/* ==========================================================================
   Challenge Pages - Premium Design with Question-First Focus
   Modern Age Coders - 2026
   ========================================================================== */

/* Google Fonts loaded in HTML */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* ========================================================================
   Design Tokens
   ======================================================================== */
:root {
    /* Primary Palette */
    --cp-primary: #4F46E5;
    --cp-primary-dark: #4338CA;
    --cp-primary-light: #818CF8;
    --cp-primary-subtle: #EEF2FF;

    /* Accent Colors */
    --cp-accent-warm: #F59E0B;
    --cp-accent-green: #10B981;
    --cp-accent-rose: #F43F5E;
    --cp-accent-cyan: #06B6D4;

    /* Neutrals */
    --cp-bg-primary: #FAFBFC;
    --cp-bg-secondary: #FFFFFF;
    --cp-bg-tertiary: #F1F5F9;
    --cp-bg-dark: #0F172A;

    --cp-text-primary: #0F172A;
    --cp-text-secondary: #475569;
    --cp-text-muted: #94A3B8;
    --cp-text-inverse: #FFFFFF;

    --cp-border: #E2E8F0;
    --cp-border-strong: #CBD5E1;

    /* Difficulty Colors */
    --cp-easy: #10B981;
    --cp-easy-bg: #D1FAE5;
    --cp-medium: #F59E0B;
    --cp-medium-bg: #FEF3C7;
    --cp-hard: #EF4444;
    --cp-hard-bg: #FEE2E2;
    --cp-ultra: #8B5CF6;
    --cp-ultra-bg: #EDE9FE;

    /* Shadows */
    --cp-shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --cp-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
    --cp-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
    --cp-shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Typography */
    --cp-font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --cp-font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;

    /* Spacing */
    --cp-space-xs: 4px;
    --cp-space-sm: 8px;
    --cp-space-md: 16px;
    --cp-space-lg: 24px;
    --cp-space-xl: 32px;
    --cp-space-2xl: 48px;
    --cp-space-3xl: 64px;

    /* Border Radius */
    --cp-radius-sm: 6px;
    --cp-radius-md: 10px;
    --cp-radius-lg: 16px;
    --cp-radius-xl: 24px;
    --cp-radius-full: 9999px;

    /* Transitions */
    --cp-transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --cp-transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

.challenge-page {
    font-family: var(--cp-font-sans);
    background: var(--cp-bg-primary);
    color: var(--cp-text-primary);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

/* ========================================================================
   Simple Clean Navigation
   ======================================================================== */
.challenge-nav {
    background: var(--cp-bg-secondary);
    border-bottom: 1px solid var(--cp-border);
    padding: 0 var(--cp-space-lg);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--cp-text-primary);
    font-weight: 700;
    font-size: 1.1rem;
}

.nav-logo svg {
    color: var(--cp-primary);
}

.nav-logo-img {
    height: 32px;
    width: auto;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--cp-space-sm);
}

.nav-link {
    padding: 8px 16px;
    text-decoration: none;
    color: var(--cp-text-secondary);
    font-weight: 500;
    font-size: 0.9rem;
    border-radius: var(--cp-radius-md);
    transition: var(--cp-transition-fast);
}

.nav-link:hover {
    color: var(--cp-text-primary);
    background: var(--cp-bg-tertiary);
}

.nav-link-highlight {
    background: var(--cp-primary);
    color: white !important;
}

.nav-link-highlight:hover {
    background: var(--cp-primary-dark);
    color: white !important;
}

/* ========================================================================
   Main Challenge Section (FIRST FOCUS)
   ======================================================================== */
.challenge-main {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--cp-space-xl) var(--cp-space-lg);
}

.challenge-intro {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--cp-space-lg);
    flex-wrap: wrap;
    gap: var(--cp-space-md);
}

.challenge-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: linear-gradient(135deg, var(--cp-primary), var(--cp-primary-dark));
    color: white;
    padding: 10px 20px;
    border-radius: var(--cp-radius-full);
    font-weight: 700;
    font-size: 1rem;
}

.challenge-badge.maths {
    background: linear-gradient(135deg, var(--cp-accent-cyan), #0891B2);
}

.streak-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--cp-bg-secondary);
    border: 2px solid var(--cp-border);
    padding: 8px 18px;
    border-radius: var(--cp-radius-full);
    font-weight: 600;
    font-size: 0.95rem;
}

