:root{--teal: #4ECDC4;--teal-dark: #3BBBB3;--dark-navy: #0D1F2D;--dark-surface: #112233;--dark-card: #1A3040;--dark-header: #0A1A27;--text-primary: #FFFFFF;--text-secondary: rgba(255, 255, 255, .6);--border-color: rgba(255, 255, 255, .08);--shadow-card: 0 8px 32px rgba(0, 0, 0, .4);--font: "Lato", sans-serif;--radius: 20px}[data-theme=light]{--dark-navy: #F2F4F6;--dark-surface: #FFFFFF;--dark-card: #FFFFFF;--dark-header: #FFFFFF;--text-primary: #0D1F2D;--text-secondary: rgba(13, 31, 45, .55);--border-color: rgba(0, 0, 0, .08);--shadow-card: 0 8px 32px rgba(0, 0, 0, .1)}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body{margin:0;padding:0;height:100%;width:100%;font-family:var(--font);background:var(--dark-navy);color:var(--text-primary);-webkit-font-smoothing:antialiased;overscroll-behavior:none}#app{height:100%;width:100%}.app-layout{display:flex;flex-direction:column;height:100%;background:var(--dark-navy)}.app-header{flex-shrink:0;min-height:60px;display:flex;align-items:center;justify-content:space-between;gap:8px;padding:6px 12px;background:var(--dark-header);border-bottom:1px solid var(--border-color);z-index:20;position:relative}.header-left{flex-shrink:0;display:flex;align-items:center}#groupPickerContainer{flex:1;min-width:0;display:flex;justify-content:center;align-items:center;position:relative;z-index:30}.header-actions{flex-shrink:0;display:flex;align-items:center;gap:4px}.member-counter{font-size:14px;font-weight:500;color:var(--text-secondary);white-space:nowrap}.icon-btn{background:none;border:none;font-size:18px;cursor:pointer;padding:8px;color:var(--text-secondary);border-radius:50%;transition:background .15s;display:flex;align-items:center;justify-content:center}.icon-btn:hover{background:var(--border-color)}.group-picker{width:100%;min-width:0;display:flex;justify-content:center}.group-picker-morph{position:relative;background:var(--dark-surface);border:1.5px solid color-mix(in srgb,var(--text-primary) 18%,transparent);border-radius:18px;box-shadow:0 2px 8px #00000026;max-width:100%;min-width:0;transition:border-color .2s ease,border-radius .2s ease,min-width .22s cubic-bezier(.2,.9,.3,1)}.group-picker-morph.open{border-color:var(--teal);border-bottom-color:transparent;border-radius:16px 16px 0 0;min-width:min(225px,100%);box-shadow:none}.group-picker-active{display:flex;align-items:center;justify-content:center;gap:6px;min-height:32px;padding:5px 11px 5px 13px;cursor:pointer;-webkit-user-select:none;user-select:none}.group-picker-active.is-single{cursor:default;padding:5px 13px}.group-name{font-size:14.5px;font-weight:700;line-height:1.22;color:var(--text-primary);text-align:center;white-space:normal;text-wrap:balance;overflow-wrap:break-word;min-width:0}.group-chevron{display:flex;align-items:center;justify-content:center;color:var(--teal);flex-shrink:0;transition:transform .22s ease}.group-picker-morph.open .group-chevron{transform:rotate(180deg)}.group-dropdown-drawer{position:absolute;top:calc(100% - 1px);left:-1.5px;right:-1.5px;background:var(--dark-surface);border:1.5px solid transparent;border-top:none;border-radius:0 0 16px 16px;display:grid;grid-template-rows:0fr;opacity:0;pointer-events:none;z-index:100;transition:grid-template-rows .22s cubic-bezier(.2,.9,.3,1),opacity .18s ease,border-color .2s ease}.group-picker-morph.open .group-dropdown-drawer{grid-template-rows:1fr;opacity:1;pointer-events:auto;border-color:var(--teal);box-shadow:0 16px 36px #00000073}[data-theme=light] .group-picker-morph.open .group-dropdown-drawer{box-shadow:0 16px 36px #00000029}.group-dropdown-inner{overflow:hidden;border-radius:0 0 14px 14px}.group-dropdown-divider{height:1px;background:var(--border-color);margin:0 10px}.group-dropdown-list{padding:4px 0 6px;max-height:60vh;overflow-y:auto;display:flex;flex-direction:column}.group-option{padding:10px 14px;cursor:pointer;font-size:14px;font-weight:600;line-height:1.25;color:var(--text-secondary);text-align:center;white-space:normal;text-wrap:balance;transition:background .15s,color .15s}.group-option:hover{background:var(--border-color);color:var(--text-primary)}.flashcards-main{flex:1;display:flex;min-height:0;position:relative}.scrubber-sidebar{width:44px;flex-shrink:0;display:flex;align-items:stretch;z-index:5}.carousel-area{flex:1;min-width:0;min-height:0;position:relative}.loading-state,.empty-state,.error-state{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;gap:12px;color:var(--text-secondary);font-size:15px}.spinner{width:36px;height:36px;border:3px