/* ===========================
   BASE STYLES
   Reset, variables, and utilities
   =========================== */

/* CSS Variables (Design Tokens) */
:root {
    /* Colors */
    --color-primary: #00BFFF;
    --color-secondary: #FF9900;
    --color-dark: #1A3A52;
    --color-white: #FFFFFF;
    --color-light-bg: #F5F5F5;
    --color-light-text: #666666;
    
    /* Typography */
    --font-family-display: 'Arial Black', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-family-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 14px;
    --font-size-lg: 18px;
    --font-weight-regular: 400;
    --font-weight-semi-bold: 600;
    --font-weight-bold: 700;
    
    /* Spacing */
    --spacing-unit: 8px;
    --spacing-xs: calc(var(--spacing-unit) * 1);    /* 8px */
    --spacing-sm: calc(var(--spacing-unit) * 2);    /* 16px */
    --spacing-md: calc(var(--spacing-unit) * 3);    /* 24px */
    --spacing-lg: calc(var(--spacing-unit) * 4);    /* 32px */
    --spacing-xl: calc(var(--spacing-unit) * 5);    /* 40px */
    --spacing-2xl: calc(var(--spacing-unit) * 6);   /* 48px */
    --spacing-3xl: calc(var(--spacing-unit) * 8);   /* 64px */
    
    /* Layout */
    --container-max-width: 1200px;
    --container-padding: var(--spacing-lg);
    
    /* Line Height */
    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.6;
    
    /* Border Radius */
    --border-radius: 4px;
    --border-radius-lg: 8px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.15);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 200ms ease-in-out;
    --transition-slow: 300ms ease-in-out;
}

/* Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-body);
    font-size: var(--font-size-base);
    line-height: var(--line-height-relaxed);
    color: var(--color-dark);
    background-color: var(--color-white);
}

/* Typography Reset */
h1, h2, h3, h4, h5, h6 {
    margin: 0;
    padding: 0;
    font-weight: var(--font-weight-bold);
    line-height: var(--line-height-tight);
}

p {
    margin: 0;
    padding: 0;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-secondary);
}

a:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: var(--border-radius);
}

button {
    font-family: inherit;
    font-size: inherit;
    cursor: pointer;
    border: none;
    background: none;
    transition: all var(--transition-base);
}

button:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Image Reset */
img {
    display: block;
    max-width: 100%;
    height: auto;
}

/* List Reset */
ul, ol {
    list-style: none;
}

/* Utility Classes */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-sm);
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* Accessibility: Reduce Motion for users who prefer it */
@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;
    }
}