:root{--primary-color: #4A90E2;--primary-dark: #357ABD;--primary-light: #6BA3E8;--accent-color: #5DADE2;--gradient-1: linear-gradient(135deg, #667eea 0%, #4A90E2 100%);--gradient-2: linear-gradient(135deg, #5DADE2 0%, #3498DB 100%);--gradient-3: linear-gradient(135deg, #A8D8EA 0%, #5DADE2 100%);--gradient-4: linear-gradient(135deg, #85C1E9 0%, #5DADE2 100%);--glass-bg: rgba(255, 255, 255, .15);--glass-border: rgba(255, 255, 255, .25);--glass-shadow: 0 8px 32px 0 rgba(74, 144, 226, .15);--liquid-glass-bg: rgba(168, 216, 234, .12);--liquid-glass-border: rgba(168, 216, 234, .3);--text-primary: #FFFFFF;--text-secondary: rgba(255, 255, 255, .85);--text-dark: #2C3E50;--text-blue: #4A90E2;--bg-primary: #1A2332;--bg-secondary: #2C3E50;--radius-sm: 10px;--radius-md: 16px;--radius-lg: 20px;--radius-xl: 28px;--shadow-sm: 0 4px 12px rgba(74, 144, 226, .08);--shadow-md: 0 8px 24px rgba(74, 144, 226, .12);--shadow-lg: 0 12px 40px rgba(74, 144, 226, .18);--transition-fast: .2s;--transition-normal: .3s;--transition-slow: .5s}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;overflow-x:hidden}#root{min-height:100vh;width:100%}.animated-background{position:fixed;top:0;left:0;width:100%;height:100%;background:linear-gradient(-45deg,#e3f2fd,#bbdefb,#90caf9,#64b5f6,#42a5f5);background-size:400% 400%;animation:gradientShift 20s ease infinite;z-index:-1}@keyframes gradientShift{0%{background-position:0% 50%}50%{background-position:100% 50%}to{background-position:0% 50%}}.floating-circles{position:fixed;top:0;left:0;width:100%;height:100%;overflow:hidden;z-index:-1;pointer-events:none}.circle{position:absolute;border-radius:50%;background:radial-gradient(circle at 30% 30%,#ffffff40,#a8d8ea26);-webkit-backdrop-filter:blur(15px);backdrop-filter:blur(15px);box-shadow:inset 0 0 20px #fff3,0 0 40px #4a90e226;animation:float 25s infinite ease-in-out}.circle:nth-child(1){width:350px;height:350px;top:8%;left:8%;animation-delay:0s}.circle:nth-child(2){width:220px;height:220px;top:55%;left:75%;animation-delay:4s}.circle:nth-child(3){width:180px;height:180px;top:75%;left:15%;animation-delay:8s}.circle:nth-child(4){width:280px;height:280px;top:25%;left:65%;animation-delay:12s}@keyframes float{0%,to{transform:translateY(0) translate(0) rotate(0);opacity:.6}25%{transform:translateY(-40px) translate(20px) rotate(90deg);opacity:.8}50%{transform:translateY(-20px) translate(-20px) rotate(180deg);opacity:.6}75%{transform:translateY(40px) translate(10px) rotate(270deg);opacity:.7}}.glass-card{background:var(--liquid-glass-bg);backdrop-filter:blur(25px) saturate(180%);-webkit-backdrop-filter:blur(25px) saturate(180%);border:1.5px solid var(--liquid-glass-border);border-radius:var(--radius-xl);box-shadow:var(--glass-shadow),inset 0 1px #ffffff4d,0 0 60px #4a90e214;padding:2.5rem;transition:all var(--transition-normal);position:relative;overflow:hidden}.glass-card:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.1),transparent);transition:left .5s}.glass-card:hover:before{left:100%}.glass-card:hover{transform:translateY(-8px);box-shadow:0 16px 50px #4a90e240,inset 0 1px #fff6;border-color:#a8d8ea66}.input-group{margin-bottom:1.5rem;position:relative}.input-label{display:block;color:var(--text-primary);font-size:.9rem;font-weight:600;margin-bottom:.6rem;letter-spacing:.3px;text-shadow:0 2px 4px rgba(0,0,0,.1)}.input-field{width:100%;padding:1.1rem 1.4rem;background:#ffffff1f;border:2px solid rgba(168,216,234,.25);border-radius:var(--radius-md);color:var(--text-primary);font-size:1rem;transition:all var(--transition-normal);outline:none;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);box-shadow:inset 0 2px 4px #0000000d}.input-field::placeholder{color:#ffffff80}.input-field:focus{background:#ffffff2e;border-color:var(--accent-color);box-shadow:0 0 0 4px #5dade226,inset 0 2px 4px #0000000d;transform:translateY(-2px)}.btn{padding:1.1rem 2.2rem;border:none;border-radius:var(--radius-md);font-size:1rem;font-weight:600;cursor:pointer;transition:all