:root {
    --primary: #3a86ff;
    --primary-dark: #2667cc;
    --secondary: #8338ec;
    --dark: #212529;
    --light: #f8f9fa;
    --gray: #6c757d;
    --success: #06d6a0;
    --warning: #ffbe0b;
    --danger: #ef476f;
    --border-radius: 12px;
    --shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s ease;
    --card-bg: #ffffff;
    --body-bg: #f5f7fa;
}

/* Modo oscuro */
@media (prefers-color-scheme: dark) {
    :root {
        --dark: #f8f9fa;
        --light: #212529;
        --card-bg: #2d3748;
        --body-bg: #1a202c;
        --gray: #a0aec0;
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.main-container {
    background: var(--body-bg);
    color: var(--dark);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
    transition: var(--transition);
}

.container {
    width: 95%;
    margin: 0 auto;
}

.header-title {
    text-align: center;
    padding: 40px 20px;
}

h1 {
    font-size: 2.8rem;
    margin-bottom: 15px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    font-weight: 800;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--gray);
    max-width: 700px;
    margin: 0 auto 30px;
}

.main-tabs {
    display: flex;
    justify-content: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 10px;
}

.tab-button {
    padding: 12px 24px;
    background: none;
    border: none;
    border-radius: 30px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    color: var(--gray);
    position: relative;
}

.tab-button.active {
    color: var(--primary);
}

.tab-button.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 50%;
    transform: translateX(-50%);
    width: 30px;
    height: 3px;
    background: var(--primary);
    border-radius: 3px;
}

.tab-button:hover {
    color: var(--primary);
}

.tab-content {
    display: none;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 30px;
    margin-bottom: 40px;
    transition: var(--transition);
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.tool-card {
    margin-bottom: 30px;
}

.tool-card h2 {
    margin-bottom: 20px;
    color: var(--primary);
    display: flex;
    align-items: center;
}

.tool-card h2 i {
    margin-right: 10px;
}

.input-group {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 10px;
    margin-bottom: 20px;
}

@media (max-width: 600px) {
    .input-group {
        grid-template-columns: 1fr;
    }
}

input, select {
    padding: 12px 15px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
    background: #fbfbfb;
    color: #000000;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(58, 134, 255, 0.2);
}

button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

button:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

button:disabled {
    background: var(--gray);
    cursor: not-allowed;
    transform: none;
}

button i {
    margin-right: 8px;
}

.result-container {
    margin-top: 30px;
    padding: 20px;
    border-radius: var(--border-radius);
    background: rgba(58, 134, 255, 0.1);
    border-left: 4px solid var(--primary);
    display: none;
}

.result-title {
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--primary);
    display: flex;
    align-items: center;
}

.result-title i {
    margin-right: 10px;
}

.result-content {
    font-size: 1.1rem;
    line-height: 1.8;
}

.prime-number {
    color: var(--success);
    font-weight: 600;
}

.not-prime {
    color: var(--danger);
    font-weight: 600;
}

.factors-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 10px;
}

.factor {
    padding: 5px 10px;
    background: rgba(6, 214, 160, 0.2);
    border-radius: 5px;
    font-weight: 600;
}

.prime-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
    gap: 8px;
    margin-top: 15px;
    max-height: 300px;
    overflow-y: auto;
    padding: 5px;
}

.prime-item {
    padding: 8px;
    text-align: center;
    background: rgba(58, 134, 255, 0.1);
    border-radius: 5px;
    transition: var(--transition);
}

.prime-item:hover {
    background: rgba(58, 134, 255, 0.2);
    transform: scale(1.05);
}

.loading {
    display: none;
    text-align: center;
    margin: 20px 0;
}

.loading-spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-radius: 50%;
    border-top: 4px solid var(--primary);
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.stat-card {
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-card h3 {
    color: var(--primary);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
}

.stat-card h3 i {
    margin-right: 10px;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.stat-description {
    color: var(--gray);
    font-size: 0.9rem;
}

.info-text {
    background: rgba(58, 134, 255, 0.1);
    padding: 20px;
    border-radius: var(--border-radius);
    margin: 30px 0;
    border-left: 4px solid var(--primary);
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin: 40px 0;
}

.feature-card {
    background: var(--card-bg);
    padding: 25px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card i {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 15px;
}

.feature-card h3 {
    margin-bottom: 10px;
    color: var(--dark);
}



@media (max-width: 600px) {
    h1 {
        font-size: 2.2rem;
    }
    
    .main-content {
        padding: 0 10px;
    }
    
    .tab-content {
        padding: 20px;
    }
}

 /* ===== ARTICLE SPECIFIC STYLES - NO BODY STYLES ===== */
 #primes-guide-article {
      width: 95%;
      margin: 0 auto;
      padding: 2rem 1.5rem 3rem 1.5rem;
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    }

    /* Hero Section */
    .primes-guide-hero {
      text-align: center;
      margin-bottom: 2.5rem;
      padding: 2rem 1.5rem;
      background: linear-gradient(135deg, #3a86ff 0%, #8338ec 100%);
      border-radius: 32px;
      box-shadow: 0 12px 30px rgba(58, 134, 255, 0.3);
    }

    .primes-guide-hero h2 {
      font-size: 2.6rem;
      font-weight: 800;
      color: white;
      margin-bottom: 1rem;
      letter-spacing: -0.02em;
      font-family: 'Montserrat', serif;
    }

