.tabs-container { display: flex; justify-content: center; gap: 1rem; margin-bottom: 3rem; flex-wrap: wrap; }
.tab-btn { padding: 1rem 2rem; border-radius: 99px; font-size: 1.1rem; font-weight: 800; cursor: pointer; border: 2px solid transparent; transition: all 0.3s ease; background: white; color: var(--text-muted); box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05); }
.tab-btn:hover { color: var(--primary); border-color: var(--primary-light); }
.tab-btn.active { background: var(--primary); color: white; box-shadow: 0 8px 20px rgba(79, 70, 229, 0.3); }
.tab-content { display: none; animation: fadeIn 0.5s ease-in-out forwards; }
.tab-content.active { display: block; }
.course-section { margin-bottom: 5rem; }
.course-title { text-align: center; font-size: 2.2rem; color: var(--primary); margin: 2rem 0 2rem; position: relative; font-weight: 900; }
.course-title span { background: white; padding: 0.6rem 2.5rem; border-radius: 99px; box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05); display: inline-block; border: 2px solid var(--primary-light); }
.course-title.advanced span { color: var(--secondary); border-color: #fbcfe8; }
.course-title.expert span { color: var(--warning); border-color: #fde68a; }
.curriculum-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(360px, 1fr)); gap: 2.5rem; }
.lesson-card { background: var(--card-bg); backdrop-filter: blur(15px); -webkit-backdrop-filter: blur(15px); border: 1px solid var(--glass-border); border-radius: 32px; padding: 2.5rem; box-shadow: var(--shadow); transition: all 0.4s cubic-bezier(0.19, 1, 0.22, 1); position: relative; display: flex; flex-direction: column; justify-content: space-between; }
.lesson-card:hover { transform: translateY(-8px); box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08); border-color: rgba(255, 255, 255, 0.8); }
.lesson-card .lesson-num { font-size: 0.85rem; font-weight: 800; color: var(--primary); text-transform: uppercase; letter-spacing: 1.5px; margin-bottom: 0.5rem; background: #e0e7ff; padding: 0.25rem 0.75rem; border-radius: 8px; display: inline-block; align-self: flex-start; }
.lesson-card.advanced-card .lesson-num { color: var(--secondary); background: #fce7f3; }
.lesson-card.expert-card .lesson-num { color: var(--warning); background: #fef3c7; }
.lesson-card h3 { font-size: 1.4rem; font-weight: 800; margin: 0.5rem 0 1rem 0; color: var(--text-main); line-height: 1.3; }
.lesson-card p { font-size: 0.95rem; color: var(--text-muted); margin-bottom: 1.5rem; flex-grow: 1; }
.lesson-actions { display: flex; flex-direction: column; gap: 0.6rem; border-top: 1px dashed rgba(0, 0, 0, 0.08); padding-top: 1.2rem; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 0.75rem 1.25rem; border-radius: 14px; font-size: 0.9rem; font-weight: 700; text-decoration: none; transition: all 0.3s ease; cursor: pointer; border: none; }
.btn-lesson { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%); color: white; box-shadow: 0 4px 15px rgba(79, 70, 229, 0.15); }
.btn-lesson:hover { transform: scale(1.02); box-shadow: 0 6px 20px rgba(79, 70, 229, 0.25); }
.btn-practice { background: #f1f5f9; color: var(--text-main); border: 1px solid #e2e8f0; }
.btn-practice:hover { background: #e2e8f0; transform: scale(1.02); }
.btn-homework { background: rgba(16, 185, 129, 0.08); color: var(--accent); border: 1px solid rgba(16, 185, 129, 0.15); }
.btn-homework:hover { background: rgba(16, 185, 129, 0.15); transform: scale(1.02); }
.btn-integrated { background: rgba(245, 158, 11, 0.08); color: var(--warning); border: 1px solid rgba(245, 158, 11, 0.15); }
.btn-integrated:hover { background: rgba(245, 158, 11, 0.15); transform: scale(1.02); }
@keyframes fadeIn { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }
@keyframes fadeInDown { from { opacity: 0; transform: translateY(-20px); } to { opacity: 1; transform: translateY(0); } }
footer { text-align: center; margin-top: 5rem; color: var(--text-muted); font-size: 0.95rem; border-top: 1px solid rgba(0,0,0,0.05); padding-top: 2rem; }