var(--transition-normal);outline:none;position:relative;overflow:hidden;letter-spacing:.3px}.btn-primary{background:var(--gradient-2);color:var(--text-primary);box-shadow:0 6px 20px #4a90e259,inset 0 1px #fff3;border:1px solid rgba(255,255,255,.2)}.btn-primary:hover{transform:translateY(-3px);box-shadow:0 10px 30px #4a90e273,inset 0 1px #ffffff4d}.btn-primary:active{transform:translateY(-1px)}.btn-secondary{background:#ffffff26;color:var(--text-primary);border:1.5px solid rgba(168,216,234,.35);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);box-shadow:0 4px 15px #4a90e226}.btn-secondary:hover{background:#ffffff38;border-color:#a8d8ea80;transform:translateY(-3px);box-shadow:0 8px 25px #4a90e240}.btn-success{background:linear-gradient(135deg,#10b981,#059669);color:var(--text-primary);box-shadow:0 6px 20px #10b98159,inset 0 1px #fff3}.btn-success:hover{transform:translateY(-3px);box-shadow:0 10px 30px #10b98173,inset 0 1px #ffffff4d}.btn-success:active{transform:translateY(-1px)}.btn:before{content:"";position:absolute;top:50%;left:50%;width:0;height:0;border-radius:50%;background:#fff6;transform:translate(-50%,-50%);transition:width var(--transition-fast),height var(--transition-fast)}.btn:active:before{width:300px;height:300px}.file-upload-area{border:2px dashed rgba(168,216,234,.4);border-radius:var(--radius-lg);padding:3rem;text-align:center;cursor:pointer;transition:all var(--transition-normal);background:#ffffff14;-webkit-backdrop-filter:blur(15px);backdrop-filter:blur(15px)}.file-upload-area:hover{border-color:var(--accent-color);background:#ffffff26;box-shadow:0 8px 30px #4a90e233;transform:translateY(-4px)}.file-upload-area.dragover{border-color:var(--primary-color);background:#5dade226;box-shadow:0 0 0 6px #5dade21a}.spinner{width:40px;height:40px;border:4px solid rgba(168,216,234,.2);border-top-color:var(--accent-color);border-radius:50%;animation:spin .8s linear infinite;margin:0 auto}@keyframes spin{to{transform:rotate(360deg)}}.alert{padding:1.1rem 1.6rem;border-radius:var(--radius-md);margin-bottom:1.5rem;font-weight:500;animation:slideDown .3s ease-out;-webkit-backdrop-filter:blur(15px);backdrop-filter:blur(15px);letter-spacing:.2px}@keyframes slideDown{0%{opacity:0;transform:translateY(-20px)}to{opacity:1;transform:translateY(0)}}.alert-success{background:#4caf5033;border:1.5px solid rgba(76,175,80,.5);color:#a5d6a7;box-shadow:0 4px 15px #4caf5026}.alert-error{background:#f4433633;border:1.5px solid rgba(244,67,54,.5);color:#ef9a9a;box-shadow:0 4px 15px #f4433626}@media(max-width:768px){.glass-card{padding:1.8rem}.btn{padding:1rem 1.8rem}.circle{opacity:.4}}::-webkit-scrollbar{width:10px}::-webkit-scrollbar-track{background:#a8d8ea14;border-radius:5px}::-webkit-scrollbar-thumb{background:linear-gradient(180deg,#a8d8ea66,#5dade266);border-radius:5px}::-webkit-scrollbar-thumb:hover{background:linear-gradient(180deg,#a8d8ea99,#5dade299)}.auth-container{min-height:100vh;display:flex;justify-content:center;align-items:center;padding:2rem}.auth-card{width:100%;max-width:450px;animation:slideUp .6s ease-out}.auth-title{font-size:2.5rem;font-weight:700;color:var(--text-primary);margin-bottom:.5rem;text-align:center}.auth-subtitle{font-size:1rem;color:var(--text-secondary);margin-bottom:2rem;text-align:center}.btn-full{width:100%;margin-top:1rem}.auth-footer{margin-top:2rem;text-align:center;color:var(--text-secondary)}.auth-footer p{margin-bottom:.5rem;font-size:.95rem}.link-button{background:none;border:none;color:var(--primary-light);font-size:1rem;font-weight:600;cursor:pointer;transition:color var(--transition-normal);padding:0}.link-button:hover{color:var(--primary-color);text-decoration:underline}.link-button:disabled{opacity:.5;cursor:not-allowed}.submit-container{min-height:100vh;padding:2rem;max-width:900px;margin:0 auto}.submit-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;padding:1.5rem;background:var(--glass-bg);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border:1px