/* ==========================================================================
   HEALTHKIT - PREMIUM HEALTH & WELLNESS TRACKING PLATFORM
   Complete Design Token System + Component Styles
   ========================================================================== */

/* ==========================================================================
   CSS CUSTOM PROPERTIES (Design Tokens)
   ========================================================================== */

:root {
    /* ===== BRAND COLORS ===== */

    /* Health Green - Primary */
    --health-50: #f0fdf4;
    --health-100: #dcfce7;
    --health-200: #bbf7d0;
    --health-300: #86efac;
    --health-400: #4ade80;
    --health-500: #22c55e;
    --health-600: #16a34a;
    --health-700: #15803d;
    --health-800: #166534;
    --health-900: #14532d;
    --health-950: #052e16;

    /* Heart Red - Accent */
    --heart-50: #fef2f2;
    --heart-100: #fee2e2;
    --heart-200: #fecaca;
    --heart-300: #fca5a5;
    --heart-400: #f87171;
    --heart-500: #ef4444;
    --heart-600: #dc2626;
    --heart-700: #b91c1c;
    --heart-800: #991b1b;
    --heart-900: #7f1d1d;

    /* Calm Blue - Secondary */
    --calm-50: #eff6ff;
    --calm-100: #dbeafe;
    --calm-200: #bfdbfe;
    --calm-300: #93c5fd;
    --calm-400: #60a5fa;
    --calm-500: #3b82f6;
    --calm-600: #2563eb;
    --calm-700: #1d4ed8;
    --calm-800: #1e40af;
    --calm-900: #1e3a8a;

    /* Sleep Purple - Tertiary */
    --sleep-50: #faf5ff;
    --sleep-100: #f3e8ff;
    --sleep-200: #e9d5ff;
    --sleep-300: #d8b4fe;
    --sleep-400: #a78bfa;
    --sleep-500: #8b5cf6;
    --sleep-600: #7c3aed;
    --sleep-700: #6d28d9;
    --sleep-800: #5b21b6;
    --sleep-900: #4c1d95;

    /* ===== NEUTRAL SCALE ===== */
    --neutral-50: #fafafa;
    --neutral-100: #f5f5f5;
    --neutral-200: #e5e5e5;
    --neutral-300: #d4d4d4;
    --neutral-400: #a3a3a3;
    --neutral-500: #737373;
    --neutral-600: #525252;
    --neutral-700: #404040;
    --neutral-800: #262626;
    --neutral-900: #171717;
    --neutral-950: #0a0a0a;

    /* ===== SEMANTIC COLORS ===== */
    --success: #22c55e;
    --success-light: #dcfce7;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --error: #ef4444;
    --error-light: #fee2e2;
    --info: #3b82f6;
    --info-light: #dbeafe;

    /* ===== TYPOGRAPHY SCALE ===== */
    --text-xs: 0.75rem;      /* 12px */
    --text-sm: 0.875rem;     /* 14px */
    --text-base: 1rem;       /* 16px */
    --text-lg: 1.125rem;     /* 18px */
    --text-xl: 1.25rem;      /* 20px */
    --text-2xl: 1.5rem;      /* 24px */
    --text-3xl: 1.875rem;    /* 30px */
    --text-4xl: 2.25rem;     /* 36px */
    --text-5xl: 3rem;        /* 48px */
    --text-6xl: 3.75rem;     /* 60px */
    --text-7xl: 4.5rem;      /* 72px */

    /* Responsive Typography */
    --text-hero: clamp(2.5rem, 6vw + 1rem, 4.5rem);
    --text-display: clamp(2rem, 4vw + 1rem, 3.75rem);
    --text-h1: clamp(1.875rem, 3vw + 0.5rem, 3rem);
    --text-h2: clamp(1.5rem, 2.5vw + 0.5rem, 2.25rem);
    --text-h3: clamp(1.25rem, 2vw + 0.25rem, 1.5rem);
    --text-h4: clamp(1.125rem, 1.5vw + 0.25rem, 1.25rem);

    /* Font Weights */
    --font-light: 300;
    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;
    --font-extrabold: 800;
    --font-black: 900;

    /* Line Heights */
    --leading-none: 1;
    --leading-tight: 1.1;
    --leading-snug: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;
    --leading-loose: 2;

    /* Letter Spacing */
    --tracking-tighter: -0.05em;
    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
    --tracking-wider: 0.05em;
    --tracking-widest: 0.1em;

