/* ============================================
   Michigan State University Science Olympiad
   Global Theming System
   ============================================ */

/* CSS Reset & Base Styles */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ============================================
   CSS Custom Properties - Light Theme (Default)
   ============================================ */
:root {
    /* Primary Green Palette - MSU-inspired */
    --color-green-900: #0d3b2e;
    --color-green-800: #165943;
    --color-green-700: #18794e;
    --color-green-600: #1a9659;
    --color-green-500: #22c55e;
    --color-green-400: #4ade80;
    --color-green-300: #86efac;
    --color-green-200: #bbf7d0;
    --color-green-100: #dcfce7;
    --color-green-50: #f0fdf4;

    /* Neutral Palette */
    --color-white: #ffffff;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;

    /* Accent Colors */
    --color-accent-warm: #f59e0b;
    --color-accent-cool: #3b82f6;
    /* Additional accents */
    --color-purple-700: #6d28d9;
    --color-purple-500: #9f7aea;
    --color-purple-100: #f3e8ff;
    --color-orange-700: #b45309;
    --color-orange-500: #f59e0b;
    --color-orange-100: #fff7ed;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;
    --color-info: #3b82f6;

    /* Light Theme Semantic Colors */
    --color-primary: var(--color-green-600);
    --color-primary-hover: var(--color-green-700);
    --color-primary-light: var(--color-green-100);
    
    --color-background: var(--color-white);
    --color-background-secondary: var(--color-gray-50);
    --color-background-tertiary: var(--color-green-50);
    
    --color-text-primary: var(--color-gray-900);
    --color-text-secondary: var(--color-gray-600);
    --color-text-tertiary: var(--color-gray-500);
    --color-text-on-primary: var(--color-white);
    
    --color-border: var(--color-gray-200);
    --color-border-light: var(--color-gray-100);
    --color-border-dark: var(--color-gray-300);
    
    --color-shadow: rgba(0, 0, 0, 0.1);
    --color-shadow-lg: rgba(0, 0, 0, 0.15);

    /* Typography */
    --font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-family-heading: 'Segoe UI', system-ui, -apple-system, sans-serif;
    --font-family-mono: 'Consolas', 'Monaco', 'Courier New', monospace;

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

    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-extrabold: 800;

    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* Spacing Scale */
    --space-1: 0.25rem;   /* 4px */
    --space-2: 0.5rem;    /* 8px */
    --space-3: 0.75rem;   /* 12px */
    --space-4: 1rem;      /* 16px */
    --space-5: 1.25rem;   /* 20px */
    --space-6: 1.5rem;    /* 24px */
    --space-8: 2rem;      /* 32px */
    --space-10: 2.5rem;   /* 40px */
    --space-12: 3rem;     /* 48px */
    --space-16: 4rem;     /* 64px */
    --space-20: 5rem;     /* 80px */
    --space-24: 6rem;     /* 96px */

    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 0.75rem;
    --radius-2xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --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-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

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

    /* Layout */
    --container-max-width: 1280px;
    --container-padding: var(--space-4);
    --header-height: 4rem;
}

/* ============================================
   Dark Theme
   ============================================ */
[data-theme="dark"] {
    /* Dark Theme Semantic Colors */
    --color-primary: var(--color-green-400);
    --color-primary-hover: var(--color-green-300);
    --color-primary-light: var(--color-green-900);
    
    --color-background: #0a0f0d;
    --color-background-secondary: #111917;
    --color-background-tertiary: #1a2622;
    
    --color-text-primary: var(--color-gray-100);
    --color-text-secondary: var(--color-gray-300);
    --color-text-tertiary: var(--color-gray-400);
    --color-text-on-primary: var(--color-gray-900);
    
    --color-border: var(--color-gray-700);
    --color-border-light: var(--color-gray-800);
    --color-border-dark: var(--color-gray-600);
    
    --color-shadow: rgba(0, 0, 0, 0.3);
    --color-shadow-lg: rgba(0, 0, 0, 0.5);

    /* Adjusted shadows for dark mode */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.4);
}