solid var(--glass-border);border-radius:var(--radius-lg)}.user-info h2{font-size:1.5rem;color:var(--text-primary);margin-bottom:.25rem}.user-info p{font-size:.95rem;color:var(--text-secondary)}.submit-card{animation:slideUp .6s ease-out}.submit-title{font-size:2rem;font-weight:700;color:var(--text-primary);margin-bottom:1.5rem;text-align:center}.assignment-selector{margin-bottom:1.5rem}.selector-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:.75rem}.selector-label{color:var(--text-primary);font-weight:600}.loading-text{color:var(--text-secondary);font-size:.9rem}.assignment-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:1rem}.assignment-card{background:#ffffff0f;border:1px solid var(--glass-border);border-radius:var(--radius-md);padding:1rem;cursor:pointer;transition:transform .2s ease,box-shadow .2s ease,border-color .2s ease}.assignment-card:hover{transform:translateY(-4px);border-color:var(--primary-light);box-shadow:0 10px 25px #0000001f}.assignment-card.selected{border-color:var(--primary-light);box-shadow:0 10px 25px #6366f140}.assignment-card-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:.5rem}.assignment-date{color:var(--text-secondary);font-size:.85rem}.assignment-card-title{color:var(--text-primary);font-size:1.1rem;margin:.25rem 0 .5rem}.assignment-card-desc{color:var(--text-secondary);font-size:.95rem;margin:0 0 .75rem;min-height:44px}.submission-chip{display:inline-block;padding:.35rem .75rem;border-radius:999px;font-size:.85rem;font-weight:600}.submission-chip.done{background:#4caf5026;color:var(--text-primary);border:1px solid rgba(76,175,80,.4)}.submission-chip.pending{background:#ffffff14;color:var(--text-secondary);border:1px dashed rgba(255,255,255,.2)}.assignment-info{background:linear-gradient(135deg,#6366f133,#8b5cf633);padding:1.5rem;border-radius:var(--radius-md);margin-bottom:2rem;text-align:center;border:1px solid rgba(99,102,241,.3)}.assignment-badge{display:inline-block;background:var(--gradient-1);color:var(--text-primary);padding:.4rem 1rem;border-radius:20px;font-size:.85rem;font-weight:600;margin-bottom:.75rem}.assignment-title{font-size:1.5rem;font-weight:600;color:var(--text-primary);margin:0}.assignment-description-box{margin-top:1rem;padding:1rem;background:#ffffff1a;border-radius:var(--radius-md);border:1px solid rgba(255,255,255,.15);text-align:left}.assignment-description-box h4{font-size:1rem;color:var(--text-primary);margin-bottom:.5rem}.assignment-description-box p{font-size:.95rem;color:var(--text-secondary);line-height:1.6;margin:0;white-space:pre-wrap}.submission-time-box{margin-top:1rem;padding:.75rem 1rem;background:#4caf5026;border:1px solid rgba(76,175,80,.3);border-radius:var(--radius-md);display:flex;flex-direction:column;gap:.25rem;align-items:center}.submission-time-box span{color:var(--text-primary);font-size:.9rem}.submission-time-box .time-text{color:var(--text-secondary);font-size:.85rem}.submission-time-box .resubmit-hint{color:var(--text-secondary);font-size:.8rem;font-style:italic}.progress-container{margin-bottom:1.5rem}.progress-bar{width:100%;height:30px;background:#ffffff1a;border-radius:var(--radius-md);overflow:hidden;border:1px solid rgba(168,216,234,.3);position:relative}.progress-fill{height:100%;background:var(--gradient-2);transition:width .3s ease;border-radius:var(--radius-md);box-shadow:0 0 10px #5dade280}.progress-text{text-align:center;color:var(--text-primary);font-size:.9rem;font-weight:600;margin-top:.5rem}.upload-icon{font-size:4rem;margin-bottom:1rem}.upload-text{font-size:1.1rem;color:var(--text-primary);font-weight:500;margin-bottom:.5rem}.upload-subtext{font-size:.95rem;color:var(--text-secondary);margin-bottom:.5rem}.upload-hint{font-size:.85rem;color:var(--text-secondary);font-style:italic}.info-box{margin-top:2rem;padding:1.5rem;background:#6366f11a;border:1px solid rgba(99,102,241,.2);border-radius:var(--radius-md)}.info-box h4{color:var(--text-primary);margin-bottom:1rem;font-size:1.1rem}.info-box