:root {
            --primary: #4361ee;
            --primary-dark: #3a56d4;
            --secondary: #f72585;
            --accent: #4cc9f0;
            --dark: #212529;
            --light: #f8f9fa;
            --gray: #6c757d;
            --light-gray: #e9ecef;
            --success: #38b000;
            --warning: #ff9e00;
            --danger: #ef233c;
            --border-radius: 12px;
            --shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
            --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s ease;
            --max-width: 1200px;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        .main-container {
            background: linear-gradient(135deg, #f5f7fa 0%, #e4e7f1 100%);
            color: var(--dark);
            line-height: 1.6;
            min-height: 100vh;
            padding: 20px;
        }
        
        .container {
            max-width: var(--max-width);
            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;
        }
        
        .calculator-tabs {
            display: flex;
            justify-content: center;
            margin-bottom: 30px;
            flex-wrap: wrap;
            gap: 10px;
        }
        
        .tab-btn {
            padding: 12px 24px;
            background: white;
            border: none;
            border-radius: 50px;
            cursor: pointer;
            font-weight: 600;
            transition: var(--transition);
            box-shadow: var(--shadow-sm);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .tab-btn i {
            font-size: 1.1rem;
        }
        
        .tab-btn.active {
            background: var(--primary);
            color: white;
        }
        
        .tab-btn:hover:not(.active) {
            background: var(--light-gray);
        }
        
        .calculator-container {
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            overflow: hidden;
            margin-bottom: 40px;
        }
        
        .tab-content {
            display: none;
            padding: 30px;
        }
        
        .tab-content.active {
            display: block;
        }
        
        .calculator-title {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 20px;
            color: var(--primary);
        }
        
        .calculator-title i {
            font-size: 1.5rem;
        }
        
        .input-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-bottom: 25px;
        }
        
        .input-group {
            display: flex;
            flex-direction: column;
            gap: 8px;
        }
        
        .input-group label {
            font-weight: 600;
            color: #cad2db;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .input-group label i {
            color: var(--gray);
            font-size: 0.9rem;
        }
        
        .input-group input, .input-group select {
            padding: 12px 15px;
            border: 1px solid var(--light-gray);
            border-radius: 8px;
            font-size: 1rem;
            transition: var(--transition);
        }
        
        .input-group input:focus, .input-group select:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
        }
        
        .proportion-selector {
            display: flex;
            gap: 15px;
            margin-bottom: 20px;
        }
        
        .proportion-btn {
            padding: 10px 20px;
            background: white;
            border: 2px solid var(--light-gray);
            border-radius: 8px;
            cursor: pointer;
            font-weight: 600;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .proportion-btn.active {
            border-color: var(--primary);
            background: rgba(67, 97, 238, 0.1);
            color: var(--primary);
        }
        
        .proportion-btn:hover:not(.active) {
            border-color: var(--gray);
        }
        
        .calculate-btn {
            background: var(--primary);
            color: white;
            border: none;
            padding: 14px 28px;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 600;
            transition: var(--transition);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            font-size: 1.1rem;
            margin: 25px auto;
            width: 100%;
            max-width: 300px;
        }
        
        .calculate-btn:hover {
            background: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: var(--shadow-sm);
        }
        
        .calculate-btn i {
            font-size: 1.2rem;
        }
        
        .result-container {
            background: #f8f9fa;
            border-radius: var(--border-radius);
            padding: 25px;
            margin-top: 30px;
            display: none;
        }
        
        .result-container.show {
            display: block;
            animation: fadeIn 0.5s ease;
        }
        
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        .result-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 15px;
            padding-bottom: 10px;
            border-bottom: 1px solid var(--light-gray);
        }
        
        .result-title {
            display: flex;
            align-items: center;
            gap: 10px;
            color: var(--success);
            font-size: 1.3rem;
        }
        
        .result-value {
            font-size: 2rem;
            font-weight: 700;
            color: var(--primary);
            text-align: center;
            margin: 20px 0;
        }
        
        .result-steps {
            background: white;
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
        }
        
        .step {
            margin-bottom: 15px;
            padding-bottom: 15px;
            border-bottom: 1px dashed var(--light-gray);
        }
        
        .step:last-child {
            margin-bottom: 0;
            padding-bottom: 0;
            border-bottom: none;
        }
        
        .step-title {
            font-weight: 600;
            margin-bottom: 8px;
            color: #edf1f5;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .step-content {
            color: var(--gray);
        }
        
        .step-formula {
            font-family: 'Courier New', Courier, monospace;
            background: var(--light-gray);
            padding: 8px 12px;
            border-radius: 6px;
            display: inline-block;
            margin: 5px 0;
            font-weight: 600;
        }
        
        .copy-btn {
            background: var(--light-gray);
            color: var(--dark);
            border: none;
            padding: 8px 15px;
            border-radius: 6px;
            cursor: pointer;
            font-weight: 500;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 6px;
            font-size: 0.9rem;
        }
        
        .copy-btn:hover {
            background: var(--gray);
            color: white;
        }
        
        .educational-content {
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            padding: 40px;
            margin-bottom: 40px;
        }
        
        .section-title {
            font-size: 1.8rem;
            margin-bottom: 20px;
            color: var(--primary);
            display: flex;
            align-items: center;
            gap: 12px;
        }
        
        .section-title i {
            font-size: 1.5rem;
        }
        
        .content-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
            margin-top: 30px;
        }
        
        .content-card {
            background: var(--light);
            border-radius: var(--border-radius);
            padding: 25px;
            transition: var(--transition);
            border-left: 4px solid var(--primary);
        }
        
