/* ============================================
   FluentMaster v4 - New Features CSS
   Grammar Visual, Cert Tests, Error History, Themes, Multi-lang
   ============================================ */

/* ===== Grammar Visual ===== */
.grammar-visual-container { padding: 1rem; }
.gv-level-section { margin-bottom: 1.5rem; }
.gv-level-title { font-size: 1.1rem; margin-bottom: 0.75rem; padding-left: 4px; }
.gv-topic-card {
    display: flex; align-items: center; gap: 12px; padding: 14px; 
    background: var(--bg-card, #fff); border-radius: var(--radius, 12px);
    border: 1px solid var(--border, #e2e8f0); margin-bottom: 8px; cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}
.gv-topic-card:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.1); }
.gv-topic-info h4 { font-size: 0.95rem; margin-bottom: 2px; }
.gv-topic-info p { font-size: 0.8rem; color: var(--text-secondary); }
.gv-topic-level { font-size: 0.75rem; padding: 2px 8px; border-radius: 20px; background: var(--primary); color: #fff; font-weight: 600; white-space: nowrap; margin-left: auto; }

.gv-active-container { padding: 0 1rem 1rem; }
.gv-top-bar { display: flex; align-items: center; gap: 12px; padding: 12px 0; }
.gv-top-bar h3 { flex: 1; font-size: 1rem; }
.gv-top-bar span { font-size: 0.85rem; color: var(--text-secondary); }

.gv-sentence-display { text-align: center; margin: 1rem 0; }
.gv-full-sentence { font-size: 1.3rem; font-weight: 600; color: var(--text); }

.gv-diagram-container { margin: 1.5rem 0; overflow-x: auto; }
.gv-parts-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; padding: 1rem 0; }

.gv-part { display: flex; flex-direction: column; align-items: center; gap: 6px; min-width: 80px; animation: gvSlideUp 0.5s ease-out both; }
.gv-part:nth-child(1) { animation-delay: 0s; }
.gv-part:nth-child(2) { animation-delay: 0.1s; }
.gv-part:nth-child(3) { animation-delay: 0.2s; }
.gv-part:nth-child(4) { animation-delay: 0.3s; }
.gv-part:nth-child(5) { animation-delay: 0.4s; }
.gv-part:nth-child(6) { animation-delay: 0.5s; }

@keyframes gvSlideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.gv-part-text { padding: 8px 14px; border: 2px solid; border-radius: 8px; font-weight: 600; font-size: 0.95rem; background: var(--bg-card, #fff); }
.gv-part-label { font-size: 0.7rem; padding: 3px 8px; border-radius: 12px; color: #fff; font-weight: 500; text-align: center; max-width: 140px; line-height: 1.3; }
.gv-part-connector { width: 2px; height: 12px; border-radius: 2px; }

.gv-explanation { padding: 1rem; background: var(--bg-secondary, #f1f5f9); border-radius: var(--radius, 12px); font-size: 0.9rem; line-height: 1.5; margin: 1rem 0; }
.gv-explanation i { color: var(--primary); margin-right: 6px; }

.gv-example-nav { display: flex; gap: 10px; justify-content: center; margin-top: 1rem; }

.gv-quiz-container { text-align: center; padding: 1rem 0; }
.gv-quiz-progress { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 1rem; }
.gv-quiz-question { font-size: 1.1rem; margin-bottom: 1.5rem; font-weight: 500; }

/* ===== Certification Tests ===== */
.cert-test-container { padding: 1rem; }
.cert-test-card {
    display: flex; align-items: flex-start; gap: 16px; padding: 16px;
    background: var(--bg-card, #fff); border-radius: var(--radius, 12px);
    border: 1px solid var(--border, #e2e8f0); margin-bottom: 12px; cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}
.cert-test-card:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.1); }
.cert-test-icon { font-size: 2.5rem; }
.cert-test-info h3 { font-size: 1.05rem; margin-bottom: 4px; }
.cert-test-info p { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 8px; }
.cert-test-meta { display: flex; gap: 12px; flex-wrap: wrap; font-size: 0.8rem; color: var(--text-secondary); }
.cert-test-meta i { margin-right: 3px; }

.cert-active-container { padding: 0 1rem 1rem; }
.cert-top-bar { display: flex; align-items: center; gap: 12px; padding: 12px 0; }
.cert-top-bar span { font-size: 0.9rem; flex: 1; text-align: center; font-weight: 500; }
.cert-timer-display { font-weight: 700; font-size: 1.1rem; color: var(--primary); }
.cert-timer-display i { margin-right: 4px; }
.cert-progress-bar { height: 4px; background: var(--bg-secondary); border-radius: 4px; overflow: hidden; }

