:root {
  --bg1: #0a1628;
  --bg2: #12203a;
  --bg3: #0d3d4a;
  --glass: rgba(255, 255, 255, 0.08);
  --glass-strong: rgba(255, 255, 255, 0.12);
  --glass-border: rgba(255, 255, 255, 0.18);
  --glass-border-soft: rgba(255, 255, 255, 0.1);
  --text: #f0f6ff;
  --muted: #a8bdd9;
  --primary: #2dd4bf;
  --primary-dim: rgba(45, 212, 191, 0.25);
  --primary-press: #14b8a6;
  --danger: #fb7185;
  --danger-dim: rgba(251, 113, 133, 0.2);
  --ok: #4ade80;
  --ok-dim: rgba(74, 222, 128, 0.2);
  --radius: 20px;
  --radius-sm: 14px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  --font: "Tahoma", "Segoe UI", system-ui, sans-serif;
  --blur: 18px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: var(--font);
  color: var(--text);
  -webkit-tap-highlight-color: transparent;
  background:
    radial-gradient(ellipse 120% 80% at 10% -10%, #1a4a5c 0%, transparent 55%),
    radial-gradient(ellipse 90% 70% at 100% 20%, #2a1a5c 0%, transparent 50%),
    radial-gradient(ellipse 80% 60% at 50% 100%, #0d3d4a 0%, transparent 45%),
    linear-gradient(160deg, var(--bg1), var(--bg2) 50%, #0c1a2e);
  background-attachment: fixed;
}

body { padding-bottom: env(safe-area-inset-bottom); }

#app {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(10, 22, 40, 0.55);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  border-bottom: 1px solid var(--glass-border-soft);
}

.brand {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #fff, var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

main { padding: 16px; flex: 1; }

.screen { animation: fade .28s ease; }
@keyframes fade {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: none; }
}
.hidden { display: none !important; }

/* Glass card */
.card {
  background: var(--glass);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow), inset 0 1px 0 rgba(255, 255, 255, 0.08);
}
.card.center { text-align: center; }

h1 { margin: 0 0 8px; font-size: 1.4rem; font-weight: 700; }
h2 { margin: 0 0 12px; font-size: 1.08rem; line-height: 1.75; font-weight: 600; }
h3 {
  margin: 20px 0 10px;
  font-size: 0.95rem;
  color: var(--primary);
  font-weight: 700;
}

.muted {
  color: var(--muted);
  margin: 0 0 16px;
  font-size: 0.92rem;
  line-height: 1.65;
}

.field { display: block; margin-bottom: 14px; }
.field span {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.82rem;
}

input {
  width: 100%;
  padding: 14px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--glass-border);
  background: rgba(0, 0, 0, 0.25);
  color: var(--text);
  font-size: 1rem;
  outline: none;
  backdrop-filter: blur(8px);
  transition: border-color 0.15s, box-shadow 0.15s;
}
input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-dim);
}
input::placeholder { color: rgba(168, 189, 217, 0.5); }

.btn {
  border: none;
  border-radius: var(--radius-sm);
  padding: 13px 16px;
  font-size: 1rem;
  cursor: pointer;
  font-family: inherit;
  transition: transform 0.08s ease, background 0.15s, box-shadow 0.15s;
}
.btn:active { transform: scale(0.98); }
.btn.block { width: 100%; margin-top: 8px; }

.btn.primary {
  background: linear-gradient(135deg, #2dd4bf, #0d9488);
  color: #042f2e;
  font-weight: 700;
  box-shadow: 0 4px 20px rgba(45, 212, 191, 0.35);
}
.btn.primary:active { background: var(--primary-press); }

.btn.secondary {
  background: var(--glass-strong);
  color: var(--text);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(8px);
}

.btn.ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--glass-border-soft);
  padding: 8px 12px;
  font-size: 0.85rem;
  backdrop-filter: blur(8px);
}

