.ux-btn:active { transform: translateY(1px); }
.ux-btn.primary { background: var(--brand); border-color: var(--brand); color: var(--on-brand); }
.ux-btn.primary:hover { background: var(--brand-600); }
.ux-btn.accent { background: var(--ux-accent); border-color: var(--ux-accent); color: #fff; }
.ux-btn.accent:hover { filter: brightness(.95); }
.ux-btn.ghost-light { background: rgb(255 255 255 / .12); border-color: rgb(255 255 255 / .4); color: #fff; }
.ux-btn.ghost-light:hover { background: rgb(255 255 255 / .2); }
.ux-btn.ux-lg { min-height: 52px; padding: 0 24px; font-size: var(--ux-fs-lg); }
.ux-btn[disabled], .ux-btn[aria-disabled="true"] { opacity: .55; cursor: not-allowed; }

/* ---- hero (landing + contest) ---- */
.ux-hero { position: relative; overflow: hidden; color: #fff; border-radius: var(--radius-lg);
  background: radial-gradient(1200px 400px at 110% -20%, var(--ux-hero-c), transparent 60%),
              linear-gradient(135deg, var(--ux-hero-a), var(--ux-hero-b)); padding: var(--ux-8) var(--ux-8); }
.ux-hero::after { content: ""; position: absolute; right: -60px; bottom: -80px; width: 260px; height: 260px;
  border-radius: 50%; background: rgb(255 255 255 / .06); pointer-events: none; }
.ux-hero h1, .ux-hero h2 { color: #fff; margin: 0; }
.ux-hero .ux-kicker { margin: 0 0 var(--ux-2); font-size: var(--ux-fs-xs); font-weight: 800; letter-spacing: .12em;
  text-transform: uppercase; color: rgb(255 255 255 / .82); }
.ux-hero .ux-lead { margin: var(--ux-3) 0 0; max-width: 62ch; font-size: var(--ux-fs-lg); color: rgb(255 255 255 / .9); }
.ux-hero .ux-lead p { margin: 0 0 .4em; }
.ux-cta { display: flex; flex-wrap: wrap; gap: var(--ux-3); margin-top: var(--ux-6); position: relative; z-index: 1; }

/* ---- đồng hồ đếm ngược ---- */
.ux-count { display: flex; flex-direction: column; gap: 2px; }
.ux-count small { font-size: var(--ux-fs-xs); text-transform: uppercase; letter-spacing: .08em; opacity: .8; font-weight: 700; }
.ux-count b { font-size: var(--ux-fs-xl); font-variant-numeric: tabular-nums; letter-spacing: .02em; }
.ux-count.urgent b { color: var(--ux-live); }

/* ---- card / lưới lối vào ---- */
.ux-grid { display: grid; gap: var(--ux-4); grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
.ux-card-link { display: flex; gap: var(--ux-3); align-items: flex-start; padding: var(--ux-4) var(--ux-5);
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg); color: var(--text);
  text-decoration: none; transition: transform .18s var(--ux-ease), border-color .18s, box-shadow .18s; }
.ux-card-link:hover { transform: translateY(-2px); border-color: var(--brand); box-shadow: var(--elevation-popover);
  text-decoration: none; }
.ux-card-link .ux-ic { flex: none; display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px;
  background: var(--brand-50); color: var(--brand); }
.ux-card-link:nth-child(4n+2) .ux-ic { background: var(--ux-accent-bg); color: var(--ux-accent); }
.ux-card-link:nth-child(4n+3) .ux-ic { background: var(--ok-bg); color: var(--ok); }
.ux-card-link:nth-child(4n+4) .ux-ic { background: var(--ux-partial-bg); color: var(--ux-partial); }
.ux-card-link b { display: block; font-size: var(--ux-fs-md); }
.ux-card-link span { display: block; font-size: var(--ux-fs-sm); color: var(--muted); margin-top: 2px; }
.ux-section { margin: var(--ux-8) 0 var(--ux-4); display: flex; align-items: baseline; justify-content: space-between;
  gap: var(--ux-3); flex-wrap: wrap; }
.ux-section h2 { margin: 0; font-size: var(--ux-fs-xl); }
.ux-section .ux-hint { color: var(--muted); font-size: var(--ux-fs-sm); }