    /* ===== SPACING SCALE (8px base) ===== */
    --space-0: 0;
    --space-px: 1px;
    --space-0-5: 0.125rem;   /* 2px */
    --space-1: 0.25rem;      /* 4px */
    --space-1-5: 0.375rem;   /* 6px */
    --space-2: 0.5rem;       /* 8px */
    --space-2-5: 0.625rem;   /* 10px */
    --space-3: 0.75rem;      /* 12px */
    --space-3-5: 0.875rem;   /* 14px */
    --space-4: 1rem;         /* 16px */
    --space-5: 1.25rem;      /* 20px */
    --space-6: 1.5rem;       /* 24px */
    --space-7: 1.75rem;      /* 28px */
    --space-8: 2rem;         /* 32px */
    --space-9: 2.25rem;      /* 36px */
    --space-10: 2.5rem;      /* 40px */
    --space-11: 2.75rem;     /* 44px */
    --space-12: 3rem;        /* 48px */
    --space-14: 3.5rem;      /* 56px */
    --space-16: 4rem;        /* 64px */
    --space-20: 5rem;        /* 80px */
    --space-24: 6rem;        /* 96px */
    --space-28: 7rem;        /* 112px */
    --space-32: 8rem;        /* 128px */
    --space-36: 9rem;        /* 144px */
    --space-40: 10rem;       /* 160px */
    --space-44: 11rem;       /* 176px */
    --space-48: 12rem;       /* 192px */
    --space-52: 13rem;       /* 208px */
    --space-56: 14rem;       /* 224px */
    --space-60: 15rem;       /* 240px */
    --space-64: 16rem;       /* 256px */
    --space-72: 18rem;       /* 288px */
    --space-80: 20rem;       /* 320px */
    --space-96: 24rem;       /* 384px */

    /* ===== BORDER RADIUS ===== */
    --radius-none: 0;
    --radius-sm: 0.125rem;   /* 2px */
    --radius-default: 0.25rem; /* 4px */
    --radius-md: 0.375rem;   /* 6px */
    --radius-lg: 0.5rem;     /* 8px */
    --radius-xl: 0.75rem;    /* 12px */
    --radius-2xl: 1rem;      /* 16px */
    --radius-3xl: 1.5rem;    /* 24px */
    --radius-4xl: 2rem;      /* 32px */
    --radius-full: 9999px;

    /* ===== SHADOWS ===== */
    --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);
    --shadow-inner: inset 0 2px 4px 0 rgb(0 0 0 / 0.05);

    /* Colored Shadows */
    --shadow-health: 0 10px 40px -10px rgba(34, 197, 94, 0.35);
    --shadow-health-lg: 0 20px 60px -15px rgba(34, 197, 94, 0.4);
    --shadow-heart: 0 10px 40px -10px rgba(239, 68, 68, 0.35);
    --shadow-calm: 0 10px 40px -10px rgba(59, 130, 246, 0.35);
    --shadow-sleep: 0 10px 40px -10px rgba(139, 92, 246, 0.35);

    /* Glow Effects */
    --glow-health: 0 0 60px rgba(34, 197, 94, 0.3);
    --glow-heart: 0 0 60px rgba(239, 68, 68, 0.3);
    --glow-calm: 0 0 60px rgba(59, 130, 246, 0.3);
    --glow-sleep: 0 0 60px rgba(139, 92, 246, 0.3);

    /* ===== GRADIENTS ===== */
    --gradient-health: linear-gradient(135deg, var(--health-400) 0%, var(--health-600) 100%);
    --gradient-heart: linear-gradient(135deg, var(--heart-400) 0%, var(--heart-600) 100%);
    --gradient-calm: linear-gradient(135deg, var(--calm-400) 0%, var(--calm-600) 100%);
    --gradient-sleep: linear-gradient(135deg, var(--sleep-400) 0%, var(--sleep-600) 100%);
    --gradient-brand: linear-gradient(135deg, var(--health-500) 0%, var(--calm-500) 100%);
    --gradient-animated: linear-gradient(270deg, var(--health-500), var(--calm-500), var(--health-500));

    /* Mesh Gradients */
    --gradient-mesh:
        radial-gradient(at 40% 20%, rgba(34, 197, 94, 0.15) 0px, transparent 50%),
        radial-gradient(at 80% 0%, rgba(59, 130, 246, 0.15) 0px, transparent 50%),
        radial-gradient(at 0% 50%, rgba(139, 92, 246, 0.1) 0px, transparent 50%);

