.sf-navbar{position:fixed;bottom:0;left:0;right:0;height:var(--nav-height, 64px);background:var(--color-surface);border-top:1px solid var(--color-border);display:flex;align-items:center;justify-content:space-around;z-index:100;padding-bottom:env(safe-area-inset-bottom,0);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px)}.sf-navbar__item{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;min-width:56px;min-height:44px;padding:6px 8px;color:var(--color-text-muted);text-decoration:none;transition:color var(--transition-fast);-webkit-tap-highlight-color:transparent;position:relative}.sf-navbar__item--active{color:var(--color-primary)}.sf-navbar__item--active:before{content:"";position:absolute;top:0;left:50%;transform:translate(-50%);width:32px;height:3px;background:var(--color-primary);border-radius:0 0 4px 4px}.sf-navbar__icon{position:relative;display:flex;align-items:center;justify-content:center;width:28px;height:28px}.sf-navbar__badge{position:absolute;top:-4px;right:-10px;min-width:18px;height:18px;padding:0 5px;font-size:.6875rem;font-weight:700;color:#fff;background:var(--color-error, #FF7675);border-radius:9999px;display:flex;align-items:center;justify-content:center;line-height:1}.sf-navbar__label{font-size:.625rem;font-weight:500;line-height:1}@media (max-width: 359px){.sf-navbar__label{display:none}.sf-navbar__item{min-width:48px;padding:6px 4px}}@media (min-width: 768px){.sf-navbar{position:fixed;top:0;left:0;bottom:0;right:auto;width:80px;height:100%;flex-direction:column;justify-content:flex-start;padding-top:2rem;gap:.5rem;border-top:none;border-right:1px solid var(--color-border)}.sf-navbar__item--active:before{top:50%;left:0;transform:translateY(-50%);width:3px;height:32px;border-radius:0 4px 4px 0}}.sf-feedback-fab{position:fixed;bottom:calc(var(--nav-height, 64px) + 16px + env(safe-area-inset-bottom,0px));right:16px;width:52px;height:52px;border-radius:9999px;background:var(--color-primary);color:#fff;display:flex;align-items:center;justify-content:center;box-shadow:0 4px 16px #6c5ce766;z-index:90;transition:transform var(--transition-fast),box-shadow var(--transition-fast)}.sf-feedback-fab:hover{transform:scale(1.08);box-shadow:0 6px 20px #6c5ce780}.sf-feedback-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#00000073;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;align-items:flex-end;justify-content:center;z-index:1000;padding:1rem;animation:feedbackFadeIn .2s ease}@keyframes feedbackFadeIn{0%{opacity:0}to{opacity:1}}.sf-feedback-modal{background:var(--color-surface);border-radius:16px 16px 12px 12px;padding:1.5rem;max-width:420px;width:100%;box-shadow:var(--shadow-lg);animation:feedbackSlideUp .3s cubic-bezier(.16,1,.3,1)}@keyframes feedbackSlideUp{0%{opacity:0;transform:translateY(24px)}to{opacity:1;transform:translateY(0)}}.sf-feedback-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem}.sf-feedback-header h3{font-size:1.125rem;font-weight:700}.sf-feedback-close{min-width:44px;min-height:44px;display:flex;align-items:center;justify-content:center;border-radius:8px;color:var(--color-text-secondary)}.sf-feedback-close:hover{background:var(--color-surface-hover)}.sf-feedback-form{display:flex;flex-direction:column;gap:.75rem}.sf-feedback-types{display:flex;gap:.5rem}.sf-feedback-type{flex:1;padding:.5rem;border-radius:8px;font-size:.8125rem;font-weight:600;border:1.5px solid var(--color-border);color:var(--color-text-secondary);transition:all