.navbar{width:100vw;max-width:none;display:flex;justify-content:space-between;align-items:center;padding:12px 24px;background-color:#fff;border-bottom:1px solid #e5e7eb;font-family:sans-serif;position:fixed;top:0;left:0;z-index:10}.navbar-left{display:flex;align-items:center;gap:24px}.logo{height:28px;cursor:pointer}.nav-links a{margin-right:16px;text-decoration:none;color:#6b7280;font-size:14px}.nav-links a:first-child{color:#000;font-weight:700;border-bottom:2px solid black}.navbar-right{display:flex;align-items:center;gap:12px}.auth-link{font-size:14px;text-decoration:none;color:#6b7280}.separator{font-size:14px;color:#9ca3af}.premium-btn{padding:6px 12px;background-color:#fff7ed;color:#fb923c;border-radius:6px;font-size:14px;font-weight:500;text-decoration:none}.study-plan-container{padding:24px}.study-plan-title{font-size:20px;font-weight:600;margin-bottom:16px}.study-plan-grid{display:grid;grid-template-columns:1fr;gap:16px}@media (min-width: 768px){.study-plan-grid{grid-template-columns:repeat(2,1fr)}}.study-plan-card{display:flex;align-items:center;padding:16px;border-radius:16px;background-color:#fff;box-shadow:0 1px 3px #0000000f;transition:box-shadow .2s ease}.study-plan-card:hover{box-shadow:0 4px 12px #0000001a}.study-plan-icon{width:48px;height:48px;border-radius:8px;margin-right:16px}.study-plan-text h3{font-weight:600}.study-plan-text p{font-size:14px;color:#6b7280}.problem-detail-container{display:flex;height:calc(100vh - 60px)}.left-section{width:50%;overflow-y:auto;padding:20px;border-right:1px solid #eee}.right-section{width:50%;overflow-y:auto;padding:20px}.problem-detail-container{display:flex;height:100vh;background-color:#f8f9fa;font-family:Segoe UI,Roboto,sans-serif}.left-section{width:50%;display:flex;flex-direction:column;border-right:1px solid #e0e0e0;background-color:#fff}.right-section{width:50%;background-color:#fff;padding:16px;overflow-y:auto}.tabs{display:flex;padding:0 16px;background-color:#fff;border-bottom:1px solid #e5e7eb;position:sticky;top:0;z-index:10}.tab-button{flex:1;padding:14px 0;text-align:center;font-size:14px;font-weight:500;color:#4b5563;border:none;background:none;cursor:pointer;transition:all .2s ease;border-bottom:2px solid transparent}.tab-button:hover{color:#111827;background-color:#f3f4f6}.tab-button.active{color:#2563eb;font-weight:600;border-bottom:2px solid #2563eb;background-color:#f9fafb}.tab-content-area{flex:1;overflow-y:auto;padding:24px}@keyframes slide-in-left{0%{transform:translate(-100%);opacity:0}to{transform:translate(0);opacity:1}}.animate-slide-in-left{animation:slide-in-left .3s ease-out forwards}@keyframes slide-out-left{0%{transform:translate(0);opacity:1}to{transform:translate(-100%);opacity:0}}.animate-slide-out-left{animation:slide-out-left .3s ease-in forwards}.item{padding:30px}