:root {
  --primary: #0098DD;
  --primary-dark: #0080BB;
  --header-bg: #1E2137;
  --text: #333333;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --bg: #ffffff;
  --bg-light: #F5F5F5;
  --correct: #16a34a;
  --wrong: #dc2626;
  --correct-bg: #f0fdf4;
  --wrong-bg: #fef2f2;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Segoe UI', Arial, sans-serif;
  background: var(--bg-light);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  background: var(--bg-light);
  border-bottom: 1px solid var(--header-bg);
}
.header__inner {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.header__logo-img {
  height: 36px;
  width: auto;
  display: block;
}
.header__subtitle {
  color: var(--text-muted);
  font-size: 13px;
  margin-left: auto;
}

/* Main wrapper */
.main {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 40px 16px;
}

.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 36px 40px;
  width: 100%;
  max-width: 680px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

/* Start screen */
.start-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}
.start-desc {
  color: var(--text-muted);
  font-size: 15px;
  margin-bottom: 28px;
  line-height: 1.6;
}

.form-group {
  margin-bottom: 24px;
}
.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
}
.form-group input {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 15px;
  outline: none;
  transition: border-color 0.15s;
}
.form-group input:focus {
  border-color: var(--primary);
}

.btn {
  display: inline-block;
  padding: 12px 28px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
  width: 100%;
  text-align: center;
}
.btn:hover { background: var(--primary-dark); }
.btn:disabled { background: #ccc; cursor: not-allowed; }

/* Progress */
.progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
  font-size: 13px;
  color: var(--text-muted);
}
.progress-bar {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  margin-bottom: 28px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.section-tag {
  display: inline-block;
  background: #e8f4fc;
  color: var(--primary);
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  margin-bottom: 12px;
}

.question-text {
  font-size: 17px;
  font-weight: 600;
  line-height: 1.55;
  margin-bottom: 24px;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 28px;
}

.option {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 16px;
  border: 2px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
  user-select: none;
}
.option:hover { border-color: var(--primary); background: #fff5f5; }
.option.selected { border-color: var(--primary); background: #fff5f5; }
.option.correct { border-color: var(--correct); background: var(--correct-bg); }
.option.wrong { border-color: var(--wrong); background: var(--wrong-bg); }
.option.disabled { cursor: default; }

.option__marker {
  width: 22px;
  height: 22px;
  min-width: 22px;
  border: 2px solid var(--border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 700;
  color: var(--text-muted);
  margin-top: 1px;
  transition: border-color 0.15s, background 0.15s, color 0.15s;
}
.option.selected .option__marker { border-color: var(--primary); background: var(--primary); color: #fff; }
.option.correct .option__marker { border-color: var(--correct); background: var(--correct); color: #fff; }
.option.wrong .option__marker { border-color: var(--wrong); background: var(--wrong); color: #fff; }

.option__text {
  font-size: 15px;
  line-height: 1.5;
  padding-top: 1px;
}

.btn-nav {
  width: 100%;
}

/* Results screen */
.result-score {
  text-align: center;
  margin-bottom: 32px;
}
.result-score__number {
  font-size: 56px;
  font-weight: 800;
  line-height: 1;
}
.result-score__number.pass { color: var(--correct); }
.result-score__number.fail { color: var(--wrong); }
.result-score__label {
  font-size: 18px;
  font-weight: 600;
  margin-top: 8px;
  margin-bottom: 4px;
}
.result-score__sub {
  font-size: 14px;
  color: var(--text-muted);
}

.result-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 28px;
}
.result-item {
  padding: 14px 16px;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 14px;
  line-height: 1.5;
}
.result-item.correct { background: var(--correct-bg); border-color: #bbf7d0; }
.result-item.wrong { background: var(--wrong-bg); border-color: #fecaca; }
.result-item__header {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  margin-bottom: 4px;
}
.result-item__icon { font-weight: 700; font-size: 16px; min-width: 20px; }
.result-item__q { font-weight: 600; }
.result-item__answer { color: var(--text-muted); margin-top: 4px; padding-left: 30px; }
.result-item__correct-label { color: var(--correct); font-weight: 600; }

.variant-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.sending-msg {
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 12px;
}

/* ── 1920px: большие экраны ── */
@media (min-width: 1920px) {
  .header__inner {
    max-width: 1600px;
    padding: 24px 40px;
  }
  .header__logo-img { height: 44px; }
  .main { padding: 60px 24px; }
  .card {
    max-width: 820px;
    padding: 48px 56px;
  }
  .start-title { font-size: 26px; }
  .question-text { font-size: 19px; }
  .option__text { font-size: 16px; }
  .result-score__number { font-size: 68px; }
}

/* ── 1400px: стандартный десктоп ── */
@media (max-width: 1400px) {
  .header__inner { max-width: 1100px; }
  .card { max-width: 640px; }
}

/* ── 990px: планшет горизонтально / маленький ноутбук ── */
@media (max-width: 990px) {
  .header__inner { padding: 16px 20px; }
  .main { padding: 32px 20px; }
  .card {
    max-width: 580px;
    padding: 32px 32px;
  }
  .question-text { font-size: 16px; }
}

/* ── 768px: планшет вертикально ── */
@media (max-width: 768px) {
  .header__inner { padding: 14px 16px; }
  .header__logo-img { height: 30px; }
  .header__subtitle { font-size: 12px; }
  .main { padding: 24px 16px; }
  .card {
    max-width: 100%;
    padding: 28px 24px;
    border-radius: 6px;
  }
  .start-title { font-size: 20px; }
  .start-desc { font-size: 14px; margin-bottom: 22px; }
  .question-text { font-size: 15px; margin-bottom: 20px; }
  .option { padding: 12px 14px; gap: 10px; }
  .option__text { font-size: 14px; }
  .progress-bar { margin-bottom: 22px; }
  .result-score__number { font-size: 48px; }
  .result-score__label { font-size: 16px; }
}

/* ── 480px: мобильные ── */
@media (max-width: 480px) {
  .header__inner {
    padding: 12px 16px;
    gap: 10px;
  }
  .header__logo-img { height: 26px; }
  .header__subtitle { display: none; }
  .main { padding: 16px 12px; }
  .card {
    padding: 20px 16px;
    border-radius: 4px;
    box-shadow: none;
  }
  .start-title { font-size: 18px; }
  .start-desc { font-size: 13px; margin-bottom: 18px; }
  .form-group { margin-bottom: 18px; }
  .form-group input { padding: 9px 12px; font-size: 14px; }
  .btn { padding: 11px 20px; font-size: 14px; }
  .progress-header { font-size: 12px; }
  .progress-bar { margin-bottom: 18px; }
  .question-text { font-size: 14px; margin-bottom: 16px; }
  .options { gap: 8px; margin-bottom: 20px; }
  .option { padding: 10px 12px; gap: 8px; }
  .option__marker { width: 20px; height: 20px; min-width: 20px; font-size: 10px; }
  .option__text { font-size: 13px; }
  .result-score__number { font-size: 40px; }
  .result-score__label { font-size: 15px; }
  .result-item { padding: 12px 14px; font-size: 13px; }
  .result-item__answer { padding-left: 24px; }
}