@import"https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Source+Serif+4:ital,wght@0,400;0,600;1,400&display=swap";:root{--color-bg: #FAFAF9;--color-surface: #FFFFFF;--color-surface-raised: #FFFFFF;--color-border: #E5E5E3;--color-border-focus: #A3A3A0;--color-text-primary: #1A1A19;--color-text-secondary: #6B6B67;--color-text-muted: #9C9C97;--color-accent: #2563EB;--color-accent-hover: #1D4ED8;--color-accent-light: #EFF6FF;--color-accent-subtle: #DBEAFE;--color-success: #16A34A;--color-success-light: #F0FDF4;--color-warning: #D97706;--color-warning-light: #FFFBEB;--color-error: #DC2626;--color-error-light: #FEF2F2;--font-sans: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;--font-serif: "Source Serif 4", Georgia, serif;--font-mono: "SF Mono", "Fira Code", monospace;--space-1: .25rem;--space-2: .5rem;--space-3: .75rem;--space-4: 1rem;--space-5: 1.25rem;--space-6: 1.5rem;--space-8: 2rem;--space-10: 2.5rem;--space-12: 3rem;--space-16: 4rem;--radius-sm: .375rem;--radius-md: .5rem;--radius-lg: .75rem;--radius-xl: 1rem;--shadow-sm: 0 1px 2px rgba(0,0,0,.04);--shadow-md: 0 2px 8px rgba(0,0,0,.06);--shadow-lg: 0 4px 16px rgba(0,0,0,.08);--shadow-focus: 0 0 0 3px var(--color-accent-subtle);--transition-fast: .15s cubic-bezier(.4, 0, .2, 1);--transition-normal: .25s cubic-bezier(.4, 0, .2, 1);--transition-slow: .35s cubic-bezier(.4, 0, .2, 1)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:16px;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{font-family:var(--font-sans);color:var(--color-text-primary);background:var(--color-bg);line-height:1.6;min-height:100vh}#root{min-height:100vh;display:flex;flex-direction:column}h1,h2,h3,h4{font-weight:600;line-height:1.3;letter-spacing:-.01em}h1{font-size:1.75rem}h2{font-size:1.375rem}h3{font-size:1.125rem}h4{font-size:1rem}p{color:var(--color-text-secondary)}.app-layout{display:flex;flex-direction:column;min-height:100vh}.app-header{background:var(--color-surface);border-bottom:1px solid var(--color-border);padding:var(--space-4) var(--space-8);display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;z-index:100}.app-header__logo{display:flex;align-items:center;gap:var(--space-3)}.app-header__logo h1{font-size:1.25rem;font-weight:700;background:linear-gradient(135deg,var(--color-accent),#7C3AED);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.app-header__logo-icon{width:32px;height:32px;background:linear-gradient(135deg,var(--color-accent),#7C3AED);border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;color:#fff}.app-header__subtitle{font-size:.8rem;color:var(--color-text-muted);font-weight:400}.app-main{flex:1;padding:var(--space-8);max-width:960px;width:100%;margin:0 auto}.progress-bar{display:flex;align-items:center;justify-content:center;padding:var(--space-6) var(--space-8);background:var(--color-surface);border-bottom:1px solid var(--color-border)}.progress-bar__steps{display:flex;align-items:center;gap:0;max-width:720px;width:100%}.progress-step{display:flex;align-items:center;gap:var(--space-2);flex-shrink:0}.progress-step__circle{width:32px;height:32px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.8rem;font-weight:600;border:2px solid var(--color-border);color:var(--color-text-muted);background:var(--color-surface);transition:all var(--transition-normal)}.progress-step--active .progress-step__circle{border-color:var(--color-accent);background:var(--color-accent);color:#fff;box-shadow:0 0 0 4px var(--color-accent-subtle)}.progress-step--completed .progress-step__circle{border-color:var(--color-success);background:var(--color-success);color:#fff}.progress-step__label{font-size:.78rem;font-weight:500;color:var(--color-text-muted);transition:color var(--transition-normal);white-space:nowrap}.progress-step--active .progress-step__label{color:var(--color-accent);font-weight:600}.progress-step--completed .progress-step__label{color:var(--color-success)}.progress-step__connector{flex:1;height:2px;background:var(--color-border);margin:0 var(--space-2);min-width:24px;transition:background