/* Weekly Board Exam Challenge (2026-10-30): /challenge page + the "My challenge" card on /student. */
.bc-wrap { max-width: 920px; margin: 0 auto; padding: 28px 18px 48px; }
.bc-hero { background: linear-gradient(135deg, #0B1F4B, #13306f); color: #fff; border-radius: 16px; padding: 26px 22px; }
.bc-hero h1 { font-size: 28px; line-height: 1.2; margin: 0 0 6px; }
.bc-lead { margin: 0; opacity: .92; font-size: 16px; }
.bc-tiles { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 18px; }
.bc-tile { background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.2); border-radius: 12px; padding: 12px 16px; flex: 1 1 180px; }
.bc-big { font-size: 30px; font-weight: 800; letter-spacing: -.02em; }
.bc-tile small { display: block; opacity: .85; }
.bc-social { margin: 14px 0 0; font-weight: 600; color: #99f6e4; }
.bc-steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 10px; padding: 0; margin: 20px 0 0; list-style: none; counter-reset: bc; }
.bc-steps li { counter-increment: bc; background: #f8fafc; border: 1px solid #e2e8f0; border-radius: 12px; padding: 12px 14px 12px 44px; position: relative; color: #334155; line-height: 1.5; font-size: 14px; }
.bc-steps li::before { content: counter(bc); position: absolute; left: 12px; top: 12px; width: 22px; height: 22px; border-radius: 50%; background: #14b8a6; color: #fff; font-weight: 800; font-size: 13px; text-align: center; line-height: 22px; }
.bc-sec { margin-top: 28px; }
.bc-sec h2 { font-size: 20px; color: var(--navy, #0B1F4B); margin: 0 0 10px; }
.bc-sec p { line-height: 1.65; color: #334155; }
.bc-class { font-size: 15px; color: #475569; margin: 16px 0 8px; text-transform: uppercase; letter-spacing: .05em; }
.bc-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 12px; }
.bc-card { border: 1px solid #e2e8f0; border-radius: 14px; padding: 14px 16px; background: #fff; display: flex; flex-direction: column; }
.bc-card h4 { margin: 0 0 4px; font-size: 17px; color: #0f172a; }
.bc-meta { margin: 0; font-size: 13px; color: #64748b; }
.bc-ch { margin: 6px 0 0; font-size: 13px; color: #334155; }
.bc-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: auto; padding-top: 12px; }
.bc-btn { display: inline-block; background: #14b8a6; color: #fff; font-weight: 700; padding: 9px 14px; border-radius: 10px; text-decoration: none; border: 0; cursor: pointer; font-size: 14px; }
.bc-btn:hover { background: #0d9488; }
.bc-btn-ghost { background: #fff; color: #0f766e; border: 1px solid #14b8a6; }
.bc-btn-ghost:hover { background: #f0fdfa; }
.bc-btn-small { padding: 6px 10px; font-size: 13px; }
.bc-upload { border: 2px solid #14b8a6; border-radius: 14px; padding: 16px 18px; background: #f0fdfa; }
.bc-upload label { display: block; font-weight: 600; margin-bottom: 6px; }
.bc-upload input[type=file] { display: block; margin-bottom: 10px; max-width: 100%; }
.bc-status { margin: 10px 0 4px; font-size: 14px; }
.bc-bar { height: 6px; background: #e2e8f0; border-radius: 4px; overflow: hidden; }
.bc-bar span { display: block; height: 100%; width: 0; background: #14b8a6; transition: width .4s; }
.bc-muted { color: #64748b; font-size: 13px; }
/* "My challenge" card */
.bc-me { border: 1px solid #e2e8f0; border-radius: 14px; padding: 16px 18px; background: #fff; }
.bc-me-head { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 8px; }
.bc-me-head h3 { margin: 0; font-size: 18px; color: var(--navy, #0B1F4B); }
.bc-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(110px, 1fr)); gap: 10px; margin: 12px 0; }
.bc-stat { text-align: center; background: #f8fafc; border-radius: 10px; padding: 8px; }
.bc-stat b { display: block; font-size: 22px; color: #0f172a; }
.bc-stat span { font-size: 11px; color: #64748b; font-weight: 700; text-transform: uppercase; letter-spacing: .04em; }
.bc-trend { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px; }
.bc-trend figure { margin: 0; border: 1px solid #f1f5f9; border-radius: 10px; padding: 8px 10px; }
.bc-trend figcaption { font-size: 13px; font-weight: 600; color: #334155; display: flex; justify-content: space-between; }
.bc-trend svg { width: 100%; height: 56px; display: block; }
.bc-fix { margin: 12px 0 0; padding: 10px 12px; border-radius: 10px; background: #fff7ed; color: #9a3412; font-size: 14px; }
.bc-share { margin: 12px 0 0; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; font-size: 14px; color: #334155; }
.bc-remind { margin: 12px 0 0; font-size: 14px; color: #334155; display: flex; gap: 8px; align-items: center; }
@media (max-width: 600px) { .bc-hero h1 { font-size: 23px; } .bc-big { font-size: 24px; } }
.bc-dash { margin: 0 0 16px; }