.streak-fire {
    font-size: 1.2rem;
}

/* Timeline */
.timeline-section {
    margin-bottom: var(--cp-space-xl);
}

.timeline-wrapper {
    display: flex;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
    background: var(--cp-bg-secondary);
    padding: var(--cp-space-md);
    border-radius: var(--cp-radius-lg);
    border: 1px solid var(--cp-border);
}

.day-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 10px 14px;
    border-radius: var(--cp-radius-md);
    background: var(--cp-bg-tertiary);
    min-width: 60px;
    transition: var(--cp-transition-normal);
}

.day-node.active {
    background: var(--cp-primary-subtle);
    border: 2px solid var(--cp-primary);
    transform: scale(1.05);
}

.day-name {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--cp-text-muted);
}

.day-node.active .day-name {
    color: var(--cp-primary);
}

.day-indicator {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    background: var(--cp-bg-secondary);
    color: var(--cp-text-muted);
}

.day-node.active .day-indicator {
    background: var(--cp-primary);
    color: white;
}

.day-diff {
    font-size: 0.6rem;
    font-weight: 600;
    padding: 2px 6px;
    border-radius: var(--cp-radius-full);
}

.day-diff.easy {
    background: var(--cp-easy-bg);
    color: var(--cp-easy);
}

.day-diff.medium {
    background: var(--cp-medium-bg);
    color: #B45309;
}

.day-diff.hard {
    background: var(--cp-hard-bg);
    color: var(--cp-hard);
}

.day-diff.ultra {
    background: var(--cp-ultra-bg);
    color: var(--cp-ultra);
}

/* ========================================================================
   Main Challenge Card (CLEAR & PROMINENT)
   ======================================================================== */
.main-challenge-card {
    background: var(--cp-bg-secondary);
    border-radius: var(--cp-radius-xl);
    border: 2px solid var(--cp-border);
    overflow: hidden;
    box-shadow: var(--cp-shadow-xl);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--cp-space-lg);
    background: var(--cp-bg-tertiary);
    border-bottom: 1px solid var(--cp-border);
}

.card-meta {
    display: flex;
    align-items: center;
    gap: var(--cp-space-md);
}

.card-date {
    font-size: 0.9rem;
    color: var(--cp-text-secondary);
    font-weight: 500;
}

.card-topic {
    padding: 4px 12px;
    background: var(--cp-bg-secondary);
    border: 1px solid var(--cp-border);
    border-radius: var(--cp-radius-full);
    font-size: 0.8rem;
    font-weight: 600;
}

.difficulty-tag {
    padding: 6px 16px;
    border-radius: var(--cp-radius-full);
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.difficulty-tag.easy {
    background: var(--cp-easy-bg);
    color: var(--cp-easy);
}

.difficulty-tag.medium {
    background: var(--cp-medium-bg);
    color: #B45309;
}

.difficulty-tag.hard {
    background: var(--cp-hard-bg);
    color: #DC2626;
}

.difficulty-tag.ultra {
    background: var(--cp-ultra-bg);
    color: var(--cp-ultra);
}

.card-body {
    padding: var(--cp-space-xl);
}

/* Question Styling */
.question-number {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--cp-primary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--cp-space-md);
    padding: 4px 12px;
    background: var(--cp-primary-subtle);
    border-radius: var(--cp-radius-full);
}

.question-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--cp-text-primary);
    line-height: 1.5;
    margin-bottom: var(--cp-space-xl);
}

/* Code Block */
.code-block {
    background: #1E293B;
    border-radius: var(--cp-radius-md);
    overflow: hidden;
    margin-bottom: var(--cp-space-xl);
}

.code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    background: #0F172A;
    border-bottom: 1px solid #334155;
}

.code-language {
    font-size: 0.7rem;
    font-weight: 600;
    color: #94A3B8;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.code-copy-btn {
    background: transparent;
    border: 1px solid #475569;
    color: #94A3B8;
    padding: 4px 12px;
    border-radius: var(--cp-radius-sm);
    font-size: 0.7rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--cp-transition-fast);
}

.code-copy-btn:hover {
    background: #334155;
    color: white;
}

.code-content {
    padding: 20px;
    font-family: var(--cp-font-mono);
    font-size: 0.9rem;
    line-height: 1.7;
    color: #E2E8F0;
    overflow-x: auto;
}

/* ========================================================================
   Options - CLEAR & PROMINENT
   ======================================================================== */
.options-grid {
    display: grid;
    gap: 14px;
}