    /* ===== TRANSITIONS ===== */
    --ease-in: cubic-bezier(0.4, 0, 1, 1);
    --ease-out: cubic-bezier(0, 0, 0.2, 1);
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-smooth: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

    --duration-75: 75ms;
    --duration-100: 100ms;
    --duration-150: 150ms;
    --duration-200: 200ms;
    --duration-300: 300ms;
    --duration-500: 500ms;
    --duration-700: 700ms;
    --duration-1000: 1000ms;

    --transition-fast: 150ms var(--ease-in-out);
    --transition-base: 200ms var(--ease-in-out);
    --transition-slow: 300ms var(--ease-in-out);
    --transition-smooth: 800ms var(--ease-smooth);

    /* ===== Z-INDEX SCALE ===== */
    --z-negative: -1;
    --z-0: 0;
    --z-10: 10;
    --z-20: 20;
    --z-30: 30;
    --z-40: 40;
    --z-50: 50;
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;

    /* ===== GLASSMORPHISM ===== */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-bg-dark: rgba(10, 10, 10, 0.7);
    --glass-border: rgba(255, 255, 255, 0.2);
    --glass-border-dark: rgba(255, 255, 255, 0.1);
    --glass-blur: 20px;
}

/* Dark Mode */
[data-theme="dark"] {
    --color-text: #F1F5F9;
    --color-text-muted: #94A3B8;
    --color-background: #0a0a0a;
    --color-surface: #171717;
    --color-border: #262626;
    --color-card: #171717;
}
[data-theme="dark"] body { background: var(--color-background); color: var(--color-text); }
[data-theme="dark"] .bg-white { background: var(--color-card) !important; }
[data-theme="dark"] .bg-gray-50 { background: var(--color-surface) !important; }
[data-theme="dark"] .bg-gray-100 { background: #262626 !important; }
[data-theme="dark"] .text-gray-900 { color: var(--color-text) !important; }
[data-theme="dark"] .text-gray-700 { color: #CBD5E1 !important; }
[data-theme="dark"] .text-gray-600 { color: var(--color-text-muted) !important; }
[data-theme="dark"] .border-gray-200 { border-color: var(--color-border) !important; }
[data-theme="dark"] nav { background: rgba(10, 10, 10, 0.9) !important; }
[data-theme="dark"] footer { background: #0a0a0a !important; }
[data-theme="dark"] input, [data-theme="dark"] textarea { background: var(--color-surface) !important; color: var(--color-text) !important; }
[data-theme="dark"] .card { background: var(--color-card) !important; }
.nav-link { padding: 0.5rem 1rem; font-weight: 500; color: #64748B; }
.nav-link:hover { color: #1E293B; }
[data-theme="dark"] .nav-link { color: #94A3B8; }
[data-theme="dark"] .nav-link:hover { color: #F1F5F9; }

/* ===== DARK MODE OVERRIDES ===== */
.dark {
    --glass-bg: rgba(10, 10, 10, 0.8);
    --glass-border: rgba(255, 255, 255, 0.1);
}

/* ==========================================================================
   RESET & BASE STYLES
   ========================================================================== */

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--neutral-900);
    background-color: white;
    transition: background-color var(--transition-base), color var(--transition-base);
}

.dark body {
    color: white;
    background-color: var(--neutral-950);
}

/* ==========================================================================
   TYPOGRAPHY
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-bold);
    line-height: var(--leading-tight);
    letter-spacing: var(--tracking-tight);
    color: var(--neutral-900);
}

.dark h1, .dark h2, .dark h3, .dark h4, .dark h5, .dark h6 {
    color: white;
}

/* ==========================================================================

/* ==========================================================================
   NAVIGATION
   ========================================================================== */

.nav-blur {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.dark .nav-blur {
    background: rgba(10, 10, 10, 0.8);
}

.nav-link {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-neutral-600);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-neutral-900);
    background: var(--color-neutral-100);
}

.dark .nav-link {
    color: var(--color-neutral-400);
}

.dark .nav-link:hover {
    color: var(--color-white);
    background: var(--color-neutral-800);
}

/* Dropdown */
.nav-dropdown {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    min-width: 400px;
    background: var(--color-white);
    border: 1px solid var(--color-neutral-200);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
    z-index: 100;
}

.dark .nav-dropdown {
    background: var(--color-neutral-900);
    border-color: var(--color-neutral-700);
}

