/* ============================================================
   ROOT STYLE.CSS - Global Design System
   Location: /front-end/style.css
   Purpose: Shared styles for ALL algorithm visualizer pages
   Children can override by linking module-specific CSS AFTER this
   ============================================================ */


/* ====== CSS RESET & BASE ====== */

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

:root {
    /* ====== COLOR PALETTE ====== */
    --color-primary: #6C63FF;
    --color-primary-dark: #5A52D5;
    --color-primary-light: #8B83FF;
    --color-secondary: #FF6584;
    --color-secondary-dark: #E55574;
    --color-bg: #0A0A1A;
    --color-bg-card: #14142B;
    --color-bg-card-hover: #1E1E3F;
    --color-text: #E8E8F0;
    --color-text-muted: #8888AA;
    --color-text-light: #FFFFFF;
    --color-success: #4ADE80;
    --color-warning: #FBBF24;
    --color-error: #F87171;
    --color-info: #60A5FA;
    --color-border: #2A2A4A;
    --color-border-light: #3A3A5A;
    /* ====== TYPOGRAPHY ====== */
    --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-mono: 'Courier New', monospace;
    /* ====== SPACING ====== */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 4rem;
    /* ====== BORDER RADIUS ====== */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    /* ====== SHADOWS ====== */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(108, 99, 255, 0.2);
    /* ====== TRANSITIONS ====== */
    --transition-fast: 0.15s ease;
    --transition-med: 0.3s ease;
    --transition-slow: 0.5s ease;
}


/* ====== HTML & BODY ====== */

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    line-height: 1.6;
    overflow-x: hidden;
}


/* ====== APP CONTAINER ====== */

.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-md);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}


/* ====== HEADER ====== */

.app-header {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-light);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.tagline {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    font-style: italic;
    -webkit-text-fill-color: var(--color-text-muted);
}


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

.main-nav {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.main-nav a {
    color: var(--color-text-muted);
    text-decoration: none;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    font-size: 0.9rem;
    position: relative;
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--color-text-light);
    background: rgba(108, 99, 255, 0.15);
}

.main-nav a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 2px;
    background: var(--color-primary);
    border-radius: 2px;
}


/* ====== GITHUB LINK ====== */

.github-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-light);
    text-decoration: none;
    background: var(--color-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    font-weight: 600;
    font-size: 0.9rem;
}

.github-link:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}


/* ====== MAIN CONTENT ====== */

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}


/* ====== HERO SECTION ====== */

.hero-section {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-lg);
    background: linear-gradient(135deg, rgba(108, 99, 255, 0.05), rgba(255, 101, 132, 0.05));
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
}

.hero-text h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.sarcasm {
    font-style: italic;
    color: var(--color-secondary);
    -webkit-text-fill-color: var(--color-secondary);
}

.hero-description {
    font-size: 1rem;
    color: var(--color-text-muted);
    max-width: 600px;
    margin: 0 auto;
}


/* ====== CATEGORIES / CARDS ====== */

.categories-section {
    padding: var(--spacing-lg) 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-light);
    text-align: center;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-lg);
    font-size: 1rem;
}


/* ====== CARDS GRID ====== */

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    padding: var(--spacing-md) 0;
}

.algorithm-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-med);
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}

.algorithm-card:hover {
    transform: translateY(-6px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    background: var(--color-bg-card-hover);
}

.algorithm-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(108, 99, 255, 0.05), transparent 70%);
    opacity: 0;
    transition: opacity var(--transition-med);
    pointer-events: none;
}

.algorithm-card:hover::before {
    opacity: 1;
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xs);
}

.card-description {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    flex: 1;
    margin-bottom: var(--spacing-md);
}


/* Child badge for modules with sub-modules */

.child-badge {
    display: inline-block;
    background: rgba(108, 99, 255, 0.2);
    color: var(--color-primary-light);
    padding: 2px var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-sm);
    align-self: flex-start;
}

.card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: var(--color-text-muted);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--color-border);
}

.card-tag {
    background: rgba(108, 99, 255, 0.15);
    color: var(--color-primary-light);
    padding: 2px var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
}

.card-runtime {
    font-family: var(--font-mono);
    font-size: 0.8rem;
}


/* ====== FEATURES SECTION ====== */

.features-section {
    padding: var(--spacing-lg) 0;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-lg);
}

.feature-item {
    text-align: center;
    padding: var(--spacing-lg);
    background: var(--color-bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    transition: all var(--transition-med);
}

.feature-item:hover {
    transform: translateY(-4px);
    border-color: var(--color-primary-light);
}

.feature-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: var(--spacing-sm);
}

.feature-item h3 {
    font-size: 1.1rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xs);
}

.feature-item p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}


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

.app-footer {
    margin-top: auto;
    padding: var(--spacing-lg) 0 var(--spacing-md);
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-content p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

.footer-acknowledgment {
    font-style: italic;
    font-size: 0.8rem !important;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    align-items: center;
}

.footer-links a {
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color var(--transition-fast);
    font-size: 0.85rem;
}

.footer-links a:hover {
    color: var(--color-primary-light);
}

.divider {
    color: var(--color-border);
}


/* ============================================================
   RESPONSIVE DESIGN
   ============================================================ */

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
    .brand {
        justify-content: center;
    }
    .main-nav {
        justify-content: center;
    }
    .github-link {
        justify-content: center;
    }
    .hero-text h2 {
        font-size: 1.8rem;
    }
    .cards-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    .app-container {
        padding: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .hero-text h2 {
        font-size: 1.5rem;
    }
    .hero-subtitle {
        font-size: 1rem;
    }
    .cards-grid {
        grid-template-columns: 1fr;
    }
    .feature-grid {
        grid-template-columns: 1fr;
    }
    .section-title {
        font-size: 1.5rem;
    }
}