var(--transition-fast);min-height:44px}.sf-feedback-type--active{border-color:var(--color-primary);color:var(--color-primary);background:#6c5ce714}.sf-feedback-textarea{resize:vertical;min-height:100px;border:1.5px solid var(--color-border);border-radius:8px;padding:.75rem;font-size:.9375rem;background:var(--color-surface);color:var(--color-text)}.sf-feedback-textarea:focus{outline:none;border-color:var(--color-primary);box-shadow:0 0 0 3px #6c5ce71f}.sf-feedback-contact{border:1.5px solid var(--color-border);border-radius:8px;padding:.625rem .75rem;font-size:.875rem}.sf-feedback-success{text-align:center;padding:2rem 1rem}.sf-feedback-check{display:inline-flex;align-items:center;justify-content:center;width:48px;height:48px;background:var(--color-success);color:#fff;border-radius:50%;font-size:1.5rem;margin-bottom:.75rem}.sf-feedback-success p{color:var(--color-text-secondary);font-size:.9375rem}@media (min-width: 768px){.sf-feedback-fab{bottom:24px;right:24px}.sf-feedback-overlay{align-items:center}}.sf-home{padding-top:2rem;padding-bottom:calc(var(--nav-height, 64px) + 2rem)}.sf-hero{animation:sfSlideUp .5s ease}@keyframes sfSlideUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.sf-hero__content{text-align:center;padding:2rem 0 2.5rem}.sf-hero__title{font-size:2.25rem;font-weight:800;line-height:1.15;letter-spacing:-.02em;color:var(--color-text)}.sf-hero__subtitle{background:linear-gradient(135deg,var(--color-primary),var(--color-secondary, #00CEC9));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.sf-hero__desc{margin-top:1rem;color:var(--color-text-secondary);font-size:1.0625rem;line-height:1.6;max-width:440px;margin-left:auto;margin-right:auto}.sf-hero__actions{display:flex;flex-direction:column;gap:.75rem;margin-top:2rem;max-width:320px;margin-left:auto;margin-right:auto}.sf-features{display:grid;grid-template-columns:1fr 1fr;gap:.75rem;margin-top:1rem}.sf-feature-card{background:var(--color-surface);border-radius:12px;padding:1.25rem;box-shadow:var(--shadow-sm);transition:transform var(--transition-fast),box-shadow var(--transition-fast);border-left:3px solid var(--feature-color, var(--color-primary))}.sf-feature-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}.sf-feature-card__icon{font-size:1.75rem;display:block;margin-bottom:.5rem}.sf-feature-card__title{font-size:.9375rem;font-weight:700;margin-bottom:.25rem}.sf-feature-card__desc{font-size:.8125rem;color:var(--color-text-secondary);line-height:1.4}.sf-dashboard{animation:sfSlideUp .4s ease}.sf-dashboard__greeting{font-size:1.5rem;font-weight:700;margin-bottom:1.25rem}.sf-dashboard__stats{display:grid;grid-template-columns:1fr auto;gap:.75rem;margin-bottom:1.25rem}.sf-dashboard__xp-card{display:flex;align-items:center;gap:1rem}.sf-xp-ring__text{fill:var(--color-text);font-size:1.25rem;font-weight:800}.sf-dashboard__streak-card{display:flex;flex-direction:column;align-items:center;justify-content:center;min-width:90px}.sf-dashboard__fire{font-size:2rem;line-height:1}.sf-dashboard__stat-label{font-size:.75rem;color:var(--color-text-muted);text-transform:uppercase;letter-spacing:.04em;font-weight:600}.sf-dashboard__stat-value{font-size:1.25rem;font-weight:800}.sf-dashboard__languages{display:flex;flex-direction:column;gap:.625rem;margin-bottom:1.25rem}.sf-dashboard__lang-card{padding:1rem 1.25rem}.sf-dashboard__lang-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:.5rem}.sf-dashboard__lang-name{font-weight:600;text-transform:capitalize}.sf-badge{display:inline-flex;align-items:center;padding:.2rem .6rem;border-radius:9999px;font-size:.75rem;font-weight:700}.sf-progress-bar{height:8px;background:var(--color-border);border-radius:9999px;overflow:hidden}.sf-progress-fill{height:100%;border-radius:9999px;background:linear-gradient(90deg,var(--color-primary),var(--color-primary-light));transition:width .6s ease}.sf-dashboard__badges{margin-bottom:1.25rem}.sf-dashboard__badges h3{font-size:.9375rem;font-weight:700;margin-bottom:.75rem}.sf-dashboard__badge-row{display:flex;gap:.75rem}.sf-dashboard__badge{display:flex;flex-direction:column;align-items:center;gap:.25rem;padding:.75rem;background:var(--color-surface);border-radius:12px;min-width:80px;box-shadow:var(--shadow-sm)}.sf-dashboard__badge-icon{font-size:1.75rem}.sf-dashboard__badge-name{font-size:.6875rem;color:var(--color-text-secondary);text-align:center}.sf-dashboard__quick h3{font-size:.9375rem;font-weight:700;margin-bottom:.75rem}.sf-dashboard__quick-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.625rem}.sf-dashboard__quick-btn{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:.375rem;padding:1rem .5rem;cursor:pointer;font-size:.8125rem;font-weight:600;color:var(--color-text);text-align:center;transition:transform var(--transition-fast);min-height:44px}.sf-dashboard__quick-btn:hover{transform:translateY(-2px)}.sf-dashboard__quick-btn span:first-child{font-size:1.5rem}@media (min-width: 768px){.sf-home{padding-left:80px}.sf-hero__title{font-size:3rem}.sf-features{grid-template-columns:repeat(4,1fr)}.sf-hero__actions{flex-direction:row}.sf-hero__actions .sf-btn{flex:1}}.sf-card{background:var(--color-surface);border-radius:12px;box-shadow:var(--shadow-sm);padding:1.25rem;transition:box-shadow var(--transition-fast),transform var(--transition-fast)}.sf-btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;min-height:44px;padding:.75rem 1.5rem;border-radius:8px;font-weight:600;font-size:1rem;transition:all var(--transition-fast);text-align:center;-webkit-user-select:none;user-select:none;-webkit-tap-highlight-color:transparent;text-decoration:none}.sf-btn-primary{background:var(--color-primary);color:#fff}.sf-btn-primary:hover{background:var(--color-primary-dark);transform:translateY(-1px);text-decoration:none}.sf-btn-secondary{background:var(--color-success, #00B894);color:#fff}.sf-btn-secondary:hover{filter:brightness(.9);transform:translateY(-1px);text-decoration:none}.sf-btn-outline{border:2px solid var(--color-primary);color:var(--color-primary);background:transparent}.sf-btn-outline:hover{background:var(--color-primary);color:#fff;text-decoration:none}.sf-btn-ghost{color:var(--color-text-secondary)}.sf-btn-ghost:hover{background:var(--color-surface-hover)}.sf-btn-danger{background:var(--color-error, #FF7675);color:#fff}.sf-btn-danger:hover{filter:brightness(.9)}.sf-btn-block{width:100%}.sf-btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}.sf-container{width:100%;max-width:480px;margin:0 auto;padding:0 1rem}@media (min-width: 768px){.sf-container{max-width:720px}}@media (min-width: 1024px){.sf-container{max-width:960px}}.sf-screen{flex:1;animation:sfFadeIn .3s ease}@keyframes sfFadeIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}:root{--color-primary: #6C5CE7;--color-primary-light: #A29BFE;--color-primary-dark: #4834D4;--color-secondary: #00CEC9;--color-secondary-light: #81ECEC;--color-accent: #FD79A8;--color-warning: #FDCB6E;--color-error: #FF7675;--color-success: #00B894;--color-bg: #FAFAFA;--color-surface: #FFFFFF;--color-surface-hover: #F5F5F5;--color-border: #E0E0E0;--color-text: #2D3436;--color-text-secondary: #636E72;--color-text-muted: #B2BEC3;--space-xs: 4px;--space-sm: 8px;--space-md: 16px;--space-lg: 24px;--space-xl: 32px;--space-2xl: 48px;--space-3xl: 64px;--font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-size-xs: .75rem;--font-size-sm: .875rem;--font-size-base: 1rem;--font-size-lg: 1.125rem;--font-size-xl: 1.25rem;--font-size-2xl: 1.5rem;--font-size-3xl: 2rem;--radius-sm: 6px;--radius-md: 10px;--radius-lg: 16px;--radius-full: 9999px;--shadow-sm: 0 1px 3px rgba(0, 0, 0, .08);--shadow-md: 0 4px 12px rgba(0, 0, 0, .1);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .12);--transition-fast: .15s ease;--transition-base: .25s ease;--transition-slow: .4s ease;--max-width: 1200px;--header-height: 60px;--nav-height: 64px}[data-theme=dark]{--color-bg: #1A1A2E;--color-surface: #16213E;--color-surface-hover: #1E2D4F;--color-border: #2A3A5C;--color-text: #EAEAEA;--color-text-secondary: #A0A0B8;--color-text-muted: #6B6B80}[data-color=green]{--color-primary: #00B894;--color-primary-light: #55EFC4;--color-primary-dark: #00A381;--color-secondary: #FDCB6E;--color-accent: #E17055}[data-color=blue]{--color-primary: #0984E3;--color-primary-light: #74B9FF;--color-primary-dark: #0652DD;--color-secondary: #00CEC9;--color-accent: #FD79A8}[data-color=pink]{--color-primary: #E84393;--color-primary-light: #FD79A8;--color-primary-dark: #C44569;--color-secondary: #6C5CE7;--color-accent: #FDCB6E}[data-color=orange]{--color-primary: #E17055;--color-primary-light: #FAB1A0;--color-primary-dark: #D63031;--color-secondary: #00CEC9;--color-accent: #6C5CE7}[data-color=teal]{--color-primary: #00CEC9;--color-primary-light: #81ECEC;--color-primary-dark: #00B894;--color-secondary: #6C5CE7;--color-accent: #FD79A8}@media (prefers-color-scheme: dark){:root:not([data-theme=light]){--color-bg: #1A1A2E;--color-surface: #16213E;--color-surface-hover: #1E2D4F;--color-border: #2A3A5C;--color-text: #EAEAEA;--color-text-secondary: #A0A0B8;--color-text-muted: #6B6B80}}:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:16px;-webkit-text-size-adjust:100%}body{font-family:var(--font-family);font-size:var(--font-size-base);color:var(--color-text);background-color:var(--color-bg);line-height:1.6;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;min-height:100dvh}a{color:var(--color-primary);text-decoration:none}a:hover{text-decoration:underline}button{cursor:pointer;font-family:inherit;font-size:inherit;border:none;background:none}img,svg{display:block;max-width:100%}input,textarea,select{font-family:inherit;font-size:inherit}ul,ol{list-style:none}.container{max-width:var(--max-width);margin:0 auto;padding:0 var(--space-md)}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.loading-screen{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100dvh;gap:var(--space-md);color:var(--color-text-secondary)}.loading-spinner{width:40px;height:40px;border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}::-webkit-scrollbar{width:8px}::-webkit-scrollbar-track{background:var(--color-bg)}::-webkit-scrollbar-thumb{background:var(--color-border);border-radius:var(--radius-full)}::-webkit-scrollbar-thumb:hover{background:var(--color-text-muted)}[dir=rtl]{text-align:right}[dir=rtl] .sf-navbar,[dir=rtl] .sf-screen,[dir=rtl] .sf-lesson__topbar,[dir=rtl] .sf-dashboard__stats,[dir=rtl] .sf-profile__badges,[dir=rtl] .sf-oauth-grid{flex-direction:row-reverse}[dir=rtl] .ml-1{margin-left:0;margin-right:.25rem}[dir=rtl] .ml-2{margin-left:0;margin-right:.5rem}[dir=rtl] .ml-3{margin-left:0;margin-right:.75rem}[dir=rtl] .ml-4{margin-left:0;margin-right:1rem}[dir=rtl] .ml-6{margin-left:0;margin-right:1.5rem}[dir=rtl] .ml-8{margin-left:0;margin-right:2rem}[dir=rtl] .mr-1{margin-right:0;margin-left:.25rem}[dir=rtl] .mr-2{margin-right:0;margin-left:.5rem}[dir=rtl] .mr-3{margin-right:0;margin-left:.75rem}[dir=rtl] .mr-4{margin-right:0;margin-left:1rem}[dir=rtl] .mr-6{margin-right:0;margin-left:1.5rem}[dir=rtl] .mr-8{margin-right:0;margin-left:2rem}[dir=rtl] .pl-1{padding-left:0;padding-right:.25rem}[dir=rtl] .pl-2{padding-left:0;padding-right:.5rem}[dir=rtl] .pl-3{padding-left:0;padding-right:.75rem}[dir=rtl] .pl-4{padding-left:0;padding-right:1rem}[dir=rtl] .pl-6{padding-left:0;padding-right:1.5rem}[dir=rtl] .pl-8{padding-left:0;padding-right:2rem}[dir=rtl] .pr-1{padding-right:0;padding-left:.25rem}[dir=rtl] .pr-2{padding-right:0;padding-left:.5rem}[dir=rtl] .pr-3{padding-right:0;padding-left:.75rem}[dir=rtl] .pr-4{padding-right:0;padding-left:1rem}[dir=rtl] .pr-6{padding-right:0;padding-left:1.5rem}[dir=rtl] .pr-8{padding-right:0;padding-left:2rem}[dir=rtl] .text-left{text-align:right}[dir=rtl] .text-right{text-align:left}[dir=rtl] .sf-navbar{left:auto;right:0;border-left:1px solid var(--border-color, #2D2D44);border-right:none}[dir=rtl] .sf-container{margin-left:0;margin-right:var(--sidebar-width, 260px)}[dir=rtl] .sf-navbar.collapsed{transform:translate(100%)}[dir=rtl] .sf-navbar.collapsed+.sf-container{margin-right:0}[dir=rtl] .icon-arrow-right,[dir=rtl] .icon-chevron-right,[dir=rtl] .icon-arrow-forward,[dir=rtl] .icon-next,[dir=rtl] .icon-arrow-left,[dir=rtl] .icon-chevron-left,[dir=rtl] .icon-arrow-back,[dir=rtl] .icon-prev{transform:scaleX(-1)}[dir=rtl] .sf-progress-bar{direction:rtl}[dir=rtl] .sf-progress-fill{transform-origin:right}[dir=rtl] ul,[dir=rtl] ol{padding-left:0;padding-right:1.5rem}[dir=rtl] input,[dir=rtl] textarea,[dir=rtl] select{text-align:right}[dir=rtl] input[type=checkbox],[dir=rtl] input[type=radio]{margin-left:.5rem;margin-right:0}[dir=rtl] label{text-align:right}[dir=rtl] .sf-profile__badge-icon{margin-right:0;margin-left:.5rem}[dir=rtl] .sf-card-header{flex-direction:row-reverse}[dir=rtl] .sf-card-actions{margin-left:0;margin-right:auto}[dir=rtl] .sf-lesson__options,[dir=rtl] .sf-lesson__word-bank{direction:rtl}[dir=rtl] .sf-review__actions{flex-direction:row-reverse}[dir=rtl] .sf-toast{left:1rem;right:auto}[dir=rtl] .sf-toast__icon{margin-right:0;margin-left:.75rem}[dir=rtl] .sf-modal__close{left:1rem;right:auto}[dir=rtl] .sf-dropdown__menu{left:0;right:auto}[dir=rtl] .sf-fab{left:1.5rem;right:auto}[dir=rtl] .sf-stat-card__icon{margin-right:0;margin-left:.5rem}[dir=rtl] .sf-roadmap__line{left:auto;right:1.5rem}[dir=rtl] .sf-roadmap__node{padding-left:0;padding-right:3rem}[dir=rtl] .rounded-l{border-radius:0 .5rem .5rem 0}[dir=rtl] .rounded-r{border-radius:.5rem 0 0 .5rem}[dir=rtl] .slide-in-right{transform:translate(-100%)}[dir=rtl] .slide-in-left{transform:translate(100%)}[dir=rtl] .sf-scrollable{direction:rtl}[dir=rtl] th,[dir=rtl] td{text-align:right}[dir=rtl] .sf-search__icon{left:auto;right:.75rem}[dir=rtl] .sf-search__input{padding-left:.75rem;padding-right:2.5rem}