ul{list-style:none;padding:0}.info-box li{color:var(--text-secondary);margin-bottom:.75rem;padding-left:1.5rem;position:relative;line-height:1.6}.info-box li:before{content:"•";position:absolute;left:0;color:var(--primary-light);font-weight:700}.info-box strong{color:var(--primary-light)}.no-assignment{text-align:center;padding:4rem 2rem}.empty-icon{font-size:5rem;margin-bottom:1.5rem;opacity:.5}.no-assignment p{font-size:1.2rem;color:var(--text-primary);margin-bottom:.5rem}.empty-subtext{font-size:1rem;color:var(--text-secondary)}@media(max-width:768px){.submit-container{padding:1rem}.submit-header{flex-direction:column;gap:1rem;text-align:center}.submit-title{font-size:1.5rem}.assignment-grid{grid-template-columns:1fr}.assignment-card{padding:.75rem}.file-upload-area{padding:2rem 1rem}}.admin-container{min-height:100vh;padding:2rem;max-width:1200px;margin:0 auto}.admin-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;padding:1.5rem;background:var(--glass-bg);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border:1px solid var(--glass-border);border-radius:var(--radius-lg)}.admin-header h2{font-size:1.8rem;color:var(--text-primary);margin-bottom:.25rem}.admin-header p{font-size:.95rem;color:var(--text-secondary)}.admin-content{display:flex;flex-direction:column;gap:2rem}.admin-section{animation:slideUp .6s ease-out}@keyframes slideUp{0%{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}.section-title{font-size:1.5rem;font-weight:600;color:var(--text-primary);margin-bottom:1.5rem;padding-bottom:.75rem;border-bottom:2px solid rgba(255,255,255,.1)}.create-form{display:flex;flex-direction:column;gap:1rem}.create-form .input-group{flex:1;margin-bottom:0}.empty-text{text-align:center;color:var(--text-secondary);padding:2rem;font-size:1rem}.assignment-list{display:flex;flex-direction:column;gap:1rem}.assignment-item{padding:1.5rem;background:#ffffff08;border:1px solid rgba(255,255,255,.1);border-radius:var(--radius-md);transition:all var(--transition-normal)}.assignment-item:hover{background:#ffffff0d;border-color:#fff3}.assignment-item-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:.75rem}.assignment-item h4{font-size:1.2rem;color:var(--text-primary);margin:0}.active-badge{background:var(--gradient-4);color:var(--text-primary);padding:.35rem .9rem;border-radius:20px;font-size:.8rem;font-weight:600}.assignment-date{font-size:.9rem;color:var(--text-secondary);margin-bottom:1rem}.assignment-description{margin-bottom:1rem}.description-text{font-size:.95rem;color:var(--text-secondary);margin-bottom:.75rem;padding:.75rem;background:#ffffff0d;border-radius:var(--radius-sm);white-space:pre-wrap;line-height:1.6}.edit-description{margin-bottom:1rem}.edit-description textarea{width:100%;margin-bottom:.75rem}.edit-actions{display:flex;gap:.5rem}.assignment-actions{display:flex;gap:.75rem;flex-wrap:wrap}.btn-sm{padding:.6rem 1.2rem;font-size:.9rem}.submission-list{display:flex;flex-direction:column;gap:1rem}.submission-item{display:flex;justify-content:space-between;align-items:center;padding:1.25rem;background:#ffffff08;border:1px solid rgba(255,255,255,.1);border-radius:var(--radius-md);transition:all var(--transition-normal)}.submission-item:hover{background:#ffffff0d;border-color:#fff3}.submission-info h4{font-size:1.1rem;color:var(--text-primary);margin-bottom:.35rem}.submission-info p{font-size:.9rem;color:var(--text-secondary);margin:.25rem 0}.submission-time{font-size:.85rem!important;font-style:italic}@media(max-width:768px){.admin-container{padding:1rem}.admin-header{flex-direction:column;gap:1rem;text-align:center}.create-form{flex-direction:column}.assignment-item-header{flex-direction:column;align-items:flex-start;gap:.75rem}.assignment-actions{flex-direction:column}.assignment-actions .btn{width:100%}.submission-item{flex-direction:column;gap:1rem;align-items:flex-start}.submission-item .btn{width:100%}}.app-content{position:relative;z-index:1}