.group:hover .nav-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    border-radius: var(--radius-lg);
    transition: background var(--transition-fast);
}

.dropdown-item:hover {
    background: var(--color-neutral-50);
}

.dark .dropdown-item:hover {
    background: var(--color-neutral-800);
}

.dropdown-icon {
    width: 2.5rem;
    height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-lg);
    flex-shrink: 0;
}

/* Mobile Menu Button */
.hamburger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-lg);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.hamburger:hover {
    background: var(--color-neutral-100);
}

.dark .hamburger:hover {
    background: var(--color-neutral-800);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 100%;
    max-width: 320px;
    background: var(--color-white);
    border-left: 1px solid var(--color-neutral-200);
    z-index: 200;
    transform: translateX(100%);
    transition: transform var(--transition-base);
    overflow-y: auto;
}

.mobile-menu.active {
    transform: translateX(0);
}

.mobile-menu.hidden {
    transform: translateX(100%);
}

.dark .mobile-menu {
    background: var(--color-neutral-900);
    border-left-color: var(--color-neutral-700);
}

.mobile-menu-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--color-neutral-200);
}

.dark .mobile-menu-header {
    border-bottom-color: var(--color-neutral-700);
}

.mobile-menu-content {
    padding: 1rem;
}

.mobile-menu-links {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.mobile-menu-link {
    display: block;
    padding: 0.75rem 1rem;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--color-neutral-700);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.mobile-menu-link:hover {
    color: var(--color-neutral-900);
    background: var(--color-neutral-100);
}

.dark .mobile-menu-link {
    color: var(--color-neutral-300);
}

.dark .mobile-menu-link:hover {
    color: var(--color-white);
    background: var(--color-neutral-800);
}

.mobile-menu-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--color-neutral-200);
    margin-top: 1rem;
}

.dark .mobile-menu-footer {
    border-top-color: var(--color-neutral-700);
}

.mobile-menu-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 199;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
}

.mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
}


   SCROLL REVEAL ANIMATIONS
   ========================================================================== */

.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity var(--transition-smooth), transform var(--transition-smooth);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

.reveal-left {
    opacity: 0;
    transform: translateX(-40px);
    transition: all var(--transition-smooth);
}

.reveal-left.active {
    opacity: 1;
    transform: translateX(0);
}

.reveal-right {
    opacity: 0;
    transform: translateX(40px);
    transition: all var(--transition-smooth);
}

.reveal-right.active {
    opacity: 1;
    transform: translateX(0);
}

.reveal-scale {
    opacity: 0;
    transform: scale(0.9);
    transition: all var(--transition-smooth);
}

.reveal-scale.active {
    opacity: 1;
    transform: scale(1);
}

.reveal-blur {
    opacity: 0;
    filter: blur(10px);
    transform: translateY(20px);
    transition: all var(--transition-smooth);
}

.reveal-blur.active {
    opacity: 1;
    filter: blur(0);
    transform: translateY(0);
}

/* Stagger Delays */
.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }
.stagger-5 { transition-delay: 0.5s; }
.stagger-6 { transition-delay: 0.6s; }
.stagger-7 { transition-delay: 0.7s; }
.stagger-8 { transition-delay: 0.8s; }

/* ==========================================================================
   CONTINUOUS ANIMATIONS
   ========================================================================== */

/* Floating Animation */
@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

.animate-float {
    animation: float 6s ease-in-out infinite;
}

/* Gradient Animation */
@keyframes gradient {
    0%, 100% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
}

.animate-gradient {
    background-size: 200% 200%;
    animation: gradient 8s ease infinite;
}

/* Pulse Ring Animation */
@keyframes pulse-ring {
    0% {
        transform: scale(1);
        opacity: 0.8;
    }
    100% {
        transform: scale(1.5);
        opacity: 0;
    }
}

.pulse-ring {
    animation: pulse-ring 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* Spin Animation */
@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.animate-spin {
    animation: spin 1s linear infinite;
}

/* Bounce Animation */
@keyframes bounce {
    0%, 100% {
        transform: translateY(-5%);
        animation-timing-function: cubic-bezier(0.8, 0, 1, 1);
    }
    50% {
        transform: translateY(0);
        animation-timing-function: cubic-bezier(0, 0, 0.2, 1);
    }
}