.option-btn {
    display: flex;
    align-items: center;
    gap: var(--cp-space-md);
    padding: 20px 24px;
    background: var(--cp-bg-secondary);
    border: 2px solid var(--cp-border);
    border-radius: var(--cp-radius-lg);
    cursor: pointer;
    transition: var(--cp-transition-normal);
    text-align: left;
    font-family: inherit;
    width: 100%;
}

.option-btn:hover:not(.locked) {
    border-color: var(--cp-primary);
    background: var(--cp-primary-subtle);
    transform: translateX(6px);
    box-shadow: var(--cp-shadow-md);
}

.option-letter {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: var(--cp-bg-tertiary);
    border: 2px solid var(--cp-border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1rem;
    color: var(--cp-text-secondary);
    flex-shrink: 0;
    transition: var(--cp-transition-normal);
}

.option-btn:hover:not(.locked) .option-letter {
    background: var(--cp-primary);
    border-color: var(--cp-primary);
    color: white;
}

.option-text {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--cp-text-primary);
    line-height: 1.5;
}

/* Selected & Answer States */
.option-btn.selected {
    border-color: var(--cp-primary);
    background: var(--cp-primary-subtle);
}

.option-btn.selected .option-letter {
    background: var(--cp-primary);
    border-color: var(--cp-primary);
    color: white;
}

.option-btn.correct {
    border-color: var(--cp-easy);
    background: var(--cp-easy-bg);
}

.option-btn.correct .option-letter {
    background: var(--cp-easy);
    border-color: var(--cp-easy);
    color: white;
}

.option-btn.wrong {
    border-color: var(--cp-hard);
    background: var(--cp-hard-bg);
}

.option-btn.wrong .option-letter {
    background: var(--cp-hard);
    border-color: var(--cp-hard);
    color: white;
}

/* Explanation Area */
.explanation-area {
    margin-top: var(--cp-space-xl);
    padding-top: var(--cp-space-xl);
    border-top: 2px solid var(--cp-border);
    display: none;
}

.explanation-area.visible {
    display: block;
    animation: fadeSlideUp 0.4s ease;
}

.explanation-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--cp-text-primary);
    margin-bottom: var(--cp-space-md);
    display: flex;
    align-items: center;
    gap: 10px;
}

.explanation-content {
    font-size: 1.05rem;
    color: var(--cp-text-secondary);
    line-height: 1.8;
}

/* Loading State */
.loading-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--cp-space-3xl);
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--cp-border);
    border-top-color: var(--cp-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-text {
    margin-top: var(--cp-space-lg);
    color: var(--cp-text-muted);
    font-size: 0.95rem;
}

/* ========================================================================
   SEO Section (Below the Fold)
   ======================================================================== */
.seo-section {
    background: var(--cp-bg-tertiary);
    padding: var(--cp-space-3xl) var(--cp-space-lg);
    margin-top: var(--cp-space-2xl);
}

.seo-container {
    max-width: 1000px;
    margin: 0 auto;
}

.seo-header {
    text-align: center;
    margin-bottom: var(--cp-space-2xl);
}

.seo-header h1 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--cp-text-primary);
    margin-bottom: var(--cp-space-md);
}

.seo-header p {
    font-size: 1.1rem;
    color: var(--cp-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.seo-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--cp-space-xl);
    margin-bottom: var(--cp-space-2xl);
}

.seo-feature {
    background: var(--cp-bg-secondary);
    padding: var(--cp-space-xl);
    border-radius: var(--cp-radius-lg);
    text-align: center;
    border: 1px solid var(--cp-border);
}

.feature-icon {
    width: 56px;
    height: 56px;
    background: var(--cp-primary-subtle);
    border-radius: var(--cp-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--cp-space-md);
    color: var(--cp-primary);
}

.seo-feature h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--cp-text-primary);
    margin-bottom: var(--cp-space-sm);
}

.seo-feature p {
    font-size: 0.95rem;
    color: var(--cp-text-secondary);
    line-height: 1.6;
}

.seo-cta {
    text-align: center;
    background: linear-gradient(135deg, var(--cp-primary-subtle), #DDD6FE);
    padding: var(--cp-space-2xl);
    border-radius: var(--cp-radius-xl);
}

.seo-cta h2 {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--cp-text-primary);
    margin-bottom: var(--cp-space-sm);
}

.seo-cta p {
    color: var(--cp-text-secondary);
    margin-bottom: var(--cp-space-xl);
}

.cta-buttons {
    display: flex;
    gap: var(--cp-space-md);
    justify-content: center;
    flex-wrap: wrap;
}

