body { font-family: sans-serif; margin: 0; color: #222; background: #fff; }
.topbar { display: flex; gap: 1rem; align-items: center; padding: 0.75rem 1rem; background: #1f4e79; color: #fff; }
.topbar a { color: #fff; }
.topbar form.inline { margin: 0; }
.topbar .logout-btn {
  appearance: none;
  background: transparent;
  border: 0;
  padding: 0;
  margin: 0;
  color: #fff;
  font: inherit;
  line-height: inherit;
  cursor: pointer;
  text-decoration: underline;
}
.topbar .logout-btn:hover { color: #d6e6f5; }
.inline { display: inline; }
main { padding: 1.25rem; }
.login-screen {
  position: relative;
  margin: -1.25rem;
  min-height: calc(100vh - 3.4rem);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: #061428;
}
.login-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.login-box {
  position: relative;
  z-index: 1;
  width: 22rem;
  max-width: calc(100% - 2rem);
  padding: 1.5rem 1.75rem 1.75rem;
  border: 1px solid rgba(213, 227, 239, 0.9);
  border-top: 4px solid #1f4e79;
  background: rgba(244, 248, 251, 0.94);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
}
.login-box h1 { margin-top: 0; }
.login-box input { width: 100%; box-sizing: border-box; }
.error { color: #b00020; }
label { display: block; margin: 0.5rem 0; }
table { border-collapse: collapse; margin-top: 1rem; }
td, th { border: 1px solid #ccc; padding: 0.35rem 0.6rem; text-align: left; }
button.primary { background: #1f4e79; color: #fff; border: 0; padding: 0.45rem 0.9rem; cursor: pointer; }
a.primary {
  display: inline-block;
  background: #1f4e79;
  color: #fff;
  border: 0;
  padding: 0.45rem 0.9rem;
  cursor: pointer;
  text-decoration: none;
  box-sizing: border-box;
  text-align: center;
}
button.primary:disabled {
  background: #8aa0b5;
  cursor: not-allowed;
}
.portal-page { max-width: 52rem; margin: 0.5rem auto 0; }
.portal-lead { color: #5a7188; }
.portal-cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(16rem, 1fr));
  gap: 1.25rem;
  margin-top: 1.25rem;
}
.portal-card { min-height: 16rem; display: flex; flex-direction: column; }
.portal-card p { flex: 1 1 auto; }
.portal-action {
  display: block;
  width: 100%;
  margin-top: 1rem;
  padding: 0.9rem 1.2rem;
  font-size: 1.15rem;
  font-weight: bold;
}
.portal-hint { margin: 0.6rem 0 0; color: #b00020; }
@media (max-width: 720px) {
  .portal-cards { grid-template-columns: 1fr; }
}
.admin-links { max-width: 52rem; margin: 2rem auto 0; }
tr.me { box-shadow: inset 3px 0 0 #1f4e79; }
tr.rank-1 { background: #f8ecd0; }
tr.rank-2-4 { background: #eee4f8; }
tr.rank-5-10 { background: #dceef8; }
.home-layout {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 2.5rem;
  max-width: 56rem;
  margin: 0.5rem auto 0;
}
.home-exams,
.home-rank {
  flex: 1 1 22rem;
  max-width: 26rem;
  min-width: 16rem;
}
.home-exams h1,
.home-rank h1 {
  margin: 0;
  line-height: 1.3;
}
.home-rank { position: sticky; top: 1rem; }
.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-top: 1rem;
}
.exam-card { border: 1px solid #ddd; padding: 1rem; }
.exam-card h2 { margin: 0 0 0.5rem; }
.exam-card.ended { opacity: 0.65; }
.rank-panel {
  margin-top: 1rem;
  background: #f4f8fb;
  border: 1px solid #d5e3ef;
  border-top: 4px solid #1f4e79;
  padding: 1rem;
  box-sizing: border-box;
}
.rank-panel h2 { margin: 0 0 0.5rem; }
.rank-panel p { margin: 0.4rem 0; }
.rank-count { color: #5a7188; font-size: 0.9rem; }
.rank-board {
  display: flex;
  align-items: stretch;
  gap: 0.55rem;
  margin-top: 0.5rem;
}
.rank-scroll {
  flex: 1 1 auto;
  min-width: 0;
  max-height: min(28rem, calc(100vh - 16rem));
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: none;
}
.rank-scroll::-webkit-scrollbar { width: 0; height: 0; }
.rank-rail {
  flex: 0 0 8px;
  position: relative;
  border-radius: 8px;
  background: #d5e3ef;
  overflow: hidden;
}
.rank-rail > i {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 30%;
  border-radius: 8px;
  background: #1f4e79;
}
.rank-table {
  width: 100%;
  table-layout: fixed;
  margin-top: 0;
  box-sizing: border-box;
}
.rank-table .col-rank { width: 22%; }
.rank-table .col-name { width: 48%; }
.rank-table .col-score { width: 30%; }
.rank-table th,
.rank-table td {
  padding: 0.45rem 0.7rem;
}
.rank-table thead th {
  position: sticky;
  top: 0;
  background: #e8f0f7;
  z-index: 1;
}
.my-rank { font-weight: bold; color: #1f4e79; }
.rank-block + .rank-block { margin-top: 1.5rem; }
.rank-page { max-width: 40rem; margin: 0 auto; }
.rank-page .rank-panel { margin-top: 0.75rem; }
.rank-page .rank-scroll { max-height: min(36rem, calc(100vh - 14rem)); }
@media (max-width: 860px) {
  .home-layout { flex-direction: column; }
  .home-rank { width: auto; flex: 1 1 auto; position: static; max-width: none; }
}
.exam-top { display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.exam-top h1 { margin: 0 0 0.75rem; }
#timer { font-size: 1.6rem; font-variant-numeric: tabular-nums; }
.exam-layout { display: flex; gap: 1.5rem; align-items: flex-start; }
.questions { flex: 1; min-width: 0; }
.q { margin: 0 0 1.5rem; padding-bottom: 1rem; border-bottom: 1px solid #eee; }
.q-image {
  display: block;
  max-width: min(100%, 36rem);
  height: auto;
  margin: 0.5rem 0 0.85rem;
  border: 1px solid #d5e3ef;
  background: #fff;
}
.q label { font-weight: normal; }
.answer-card { position: sticky; top: 1rem; width: 11rem; }
.remain-block {
  margin: 0 0 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid #d5e3ef;
}
.remain-label { margin: 0 0 0.2rem; color: #1f4e79; font-weight: bold; }
.answer-card #timer { line-height: 1.2; }
.card-grid { display: grid; grid-template-columns: repeat(5, 1.8rem); gap: 0.35rem; margin-bottom: 1rem; }
.card-grid a { display: block; text-align: center; border: 1px solid #ccc; color: #222; text-decoration: none; line-height: 1.8rem; }
.card-grid a.done { background: #1f4e79; color: #fff; border-color: #1f4e79; }
.save-error { background: #b00020; color: #fff; padding: 0.5rem 0.8rem; }
.wrong { color: #b00020; }
.score-line { font-size: 1.3rem; }