.animate-bounce {
    animation: bounce 1s infinite;
}

/* Shimmer Effect */
@keyframes shimmer {
    0% {
        background-position: -200% 0;
    }
    100% {
        background-position: 200% 0;
    }
}

.animate-shimmer {
    background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.2) 50%, transparent 100%);
    background-size: 200% 100%;
    animation: shimmer 2s infinite;
}

/* ==========================================================================
   ACTIVITY RINGS
   ========================================================================== */

.activity-ring {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.activity-ring-progress {
    transition: stroke-dashoffset 1s var(--ease-smooth);
}

.activity-ring-icon {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ==========================================================================
   ACCESSIBILITY
   ========================================================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.sr-only:focus,
.sr-only.focus\:not-sr-only:focus {
    position: static;
    width: auto;
    height: auto;
    padding: inherit;
    margin: inherit;
    overflow: visible;
    clip: auto;
    white-space: normal;
}

:focus-visible {
    outline: 2px solid var(--health-500);
    outline-offset: 2px;
}

/* Skip Link */
a.skip-link:focus {
    position: fixed;
    top: var(--space-4);
    left: var(--space-4);
    z-index: var(--z-tooltip);
    padding: var(--space-2) var(--space-4);
    background: var(--health-500);
    color: white;
    font-weight: var(--font-semibold);
    border-radius: var(--radius-lg);
    text-decoration: none;
}

/* ==========================================================================
   REDUCED MOTION
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .reveal,
    .reveal-left,
    .reveal-right,
    .reveal-scale,
    .reveal-blur {
        opacity: 1;
        transform: none;
        filter: none;
    }

    .animate-float,
    .animate-gradient,
    .animate-spin,
    .animate-bounce {
        animation: none;
    }
}

/* ==========================================================================
   CUSTOM SCROLLBAR
   ========================================================================== */

::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--neutral-100);
    border-radius: var(--radius-full);
}

.dark ::-webkit-scrollbar-track {
    background: var(--neutral-900);
}

::-webkit-scrollbar-thumb {
    background: var(--neutral-300);
    border-radius: var(--radius-full);
    border: 2px solid var(--neutral-100);
}

.dark ::-webkit-scrollbar-thumb {
    background: var(--neutral-700);
    border-color: var(--neutral-900);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--health-500);
}

/* Firefox */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--neutral-300) var(--neutral-100);
}

.dark * {
    scrollbar-color: var(--neutral-700) var(--neutral-900);
}

/* ==========================================================================
   SELECTION
   ========================================================================== */

::selection {
    background: var(--health-500);
    color: white;
}

::-moz-selection {
    background: var(--health-500);
    color: white;
}

/* ==========================================================================
   PERFORMANCE OPTIMIZATIONS
   ========================================================================== */

section {
    content-visibility: auto;
    contain-intrinsic-size: 0 500px;
}

.gpu-accelerated {
    transform: translateZ(0);
    will-change: transform;
}

/* ==========================================================================
   PRINT STYLES
   ========================================================================== */

@media print {
    nav,
    footer,
    button,
    .no-print {
        display: none !important;
    }

    body {
        background: white;
        color: black;
    }

    a {
        text-decoration: underline;
    }

    a[href]::after {
        content: " (" attr(href) ")";
        font-size: var(--text-sm);
        color: var(--neutral-600);
    }
}

/* ==========================================================================
   UTILITY CLASSES
   ========================================================================== */

/* Text Gradient */
.text-gradient {
    background: var(--gradient-brand);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Glass Effect */
.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
}

.dark .glass {
    background: var(--glass-bg-dark);
    border-color: var(--glass-border-dark);
}

/* Hover Lift */
.hover-lift {
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.hover-lift:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

/* Hover Glow */
.hover-glow-health:hover {
    box-shadow: var(--glow-health);
}

.hover-glow-heart:hover {
    box-shadow: var(--glow-heart);
}

.hover-glow-calm:hover {
    box-shadow: var(--glow-calm);
}

.hover-glow-sleep:hover {
    box-shadow: var(--glow-sleep);
}

/* Line Clamp */
.line-clamp-1 {
    display: -webkit-box;
    -webkit-line-clamp: 1;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.line-clamp-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.line-clamp-3 {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Aspect Ratio Fallback for Older Browsers */
.aspect-square {
    aspect-ratio: 1 / 1;
}

.aspect-video {
    aspect-ratio: 16 / 9;
}

.aspect-4-3 {
    aspect-ratio: 4 / 3;
}

/* ==========================================================================
   CHART BAR ANIMATION
   ========================================================================== */

