/* =========================================
   BASE.CSS - Design System Tokens
   Based on UI_UX_GUIDELINES.md
   ========================================= */

/* =========================================
   1. DESIGN TOKENS - COLORS
   ========================================= */
:root {
    /* Brand Colors */
    --primary-orange: #F97316;
    --primary-dark: #EA580C;
    --primary-light: #FB923C;
    --secondary-gold: #F59E0B;
    --gold-light: #FBBF24;

    /* Neutral Colors */
    --bg-white: #FFFFFF;
    --bg-surface: #FAFAFA;
    --bg-input: #F5F5F5;
    --text-primary: #262626;
    --text-secondary: #525252;
    --text-tertiary: #737373;
    --border-color: #E5E5E5;

    /* Semantic Colors */
    --success: #22C55E;
    --error: #EF4444;
    --warning: #F59E0B;
    --info: #3B82F6;

    /* Skill Level Colors */
    --skill-beginner: #22C55E;
    --skill-beginner-light: rgba(34, 197, 94, 0.1);
    --skill-intermediate: #F59E0B;
    --skill-intermediate-light: rgba(245, 158, 11, 0.1);
    --skill-advanced: #EF4444;
    --skill-advanced-light: rgba(239, 68, 68, 0.1);

    /* Dark Theme (for Pro pages) */
    --bg-dark: #0f1724;
    --bg-dark-card: rgba(255, 255, 255, 0.06);
    --bg-dark-card-hover: rgba(255, 255, 255, 0.1);
    --border-dark: rgba(255, 255, 255, 0.12);
    --text-dark: #eef2ff;
    --accent-dark-orange: #EA580C;
    --accent-dark-gold: #FBBF24;

    /* Typography */
    --font-family: 'Archivo', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;

    /* Spacing - 8px Base Grid */
    --spacing-xxs: 4px;
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    --spacing-xxxl: 64px;

    /* Border Radius */
    --radius-none: 0;
    --radius-xs: 4px;
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-xxl: 24px;
    --radius-full: 9999px;

    /* Max Widths */
    --max-width-container: 1200px;
    --max-width-content: 800px;
    --max-width-narrow: 600px;

    /* Shadows */
    --shadow-none: none;
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-card-elevated: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-brand: 0 10px 15px -3px rgba(249, 115, 22, 0.3);

    /* Type Scale */
    --font-size-display-large: 32px;
    --font-size-display-medium: 28px;
    --font-size-h1: 26px;
    --font-size-h2: 22px;
    --font-size-h3: 20px;
    --font-size-h4: 18px;
    --font-size-body-large: 16px;
    --font-size-body: 15px;
    --font-size-body-small: 14px;
    --font-size-caption: 13px;
    --font-size-caption-small: 12px;

    /* Font Weights */
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-black: 900;

    /* Transitions */
    --transition-fast: 150ms;
    --transition-base: 200ms;
    --transition-slow: 300ms;
    --easing-default: ease;
    --easing-in: ease-in;
    --easing-out: ease-out;
}

/* =========================================
   2. RESET & BASE
   ========================================= */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--text-primary);
    background-color: var(--bg-white);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

img,
picture,
video,
canvas,
svg {
    display: block;
    max-width: 100%;
}

input,
button,
textarea,
select {
    font: inherit;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-base) var(--easing-default);
}

ul, ol {
    list-style: none;
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

/* =========================================
   3. LAYOUT UTILITIES
   ========================================= */
.container {
    width: 100%;
    max-width: var(--max-width-container);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.container-narrow {
    width: 100%;
    max-width: var(--max-width-content);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.container-wide {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* =========================================
   4. TYPOGRAPHY UTILITIES
   ========================================= */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-bold);
    line-height: 1.2;
    color: var(--text-primary);
}

h1 {
    font-size: var(--font-size-display-large);
    font-weight: var(--font-weight-black);
}

h2 {
    font-size: var(--font-size-display-medium);
}

h3 {
    font-size: var(--font-size-h1);
}

h4 {
    font-size: var(--font-size-h2);
}

p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.text-gradient {
    background: linear-gradient(135deg, var(--primary-orange), var(--secondary-gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.text-center {
    text-align: center;
}

.text-ellipsis {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* =========================================
   5. SPACING UTILITIES
   ========================================= */
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

/* =========================================
   6. DISPLAY UTILITIES
   ========================================= */
.hidden {
    display: none !important;
}

.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;
}

/* =========================================
   7. ACCESSIBILITY
   ========================================= */
:focus-visible {
    outline: 2px solid var(--primary-orange);
    outline-offset: 2px;
}

button:focus-visible,
a:focus-visible {
    outline: 2px solid var(--primary-orange);
    outline-offset: 2px;
}

/* Skip to content link */
.skip-to-content {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-orange);
    color: white;
    padding: 8px;
    text-decoration: none;
    z-index: 10000;
}

.skip-to-content:focus {
    top: 0;
}

/* =========================================
   8. ANIMATIONS
   ========================================= */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

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

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

.animate-fadeIn {
    animation: fadeIn var(--transition-slow) var(--easing-out);
}

.animate-slideUp {
    animation: slideUp var(--transition-slow) var(--easing-out);
}

.animate-scaleIn {
    animation: scaleIn var(--transition-slow) var(--easing-out);
}

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

.animate-bounce {
    animation: bounce 2s infinite;
}