:root{--color-primary: hsl(30, 90%, 55%);--color-primary-hover: hsl(30, 90%, 45%);--color-secondary: hsl(200, 70%, 50%);--color-secondary-hover: hsl(200, 70%, 40%);--color-text: hsl(210, 10%, 20%);--color-text-muted: hsl(210, 10%, 45%);--color-text-light: hsl(0, 0%, 100%);--color-bg: hsl(210, 20%, 98%);--color-surface: hsl(0, 0%, 100%);--color-border: hsl(210, 15%, 90%);--color-border-strong: hsl(210, 15%, 80%);--color-shadow: rgba(0, 0, 0, .08);--color-shadow-medium: rgba(0, 0, 0, .12);--color-success: hsl(140, 60%, 45%);--color-success-bg: hsl(140, 60%, 95%);--color-error: hsl(350, 70%, 55%);--color-error-bg: hsl(350, 70%, 95%);--color-warning: hsl(45, 95%, 55%);--color-warning-bg: hsl(45, 95%, 95%);--space-xs: .5rem;--space-sm: .75rem;--space-md: 1rem;--space-lg: 1.5rem;--space-xl: 2rem;--space-xxl: 3rem;--font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-size-sm: .875rem;--font-size-base: 1rem;--font-size-lg: 1.125rem;--font-size-xl: 1.5rem;--font-size-xxl: 2rem;--radius-sm: .25rem;--radius-md: .5rem;--radius-lg: .75rem;--sidebar-width: 280px;--bottom-nav-height: 64px}@media (prefers-color-scheme: dark){:root:not([data-theme=light]){--color-primary: hsl(30, 85%, 60%);--color-primary-hover: hsl(30, 85%, 50%);--color-secondary: hsl(200, 65%, 55%);--color-secondary-hover: hsl(200, 65%, 45%);--color-text: hsl(210, 15%, 90%);--color-text-muted: hsl(210, 10%, 65%);--color-text-light: hsl(0, 0%, 100%);--color-bg: hsl(220, 20%, 12%);--color-surface: hsl(220, 18%, 18%);--color-border: hsl(220, 15%, 25%);--color-border-strong: hsl(220, 15%, 35%);--color-shadow: rgba(0, 0, 0, .3);--color-shadow-medium: rgba(0, 0, 0, .4);--color-success: hsl(140, 55%, 50%);--color-success-bg: hsl(140, 40%, 15%);--color-error: hsl(350, 65%, 55%);--color-error-bg: hsl(350, 50%, 15%);--color-warning: hsl(45, 90%, 55%);--color-warning-bg: hsl(45, 60%, 15%)}}:root[data-theme=dark]{--color-primary: hsl(30, 85%, 60%);--color-primary-hover: hsl(30, 85%, 50%);--color-secondary: hsl(200, 65%, 55%);--color-secondary-hover: hsl(200, 65%, 45%);--color-text: hsl(210, 15%, 90%);--color-text-muted: hsl(210, 10%, 65%);--color-text-light: hsl(0, 0%, 100%);--color-bg: hsl(220, 20%, 12%);--color-surface: hsl(220, 18%, 18%);--color-border: hsl(220, 15%, 25%);--color-border-strong: hsl(220, 15%, 35%);--color-shadow: rgba(0, 0, 0, .3);--color-shadow-medium: rgba(0, 0, 0, .4);--color-success: hsl(140, 55%, 50%);--color-success-bg: hsl(140, 40%, 15%);--color-error: hsl(350, 65%, 55%);--color-error-bg: hsl(350, 50%, 15%);--color-warning: hsl(45, 90%, 55%);--color-warning-bg: hsl(45, 60%, 15%)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html,body{height:100%;font-family:var(--font-sans);font-size:var(--font-size-base);line-height:1.6;color:var(--color-text);background-color:var(--color-bg);-webkit-font-smoothing:antialiased}a{color:var(--color-primary);text-decoration:none}a:hover{text-decoration:underline}ul{list-style:none}h1,h2,h3,h4{line-height:1.3;font-weight:600}h1{font-size:var(--font-size-xxl)}h2{font-size:var(--font-size-xl)}h3{font-size:var(--font-size-lg)}h4{font-size:var(--font-size-base)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--space-xs);padding:var(--space-sm) var(--space-md);font-family:var(--font-sans);font-size:var(--font-size-base);font-weight:500;border:none;border-radius:var(--radius-md);cursor:pointer;min-height:44px;min-width:44px;transition:all .2s ease}.btn-primary{background:var(--color-primary);color:var(--color-text-light)}.btn-primary:hover{background:var(--color-primary-hover);transform:translateY(-1px);box-shadow:0 4px 12px var(--color-shadow-medium)}.btn-secondary{background:var(--color-secondary);color:var(--color-text-light)}.btn-secondary:hover{background:var(--color-secondary-hover)}.btn-ghost{background:transparent;color:var(--color-text);border:1px solid