:root {
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #1f2430;
  --muted: #6b7280;
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --green: #16a34a;
  --green-bg: #dcfce7;
  --red: #dc2626;
  --red-bg: #fee2e2;
  --border: #e5e7eb;
  --yellow: #d97706;
  --yellow-bg: #fef3c7;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", Verdana, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
}

.topbar {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}
.brand { font-weight: 700; font-size: 1.1rem; color: var(--primary); text-decoration: none; }
.topnav { display: flex; gap: 18px; }
.topnav a { color: var(--muted); text-decoration: none; font-weight: 500; }
.topnav a:hover { color: var(--primary); }

.container {
  max-width: 820px;
  margin: 0 auto;
  padding: 28px 20px 80px;
}

h1 { font-size: 1.6rem; margin-bottom: 8px; }
h2 { font-size: 1.2rem; }

.back-link { display: inline-block; margin-bottom: 14px; color: var(--muted); text-decoration: none; }
.back-link:hover { color: var(--primary); }

/* progress bars */
.progress-bar {
  background: var(--border);
  border-radius: 999px;
  height: 10px;
  overflow: hidden;
  margin: 8px 0 4px;
}
.progress-bar.big { height: 14px; }
.progress-fill { background: linear-gradient(90deg, var(--primary), #7c3aed); height: 100%; transition: width .3s; }
.percent-label { color: var(--muted); font-size: .9rem; }

/* subject cards */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 16px; margin-top: 20px; }
.subject-card {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
  text-decoration: none;
  color: var(--text);
  transition: box-shadow .15s, transform .15s;
}
.subject-card:hover { box-shadow: 0 6px 18px rgba(0,0,0,.08); transform: translateY(-2px); }

/* topic list */
.section-block { margin-top: 28px; }
.topic-list { list-style: none; padding: 0; margin: 10px 0; }
.topic-row {
  display: flex; align-items: center; gap: 10px;
  background: var(--card); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 16px; margin-bottom: 8px;
}
.topic-row a { color: var(--text); text-decoration: none; font-weight: 500; }
.topic-row a:hover { color: var(--primary); }
.topic-disabled { color: var(--muted); }
.status-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--border); flex-shrink: 0; }
.status-passed .status-dot { background: var(--green); }
.status-needs_review .status-dot { background: var(--yellow); }
.badge { margin-left: auto; font-size: .82rem; padding: 3px 10px; border-radius: 999px; font-weight: 600; }
.badge-passed { background: var(--green-bg); color: var(--green); }
.badge-review { background: var(--yellow-bg); color: var(--yellow); }

/* lesson */
.lesson-content { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 24px 28px; margin: 18px 0 24px; }
.lesson-content h1, .lesson-content h2 { margin-top: 1.2em; }
.lesson-content code { background: #f1f2f6; padding: 1px 5px; border-radius: 4px; }

.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 8px;
  border: none;
  font-size: 1rem;
  cursor: pointer;
  text-decoration: none;
  margin-right: 10px;
  margin-top: 6px;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: var(--card); color: var(--text); border: 1px solid var(--border); }

/* quiz */
.quiz-hint { color: var(--muted); }
.question-card {
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  padding: 20px 22px; margin-bottom: 16px;
}
.question-card.result-correct { border-color: var(--green); background: var(--green-bg); }
.question-card.result-incorrect { border-color: var(--red); background: var(--red-bg); }
.question-text { font-weight: 600; margin-bottom: 12px; }
.q-type-label { font-size: .75rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); margin-bottom: 6px; }

.option-list { display: flex; flex-direction: column; gap: 8px; }
.option {
  display: flex; align-items: center; gap: 8px;
  border: 1px solid var(--border); border-radius: 8px; padding: 9px 12px;
  cursor: pointer; background: #fafbff;
}
.option:hover { border-color: var(--primary); }
.option.selected { border-color: var(--primary); background: #eef2ff; }
.option.correct { border-color: var(--green); background: var(--green-bg); }
.option.incorrect { border-color: var(--red); background: var(--red-bg); }
.option.correct-missed { border-color: var(--green); box-shadow: inset 0 0 0 1px var(--green); }

select.q-select, input.q-fill {
  width: 100%; padding: 9px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 1rem;
}
select.q-select.correct, input.q-fill.correct { border-color: var(--green); background: var(--green-bg); }
select.q-select.incorrect, input.q-fill.incorrect { border-color: var(--red); background: var(--red-bg); }

.explanation { margin-top: 10px; font-size: .92rem; color: var(--muted); background: #f4f5fa; border-radius: 8px; padding: 8px 12px; display: none; }
.question-card.answered .explanation { display: block; }

/* matching */
.match-wrap { position: relative; }
.match-cols { display: flex; justify-content: space-between; gap: 40px; }
.match-col { display: flex; flex-direction: column; gap: 10px; flex: 1; }
.match-item {
  border: 1px solid var(--border); border-radius: 8px; padding: 8px 12px; background: #fafbff;
  cursor: pointer; user-select: none; text-align: left;
}
.match-item.selected { border-color: var(--primary); background: #eef2ff; }
.match-item.paired { border-color: var(--primary); }
.match-item.correct { border-color: var(--green); background: var(--green-bg); }
.match-item.incorrect { border-color: var(--red); background: var(--red-bg); }
.match-svg { position: absolute; top: 0; left: 0; width: 100%; height: 100%; pointer-events: none; }
.match-svg line { stroke: var(--primary); stroke-width: 2; }
.match-svg line.correct { stroke: var(--green); }
.match-svg line.incorrect { stroke: var(--red); }

.quiz-summary {
  border-radius: 12px; padding: 18px 22px; margin: 20px 0; font-weight: 600; font-size: 1.05rem;
}
.quiz-summary.pass { background: var(--green-bg); color: var(--green); }
.quiz-summary.fail { background: var(--red-bg); color: var(--red); }

/* schedule */
.schedule-list { display: flex; flex-direction: column; gap: 14px; margin-top: 20px; }
.week-card {
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  padding: 14px 16px;
}
.week-card.week-current { border-color: var(--primary); box-shadow: 0 0 0 2px rgba(79,70,229,.15); }
.week-title { font-weight: 700; margin-bottom: 10px; }
.week-dates { font-weight: 400; font-size: .8rem; color: var(--muted); margin-left: 6px; }
.day-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
.day-cell {
  border: 1px solid var(--border); border-radius: 8px; padding: 8px 10px; background: #fafbff;
  display: flex; flex-direction: column; gap: 6px; min-width: 0;
}
.day-cell.day-today { border-color: var(--primary); background: #eef2ff; }
.day-head { font-size: .78rem; font-weight: 700; color: var(--muted); }
.day-date { font-weight: 400; }
.day-subject { display: flex; align-items: baseline; gap: 5px; font-size: .82rem; line-height: 1.3; }
.day-subject a { color: var(--text); text-decoration: none; }
.day-subject a:hover { color: var(--primary); }
.subject-tag {
  font-size: .68rem; font-weight: 700; padding: 1px 6px; border-radius: 5px; flex-shrink: 0;
  background: #ede9fe; color: #6d28d9;
}
.subject-tag.subject-math { background: #dbeafe; color: #1d4ed8; }
.subject-tag.subject-literature { background: #fce7f3; color: #be185d; }
.subject-tag.subject-history { background: #fef3c7; color: #b45309; }
.subject-tag.subject-biology { background: #dcfce7; color: #15803d; }
.subject-tag.subject-geography { background: #cffafe; color: #0e7490; }
.lesson-count { color: var(--muted); font-size: .78em; }