/* ---- thẻ Contest (danh sách, landing, trang chủ HS) ---- */
.ux-clist { display: grid; gap: var(--ux-3); }
.ux-ccard { display: grid; grid-template-columns: 1fr auto; gap: var(--ux-3) var(--ux-6); align-items: center;
  padding: var(--ux-4) var(--ux-5); background: var(--surface); border: 1px solid var(--line);
  border-left: 4px solid var(--ux-ended); border-radius: var(--radius-lg); }
.ux-ccard.is-live { border-left-color: var(--ux-live); }
.ux-ccard.is-upcoming { border-left-color: var(--ux-up); }
.ux-ccard .ux-ctitle { font-size: var(--ux-fs-lg); font-weight: 700; color: var(--text); text-decoration: none; }
.ux-ccard .ux-ctitle:hover { color: var(--brand); text-decoration: underline; }
.ux-ccard .ux-cmeta { display: flex; flex-wrap: wrap; gap: 4px var(--ux-4); margin-top: 6px; color: var(--muted);
  font-size: var(--ux-fs-sm); }
.ux-ccard .ux-cmeta > span { display: inline-flex; align-items: center; gap: 5px; }
.ux-ccard .ux-cside { display: flex; align-items: center; gap: var(--ux-4); }
.ux-ccard .ux-count b { font-size: var(--ux-fs-lg); }
.ux-ccard .ux-count small { color: var(--muted); opacity: 1; }
.ux-empty { padding: var(--ux-6); text-align: center; color: var(--muted); background: var(--surface);
  border: 1px dashed var(--border); border-radius: var(--radius-lg); }

/* ---- trang Contest: hero trạng thái + lưới bài ---- */
.ux-chero { display: grid; grid-template-columns: 1fr auto; gap: var(--ux-6); align-items: center; }
.ux-chero .ux-facts { display: flex; flex-wrap: wrap; gap: 6px var(--ux-5); margin-top: var(--ux-3); font-size: var(--ux-fs-sm);
  color: rgb(255 255 255 / .9); }
.ux-chero .ux-facts > span { display: inline-flex; align-items: center; gap: 6px; }
.ux-chero .ux-side { display: flex; flex-direction: column; align-items: flex-end; gap: var(--ux-3); text-align: right; }
.ux-chero .ux-chip { background: rgb(255 255 255 / .16); color: #fff; }
.ux-chero .ux-chip.is-live { background: #fff; color: var(--ux-live); }
.ux-pgrid { display: grid; gap: var(--ux-3); grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.ux-pcard { display: flex; align-items: center; gap: var(--ux-4); padding: var(--ux-4); background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--radius-lg); color: var(--text); text-decoration: none;
  transition: border-color .15s, transform .15s var(--ux-ease); }
a.ux-pcard:hover { border-color: var(--brand); transform: translateY(-1px); text-decoration: none; }
.ux-pcard .ux-plabel { flex: none; display: grid; place-items: center; width: 44px; height: 44px; border-radius: 12px;
  font-weight: 800; font-size: var(--ux-fs-lg); background: var(--secondary); color: var(--text); }
.ux-pcard.m-ac .ux-plabel { background: var(--ok); color: #fff; }
.ux-pcard.m-partial .ux-plabel { background: var(--ux-partial-bg); color: var(--ux-partial); }
.ux-pcard.m-tried .ux-plabel { background: var(--bad-bg); color: var(--bad); }
.ux-pcard.m-pending .ux-plabel { background: var(--info-bg); color: var(--brand); }
.ux-pcard.locked { color: var(--muted); background: var(--surface-2); border-style: dashed; }
.ux-pcard .ux-pbody { min-width: 0; flex: 1; }
.ux-pcard .ux-ptitle { display: block; font-weight: 650; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.ux-pcard .ux-psub { display: block; font-size: var(--ux-fs-xs); color: var(--muted); margin-top: 2px; }
.ux-progress { display: flex; align-items: center; gap: var(--ux-3); font-size: var(--ux-fs-sm); color: var(--muted); }
.ux-progress .ux-bar { display: block; flex: 1 1 140px; min-width: 120px; max-width: 220px; height: 8px; border-radius: 999px;
  background: var(--border); overflow: hidden; }
.ux-progress .ux-bar > span { display: block; height: 100%; border-radius: inherit;
  background: linear-gradient(90deg, var(--ok), #2fb36d); transition: width .4s var(--ux-ease); }
.ux-rules { display: grid; gap: var(--ux-2) var(--ux-6); grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  margin: 0; font-size: var(--ux-fs-sm); }
.ux-rules > div { display: flex; gap: var(--ux-2); align-items: baseline; }
.ux-rules dt { color: var(--muted); min-width: 92px; }
.ux-rules dd { margin: 0; font-weight: 600; }
.ux-wait { display: flex; gap: var(--ux-4); align-items: center; padding: var(--ux-5); border-radius: var(--radius-lg);
  background: var(--ux-up-bg); color: var(--text); border: 1px solid var(--line); }
.ux-wait .ux-wait-ic { flex: none; width: 48px; height: 48px; border-radius: 14px; display: grid; place-items: center;
  background: var(--surface); color: var(--brand); }

