:root {
  --bg: #f4f6fb;
  --card-bg: #ffffff;
  --text: #1a1d29;
  --muted: #6b7280;
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --border: #e5e7eb;
  --success: #16a34a;
  --danger: #dc2626;
  --warn: #d97706;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  min-height: 100vh;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 20px;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand { font-weight: 700; font-size: 1.1rem; color: var(--primary); }

.user-badge {
  display: none;
  align-items: center;
  gap: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 600;
}

.avatar {
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.8rem; font-weight: 700;
}

.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 24px 16px 60px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px 24px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.05);
}

h1 { font-size: 1.4rem; margin: 0 0 4px; }
.subtitle { color: var(--muted); margin: 0 0 22px; font-size: 0.92rem; }

label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin: 16px 0 6px;
}

input, select {
  width: 100%;
  padding: 11px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
  outline: none;
}

input:focus, select:focus { border-color: var(--primary); }

.req { color: var(--danger); }
.opt { color: var(--muted); font-weight: 400; }

.btn {
  margin-top: 24px;
  width: 100%;
  padding: 13px;
  border: none;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
}

.btn:hover { background: var(--primary-dark); }
.btn:disabled { opacity: 0.6; cursor: not-allowed; }

.error {
  color: var(--danger);
  font-size: 0.8rem;
  margin-top: 4px;
  display: none;
}

.hidden { display: none !important; }

/* Start test card */
.start-card {
  text-align: center;
  padding: 40px 24px;
}
.start-card .emoji { font-size: 2.6rem; margin-bottom: 10px; }
.motivate {
  font-style: italic;
  color: var(--muted);
  margin: 10px 0 26px;
  font-size: 0.95rem;
  line-height: 1.5;
}

/* Test screen */
.test-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}

.timer {
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--danger);
}

.progress-track {
  height: 6px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 20px;
}

.progress-fill {
  height: 100%;
  background: var(--primary);
  transition: width 0.25s;
}

.q-number {
  font-size: 0.85rem;
  color: var(--muted);
  font-weight: 600;
  margin-bottom: 6px;
}

.q-text {
  font-size: 1.08rem;
  font-weight: 600;
  margin-bottom: 18px;
  line-height: 1.5;
}

.option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 10px;
  cursor: pointer;
  font-size: 0.95rem;
  transition: border-color 0.15s, background 0.15s;
}

.option:hover { border-color: var(--primary); }
.option.selected {
  border-color: var(--primary);
  background: rgba(79, 70, 229, 0.12);
  font-weight: 600;
}

.option input[type="radio"] { accent-color: var(--primary); width: 16px; height: 16px; }

.nav-btns {
  display: flex;
  gap: 10px;
  margin-top: 24px;
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--border); }

.dots {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-top: 20px;
  flex-wrap: wrap;
}

.dot {
  width: 30px; height: 30px;
  border-radius: 50%;
  border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
  background: var(--card-bg);
}

.dot.answered { background: var(--success); color: #fff; border-color: var(--success); }
.dot.current { outline: 2px solid var(--primary); }

/* Popup */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 16px;
}

.popup {
  background: var(--card-bg);
  border-radius: 18px;
  padding: 30px 26px;
  max-width: 400px;
  width: 100%;
  text-align: center;
}

.popup h2 { margin-top: 0; }

.result-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin: 22px 0;
}

.result-box {
  padding: 14px 6px;
  border-radius: 12px;
  background: var(--bg);
  border: 1px solid var(--border);
}

.result-box .num { font-size: 1.5rem; font-weight: 800; }
.result-box.correct .num { color: var(--success); }
.result-box.wrong .num { color: var(--danger); }
.result-box.skip .num { color: var(--warn); }
.result-box .lbl { font-size: 0.78rem; color: var(--muted); margin-top: 2px; }

.score-line { font-size: 0.95rem; color: var(--muted); margin-bottom: 6px; }

.loading-text { text-align: center; color: var(--muted); padding: 40px 0; }
.server-error { color: var(--danger); text-align: center; font-size: 0.85rem; margin-top: 10px; display: none; }