.chart-bar {
    transform-origin: bottom;
    transition: height 0.7s var(--ease-smooth);
}

/* ==========================================================================
   FORM STYLES
   ========================================================================== */

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
    font-family: inherit;
    color: var(--neutral-900);
    background: white;
    border: 1px solid var(--neutral-200);
    border-radius: var(--radius-xl);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.dark .form-input,
.dark .form-textarea,
.dark .form-select {
    color: white;
    background: var(--neutral-900);
    border-color: var(--neutral-700);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--health-500);
    box-shadow: 0 0 0 3px rgba(34, 197, 94, 0.15);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--neutral-400);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

.form-label {
    display: block;
    margin-bottom: var(--space-2);
    font-weight: var(--font-medium);
    color: var(--neutral-700);
}

.dark .form-label {
    color: var(--neutral-300);
}

/* ==========================================================================
   BUTTON STYLES
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-size: var(--text-base);
    font-weight: var(--font-semibold);
    font-family: inherit;
    line-height: var(--leading-normal);
    text-decoration: none;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn-primary {
    background: var(--gradient-health);
    color: white;
    box-shadow: var(--shadow-health);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-health-lg);
}

.btn-secondary {
    background: white;
    color: var(--neutral-900);
    border: 2px solid var(--neutral-200);
}

.dark .btn-secondary {
    background: var(--neutral-900);
    color: white;
    border-color: var(--neutral-700);
}

.btn-secondary:hover {
    border-color: var(--health-500);
}

.btn-lg {
    padding: var(--space-4) var(--space-8);
    font-size: var(--text-lg);
}

.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
}

/* ==========================================================================
   CARD STYLES
   ========================================================================== */

.card {
    background: white;
    border: 1px solid var(--neutral-200);
    border-radius: var(--radius-3xl);
    padding: var(--space-6);
    transition: all var(--transition-base);
}

.dark .card {
    background: var(--neutral-900);
    border-color: var(--neutral-800);
}

.card:hover {
    border-color: var(--health-300);
    box-shadow: var(--shadow-xl);
    transform: translateY(-4px);
}

.dark .card:hover {
    border-color: var(--health-700);
}

/* ==========================================================================
   PRICING TOGGLE
   ========================================================================== */

.pricing-toggle {
    position: relative;
    display: inline-block;
    width: 56px;
    height: 28px;
}

.pricing-toggle input {
    opacity: 0;
    width: 0;
    height: 0;
}

.pricing-toggle-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background: var(--neutral-300);
    border-radius: var(--radius-full);
    transition: var(--transition-base);
}

.pricing-toggle-slider::before {
    content: '';
    position: absolute;
    height: 20px;
    width: 20px;
    left: 4px;
    bottom: 4px;
    background: white;
    border-radius: 50%;
    transition: var(--transition-base);
}

.pricing-toggle input:checked + .pricing-toggle-slider {
    background: var(--gradient-health);
}

.pricing-toggle input:checked + .pricing-toggle-slider::before {
    transform: translateX(28px);
}

/* ==========================================================================
   BADGE STYLES
   ========================================================================== */

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1-5);
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
    font-weight: var(--font-medium);
    border-radius: var(--radius-full);
}

.badge-health {
    background: var(--health-100);
    color: var(--health-700);
}

.dark .badge-health {
    background: rgba(34, 197, 94, 0.15);
    color: var(--health-400);
}

.badge-heart {
    background: var(--heart-100);
    color: var(--heart-700);
}

.badge-calm {
    background: var(--calm-100);
    color: var(--calm-700);
}

.badge-sleep {
    background: var(--sleep-100);
    color: var(--sleep-700);
}

/* ==========================================================================
   NAVIGATION STYLES
   ========================================================================== */

.nav-link {
    color: var(--neutral-600);
    font-weight: var(--font-medium);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.dark .nav-link {
    color: var(--neutral-400);
}

.nav-link:hover,
.nav-link.active {
    color: var(--health-600);
}

.dark .nav-link:hover,
.dark .nav-link.active {
    color: var(--health-400);
}

/* ==========================================================================
   FOOTER STYLES
   ========================================================================== */

.footer-link {
    color: var(--neutral-600);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.dark .footer-link {
    color: var(--neutral-400);
}

.footer-link:hover {
    color: var(--health-600);
}

.dark .footer-link:hover {
    color: var(--health-400);
}

/* ==========================================================================
   TESTIMONIAL STYLES
   ========================================================================== */