.error {
  color: var(--danger);
  margin-top: 10px;
  font-size: 0.9rem;
}

.list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 12px 0 16px;
}

.list button.item {
  text-align: right;
  background: var(--glass);
  color: var(--text);
  border: 1px solid var(--glass-border-soft);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font-size: 1rem;
  cursor: pointer;
  font-family: inherit;
  backdrop-filter: blur(10px);
  transition: border-color 0.15s, background 0.15s;
}
.list button.item:active,
.list button.item:hover {
  border-color: var(--primary);
  background: var(--primary-dim);
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.85rem;
  margin-bottom: 12px;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 16px 0;
}

.options button {
  text-align: right;
  background: var(--glass);
  color: var(--text);
  border: 1px solid var(--glass-border-soft);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font-size: 0.98rem;
  cursor: pointer;
  font-family: inherit;
  line-height: 1.5;
  backdrop-filter: blur(10px);
  transition: border-color 0.15s, background 0.15s;
}
.options button:disabled { opacity: 0.9; cursor: default; }
.options button.correct {
  border-color: var(--ok);
  background: var(--ok-dim);
}
.options button.wrong {
  border-color: var(--danger);
  background: var(--danger-dim);
}

.feedback { margin: 8px 0; font-weight: 700; font-size: 0.95rem; }
.feedback.ok { color: var(--ok); }
.feedback.bad { color: var(--danger); }

.score {
  font-size: 3.2rem;
  font-weight: 800;
  margin: 16px 0;
  direction: ltr;
  background: linear-gradient(135deg, #fff, var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 8px;
}

.stat {
  background: var(--glass);
  border: 1px solid var(--glass-border-soft);
  border-radius: var(--radius-sm);
  padding: 14px 10px;
  text-align: center;
  backdrop-filter: blur(10px);
}
.stat b {
  display: block;
  font-size: 1.45rem;
  color: var(--primary);
}
.stat span {
  color: var(--muted);
  font-size: 0.78rem;
}

.table-wrap {
  overflow-x: auto;
  margin-bottom: 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--glass-border-soft);
  background: rgba(0, 0, 0, 0.15);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.78rem;
}
th, td {
  border-bottom: 1px solid var(--glass-border-soft);
  padding: 10px 8px;
  text-align: right;
  white-space: nowrap;
}
th {
  color: var(--muted);
  font-weight: 600;
  background: rgba(255, 255, 255, 0.04);
}
tr:last-child td { border-bottom: none; }

.admin-form {
  display: grid;
  gap: 10px;
  margin-bottom: 12px;
  padding: 14px;
  border-radius: var(--radius-sm);
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--glass-border-soft);
}
.admin-form .row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
@media (max-width: 400px) {
  .admin-form .row { grid-template-columns: 1fr; }
}

.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(30, 41, 59, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  color: var(--text);
  padding: 12px 18px;
  border-radius: 999px;
  font-size: 0.9rem;
  z-index: 50;
  max-width: 90%;
  border: 1px solid var(--glass-border);
  box-shadow: var(--shadow);
}

/* Welcome guide */
.guide {
  margin: 0 0 16px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background: var(--primary-dim);
  border: 1px solid rgba(45, 212, 191, 0.35);
}
.guide-title {
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--primary);
}
.guide ol {
  margin: 0 0 12px;
  padding-right: 18px;
  color: var(--text);
  font-size: 0.9rem;
  line-height: 1.7;
}
.guide li { margin-bottom: 4px; }

/* Inline action buttons in tables */
.actions {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.btn.tiny {
  padding: 6px 10px;
  font-size: 0.75rem;
  border-radius: 10px;
}
.btn.danger {
  background: var(--danger-dim);
  color: #fecdd3;
  border: 1px solid rgba(251, 113, 133, 0.4);
}
.btn.danger:active { background: rgba(251, 113, 133, 0.35); }

.q-preview {
  max-width: 160px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.success-msg { color: var(--ok) !important; }

.filter-row { display: flex; gap: 10px; margin-top: 8px; }
select {
  width: 100%;
  padding: 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--glass-border);
  background: rgba(0, 0, 0, 0.25);
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
}
.upload-name {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 6px;
}