/* ============================================
   Base Typography
   ============================================ */
html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--color-text-primary);
    background-color: var(--color-background);
    transition: background-color var(--transition-base), color var(--transition-base);
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-heading);
    font-weight: var(--font-weight-bold);
    line-height: var(--line-height-tight);
    color: var(--color-text-primary);
    margin-bottom: var(--space-4);
}

h1 {
    font-size: var(--font-size-5xl);
    font-weight: var(--font-weight-extrabold);
}

h2 {
    font-size: var(--font-size-4xl);
}

h3 {
    font-size: var(--font-size-3xl);
}

h4 {
    font-size: var(--font-size-2xl);
}

h5 {
    font-size: var(--font-size-xl);
}

h6 {
    font-size: var(--font-size-lg);
}

p {
    margin-bottom: var(--space-4);
    color: var(--color-text-secondary);
}

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

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

strong, b {
    font-weight: var(--font-weight-semibold);
}

/* ============================================
   Layout Utilities
   ============================================ */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
    width: 100%;
}

.section {
    padding: var(--space-16) 0;
}

.section-lg {
    padding: var(--space-24) 0;
}

.grid {
    display: grid;
    gap: var(--space-6);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

.flex {
    display: flex;
}

.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}

.flex-between {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.flex-col {
    display: flex;
    flex-direction: column;
}

/* ============================================
   Component Styles
   ============================================ */

/* Buttons */
.btn {
    display: inline-block;
    padding: var(--space-3) var(--space-6);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    text-align: center;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    line-height: 1;
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-text-on-primary);
}

.btn-primary:hover {
    background-color: var(--color-primary-hover);
    color: var(--color-text-on-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

.btn-secondary:hover {
    background-color: var(--color-primary);
    color: var(--color-text-on-primary);
}

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

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

/* Cards */
.card {
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

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

.card-title {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--space-3);
    color: var(--color-text-primary);
}

.card-text {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-4);
}

.card-green {
    background: linear-gradient(135deg, var(--color-green-50) 0%, var(--color-white) 100%);
    border-color: var(--color-green-200);
}

[data-theme="dark"] .card-green {
    background: linear-gradient(135deg, var(--color-green-900) 0%, var(--color-background-secondary) 100%);
    border-color: var(--color-green-800);
}

/* Navigation */
.navbar {
    background-color: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.95);
}

[data-theme="dark"] .navbar {
    background-color: rgba(10, 15, 13, 0.95);
}

.navbar-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    z-index: 2001;
}

.navbar-brand {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: var(--space-3);
    text-decoration: none;
    transition: opacity var(--transition-fast);
}

.navbar-brand:hover {
    opacity: 0.8;
}

.navbar-logo {
    height: 2.5rem;
    width: auto;
    transition: opacity var(--transition-fast);
}

/* Theme-based logo visibility */
.navbar-logo-light {
    display: block;
}

.navbar-logo-dark {
    display: none;
}

[data-theme="dark"] .navbar-logo-light {
    display: none;
}

[data-theme="dark"] .navbar-logo-dark {
    display: block;
}

.navbar-brand-text {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
}

.navbar-nav {
    display: flex;
    gap: var(--space-6);
    list-style: none;
}

.navbar-link {
    color: var(--color-text-secondary);
    font-weight: var(--font-weight-medium);
    transition: color var(--transition-fast);
}

.navbar-link:hover {
    color: var(--color-primary);
}

/* Mobile Menu Toggle Button */
.navbar-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-2);
    color: var(--color-text-primary);
    font-size: var(--font-size-2xl);
    line-height: 1;
    transition: color var(--transition-fast);
}

.navbar-toggle:hover {
    color: var(--color-primary);
}

.navbar-toggle:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

/* Mobile Menu Overlay */
.mobile-menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1999;
    opacity: 0;
    transition: opacity var(--transition-base);
    pointer-events: none;
}

.mobile-menu-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

/* Mobile Menu Drawer */
.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 280px;
    max-width: 85vw;
    background-color: var(--color-background);
    box-shadow: var(--shadow-2xl);
    z-index: 2000;
    transform: translateX(-100%);
    transition: transform var(--transition-slow);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

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

.mobile-menu-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4);
    border-bottom: 1px solid var(--color-border);
}

.mobile-menu-brand {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.mobile-menu-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-2);
    color: var(--color-text-primary);
    font-size: var(--font-size-2xl);
    line-height: 1;
    transition: color var(--transition-fast);
}

.mobile-menu-close:hover {
    color: var(--color-primary);
}

.mobile-menu-nav {
    list-style: none;
    padding: var(--space-4) 0;
    flex: 1;
}