solid var(--border-color);border-top-color:var(--teal);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.login-page{display:flex;flex-direction:column;justify-content:space-between;min-height:100%;height:100dvh;box-sizing:border-box;padding:24px;padding-top:max(20px,env(safe-area-inset-top));padding-bottom:max(24px,env(safe-area-inset-bottom));background:var(--dark-navy);overflow-y:auto}.login-header{margin-top:4vh;text-align:center;flex-shrink:0}.login-logo-img{width:96px;height:96px;display:block;margin:0 auto 12px;border-radius:20px}.login-logo{font-size:32px;font-weight:900;color:var(--teal);letter-spacing:-.5px}.login-actions{margin-bottom:max(72px,calc(11vh + env(safe-area-inset-bottom)));width:100%;max-width:380px;margin-left:auto;margin-right:auto;flex-shrink:0}@media (min-width: 768px){.login-header{margin-top:10vh}.login-logo-img{width:120px;height:120px;margin:0 auto 16px;border-radius:24px}.login-logo{font-size:36px}.login-actions{margin-bottom:20vh}}.btn-primary{display:flex;align-items:center;justify-content:center;gap:10px;width:100%;padding:14px 24px;background:var(--teal);color:#0d1f2d;font-size:15px;font-weight:800;border:none;border-radius:12px;cursor:pointer;transition:background .2s,transform .1s;font-family:var(--font)}.btn-primary:hover{background:var(--teal-dark)}.btn-primary:active{transform:scale(.98)}.login-btn-large{font-size:22px;padding:16px 24px;border-radius:14px}.login-subtitle{margin:10px 0 0;font-size:14px;color:var(--text-secondary);line-height:1.5;text-align:center}.login-actions .login-subtitle{margin:0 0 16px}.login-subtitle strong{color:var(--text-primary)}.login-tab-row{display:flex;gap:8px;margin-bottom:16px;background:var(--dark-surface);border-radius:10px;padding:4px}.login-tab{flex:1;padding:9px;border:none;border-radius:8px;background:transparent;color:var(--text-secondary);font-size:14px;font-weight:600;font-family:var(--font);cursor:pointer;transition:background .15s,color .15s}.login-tab.active{background:var(--dark-card);color:var(--teal)}.login-input{width:100%;padding:14px 16px;margin-bottom:12px;background:var(--dark-surface);border:1px solid var(--border-color);border-radius:12px;color:var(--text-primary);font-size:16px;font-family:var(--font);outline:none;transition:border-color .2s;display:block}.login-input:focus{border-color:var(--teal)}.login-input::placeholder{color:var(--text-secondary)}.login-error{background:#e74c3c1f;border:1px solid rgba(231,76,60,.4);border-radius:10px;color:#e74c3c;font-size:13px;line-height:1.5;padding:10px 14px;margin-bottom:14px}.login-error.hidden{display:none}.otp-input-row{display:flex;gap:8px;justify-content:center;margin-bottom:20px;position:relative}.otp-digit{width:44px;height:56px;display:flex;align-items:center;justify-content:center;font-size:24px;font-weight:700;font-family:var(--font);color:var(--text-primary);background:var(--dark-surface);border:1.5px solid var(--border-color);border-radius:10px;transition:border-color .2s,box-shadow .2s;-webkit-user-select:none;user-select:none;cursor:text}.otp-digit--active{border-color:var(--teal);box-shadow:0 0 0 2px color-mix(in srgb,var(--teal) 25%,transparent)}.otp-digit--filled{border-color:var(--border-color)}.otp-resend-row{display:flex;justify-content:center;align-items:center;gap:10px;margin-top:14px}.otp-divider{color:var(--text-secondary);font-size:13px}.login-link{background:none;border:none;color:var(--teal);font-size:13px;font-family:var(--font);cursor:pointer;padding:0;transition:opacity .15s}.login-link:hover{opacity:.75}.login-link:disabled{color:var(--text-secondary);cursor:default}.profile-list{display:flex;flex-direction:column;gap:10px}.profile-option{display:flex;align-items:center;gap:14px;padding:14px 18px;background:var(--dark-surface);border:1px solid var(--border-color);border-radius:14px;color:var(--text-primary);font-size:16px;font-family:var(--font);font-weight:600;cursor:pointer;transition:border-color .2s,background .15s;text-align:left;width:100%}.profile-option:hover{border-color:var(--teal);background:var(--dark-card)}.profile-avatar{width:40px;height:40px;border-radius:50%;background:var(--dark-card);border:1.5px