var(--transition-normal)}.progress-step__connector--completed{background:var(--color-success)}.card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:var(--space-8);box-shadow:var(--shadow-sm)}.card__header{margin-bottom:var(--space-6)}.card__header h2{margin-bottom:var(--space-2)}.card__header p{font-size:.9rem}.form-group{margin-bottom:var(--space-6)}.form-group label{display:block;font-size:.85rem;font-weight:600;color:var(--color-text-primary);margin-bottom:var(--space-2)}.form-group .hint{font-size:.78rem;color:var(--color-text-muted);margin-top:var(--space-1)}.input{width:100%;padding:var(--space-3) var(--space-4);border:1px solid var(--color-border);border-radius:var(--radius-md);font-size:.9rem;font-family:var(--font-sans);color:var(--color-text-primary);background:var(--color-surface);transition:border-color var(--transition-fast),box-shadow var(--transition-fast);outline:none}.input:focus{border-color:var(--color-accent);box-shadow:var(--shadow-focus)}.input::placeholder{color:var(--color-text-muted)}.input--error{border-color:var(--color-error)}.textarea{resize:vertical;min-height:100px;line-height:1.6}.select{appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236B6B67' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 12px center;padding-right:36px;cursor:pointer}.slider-group{display:flex;align-items:center;gap:var(--space-4)}.slider{flex:1;-webkit-appearance:none;height:6px;border-radius:3px;background:var(--color-border);outline:none;transition:background var(--transition-fast)}.slider::-webkit-slider-thumb{-webkit-appearance:none;width:20px;height:20px;border-radius:50%;background:var(--color-accent);cursor:pointer;box-shadow:var(--shadow-sm);transition:transform var(--transition-fast)}.slider::-webkit-slider-thumb:hover{transform:scale(1.15)}.slider-value{min-width:28px;text-align:center;font-weight:600;font-size:.9rem;color:var(--color-accent)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--space-2);padding:var(--space-3) var(--space-5);border-radius:var(--radius-md);font-family:var(--font-sans);font-size:.875rem;font-weight:600;cursor:pointer;border:1px solid transparent;transition:all var(--transition-fast);line-height:1;white-space:nowrap}.btn:disabled{opacity:.5;cursor:not-allowed}.btn--primary{background:var(--color-accent);color:#fff}.btn--primary:not(:disabled):hover{background:var(--color-accent-hover);box-shadow:var(--shadow-md);transform:translateY(-1px)}.btn--secondary{background:var(--color-surface);color:var(--color-text-primary);border-color:var(--color-border)}.btn--secondary:not(:disabled):hover{background:var(--color-bg);border-color:var(--color-border-focus)}.btn--ghost{background:transparent;color:var(--color-text-secondary)}.btn--ghost:not(:disabled):hover{background:var(--color-bg);color:var(--color-text-primary)}.btn--danger{background:var(--color-error);color:#fff}.btn--danger:not(:disabled):hover{background:#b91c1c}.btn--success{background:var(--color-success);color:#fff}.btn--lg{padding:var(--space-4) var(--space-8);font-size:.95rem}.btn-group{display:flex;align-items:center;gap:var(--space-3);margin-top:var(--space-8)}.btn-group--right{justify-content:flex-end}.btn-group--between{justify-content:space-between}.spinner{width:20px;height:20px;border:2px solid var(--color-border);border-top-color:var(--color-accent);border-radius:50%;animation:spin .6s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.loading-overlay{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:var(--space-4);padding:var(--space-12);color:var(--color-text-secondary);font-size:.9rem}.loading-overlay .spinner{width:32px;height:32px}.alert{padding:var(--space-4);border-radius:var(--radius-md);font-size:.85rem;display:flex;align-items:flex-start;gap:var(--space-3);margin-bottom:var(--space-4)}.alert--info{background:var(--color-accent-light);color:var(--color-accent);border:1px solid var(--color-accent-subtle)}.alert--success{background:var(--color-success-light);color:var(--color-success);border:1px solid #BBF7D0}.alert--warning{background:var(--color-warning-light);color:var(--color-warning);border:1px solid #FDE68A}.alert--error{background:var(--color-error-light);color:var(--color-error);border:1px solid #FECACA}.data-table{width:100%;border-collapse:collapse;font-size:.85rem}.data-table th{text-align:left;padding:var(--space-3) var(--space-4);font-weight:600;font-size:.78rem;text-transform:uppercase;letter-spacing:.05em;color:var(--color-text-muted);border-bottom:2px solid var(--color-border);background:var(--color-bg)}.data-table td{padding:var(--space-3) var(--space-4);border-bottom:1px solid var(--color-border);vertical-align:top}.data-table tbody tr:hover{background:var(--color-accent-light)}.topic-section{display:flex;align-items:flex-start;gap:var(--space-4);padding:var(--space-4);border:1px solid var(--color-border);border-radius:var(--radius-md);margin-bottom:var(--space-3);background:var(--color-surface);transition:border-color var(--transition-fast)}.topic-section:hover{border-color:var(--color-border-focus)}.topic-section__number{width:28px;height:28px;border-radius:50%;background:var(--color-accent-subtle);color:var(--color-accent);display:flex;align-items:center;justify-content:center;font-size:.78rem;font-weight:700;flex-shrink:0}.topic-section__content{flex:1}.topic-section__title{font-weight:600;font-size:.9rem;margin-bottom:var(--space-1)}.topic-section__time{font-size:.78rem;color:var(--color-text-muted);font-family:var(--font-mono)}.question-panel{border:1px solid var(--color-border);border-radius:var(--radius-lg);overflow:hidden;margin-bottom:var(--space-6)}.question-panel__header{padding:var(--space-4) var(--space-5);background:var(--color-bg);border-bottom:1px solid var(--color-border);display:flex;align-items:center;justify-content:space-between}.question-panel__header h3{display:flex;align-items:center;gap:var(--space-2)}.question-panel__body{padding:var(--space-5)}.question-card{border:1px solid var(--color-border);border-radius:var(--radius-md);padding:var(--space-5);margin-bottom:var(--space-4);transition:border-color var(--transition-fast)}.question-card:hover{border-color:var(--color-border-focus)}.question-card__type{font-size:.72rem;text-transform:uppercase;letter-spacing:.08em;font-weight:700;color:var(--color-accent);background:var(--color-accent-light);padding:var(--space-1) var(--space-2);border-radius:var(--radius-sm);display:inline-block;margin-bottom:var(--space-3)}.question-card__stem{font-weight:600;margin-bottom:var(--space-3);font-size:.9rem}.question-card__options{list-style:none;display:flex;flex-direction:column;gap:var(--space-2)}.question-card__option{display:flex;align-items:flex-start;gap:var(--space-2);font-size:.85rem;padding:var(--space-2) var(--space-3);border-radius:var(--radius-sm)}.question-card__option--correct{background:var(--color-success-light);color:var(--color-success);font-weight:500}.question-card__actions{display:flex;gap:var(--space-2);margin-top:var(--space-4);padding-top:var(--space-3);border-top:1px solid var(--color-border)}.checklist{list-style:none;display:flex;flex-direction:column;gap:var(--space-3)}.checklist__item{display:flex;align-items:center;gap:var(--space-3);font-size:.85rem;padding:var(--space-3);border-radius:var(--radius-sm);background:var(--color-success-light);color:var(--color-success);font-weight:500}.checklist__item--fail{background:var(--color-error-light);color:var(--color-error)}.video-info{display:flex;align-items:center;gap:var(--space-4);padding:var(--space-4);background:var(--color-accent-light);border:1px solid var(--color-accent-subtle);border-radius:var(--radius-md);margin-top:var(--space-4)}.video-info__title{font-weight:600;font-size:.9rem;color:var(--color-text-primary)}.video-info__duration{font-size:.8rem;color:var(--color-accent);font-family:var(--font-mono)}.export-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:var(--space-4);margin-bottom:var(--space-8)}.export-card{padding:var(--space-5);border:1px solid var(--color-border);border-radius:var(--radius-lg);text-align:center;transition:all var(--transition-fast);cursor:pointer}.export-card:hover{border-color:var(--color-accent);box-shadow:var(--shadow-md);transform:translateY(-2px)}.export-card__icon{width:48px;height:48px;margin:0 