.mobile-menu-nav li {
    border-bottom: 1px solid var(--color-border-light);
}

.mobile-menu-nav li:last-child {
    border-bottom: none;
}

.mobile-menu-link {
    display: block;
    padding: var(--space-4);
    color: var(--color-text-primary);
    font-weight: var(--font-weight-medium);
    transition: all var(--transition-fast);
}

.mobile-menu-link:hover {
    background-color: var(--color-background-tertiary);
    color: var(--color-primary);
    padding-left: var(--space-5);
}

.mobile-menu-footer {
    padding: var(--space-4);
    border-top: 1px solid var(--color-border);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--color-green-600) 0%, var(--color-green-700) 100%);
    color: var(--color-white);
    padding: var(--space-24) 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

[data-theme="dark"] .hero {
    background: linear-gradient(135deg, var(--color-green-800) 0%, var(--color-green-900) 100%);
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero h1 {
    color: var(--color-white);
    margin-bottom: var(--space-6);
    font-size: var(--font-size-6xl);
}

.hero p {
    color: rgba(255, 255, 255, 0.9);
    font-size: var(--font-size-xl);
    max-width: 600px;
    margin: 0 auto var(--space-8);
}

/* Dark theme adjustments for badges */
[data-theme="dark"] .purple-badge {
    background: linear-gradient(90deg, rgba(109,40,217,0.28), rgba(159,122,234,0.28));
    color: var(--color-white);
    border-color: rgba(159,122,234,0.08);
}

[data-theme="dark"] .orange-badge {
    background: linear-gradient(90deg, rgba(180,83,9,0.28), rgba(245,158,11,0.28));
    color: var(--color-white);
    border-color: rgba(245,158,11,0.08);
}

/* Card badges container */
.card-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 0;
    margin-top: var(--space-3);
}

/* Theme Toggle Button */
.theme-toggle {
    background-color: var(--color-background-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    padding: var(--space-2) var(--space-4);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--space-2);
    transition: all var(--transition-base);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-primary);
}

.theme-toggle:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.text-primary {
    color: var(--color-primary);
}

.bg-secondary {
    background-color: var(--color-background-secondary);
}

.bg-tertiary {
    background-color: var(--color-background-tertiary);
}

.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.py-8 { padding-top: var(--space-8); padding-bottom: var(--space-8); }

/* ============================================
   Responsive Design - Mobile First
   ============================================ */

/* Tablet (768px and up) */
@media (max-width: 768px) {
    :root {
        --font-size-5xl: 2.5rem;
        --font-size-4xl: 2rem;
        --font-size-3xl: 1.5rem;
        --space-16: 3rem;
        --space-24: 4rem;
    }

    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

    /* Show mobile menu toggle, hide desktop nav */
    .navbar-toggle {
        display: block;
    }

    .navbar-nav {
        display: none;
    }

    .mobile-menu-overlay {
        display: block;
    }

    /* Navbar logo responsive sizing */
    .navbar-logo {
        height: 2rem;
    }

    .navbar-brand-text {
        font-size: var(--font-size-lg);
    }

    .hero h1 {
        font-size: var(--font-size-4xl);
    }

    .hero p {
        font-size: var(--font-size-lg);
    }
}

/* Mobile (480px and up) */
@media (max-width: 480px) {
    :root {
        --font-size-5xl: 2rem;
        --font-size-4xl: 1.75rem;
        --space-16: 2rem;
        --space-24: 3rem;
        --container-padding: var(--space-3);
    }

    /* Smaller logo for mobile */
    .navbar-logo {
        height: 1.75rem;
    }

    .navbar-brand-text {
        font-size: var(--font-size-base);
    }

    .navbar-brand {
        gap: var(--space-2);
    }

    h1 {
        font-size: var(--font-size-4xl);
    }

    h2 {
        font-size: var(--font-size-3xl);
    }

    .btn-lg {
        padding: var(--space-3) var(--space-6);
        font-size: var(--font-size-base);
    }

    .card {
        padding: var(--space-4);
    }
}

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

/* Focus styles */
*:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Reduced 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;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --color-border: var(--color-gray-900);
    }

    [data-theme="dark"] {
        --color-border: var(--color-white);
    }
}