/* ============================================
   IonPap — Design Tokens & Base Styles
   ============================================ */

:root {
    /* Colors */
    --color-primary-gradient: linear-gradient(135deg, #005cff 0%, #00d2ff 50%, #28ff57 100%);
    --color-primary-gradient-text: linear-gradient(to right, #005cff, #00d2ff 50%, #28ff57);
    --color-primary-gradient-h: linear-gradient(to right, #005cff, #00d2ff 50%, #28ff57);
    --color-glow: rgba(0, 210, 255, 0.25);
    --color-glow-accent: rgba(0, 210, 255, 0.1);

    --color-text-dark: #0f172a;
    --color-text: #475569;
    --color-text-light: #64748b;
    --color-text-muted: #94a3b8;
    --color-white: #ffffff;

    --color-border: #e2e8f0;
    --color-border-light: #f1f5f9;

    --color-bg: #ffffff;
    --color-bg-light: #f8fafc;
    --color-bg-glass: rgba(255, 255, 255, 0.8);
    --color-bg-glass-border: rgba(226, 232, 240, 0.8);

    --color-overlay-start: rgba(0, 0, 0, 0.6);
    --color-overlay-mid: rgba(0, 0, 0, 0.5);
    --color-overlay-end: rgba(0, 0, 0, 0.4);

    /* Typography */
    --font-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    --font-size-xs: 0.6875rem;    /* 11px */
    --font-size-sm: 0.75rem;      /* 12px */
    --font-size-base: 1rem;       /* 16px */
    --font-size-lg: 1.25rem;      /* 20px */
    --font-size-xl: 1.75rem;      /* 28px */
    --font-size-2xl: 1.875rem;    /* 30px */
    --font-size-hero: 4.5rem;     /* 72px */

    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    --line-height-tight: 1;
    --line-height-snug: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.625;

    --letter-spacing-tight: -1.8px;
    --letter-spacing-wide: 1.2px;

    /* Spacing */
    --spacing-xs: 0.25rem;   /* 4px */
    --spacing-sm: 0.5rem;    /* 8px */
    --spacing-md: 1rem;      /* 16px */
    --spacing-lg: 1.5rem;    /* 24px */
    --spacing-xl: 2rem;      /* 32px */
    --spacing-2xl: 3rem;     /* 48px */
    --spacing-3xl: 4rem;     /* 64px */
    --spacing-4xl: 6rem;     /* 96px */

    /* Border Radius */
    --radius-sm: 1rem;       /* 16px */
    --radius-md: 1.5rem;     /* 24px */
    --radius-lg: 2rem;       /* 32px */
    --radius-xl: 3rem;       /* 48px */
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 8px 30px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 20px 60px -15px rgba(0, 0, 0, 0.05);
    --shadow-glow: 0 8px 20px rgba(0, 210, 255, 0.25);
    --shadow-text: 0 25px 25px rgba(0, 0, 0, 0.15);
    --shadow-text-sm: 0 4px 3px rgba(0, 0, 0, 0.1), 0 10px 8px rgba(0, 0, 0, 0.04);
    --shadow-card: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.6s ease;

    /* Z-index */
    --z-header: 100;
    --z-overlay: 10;
    --z-content: 1;

    /* Layout */
    --max-width: 1280px;
    --max-width-content: 1152px;
    --max-width-text: 896px;
}

/* ============================================
   Reset
   ============================================ */

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-base);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-normal);
    line-height: var(--line-height-normal);
    color: var(--color-text-dark);
    background: var(--color-bg);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    background: linear-gradient(
        135deg,
        transparent 0%,
        rgba(0, 92, 255, 0.12) 20%,
        rgba(0, 210, 255, 0.15) 40%,
        rgba(40, 255, 87, 0.12) 60%,
        transparent 80%
    );
    background-size: 300% 300%;
    animation: body-waves 12s ease-in-out infinite;
}

@keyframes body-waves {
    0%, 100% {
        background-position: 0% 0%;
    }
    33% {
        background-position: 100% 50%;
    }
    66% {
        background-position: 50% 100%;
    }
}

a {
    text-decoration: none;
    color: inherit;
}

img {
    display: block;
    max-width: 100%;
    height: auto;
}

/* ============================================
   Accessibility
   ============================================ */

.skip-link {
    position: absolute;
    top: -100%;
    left: var(--spacing-md);
    z-index: 9999;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-text-dark);
    color: var(--color-white);
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-sm);
}

.skip-link:focus {
    top: var(--spacing-md);
}

/* ============================================
   Utilities
   ============================================ */

.fade-in-section {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.fade-in-section.is-visible {
    opacity: 1;
    transform: translateY(0);
}