auto var(--space-3);background:var(--color-accent-light);border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;color:var(--color-accent)}.export-card__name{font-weight:600;font-size:.9rem;margin-bottom:var(--space-1)}.export-card__desc{font-size:.78rem;color:var(--color-text-muted)}.modal-backdrop{position:fixed;inset:0;background:#0000004d;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;align-items:center;justify-content:center;z-index:1000;animation:fadeIn .15s ease-out}.modal{background:var(--color-surface);border-radius:var(--radius-xl);padding:var(--space-8);max-width:420px;width:90%;box-shadow:var(--shadow-lg);animation:slideUp .2s ease-out}.modal h3{margin-bottom:var(--space-3)}.modal p{margin-bottom:var(--space-6);font-size:.9rem}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes slideUp{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.editable-field{padding:var(--space-1) var(--space-2);border:1px solid transparent;border-radius:var(--radius-sm);transition:all var(--transition-fast);cursor:text}.editable-field:hover{background:var(--color-bg);border-color:var(--color-border)}.editable-field:focus{background:var(--color-surface);border-color:var(--color-accent);box-shadow:var(--shadow-focus);outline:none}.toggle{position:relative;width:40px;height:22px;flex-shrink:0}.toggle input{opacity:0;width:0;height:0}.toggle__slider{position:absolute;inset:0;background:var(--color-border);border-radius:11px;cursor:pointer;transition:background var(--transition-fast)}.toggle__slider:before{content:"";position:absolute;width:16px;height:16px;border-radius:50%;background:#fff;left:3px;top:3px;transition:transform var(--transition-fast);box-shadow:var(--shadow-sm)}.toggle input:checked+.toggle__slider{background:var(--color-accent)}.toggle input:checked+.toggle__slider:before{transform:translate(18px)}.account-bar{display:flex;align-items:center;gap:var(--space-3);flex-shrink:0}.account-bar__email{font-size:.78rem;color:var(--color-text-muted);max-width:180px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.btn--sm{padding:var(--space-2) var(--space-3);font-size:.78rem}.credit-badge{display:inline-flex;align-items:center;gap:var(--space-2);padding:var(--space-2) var(--space-3);background:var(--color-accent-light);border:1px solid var(--color-accent-subtle);border-radius:999px;font-size:.78rem;color:var(--color-accent);font-weight:500;white-space:nowrap}.credit-badge strong{font-weight:700}.auth-modal{max-width:440px}.auth-modal__header{display:flex;align-items:flex-start;justify-content:space-between;gap:var(--space-4)}.auth-modal__header h3{margin-bottom:var(--space-1)}.auth-modal__subtitle{font-size:.85rem;color:var(--color-text-muted)}.auth-modal__close{flex-shrink:0;padding:var(--space-2);margin:calc(-1 * var(--space-2))}.auth-modal__form{margin-top:var(--space-6)}.auth-modal__form .form-group{margin-bottom:var(--space-4)}.auth-modal__toggle{display:flex;align-items:center;justify-content:center;gap:var(--space-2);margin-top:var(--space-5);padding-top:var(--space-4);border-top:1px solid var(--color-border);font-size:.82rem;color:var(--color-text-muted)}.topup-modal{max-width:560px}.topup-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:var(--space-3);margin-top:var(--space-6)}.topup-card{position:relative;display:flex;flex-direction:column;align-items:center;gap:var(--space-2);padding:var(--space-5) var(--space-3);border:1px solid var(--color-border);border-radius:var(--radius-lg);background:var(--color-surface);cursor:pointer;transition:all var(--transition-fast);text-align:center;font-family:var(--font-sans)}.topup-card:hover{border-color:var(--color-accent);box-shadow:var(--shadow-md);transform:translateY(-2px)}.topup-card--popular{border-color:var(--color-accent);background:var(--color-accent-light)}.topup-card--popular:hover{background:var(--color-accent-subtle)}.topup-card__badge{position:absolute;top:-8px;left:50%;transform:translate(-50%);display:inline-flex;align-items:center;gap:3px;padding:2px 