var(--color-border)}.btn-ghost:hover{background:var(--color-surface);border-color:var(--color-border-strong)}input,textarea,select{width:100%;padding:var(--space-sm) var(--space-md);font-family:var(--font-sans);font-size:var(--font-size-base);color:var(--color-text);background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);min-height:44px;transition:border-color .2s ease,box-shadow .2s ease}input:focus,textarea:focus,select:focus{outline:none;border-color:var(--color-primary);box-shadow:0 0 0 3px #f48c2533}.card{background:var(--color-surface);border-radius:var(--radius-lg);box-shadow:0 2px 8px var(--color-shadow);transition:transform .2s ease,box-shadow .2s ease}.card:hover{transform:translateY(-2px);box-shadow:0 4px 16px var(--color-shadow-medium)}.alert{padding:var(--space-md);border-radius:var(--radius-md);font-weight:500}.alert-success{background:var(--color-success-bg);color:var(--color-success)}.alert-error{background:var(--color-error-bg);color:var(--color-error)}.alert-warning{background:var(--color-warning-bg);color:#ae8404}.loading{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--space-xl);gap:var(--space-md)}.spinner{width:32px;height:32px;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)}}.grid{display:grid;gap:var(--space-md)}.grid-2{grid-template-columns:repeat(2,1fr)}.grid-3{grid-template-columns:repeat(3,1fr)}@media (max-width: 768px){.grid-2,.grid-3{grid-template-columns:1fr}}.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}.skip-link.svelte-1f9ss1g.svelte-1f9ss1g{position:absolute;top:-100px;left:50%;transform:translate(-50%);background:var(--color-primary);color:#fff;padding:var(--space-sm) var(--space-md);border-radius:var(--radius-md);z-index:9999;text-decoration:none;font-weight:600;transition:top .2s}.skip-link.svelte-1f9ss1g.svelte-1f9ss1g:focus{top:var(--space-sm);outline:2px solid var(--color-primary);outline-offset:2px}.app.svelte-1f9ss1g.svelte-1f9ss1g{display:flex;min-height:100vh}.sidebar.svelte-1f9ss1g.svelte-1f9ss1g{--sidebar-bg:hsl(220, 25%, 18%);--sidebar-bg-dark:hsl(220, 30%, 10%);--sidebar-text:hsl(210, 20%, 90%);--sidebar-text-muted:hsl(210, 15%, 70%);--sidebar-border:hsl(220, 20%, 28%);width:280px;background:var(--sidebar-bg);color:var(--sidebar-text);display:flex;flex-direction:column;flex-shrink:0;height:100vh;overflow:hidden}.sidebar-header.svelte-1f9ss1g.svelte-1f9ss1g{padding:var(--space-md);background:var(--sidebar-bg-dark);border-bottom:1px solid var(--sidebar-border)}.sidebar-header.svelte-1f9ss1g h1.svelte-1f9ss1g{font-size:1.1rem;margin:0 0 var(--space-xs) 0;color:var(--color-primary)}.sidebar-header.svelte-1f9ss1g p.svelte-1f9ss1g{font-size:.8rem;color:var(--sidebar-text-muted);margin:0}.grade-picker.svelte-1f9ss1g.svelte-1f9ss1g{display:flex;align-items:center;gap:var(--space-sm);margin-top:var(--space-md);padding:var(--space-sm);background:#ffffff0d;border:1px solid var(--sidebar-border);border-radius:var(--radius-md)}.grade-picker.svelte-1f9ss1g label.svelte-1f9ss1g{font-size:.8rem;color:var(--sidebar-text-muted)}.grade-picker.svelte-1f9ss1g select.svelte-1f9ss1g{flex:1;padding:var(--space-xs) var(--space-sm);background:var(--sidebar-bg-dark);color:var(--sidebar-text);border:1px solid var(--sidebar-border);border-radius:var(--radius-sm);min-height:36px}.nav-links.svelte-1f9ss1g.svelte-1f9ss1g{margin-top:var(--space-md)}.nav-link.svelte-1f9ss1g.svelte-1f9ss1g{display:block;color:var(--sidebar-text-muted);text-decoration:none;font-size:.85rem}.nav-link.svelte-1f9ss1g.svelte-1f9ss1g:hover{color:var(--sidebar-text);text-decoration:underline}.chapters.svelte-1f9ss1g.svelte-1f9ss1g{flex:1;overflow-y:auto}.loading-small.svelte-1f9ss1g.svelte-1f9ss1g{padding:var(--space-md);font-size:.85rem;color:var(--sidebar-text-muted)}.chapter.svelte-1f9ss1g.svelte-1f9ss1g{border-bottom:1px solid