.site-header { padding: 20px; color: #fff; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); box-shadow: 0 4px 12px rgb(99 102 241 / 20%); }
.header-content { display: flex; align-items: center; justify-content: space-between; max-width: 750px; margin: 0 auto; }
.header-content h1 { margin: 0; font-size: 22px; }
.month-group { margin-bottom: 30px; }
.month-title { padding-bottom: 8px; margin-bottom: 14px; border-bottom: 2px solid #eef2ff; color: var(--primary); font-size: 18px; font-weight: 700; }
.lesson-card { display: flex; align-items: center; justify-content: space-between; width: 100%; padding: 16px 20px; margin-bottom: 12px; border: 2px solid var(--border); border-radius: 12px; background: var(--card); color: var(--text); text-align: left; cursor: pointer; transition: .2s ease; }
.lesson-card:hover, .lesson-card:focus-visible { border-color: var(--primary); transform: translateY(-2px); box-shadow: 0 4px 12px rgb(0 0 0 / 5%); }
.lesson-card-title { margin: 0; font-weight: 700; }
.badge { padding: 4px 10px; border-radius: 20px; font-size: 12px; font-weight: 700; white-space: nowrap; }
.badge-done { background: #dcfce7; color: #15803d; }
.badge-pending { background: #f1f5f9; color: var(--muted); }
.lesson-meta { margin-top: -10px; color: var(--muted); font-size: 14px; }
.progress-track { width: 100%; height: 12px; margin: 15px 0 20px; overflow: hidden; border: 1px solid var(--border); border-radius: 999px; background: #f1f5f9; }
.progress-bar { width: 0; height: 100%; background: linear-gradient(90deg, #4f46e5, #7c3aed); transition: width .4s ease-in-out; }
.theory-box { padding: 18px; margin-bottom: 25px; border-left: 5px solid var(--primary); border-radius: 8px; background: #eef2ff; line-height: 1.6; }
.reading-box { margin-top: 10px; border-left-color: var(--muted); background: #f8fafc; }
.exercise-item { padding: 20px; margin-bottom: 20px; border: 1.5px solid var(--border); border-radius: 16px; background: #fff; box-shadow: 0 4px 12px rgb(0 0 0 / 3%); }
.exercise-title { margin-bottom: 14px; color: #1e293b; font-size: 17px; font-weight: 700; }
.options-grid { display: grid; gap: 12px; }
.opt-btn { padding: 14px; border: 2px solid var(--border); border-radius: 12px; background: #f8fafc; color: #334155; text-align: left; font-weight: 600; cursor: pointer; }
.opt-btn:hover { border-color: #818cf8; background: #eef2ff; color: #4338ca; }
.opt-btn.selected { border-color: var(--primary-dark); background: var(--primary-dark); color: #fff; }
.text-answer { width: 100%; padding: 14px; border: 2px solid var(--border); border-radius: 10px; }
textarea.text-answer { min-height: 110px; resize: vertical; }
.btn-check { margin-top: 14px; padding: 12px 24px; border-radius: 12px; background: var(--success); box-shadow: 0 4px 0 #059669; }
.btn-back { margin-bottom: 20px; }
.btn-complete { width: 100%; padding: 14px; margin-top: 20px; font-size: 16px; }
.feedback { padding: 12px; margin-top: 12px; border-radius: 8px; font-weight: 600; }
.feedback.correct { background: #dcfce7; color: #15803d; }
.feedback.incorrect { background: #fee2e2; color: #b91c1c; }
.feedback.info { background: #fef3c7; color: #b45309; }
.media-frame { margin: 12px 0; overflow: hidden; border: 1px solid var(--border); border-radius: 12px; }
.media-audio { padding: 10px; background: #f8fafc; }
.media-audio audio { width: 100%; height: 40px; }
.media-image { display: block; max-width: 100%; max-height: 350px; margin: 12px auto; object-fit: contain; border: 1px solid var(--border); border-radius: 12px; }
.media-video { position: relative; height: 0; padding-bottom: 56.25%; }
.media-video iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.matching-container { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; }
.match-column { display: flex; flex-direction: column; gap: 10px; }
.match-item { padding: 12px; border: 2px solid var(--border); border-radius: 8px; background: #f8fafc; font-weight: 600; cursor: pointer; }
.match-item.active { border-color: var(--primary); background: #eef2ff; }
.match-item.matched { border-color: var(--success); background: #dcfce7; color: #15803d; cursor: default; }
.match-item.incorrect { border-color: var(--danger); background: #fee2e2; color: #991b1b; }
.paraphrase-box { padding: 14px; margin-bottom: 12px; border: 1px solid var(--border); border-radius: 8px; background: #f8fafc; line-height: 1.6; }
.keyword { display: inline-block; padding: 4px 10px; margin: 8px 0; border: 1px solid #c7d2fe; border-radius: 6px; background: #eef2ff; color: #4f46e5; font-size: 13px; font-weight: 700; }
@media (max-width: 600px) { .matching-container { grid-template-columns: 1fr; } .lesson-card { gap: 12px; } }