.cta-primary {
    padding: 14px 32px;
    background: linear-gradient(135deg, var(--cp-primary), var(--cp-primary-dark));
    color: white;
    text-decoration: none;
    border-radius: var(--cp-radius-full);
    font-weight: 700;
    transition: var(--cp-transition-normal);
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

.cta-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.4);
}

.cta-secondary {
    padding: 14px 32px;
    background: var(--cp-bg-secondary);
    color: var(--cp-text-primary);
    text-decoration: none;
    border-radius: var(--cp-radius-full);
    font-weight: 700;
    border: 2px solid var(--cp-border);
    transition: var(--cp-transition-normal);
}

.cta-secondary:hover {
    border-color: var(--cp-primary);
    color: var(--cp-primary);
}

/* Quote Banner */
.quote-banner {
    background: var(--cp-bg-dark);
    padding: var(--cp-space-2xl) var(--cp-space-lg);
    text-align: center;
}

.quote-banner blockquote {
    font-size: 1.4rem;
    font-style: italic;
    color: var(--cp-text-inverse);
    margin-bottom: var(--cp-space-md);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.quote-banner cite {
    color: var(--cp-text-muted);
    font-size: 0.95rem;
}

/* ========================================================================
   Simple Clean Footer
   ======================================================================== */
.challenge-footer {
    background: var(--cp-bg-secondary);
    border-top: 1px solid var(--cp-border);
    padding: var(--cp-space-2xl) var(--cp-space-lg);
}

.footer-container {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--cp-space-2xl);
}

.footer-brand {
    margin-bottom: var(--cp-space-lg);
}

.footer-logo {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--cp-text-primary);
    text-decoration: none;
    display: inline-block;
    margin-bottom: var(--cp-space-sm);
}

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

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--cp-space-xl);
}

.footer-col h4 {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--cp-text-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--cp-space-md);
}

.footer-col a {
    display: block;
    color: var(--cp-text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    padding: 4px 0;
    transition: var(--cp-transition-fast);
}

.footer-col a:hover {
    color: var(--cp-primary);
}

.footer-bottom {
    max-width: 1000px;
    margin: var(--cp-space-xl) auto 0;
    padding-top: var(--cp-space-lg);
    border-top: 1px solid var(--cp-border);
    text-align: center;
}

.footer-bottom p {
    color: var(--cp-text-muted);
    font-size: 0.85rem;
}

/* ========================================================================
   Article Page Styles (Mistakes Students Make)
   ======================================================================== */
.article-page {
    font-family: var(--cp-font-sans);
    background: var(--cp-bg-primary);
    color: var(--cp-text-primary);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

.article-hero {
    background: linear-gradient(135deg, #0F172A 0%, #1E293B 50%, #334155 100%);
    padding: 100px 24px 120px;
    position: relative;
    overflow: hidden;
}

.article-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(ellipse 80% 50% at 50% 0%, rgba(244, 63, 94, 0.2), transparent),
        radial-gradient(ellipse 60% 40% at 20% 100%, rgba(79, 70, 229, 0.2), transparent);
    pointer-events: none;
}

.article-header {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.article-category {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(244, 63, 94, 0.2);
    border: 1px solid rgba(244, 63, 94, 0.3);
    padding: 8px 20px;
    border-radius: var(--cp-radius-full);
    font-size: 0.8rem;
    font-weight: 700;
    color: #FDA4AF;
    margin-bottom: var(--cp-space-lg);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.article-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    color: var(--cp-text-inverse);
    line-height: 1.2;
    margin-bottom: var(--cp-space-lg);
    letter-spacing: -0.02em;
}

.article-meta {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--cp-space-md);
    color: #94A3B8;
    font-size: 0.9rem;
}

.article-meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.article-meta-divider {
    width: 4px;
    height: 4px;
    background: #475569;
    border-radius: 50%;
}

/* Article Content */
.article-content {
    max-width: 720px;
    margin: -60px auto 0;
    padding: 0 24px var(--cp-space-3xl);
    position: relative;
    z-index: 10;
}

.article-body {
    background: var(--cp-bg-secondary);
    border-radius: var(--cp-radius-xl);
    padding: var(--cp-space-2xl);
    box-shadow: var(--cp-shadow-xl);
    border: 1px solid var(--cp-border);
}

.article-intro {
    font-size: 1.2rem;
    color: var(--cp-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--cp-space-2xl);
    padding-bottom: var(--cp-space-xl);
    border-bottom: 1px solid var(--cp-border);
}

.article-section {
    margin-bottom: var(--cp-space-2xl);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--cp-text-primary);
    margin-bottom: var(--cp-space-md);
    display: flex;
    align-items: center;
    gap: 12px;
}