/* ---- thanh Contest trên trang giải bài — kiểu ARENA (UX V2, hướng A) ----
   Trang đọc đề giữ giao diện người dùng chọn (sáng / tối); riêng thanh kỳ thi mang màu Arena cố định để học sinh
   luôn nhận ra mình đang ở trong kỳ thi. Màu khai báo tại chỗ, không phụ thuộc ux-arena.css. */
.ux-cbar { --cb-n: #131938; --cb-d: #232c62; --cb-e: #313c7e; --cb-t: #eef1ff; --cb-m: #a9b2dd; --cb-s: #ffd23f;
  display: flex; align-items: center; gap: var(--ux-3) var(--ux-5); flex-wrap: wrap; padding: var(--ux-2) var(--ux-3);
  margin-bottom: var(--ux-4); background: var(--cb-n); color: var(--cb-t); border: 1px solid var(--cb-e); border-radius: 12px;
  position: sticky; top: 0; z-index: 5; color-scheme: dark; }
.ux-cbar .ux-cname { display: inline-flex; align-items: center; gap: var(--ux-2); font: 600 1rem/1.2 "CVP Chakra Petch", system-ui, sans-serif;
  color: var(--cb-t); text-decoration: none; max-width: 32ch; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.ux-cbar .ux-cname:hover { color: var(--cb-s); text-decoration: none; }
.ux-cbar .ux-chip { background: var(--cb-d); color: var(--cb-t); border-radius: 6px; }
.ux-cbar .ux-chip.is-live { background: var(--cb-s); color: #1a1a2e; }
.ux-ptabs { display: flex; gap: 6px; flex-wrap: wrap; align-items: center; }
.ux-ptab { position: relative; display: inline-grid; place-items: center; min-width: 40px; height: 36px; padding: 0 10px;
  border-radius: 8px; font: 700 .95rem/1 "CVP Chakra Petch", system-ui, sans-serif; background: var(--cb-d, var(--secondary)); color: var(--cb-t, var(--text));
  text-decoration: none; border: 2px solid transparent; transition: background .12s; }
.ux-ptab:hover { background: #2d3775; text-decoration: none; }
.ux-ptab.current { border-color: var(--cb-s, var(--brand)); box-shadow: 0 3px 0 var(--cb-s, var(--brand)); }
.ux-ptab.m-ac { background: #22c76f; color: #062b16; }
.ux-ptab.m-partial { background: #3a3010; color: #ffd166; }
.ux-ptab.m-tried { background: #4a2338; color: #ffc2b9; }
.ux-ptab.m-pending { background: repeating-linear-gradient(135deg, rgb(155 123 255 / .5) 0 6px, rgb(155 123 255 / .22) 6px 12px); color: #efeaff; }
.ux-ptab.locked { color: var(--cb-m, var(--muted)); background: transparent; border: 1px dashed var(--cb-e, var(--border)); cursor: default; }
.ux-cbar .ux-cright { margin-left: auto; display: flex; align-items: center; gap: var(--ux-4); flex-wrap: wrap; }
.ux-cbar .ux-count { flex-direction: row; align-items: baseline; gap: var(--ux-2); }
.ux-cbar .ux-count small { color: var(--cb-m); opacity: 1; text-transform: none; letter-spacing: 0; font-weight: 600; }
.ux-cbar .ux-count b { font: 600 1.2rem/1 "CVP JetBrains Mono", ui-monospace, monospace; color: var(--cb-t); }
.ux-cbar .ux-count[data-urgent] b { color: var(--cb-s); }
.ux-cbar .ux-solved { font-size: var(--ux-fs-sm); color: var(--cb-m); }
.ux-cbar .ux-solved b { color: #5ee39a; }
.ux-cbar .btn { background: var(--cb-d); border-color: var(--cb-e); color: var(--cb-t); }
.ux-cbar .btn:hover { background: #2d3775; }
.ux-cbar :focus-visible { outline: 3px solid var(--cb-s); outline-offset: 2px; box-shadow: none; }