.cert-question-area { padding: 1rem 0; }
.cert-section-label { font-size: 0.85rem; font-weight: 600; color: var(--primary); margin-bottom: 1rem; display: flex; align-items: center; gap: 6px; }
.cert-passage { padding: 1rem; background: var(--bg-secondary, #f1f5f9); border-radius: var(--radius, 12px); font-size: 0.9rem; line-height: 1.7; margin-bottom: 1.5rem; border-left: 3px solid var(--primary); }
.cert-question { font-size: 1.05rem; font-weight: 500; margin-bottom: 1rem; line-height: 1.5; }
.cert-nav-buttons { display: flex; justify-content: space-between; margin-top: 1.5rem; }

.answer-option.selected { border-color: var(--primary); background: rgba(108, 99, 255, 0.08); color: var(--primary); font-weight: 600; }

/* ===== Error History ===== */
.error-history-container { padding: 1rem; }
.error-stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-bottom: 1rem; }
.error-stat-card { text-align: center; padding: 12px 8px; background: var(--bg-card, #fff); border-radius: var(--radius, 12px); border: 1px solid var(--border, #e2e8f0); }
.error-stat-card strong { display: block; font-size: 1.3rem; color: var(--primary); }
.error-stat-card span { font-size: 0.7rem; color: var(--text-secondary); }

.error-freq-item { display: flex; align-items: center; gap: 10px; padding: 10px; background: var(--bg-card, #fff); border-radius: 8px; margin-bottom: 6px; border: 1px solid var(--border); }
.error-freq-count { font-weight: 700; color: var(--danger); font-size: 0.9rem; min-width: 30px; }
.error-freq-info strong { display: block; font-size: 0.9rem; }
.error-freq-info span { font-size: 0.75rem; color: var(--text-secondary); }

.error-history-item { padding: 12px; background: var(--bg-card, #fff); border-radius: 8px; margin-bottom: 8px; border: 1px solid var(--border); }
.error-history-item.reviewed { opacity: 0.6; }
.error-item-header { display: flex; gap: 8px; align-items: center; margin-bottom: 6px; }
.error-item-type { font-size: 0.7rem; padding: 2px 8px; border-radius: 12px; background: var(--primary); color: #fff; font-weight: 500; text-transform: uppercase; }
.error-item-level { font-size: 0.7rem; padding: 2px 6px; border-radius: 8px; background: var(--bg-secondary); color: var(--text-secondary); font-weight: 600; }
.error-item-date { font-size: 0.7rem; color: var(--text-secondary); margin-left: auto; }
.error-item-question { font-size: 0.85rem; margin-bottom: 6px; font-weight: 500; }
.error-item-answers { display: flex; gap: 12px; font-size: 0.8rem; }
.error-item-wrong { color: var(--danger); text-decoration: line-through; }
.error-item-correct { color: var(--secondary); font-weight: 600; }

.error-review-active-container { padding: 0 1rem 1rem; }
.error-review-top-bar { display: flex; align-items: center; gap: 12px; padding: 12px 0; }
.error-review-top-bar h3 { flex: 1; font-size: 1rem; }
.error-review-area { padding-top: 1rem; }

/* ===== Theme Customization ===== */
.theme-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 10px; }
.theme-option { cursor: pointer; border-radius: 10px; overflow: hidden; border: 2px solid transparent; transition: all 0.2s; }
.theme-option.active { border-color: var(--primary); box-shadow: 0 0 0 2px rgba(108, 99, 255, 0.3); }
.theme-option:hover { transform: translateY(-2px); }
.theme-preview { padding: 10px; border-radius: 8px; min-height: 55px; display: flex; flex-direction: column; gap: 6px; }
.theme-preview-bar { height: 8px; border-radius: 4px; width: 80%; }
.theme-preview-dots { display: flex; gap: 4px; }
.theme-preview-dots span { width: 10px; height: 10px; border-radius: 50%; }
.theme-name { display: block; text-align: center; font-size: 0.75rem; padding: 6px 4px; font-weight: 500; }

.font-grid { display: flex; flex-wrap: wrap; gap: 8px; }
.font-option { padding: 8px 14px; border: 2px solid var(--border); border-radius: 8px; background: var(--bg-card); cursor: pointer; font-size: 0.85rem; transition: all 0.2s; }
.font-option.active { border-color: var(--primary); color: var(--primary); font-weight: 600; background: rgba(108, 99, 255, 0.06); }
.font-option:hover { border-color: var(--primary); }

.font-size-control { display: flex; align-items: center; gap: 12px; }
.font-size-control span { font-weight: 600; min-width: 50px; text-align: center; }

/* ===== Multi-language indicator ===== */
.lang-indicator { display: inline-flex; align-items: center; gap: 6px; padding: 4px 10px; border-radius: 20px; background: var(--bg-secondary); font-size: 0.8rem; font-weight: 500; }

/* ===== Responsive for new features ===== */
@media (max-width: 480px) {
    .error-stats-grid { grid-template-columns: repeat(2, 1fr); }
    .gv-parts-row { gap: 8px; }
    .gv-part { min-width: 65px; }
    .gv-part-text { font-size: 0.85rem; padding: 6px 10px; }
    .gv-part-label { font-size: 0.65rem; }
    .theme-grid { grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); }
    .cert-passage { font-size: 0.85rem; padding: 0.75rem; }
}