.section-number {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--cp-primary), var(--cp-primary-dark));
    color: white;
    border-radius: var(--cp-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    font-weight: 700;
    flex-shrink: 0;
}

.section-content p {
    font-size: 1.05rem;
    color: var(--cp-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--cp-space-md);
}

/* Mistake Card */
.mistake-card {
    background: linear-gradient(135deg, #FEF2F2, #FEE2E2);
    border-left: 4px solid var(--cp-hard);
    border-radius: 0 var(--cp-radius-md) var(--cp-radius-md) 0;
    padding: var(--cp-space-lg);
    margin: var(--cp-space-lg) 0;
}

.mistake-label {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--cp-hard);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--cp-space-sm);
}

.mistake-text {
    font-size: 1rem;
    color: #7F1D1D;
    line-height: 1.7;
}

/* Fix Card */
.fix-card {
    background: linear-gradient(135deg, #ECFDF5, #D1FAE5);
    border-left: 4px solid var(--cp-easy);
    border-radius: 0 var(--cp-radius-md) var(--cp-radius-md) 0;
    padding: var(--cp-space-lg);
    margin: var(--cp-space-lg) 0;
}

.fix-label {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--cp-easy);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--cp-space-sm);
}

.fix-text {
    font-size: 1rem;
    color: #064E3B;
    line-height: 1.7;
}

/* Inline Code */
.article-body code {
    background: var(--cp-bg-tertiary);
    padding: 2px 8px;
    border-radius: var(--cp-radius-sm);
    font-family: var(--cp-font-mono);
    font-size: 0.9em;
    color: var(--cp-primary);
    border: 1px solid var(--cp-border);
}

/* CTA Section */
.article-cta {
    background: linear-gradient(135deg, var(--cp-primary-subtle), #DDD6FE);
    border-radius: var(--cp-radius-xl);
    padding: var(--cp-space-2xl);
    text-align: center;
    margin-top: var(--cp-space-2xl);
}

.cta-title {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--cp-text-primary);
    margin-bottom: var(--cp-space-md);
}

.cta-description {
    font-size: 1rem;
    color: var(--cp-text-secondary);
    margin-bottom: var(--cp-space-xl);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 16px 32px;
    background: linear-gradient(135deg, var(--cp-primary), var(--cp-primary-dark));
    color: white;
    text-decoration: none;
    border-radius: var(--cp-radius-full);
    font-weight: 700;
    font-size: 1rem;
    transition: var(--cp-transition-normal);
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(79, 70, 229, 0.4);
}

/* ========================================================================
   Animations
   ======================================================================== */
@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========================================================================
   Responsive Design
   ======================================================================== */
@media (max-width: 768px) {
    .nav-container {
        flex-wrap: wrap;
        height: auto;
        padding: var(--cp-space-md) 0;
        gap: var(--cp-space-md);
    }

    .nav-links {
        width: 100%;
        justify-content: center;
    }

    .nav-link {
        padding: 6px 12px;
        font-size: 0.8rem;
    }

    .challenge-intro {
        justify-content: center;
        text-align: center;
    }

    .challenge-badge {
        font-size: 0.9rem;
        padding: 8px 16px;
    }

    .main-challenge-card {
        border-width: 1px;
    }

    .card-header {
        flex-direction: column;
        gap: var(--cp-space-md);
        align-items: flex-start;
    }

    .card-body {
        padding: var(--cp-space-lg);
    }

    .question-text {
        font-size: 1.25rem;
    }

    .option-btn {
        padding: 16px 18px;
    }

    .option-letter {
        width: 36px;
        height: 36px;
        font-size: 0.9rem;
    }

    .option-text {
        font-size: 1rem;
    }

    .seo-header h1 {
        font-size: 1.5rem;
    }

    .footer-container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-links {
        grid-template-columns: repeat(3, 1fr);
        text-align: left;
    }

    .article-hero {
        padding: 80px 16px 100px;
    }

    .article-title {
        font-size: 1.75rem;
    }

    .article-body {
        padding: var(--cp-space-xl);
    }
}

@media (max-width: 480px) {
    .nav-links {
        flex-wrap: wrap;
    }

    .day-node {
        min-width: 45px;
        padding: 8px 10px;
    }

    .day-name {
        font-size: 0.55rem;
    }

    .footer-links {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--cp-space-lg);
    }

    .cta-buttons {
        flex-direction: column;
    }

    .article-meta {
        flex-direction: column;
        gap: var(--cp-space-sm);
    }
}