    .primes-guide-hero .primes-hero-sub {
      font-size: 1.2rem;
      color: rgba(255, 255, 255, 0.9);
      max-width: 720px;
      margin: 0 auto;
      line-height: 1.5;
    }

    .primes-guide-meta {
      display: flex;
      justify-content: center;
      gap: 2rem;
      color: rgba(255, 255, 255, 0.8);
      font-weight: 500;
      margin-top: 1.2rem;
      flex-wrap: wrap;
    }

    .primes-guide-meta span i {
      margin-right: 0.5rem;
    }

    /* Main Content */
    .primes-main-content {
      background: white;
      border-radius: 28px;
      padding: 2rem 2rem 2.5rem 2rem;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
      border: 1px solid rgba(58, 134, 255, 0.15);
    }

    .primes-main-content h2 {
      font-size: 1.8rem;
      font-weight: 700;
      margin-top: 2rem;
      margin-bottom: 1rem;
      color: #3a86ff;
      border-left: 5px solid #8338ec;
      padding-left: 1rem;
      font-family: 'Montserrat', serif;
    }

    .primes-main-content h2:first-of-type {
      margin-top: 0;
    }

    .primes-main-content h3 {
      font-size: 1.35rem;
      font-weight: 600;
      margin: 1.5rem 0 0.75rem 0;
      color: #8338ec;
    }

    .primes-main-content p {
      font-size: 1.05rem;
      color: #2d3748;
      margin-bottom: 1.2rem;
      line-height: 1.6;
    }

    .primes-main-content ul, .primes-main-content ol {
      margin: 1rem 0 1.2rem 1.8rem;
      color: #2d3748;
      line-height: 1.6;
    }

    .primes-main-content li {
      margin-bottom: 0.5rem;
    }

    .primes-highlight-box {
      background: linear-gradient(135deg, rgba(58, 134, 255, 0.08), rgba(131, 56, 236, 0.05));
      border-left: 6px solid #8338ec;
      padding: 1.25rem 1.5rem;
      border-radius: 20px;
      margin: 1.75rem 0;
    }

    .primes-formula-box {
      background: rgba(58, 134, 255, 0.1);
      border-radius: 16px;
      padding: 1rem 1.5rem;
      margin: 1rem 0;
      font-family: 'Courier New', monospace;
      font-size: 1.1rem;
      text-align: center;
      border: 1px dashed #3a86ff;
    }

    .primes-pro-tip {
      background: rgba(131, 56, 236, 0.1);
      border-radius: 20px;
      padding: 1.2rem 1.5rem;
      margin: 1.5rem 0;
      display: flex;
      gap: 1rem;
      align-items: flex-start;
      border: 1px solid rgba(58, 134, 255, 0.3);
    }

    .primes-pro-tip i {
      font-size: 1.8rem;
      color: #8338ec;
    }

    .primes-stats-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 1.2rem;
      margin: 2rem 0;
    }

    .primes-stat-card {
      background: #f5f7fa;
      border-radius: 20px;
      padding: 1.2rem;
      text-align: center;
      transition: all 0.2s;
      border: 1px solid rgba(58, 134, 255, 0.2);
    }

    .primes-stat-card .stat-number {
      font-size: 2rem;
      font-weight: 800;
      color: #3a86ff;
      margin-bottom: 0.25rem;
    }

    .primes-quote-block {
      background: #f5f7fa;
      padding: 1.5rem;
      border-radius: 24px;
      text-align: center;
      font-style: italic;
      margin: 1.5rem 0;
      border: 1px solid rgba(58, 134, 255, 0.2);
    }

    .primes-quote-block i {
      font-size: 2rem;
      color: #8338ec;
      margin-bottom: 0.5rem;
      display: inline-block;
    }

    .primes-table-wrapper {
      overflow-x: auto;
      margin: 1.5rem 0;
    }

    .primes-famous-table {
      width: 100%;
      border-collapse: collapse;
      background: #f5f7fa;
      border-radius: 16px;
      overflow: hidden;
    }

    .primes-famous-table th, .primes-famous-table td {
      padding: 12px 16px;
      text-align: left;
      border-bottom: 1px solid rgba(58, 134, 255, 0.2);
    }

    .primes-famous-table th {
      background: rgba(58, 134, 255, 0.1);
      font-weight: 600;
      color: #3a86ff;
    }

    .primes-famous-table tr:hover {
      background: rgba(131, 56, 236, 0.05);
    }

    .primes-algorithms-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 1.2rem;
      margin: 1.5rem 0;
    }

    .primes-algorithm-card {
      background: #f5f7fa;
      border-radius: 16px;
      padding: 1.2rem;
      border: 1px solid rgba(58, 134, 255, 0.2);
      transition: all 0.2s;
    }

    .primes-algorithm-card:hover {
      transform: translateY(-3px);
      box-shadow: 0 8px 20px rgba(58, 134, 255, 0.1);
    }

    .primes-algorithm-title {
      font-weight: 700;
      color: #3a86ff;
      margin-bottom: 0.5rem;
      font-size: 1.1rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .primes-footer-note {
      margin-top: 2.5rem;
      text-align: center;
      font-size: 0.85rem;
      color: #718096;
      border-top: 1px solid #e2e8f0;
      padding-top: 2rem;
    }

    @media (max-width: 768px) {
      .primes-guide-hero h2 {
        font-size: 2rem;
      }
      .primes-main-content {
        padding: 1.5rem;
      }
      #primes-guide-article {
        padding: 1rem;
      }
    }