/* ---- bảng xếp hạng: "vị trí của em" (IN) + chế độ trình chiếu (OUT) ---- */
.ux-me { display: flex; align-items: center; gap: var(--ux-5); flex-wrap: wrap; padding: var(--ux-4) var(--ux-5);
  margin-bottom: var(--ux-4); border-radius: var(--radius-lg); background: var(--brand-50); border: 1px solid var(--line); }
.ux-me .ux-me-rank { font-size: var(--ux-fs-2xl); font-weight: 800; color: var(--brand); font-variant-numeric: tabular-nums; }
.ux-me .ux-me-rank small { font-size: var(--ux-fs-sm); color: var(--muted); font-weight: 600; }
.ux-me .ux-me-stat { display: flex; flex-direction: column; }
.ux-me .ux-me-stat small { font-size: var(--ux-fs-xs); color: var(--muted); text-transform: uppercase; letter-spacing: .06em; font-weight: 700; }
.ux-me .ux-me-stat b { font-size: var(--ux-fs-lg); font-variant-numeric: tabular-nums; }
.ux-me .ux-me-cells { display: flex; gap: 6px; flex-wrap: wrap; }
.ux-me .ux-btn { margin-left: auto; min-height: 38px; }
.cboard tr.me { scroll-margin-top: 90px; }
.cboard tr.me > td { background: color-mix(in srgb, var(--brand-50) 80%, transparent); }
.cboard tr.me > td:first-child { box-shadow: inset 4px 0 0 var(--brand); }
.ux-board-tools { display: flex; gap: var(--ux-2); flex-wrap: wrap; align-items: center; justify-content: flex-end; margin: 0 0 var(--ux-3); }
.ux-format { display: inline-flex; align-items: center; gap: 6px; font-size: var(--ux-fs-sm); color: var(--muted); }
body.ux-projector .pb-wrap { max-width: none; }
body.ux-projector .cboard { font-size: 1.18rem; }
body.ux-projector .cboard th, body.ux-projector .cboard td { padding-top: .7rem; padding-bottom: .7rem; }
body.ux-projector .pb-rule, body.ux-projector .cb-legend { font-size: 1rem; }