var(--sidebar-border)}.chapter-title.svelte-1f9ss1g.svelte-1f9ss1g{width:100%;display:flex;justify-content:space-between;align-items:center;padding:var(--space-sm) var(--space-md);background:none;border:none;color:var(--sidebar-text);font-size:.9rem;cursor:pointer;text-align:left;transition:background .15s}.chapter-title.svelte-1f9ss1g.svelte-1f9ss1g:hover{background:var(--sidebar-border)}.arrow.svelte-1f9ss1g.svelte-1f9ss1g{font-size:.6rem;opacity:.8;transition:transform .2s}.chapter.open.svelte-1f9ss1g .arrow.svelte-1f9ss1g{transform:rotate(90deg)}.chapter-pages.svelte-1f9ss1g.svelte-1f9ss1g{background:var(--sidebar-bg-dark)}.page-link.svelte-1f9ss1g.svelte-1f9ss1g{width:100%;display:flex;align-items:center;gap:var(--space-xs);padding:var(--space-sm) var(--space-md) var(--space-sm) var(--space-lg);background:none;border:none;border-left:3px solid transparent;color:var(--sidebar-text-muted);font-size:.85rem;cursor:pointer;text-align:left;transition:all .15s}.page-link.svelte-1f9ss1g.svelte-1f9ss1g:hover{background:var(--sidebar-bg);color:var(--sidebar-text);border-left-color:var(--color-primary)}.page-link.svelte-1f9ss1g.svelte-1f9ss1g:disabled{opacity:.6;cursor:wait}.loading-dot.svelte-1f9ss1g.svelte-1f9ss1g{width:6px;height:6px;background:var(--color-primary);border-radius:50%;animation:svelte-1f9ss1g-pulse 1s infinite}@keyframes svelte-1f9ss1g-pulse{50%{opacity:.3}}.sidebar-footer.svelte-1f9ss1g.svelte-1f9ss1g{padding:var(--space-md);border-top:1px solid var(--sidebar-border);background:var(--sidebar-bg-dark)}.user-info.svelte-1f9ss1g.svelte-1f9ss1g{font-size:.85rem;margin-bottom:var(--space-sm);color:var(--sidebar-text-muted)}.btn-logout.svelte-1f9ss1g.svelte-1f9ss1g{width:100%;padding:var(--space-sm);background:var(--sidebar-border);border:1px solid var(--sidebar-text-muted);border-radius:var(--radius-md);color:var(--sidebar-text);font-size:.85rem;cursor:pointer;transition:all .15s}.btn-logout.svelte-1f9ss1g.svelte-1f9ss1g:hover{background:var(--sidebar-text-muted);color:var(--sidebar-bg-dark)}.sidebar-branding.svelte-1f9ss1g.svelte-1f9ss1g{padding:var(--space-sm) var(--space-md);font-size:.7rem;color:var(--sidebar-text-muted);text-align:center;border-top:1px solid var(--sidebar-border)}.branding-row.svelte-1f9ss1g.svelte-1f9ss1g{display:flex;justify-content:center;align-items:center;gap:var(--space-md);margin-bottom:var(--space-xs)}.branding-row.svelte-1f9ss1g a.svelte-1f9ss1g{color:var(--sidebar-text-muted);text-decoration:none;font-size:.75rem}.branding-row.svelte-1f9ss1g a.svelte-1f9ss1g:hover{color:var(--sidebar-text);text-decoration:underline}.theme-toggle.svelte-1f9ss1g.svelte-1f9ss1g{background:none;border:none;cursor:pointer;font-size:1rem;padding:0;line-height:1;opacity:.8;transition:opacity .15s}.theme-toggle.svelte-1f9ss1g.svelte-1f9ss1g:hover{opacity:1}.main-content.svelte-1f9ss1g.svelte-1f9ss1g{flex:1;background:var(--color-bg);overflow-y:auto}.welcome.svelte-1f9ss1g.svelte-1f9ss1g{display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:var(--space-xxl);min-height:60vh}.welcome.svelte-1f9ss1g h2.svelte-1f9ss1g{font-size:1.5rem;margin-bottom:var(--space-sm);color:var(--color-text)}.welcome.svelte-1f9ss1g p.svelte-1f9ss1g{color:var(--color-text-muted);max-width:400px}.welcome.svelte-1f9ss1g .hint.svelte-1f9ss1g{margin-top:var(--space-lg);font-size:.9rem}@media (max-width: 768px){.app.svelte-1f9ss1g.svelte-1f9ss1g{flex-direction:column}.sidebar.svelte-1f9ss1g.svelte-1f9ss1g{width:100%;height:auto;max-height:40vh;overflow-y:auto}.sidebar-header.svelte-1f9ss1g.svelte-1f9ss1g{padding:var(--space-sm)}.sidebar-header.svelte-1f9ss1g h1.svelte-1f9ss1g{font-size:1rem}.grade-picker.svelte-1f9ss1g.svelte-1f9ss1g{margin-top:var(--space-sm)}.chapters.svelte-1f9ss1g.svelte-1f9ss1g{max-height:25vh}.sidebar-footer.svelte-1f9ss1g.svelte-1f9ss1g{padding:var(--space-sm)}.main-content.svelte-1f9ss1g.svelte-1f9ss1g{flex:1;min-height:60vh}.welcome.svelte-1f9ss1g.svelte-1f9ss1g{padding:var(--space-lg);min-height:40vh}}