.testimonial-card {
    background: white;
    border: 1px solid var(--neutral-200);
    border-radius: var(--radius-3xl);
    padding: var(--space-8);
    transition: all var(--transition-base);
}

.dark .testimonial-card {
    background: var(--neutral-900);
    border-color: var(--neutral-800);
}

.testimonial-card:hover {
    box-shadow: var(--shadow-xl);
}

/* ==========================================================================
   STAT COUNTER
   ========================================================================== */

.stat-counter {
    font-size: var(--text-5xl);
    font-weight: var(--font-extrabold);
    line-height: var(--leading-none);
    letter-spacing: var(--tracking-tight);
}

/* ==========================================================================
   DASHBOARD MOCKUP
   ========================================================================== */

.dashboard-mockup {
    background: white;
    border: 1px solid var(--neutral-200);
    border-radius: var(--radius-3xl);
    overflow: hidden;
    box-shadow: var(--shadow-2xl);
}

.dark .dashboard-mockup {
    background: var(--neutral-900);
    border-color: var(--neutral-800);
}

.dashboard-header {
    display: flex;
    gap: var(--space-1-5);
    padding: var(--space-3) var(--space-4);
    background: var(--neutral-50);
    border-bottom: 1px solid var(--neutral-100);
}

.dark .dashboard-header {
    background: var(--neutral-800);
    border-bottom-color: var(--neutral-700);
}

.dashboard-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dashboard-dot:nth-child(1) { background: #ef4444; }
.dashboard-dot:nth-child(2) { background: #f59e0b; }
.dashboard-dot:nth-child(3) { background: #22c55e; }

/* ==========================================================================
   LOADING STATES
   ========================================================================== */

.skeleton {
    background: linear-gradient(90deg, var(--neutral-200) 25%, var(--neutral-100) 50%, var(--neutral-200) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-md);
}

.dark .skeleton {
    background: linear-gradient(90deg, var(--neutral-800) 25%, var(--neutral-700) 50%, var(--neutral-800) 75%);
}

/* ==========================================================================
   TOOLTIP STYLES
   ========================================================================== */

.tooltip {
    position: relative;
}

.tooltip::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    padding: var(--space-2) var(--space-3);
    background: var(--neutral-900);
    color: white;
    font-size: var(--text-xs);
    font-weight: var(--font-medium);
    border-radius: var(--radius-md);
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-fast), visibility var(--transition-fast);
    pointer-events: none;
    z-index: var(--z-tooltip);
}

.tooltip:hover::after {
    opacity: 1;
    visibility: visible;
}

/* ==========================================================================
   PROGRESS BAR
   ========================================================================== */

.progress-bar {
    height: 8px;
    background: var(--neutral-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.dark .progress-bar {
    background: var(--neutral-800);
}

.progress-bar-fill {
    height: 100%;
    background: var(--gradient-health);
    border-radius: var(--radius-full);
    transition: width 0.5s var(--ease-smooth);
}

/* ==========================================================================
   DIVIDER
   ========================================================================== */

.divider {
    height: 1px;
    background: var(--neutral-200);
    margin: var(--space-8) 0;
}

.dark .divider {
    background: var(--neutral-800);
}

.divider-vertical {
    width: 1px;
    height: 100%;
    background: var(--neutral-200);
}

.dark .divider-vertical {
    background: var(--neutral-800);
}

/* ==========================================================================
   FEATURE FLAG BANNER
   ========================================================================== */

.feature-banner {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: var(--health-50);
    border: 1px solid var(--health-200);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--health-700);
}

.dark .feature-banner {
    background: rgba(34, 197, 94, 0.1);
    border-color: var(--health-800);
    color: var(--health-400);
}

/* ==========================================================================
   RESPONSIVE CONTAINER
   ========================================================================== */

.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

@media (min-width: 640px) {
    .container {
        padding: 0 var(--space-6);
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 0 var(--space-8);
    }
}

/* ==========================================================================
   RESPONSIVE BREAKPOINT UTILITIES
   ========================================================================== */

.hide-mobile {
    display: none;
}

@media (min-width: 768px) {
    .hide-mobile {
        display: block;
    }

    .hide-tablet {
        display: none;
    }
}

@media (min-width: 1024px) {
    .hide-tablet {
        display: block;
    }

    .hide-desktop {
        display: none;
    }
}