:root {
  --bg: #0f172a;
  --panel: #ffffff;
  --ink: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --brand: #ec7211;       /* AWS orange */
  --brand-dark: #d35400;
  --navy: #232f3e;        /* AWS navy */
  --ok: #15803d;
  --ok-bg: #dcfce7;
  --bad: #b91c1c;
  --bad-bg: #fee2e2;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(15, 23, 42, .08), 0 8px 24px rgba(15, 23, 42, .06);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: #f1f5f9;
  line-height: 1.55;
}

a { color: var(--brand-dark); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Top bar */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--navy);
  color: #fff;
  padding: 0 24px;
  height: 60px;
}
.brand {
  color: #fff;
  font-weight: 700;
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.brand:hover { text-decoration: none; }
.brand-badge {
  background: var(--brand);
  color: #fff;
  font-size: 12px;
  padding: 3px 8px;
  border-radius: 6px;
  letter-spacing: .5px;
}
.topbar nav { display: flex; align-items: center; gap: 18px; }
.topbar nav a { color: #cbd5e1; font-size: 14px; }
.topbar nav a:hover { color: #fff; text-decoration: none; }
.topbar .who { color: #fff; font-weight: 600; font-size: 14px; }

.btn-ghost {
  border: 1px solid #475569;
  padding: 6px 12px;
  border-radius: 8px;
}

/* Layout */
.container { max-width: 860px; margin: 32px auto; padding: 0 20px; }
.page-head { margin-bottom: 24px; }
.page-head h1 { margin: 0 0 6px; font-size: 26px; }
.muted { color: var(--muted); }
small.muted { font-size: 12px; }

.footer {
  max-width: 860px;
  margin: 40px auto;
  padding: 16px 20px;
  color: var(--muted);
  font-size: 12px;
  border-top: 1px solid var(--line);
}

/* Flash */
.flash { padding: 10px 14px; border-radius: 8px; margin-bottom: 16px; font-size: 14px; }
.flash-error { background: var(--bad-bg); color: var(--bad); }
.flash-success { background: var(--ok-bg); color: var(--ok); }

/* Buttons */
.btn {
  display: inline-block;
  background: var(--brand);
  color: #fff;
  border: none;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}
.btn:hover { background: var(--brand-dark); text-decoration: none; }
.btn-lg { padding: 13px 26px; font-size: 16px; }

/* Auth */
.auth-card {
  background: var(--panel);
  max-width: 400px;
  margin: 40px auto;
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.auth-card h1 { margin-top: 0; }
.auth-card form { display: flex; flex-direction: column; gap: 16px; margin: 20px 0; }
.auth-card label { display: flex; flex-direction: column; gap: 6px; font-weight: 600; font-size: 14px; }
.auth-card input {
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 15px;
}
.auth-card input:focus { outline: 2px solid var(--brand); border-color: var(--brand); }

/* Exam grid */
.exam-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}
.exam-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  color: var(--ink);
  box-shadow: var(--shadow);
  transition: transform .08s ease, box-shadow .08s ease;
}
.exam-card:hover { transform: translateY(-2px); text-decoration: none; box-shadow: 0 8px 28px rgba(15,23,42,.12); }
.exam-card-final { border-color: var(--brand); }
.exam-card-top { display: flex; justify-content: space-between; align-items: center; }
.exam-title { font-weight: 700; font-size: 17px; }
.exam-meta { color: var(--muted); font-size: 13px; margin-top: 4px; }
.exam-score { margin-top: 12px; font-size: 14px; font-weight: 600; }

.tag {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 999px;
  font-weight: 700;
  letter-spacing: .3px;
}
.tag-final { background: var(--brand); color: #fff; }
.tag-multi { background: #e0e7ff; color: #3730a3; }

/* Questions */
.question {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}
.q-head { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; }
.q-num { font-weight: 700; color: var(--navy); }
.q-id { font-size: 13px; }
.q-text { font-size: 15.5px; white-space: pre-wrap; }

.options { list-style: none; margin: 14px 0 0; padding: 0; }
.options li { margin-bottom: 10px; }
.option {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px 14px;
  cursor: pointer;
}
.option:hover { border-color: var(--brand); background: #fff7f0; }
.option input { margin-top: 3px; }
.opt-key { font-weight: 700; min-width: 18px; }
.opt-text { flex: 1; }

/* Submit bar */
.submit-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 24px 0 40px;
}

/* Results */
.score-banner {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 10px;
  font-size: 18px;
  margin: 6px 0 4px;
}
.score-banner.pass { background: var(--ok-bg); color: var(--ok); }
.score-banner.mid { background: #fef9c3; color: #854d0e; }
.score-banner.low { background: var(--bad-bg); color: var(--bad); }

.result-q.is-correct { border-left: 4px solid var(--ok); }
.result-q.is-wrong { border-left: 4px solid var(--bad); }
.verdict { margin-left: auto; font-weight: 700; font-size: 13px; padding: 2px 10px; border-radius: 999px; }
.verdict.ok { background: var(--ok-bg); color: var(--ok); }
.verdict.bad { background: var(--bad-bg); color: var(--bad); }

.opt-review {
  display: flex;
  gap: 10px;
  align-items: baseline;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 11px 14px;
  flex-wrap: wrap;
}
.opt-review.opt-answer { border-color: var(--ok); background: var(--ok-bg); }
.opt-review.opt-picked { border-color: var(--bad); background: var(--bad-bg); }
.badge { font-size: 11px; font-weight: 700; padding: 2px 8px; border-radius: 999px; margin-left: auto; }
.badge-correct { background: var(--ok); color: #fff; }
.badge-you { background: var(--navy); color: #fff; }

.explanation {
  margin-top: 16px;
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px;
}
.explanation h4 { margin: 0 0 8px; color: var(--navy); }
.docs { margin-top: 12px; font-size: 14px; }
.docs-label { font-weight: 700; }
.docs ul { margin: 6px 0 0; padding-left: 18px; }
.docs a { word-break: break-all; }

/* History */
.history { width: 100%; border-collapse: collapse; background: var(--panel); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.history th, .history td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--line); font-size: 14px; }
.history th { background: #f8fafc; }

/* Admin */
.admin-actions { display: flex; gap: 8px; }
.admin-actions form { margin: 0; }
.btn-sm { border: none; padding: 6px 12px; border-radius: 8px; font-size: 13px; font-weight: 600; cursor: pointer; color: #fff; }
.btn-sm:hover { filter: brightness(1.08); }
.btn-ok { background: var(--ok); }
.btn-warn { background: #b45309; }
.btn-danger { background: var(--bad); }
.status { font-size: 12px; font-weight: 700; padding: 2px 10px; border-radius: 999px; }
.status-ok { background: var(--ok-bg); color: var(--ok); }
.status-pending { background: #fef9c3; color: #854d0e; }
.status-admin { background: #e0e7ff; color: #3730a3; }