:root{--color-background: #ffffff;--color-surface: #f8fafc;--color-border: #e2e8f0;--color-primary: #3b82f6;--color-secondary: #64748b;--color-success: #10b981;--color-text-primary: #0f172a;--color-text-secondary: #475569;--color-text-muted: #94a3b8;--color-sidebar-bg: #1e293b;--color-sidebar-border: #334155;--color-sidebar-text: #ffffff;--color-sidebar-text-muted: #94a3b8;--color-sidebar-hover: #334155;--color-input-border: #d1d5db;--color-input-placeholder: #9ca3af;--color-input-focus: #3b82f6;--spacing-xs: 4px;--spacing-sm: 8px;--spacing-md: 16px;--spacing-lg: 24px;--spacing-xl: 32px;--spacing-2xl: 48px;--font-size-heading: 1.125rem;--font-size-body: .875rem;--font-size-small: .75rem;--font-size-button: .875rem;--font-weight-normal: 400;--font-weight-medium: 500;--font-weight-semibold: 600;--line-height-heading: 1.5;--line-height-body: 1.5;--line-height-small: 1.4;--line-height-button: 1.2;--breakpoint-mobile: 320px;--breakpoint-tablet: 768px;--breakpoint-desktop: 1024px;--breakpoint-wide: 1280px;--duration-fast: .15s;--duration-normal: .3s;--duration-slow: .5s;--easing-ease: cubic-bezier(.4, 0, .2, 1);--easing-ease-in: cubic-bezier(.4, 0, 1, 1);--easing-ease-out: cubic-bezier(0, 0, .2, 1);--header-height-desktop: 64px;--header-height-mobile: 56px;--sidebar-width-expanded: 256px;--sidebar-width-collapsed: 64px;--message-container-max-width: 768px;--message-bubble-border-radius: 18px;--message-bubble-border-radius-small: 4px;--input-height: 40px;--input-border-radius: 12px;--button-border-radius: 8px;--avatar-size: 32px;--icon-size-small: 16px;--icon-size-medium: 20px;--icon-size-large: 24px;--shadow-sm: 0 1px 2px 0 rgb(0 0 0 / .05);--shadow-md: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);--shadow-lg: 0 10px 15px -3px rgb(0 0 0 / .1), 0 4px 6px -4px rgb(0 0 0 / .1);--focus-ring: 0 0 0 2px var(--color-primary);--focus-ring-offset: 0 0 0 2px var(--color-background), 0 0 0 4px var(--color-primary)}.text-heading{font-size:var(--font-size-heading);font-weight:var(--font-weight-semibold);line-height:var(--line-height-heading);color:var(--color-text-primary)}.text-body{font-size:var(--font-size-body);font-weight:var(--font-weight-normal);line-height:var(--line-height-body);color:var(--color-text-primary)}.text-small{font-size:var(--font-size-small);font-weight:var(--font-weight-normal);line-height:var(--line-height-small);color:var(--color-text-secondary)}.text-button{font-size:var(--font-size-button);font-weight:var(--font-weight-medium);line-height:var(--line-height-button)}.spacing-xs{margin:var(--spacing-xs)}.spacing-sm{margin:var(--spacing-sm)}.spacing-md{margin:var(--spacing-md)}.spacing-lg{margin:var(--spacing-lg)}.spacing-xl{margin:var(--spacing-xl)}.spacing-2xl{margin:var(--spacing-2xl)}.transition-fast{transition-duration:var(--duration-fast);transition-timing-function:var(--easing-ease)}.transition-normal{transition-duration:var(--duration-normal);transition-timing-function:var(--easing-ease)}.transition-slow{transition-duration:var(--duration-slow);transition-timing-function:var(--easing-ease)}.focus-ring:focus{outline:none;box-shadow:var(--focus-ring)}.focus-ring-offset:focus{outline:none;box-shadow:var(--focus-ring-offset)}@keyframes fade-in{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.animate-fade-in{animation:fade-in var(--duration-normal) var(--easing-ease-out) forwards}@media(max-width:767px){:root{--header-height: var(--header-height-mobile)}}@media(min-width:768px){:root{--header-height: var(--header-height-desktop)}}