solid var(--teal);display:flex;align-items:center;justify-content:center;font-size:14px;font-weight:700;color:var(--teal);flex-shrink:0;text-transform:uppercase;letter-spacing:.5px}.profile-name{flex:1}.btn-spinner{display:inline-block;width:20px;height:20px;border:2.5px solid rgba(13,31,45,.35);border-top-color:#0d1f2d;border-radius:50%;animation:spin .7s linear infinite}.carousel-scroller{height:100%;overflow-y:scroll;scroll-snap-type:y mandatory;-webkit-overflow-scrolling:touch;scrollbar-width:none;display:flex;flex-direction:column;align-items:center;padding-top:15vh;padding-bottom:15vh}.carousel-scroller::-webkit-scrollbar{display:none}.card-wrapper{width:100%;height:75vh;display:flex;align-items:center;justify-content:center;scroll-snap-align:center;scroll-snap-stop:always;padding:32px 16px 32px 8px;transition:opacity .3s}.flashcard{width:100%;max-width:360px;background:var(--dark-card);border-radius:var(--radius);box-shadow:var(--shadow-card);overflow:hidden;border:2px solid transparent;transition:border-color .3s,transform .3s;cursor:pointer;-webkit-user-select:none;user-select:none}.card-photo-wrap{width:100%;aspect-ratio:1 / 1;overflow:hidden;background:var(--dark-surface);position:relative}.card-avatar{width:100%;height:100%;object-fit:cover;display:block;opacity:0;transition:opacity .25s ease}.card-avatar.is-loaded{opacity:1}.card-avatar--deferred{width:100%;height:100%;display:block}.card-photo-wrap.is-loading:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;background:linear-gradient(100deg,var(--dark-surface) 30%,color-mix(in srgb,var(--dark-surface) 80%,#ffffff) 50%,var(--dark-surface) 70%);background-size:200% 100%;animation:card-shimmer 1.4s ease-in-out infinite}.card-photo-wrap.is-loading .card-avatar{position:relative}@keyframes card-shimmer{0%{background-position:150% 0}to{background-position:-50% 0}}.card-avatar-placeholder{width:100%;height:100%;display:flex;align-items:center;justify-content:center;font-size:72px;font-weight:900;color:var(--teal);background:linear-gradient(135deg,var(--dark-surface),var(--dark-card));letter-spacing:-2px}.card-info{padding:16px 16px 20px;text-align:center}.card-name{margin:0;font-size:20px;font-weight:700;color:var(--text-primary);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.skeleton-shimmer{background:linear-gradient(100deg,var(--dark-surface) 30%,color-mix(in srgb,var(--dark-surface) 80%,#ffffff) 50%,var(--dark-surface) 70%);background-size:200% 100%;animation:card-shimmer 1.4s ease-in-out infinite}[data-theme=light] .skeleton-shimmer,[data-theme=light] .card-photo-wrap.is-loading:before{background-image:linear-gradient(100deg,#e6eaee 30%,#f4f6f8,#e6eaee 70%)}.skeleton-carousel{height:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;overflow:hidden}.skeleton-carousel .card-wrapper{flex-shrink:0}.skeleton-peek{opacity:.45}.skeleton-card{cursor:default}.skeleton-line{height:22px;width:60%;margin:1px auto;border-radius:6px}.skeleton-pill{width:160px;height:34px;border-radius:999px}.scrubber-sidebar.is-skeleton .scrubber-letter{opacity:.15}.carousel-scroller{animation:fade-in .3s ease}@keyframes fade-in{0%{opacity:0}to{opacity:1}}.error-state svg{color:var(--teal);opacity:.8}.btn-retry{margin-top:4px;padding:10px 22px;border:none;border-radius:999px;background:var(--teal);color:#0d1f2d;font-family:var(--font);font-size:15px;font-weight:700;cursor:pointer}.btn-retry:active{background:var(--teal-dark)}@media (prefers-reduced-motion: reduce){.skeleton-shimmer,.card-photo-wrap.is-loading:before{animation:none}.carousel-scroller{animation:none}}.scrubber-list{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;width:100%;padding:10px 0;font-size:13px;font-weight:700;color:var(--text-secondary);background:#0000001a;border-right:1px solid var(--border-color)}.scrubber-letter{flex:1;display:flex;align-items:center;justify-content:center;width:100%;cursor:default;opacity:.3;transition:all .2s;-webkit-user-select:none;user-select:none}.scrubber-letter.has-members{opacity:.7;color:var(--text-primary);cursor:pointer}.scrubber-letter.has-members:hover{opacity:1}.scrubber-letter.is-active{color:var(--teal);opacity:1;font-size:16px;font-weight:900;transform:scale(1.2)}