8px;background:var(--color-accent);color:#fff;font-size:.65rem;font-weight:700;border-radius:999px;white-space:nowrap;text-transform:uppercase;letter-spacing:.04em}.topup-card__credits{display:flex;align-items:center;gap:var(--space-2);font-size:1.5rem;font-weight:700;color:var(--color-accent)}.topup-card__label{font-size:.78rem;font-weight:600;color:var(--color-text-primary)}.topup-card__price{font-size:1.1rem;font-weight:700;color:var(--color-text-primary)}.topup-card__unit{font-size:.72rem;color:var(--color-text-muted)}.export-card--locked{opacity:.7;border-style:dashed}.export-card--locked .export-card__icon{background:var(--color-bg);color:var(--color-text-muted)}.export-card--locked:hover{border-color:var(--color-accent);opacity:1}.export-card__cost{display:inline-flex;align-items:center;gap:4px;margin-top:var(--space-2);font-size:.72rem;font-weight:600;color:var(--color-accent);background:var(--color-accent-light);padding:2px 8px;border-radius:999px}.preview-card{border-color:var(--color-accent-subtle);background:linear-gradient(180deg,var(--color-accent-light) 0%,var(--color-surface) 100%)}.topup-selector{margin-top:var(--space-6);display:flex;flex-direction:column;gap:var(--space-4)}.topup-selector__label{font-size:.85rem;font-weight:600;color:var(--color-text-muted);text-transform:uppercase;letter-spacing:.05em}.topup-selector__controls{display:flex;align-items:center;gap:var(--space-4)}.topup-selector__slider{flex:1;-webkit-appearance:none;appearance:none;height:6px;background:var(--color-border);border-radius:999px;outline:none}.topup-selector__slider::-webkit-slider-thumb{-webkit-appearance:none;appearance:none;width:20px;height:20px;border-radius:50%;background:var(--color-accent);cursor:pointer;border:2px solid var(--color-surface);box-shadow:0 2px 4px #0000001a;transition:transform .15s ease}.topup-selector__slider::-webkit-slider-thumb:hover{transform:scale(1.1)}.topup-selector__input-wrapper{position:relative;display:flex;align-items:center}.topup-selector__input{width:90px;padding:var(--space-2) var(--space-3) var(--space-2) 36px;border:1px solid var(--color-border);border-radius:var(--radius-md);font-family:inherit;font-size:1rem;font-weight:600;color:var(--color-text);background:var(--color-bg);text-align:right}.topup-selector__input:focus{outline:none;border-color:var(--color-accent);box-shadow:0 0 0 3px var(--color-accent-light)}.topup-selector__icon{position:absolute;left:12px;color:var(--color-accent)}.topup-selector__nudge{display:flex;align-items:center;gap:6px;font-size:.75rem;color:var(--color-accent);background:var(--color-accent-light);padding:var(--space-2) var(--space-3);border-radius:var(--radius-sm);animation:pulse 2s infinite}@keyframes pulse{0%{opacity:.8}50%{opacity:1}to{opacity:.8}}.topup-summary{margin-top:var(--space-5);padding-top:var(--space-4);border-top:1px solid var(--color-border);display:flex;flex-direction:column;gap:var(--space-2)}.topup-summary__row{display:flex;justify-content:space-between;align-items:center;font-size:.9rem;color:var(--color-text-muted)}.topup-summary__total{font-size:1.25rem;font-weight:700;color:var(--color-text);margin-top:var(--space-2)}@media(max-width:768px){.app-main{padding:var(--space-4)}.card{padding:var(--space-5)}.progress-step__label{display:none}.btn-group{flex-wrap:wrap}.account-bar{gap:var(--space-2)}.account-bar__email{display:none}.topup-grid{grid-template-columns:repeat(2,1fr)}}.auth-modal__divider{display:flex;align-items:center;text-align:center;margin:var(--space-4) 0;color:var(--color-text-muted);font-size:.8rem;text-transform:uppercase;letter-spacing:.05em}.auth-modal__divider:before,.auth-modal__divider:after{content:"";flex:1;border-bottom:1px solid var(--color-border)}.auth-modal__divider:not(:empty):before{margin-right:.5em}.auth-modal__divider:not(:empty):after{margin-left:.5em}.google-auth-btn{background:#fff!important;border:1px solid var(--color-border)!important;color:var(--color-text-primary)!important;transition:all var(--transition-fast)!important}.google-auth-btn:hover{background:var(--color-bg)!important;border-color:var(--color-border-focus)!important}