/* ---- thanh tỉ lệ điểm IOI trong ô bảng xếp hạng + nút theo dõi (OUT Rank); Arena đổi màu trong ux-arena.css ---- */
.ux-meter { display: block; height: 5px; margin: 4px auto 0; width: 82%; border-radius: 5px; background: rgb(0 0 0 / .12); overflow: hidden; }
.ux-meter > i { display: block; height: 100%; width: calc(var(--p, 0) * 1%); background: currentColor; border-radius: inherit; }
.ux-follow { margin-left: 6px; padding: 2px 4px; border: 0; background: none; color: var(--muted); cursor: pointer; border-radius: 4px;
  vertical-align: -3px; line-height: 0; }
.ux-follow[aria-pressed="true"] { color: #e3a008; }
.ux-follow svg { width: 17px; height: 17px; }
.ux-ccard .ux-fx-date { display: none; }

/* ---- thông báo nổi (aria-live) ---- */
.ux-toast-host { position: fixed; right: var(--ux-4); bottom: var(--ux-4); z-index: 60; display: flex; flex-direction: column;
  gap: var(--ux-2); pointer-events: none; max-width: min(380px, calc(100vw - 32px)); }
.ux-toast { pointer-events: auto; display: flex; gap: var(--ux-3); align-items: flex-start; padding: var(--ux-3) var(--ux-4);
  background: var(--surface); color: var(--text); border: 1px solid var(--line); border-left: 4px solid var(--brand);
  border-radius: var(--radius); box-shadow: var(--elevation-modal); font-size: var(--ux-fs-sm);
  animation: ux-in .25s var(--ux-ease); }
.ux-toast.ok { border-left-color: var(--ok); }
.ux-toast.bad { border-left-color: var(--bad); }
.ux-toast b { display: block; font-size: var(--ux-fs-md); }
.ux-toast .ux-x { margin-left: auto; background: none; border: 0; color: var(--muted); cursor: pointer; font-size: 1.1rem; line-height: 1; }
@keyframes ux-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.ux-celebrate { animation: ux-pop .5s var(--ux-ease); }
@keyframes ux-pop { 0% { transform: scale(1); } 40% { transform: scale(1.12); } 100% { transform: scale(1); } }

/* ---- trang chủ học sinh ---- */
.ux-home-hero { display: grid; grid-template-columns: 1fr auto; gap: var(--ux-6); align-items: end; }
.ux-home-hero .ux-stats { display: flex; gap: var(--ux-6); flex-wrap: wrap; margin-top: var(--ux-4); }
.ux-home-hero .ux-stats > div { display: flex; flex-direction: column; }
.ux-home-hero .ux-stats small { font-size: var(--ux-fs-xs); text-transform: uppercase; letter-spacing: .08em; color: rgb(255 255 255 / .78); font-weight: 700; }
.ux-home-hero .ux-stats b { font-size: var(--ux-fs-xl); font-variant-numeric: tabular-nums; }
.ux-continue { display: flex; flex-direction: column; align-items: flex-end; gap: var(--ux-2); text-align: right;
  position: relative; z-index: 1; }
.ux-continue small { color: rgb(255 255 255 / .8); font-size: var(--ux-fs-sm); }

/* ---- màn hình hẹp ---- */
@media (max-width: 760px) {
  .ux-hero { padding: var(--ux-6) var(--ux-5); }
  .ux-chero, .ux-home-hero, .ux-ccard { grid-template-columns: 1fr; }
  .ux-chero .ux-side, .ux-continue { align-items: flex-start; text-align: left; }
  .ux-ccard .ux-cside { justify-content: space-between; }
  .ux-cbar { position: static; }
  .ux-cbar .ux-cright { margin-left: 0; width: 100%; justify-content: space-between; }
  .ux-me .ux-btn { margin-left: 0; }
  .ux-cta .ux-btn { flex: 1 1 auto; white-space: normal; text-align: center; }
}