        .content-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-sm);
        }
        
        .content-card h3 {
            color: var(--primary);
            margin-bottom: 15px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .content-card h3 i {
            font-size: 1.3rem;
        }
        
        .examples-container {
            margin: 30px 0;
        }
        
        .example {
            background: var(--light);
            border-radius: var(--border-radius);
            padding: 20px;
            margin-bottom: 15px;
        }
        
        .example-title {
            font-weight: 600;
            margin-bottom: 10px;
            color: #4361ee;
        }
        
        .faq-container {
            margin-top: 40px;
        }
        
        .faq-item {
            margin-bottom: 15px;
            border: 1px solid var(--light-gray);
            border-radius: var(--border-radius);
            overflow: hidden;
        }
        
        .faq-question {
            background: var(--light);
            padding: 15px 20px;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .faq-question:hover {
            background: #f1f3f5;
        }
        
        .faq-answer {
            padding: 0 20px;
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease, padding 0.3s ease;
        }
        
        .faq-item.active .faq-answer {
            padding: 15px 20px;
            max-height: 500px;
        }
        
        
        
        .notification {
            position: fixed;
            top: 20px;
            right: 20px;
            padding: 15px 25px;
            background: var(--success);
            color: white;
            border-radius: 8px;
            box-shadow: var(--shadow);
            transform: translateX(150%);
            transition: transform 0.3s ease;
            z-index: 1000;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .notification.show {
            transform: translateX(0);
        }
        
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            
            .calculator-tabs {
                flex-direction: column;
                align-items: stretch;
            }
            
            .tab-btn {
                justify-content: center;
            }
            
            .educational-content, .calculator-container {
                padding: 20px;
            }
            
            .input-grid {
                grid-template-columns: 1fr;
            }
            
            .proportion-selector {
            display: grid;
        }
        }
        
        
        @media (prefers-color-scheme: dark) {
            body {
               
            }
            
            .calculator-container, .educational-content, 
            .content-card, .example, .faq-item,
            .tab-btn, .proportion-btn, .input-group input,
            .input-group select, .result-steps {
                background: #1e1e1e;
                color: #8488f7;
            }
            
            .input-group input, .input-group select {
                border-color: #333;
                background: #2d2d2d;
                color: #e0e0e0;
            }
            
            .result-container {
                background: #252525;
            }
            
            .step-formula {
                background: #333;
                color: #fff;
            }
            
            .copy-btn {
                background: #333;
                color: #e0e0e0;
            }
            
            .copy-btn:hover {
                background: #444;
            }
            
            .faq-question {
                background: #252525;
            }
            
            .faq-question:hover {
                background: #2d2d2d;
            }
        }

 /* ===== ARTICLE SPECIFIC STYLES - NO BODY STYLES ===== */
 #proportion-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 */
    .proportion-guide-hero {
      text-align: center;
      margin-bottom: 2.5rem;
      padding: 2rem 1.5rem;
      background: linear-gradient(135deg, #4361ee 0%, #f72585 100%);
      border-radius: 32px;
      box-shadow: 0 12px 30px rgba(67, 97, 238, 0.3);
    }

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

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

    .proportion-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;
    }

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

    /* Main Content */
    .proportion-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(67, 97, 238, 0.15);
    }

    .proportion-main-content h2 {
      font-size: 1.8rem;
      font-weight: 700;
      margin-top: 2rem;
      margin-bottom: 1rem;
      color: #4361ee;
      border-left: 5px solid #f72585;
      padding-left: 1rem;
      font-family: 'Montserrat', serif;
    }

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

    .proportion-main-content h3 {
      font-size: 1.35rem;
      font-weight: 600;
      margin: 1.5rem 0 0.75rem 0;
      color: #f72585;
    }

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

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

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

    .proportion-highlight-box {
      background: linear-gradient(135deg, rgba(67, 97, 238, 0.08), rgba(247, 37, 133, 0.05));
      border-left: 6px solid #f72585;
      padding: 1.25rem 1.5rem;
      border-radius: 20px;
      margin: 1.75rem 0;
    }

    .proportion-pro-tip {
      background: rgba(247, 37, 133, 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(67, 97, 238, 0.3);
    }

    .proportion-pro-tip i {
      font-size: 1.8rem;
      color: #f72585;
    }

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

    .proportion-stat-card {
      background: #f8f9fa;
      border-radius: 20px;
      padding: 1.2rem;
      text-align: center;
      transition: all 0.2s;
      border: 1px solid rgba(67, 97, 238, 0.2);
    }

    .proportion-stat-card .stat-number {
      font-size: 2rem;
      font-weight: 800;
      color: #4361ee;
      margin-bottom: 0.25rem;
    }

    .proportion-quote-block {
      background: #f8f9fa;
      padding: 1.5rem;
      border-radius: 24px;
      text-align: center;
      font-style: italic;
      margin: 1.5rem 0;
      border: 1px solid rgba(67, 97, 238, 0.2);
    }

    .proportion-quote-block i {
      font-size: 2rem;
      color: #f72585;
      margin-bottom: 0.5rem;
      display: inline-block;
    }

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

    .proportion-examples-table {
      width: 100%;
      border-collapse: collapse;
      background: #f8f9fa;
      border-radius: 16px;
      overflow: hidden;
    }

    .proportion-examples-table th, .proportion-examples-table td {
      padding: 12px 16px;
      text-align: left;
      border-bottom: 1px solid rgba(67, 97, 238, 0.2);
    }

    .proportion-examples-table th {
      background: rgba(67, 97, 238, 0.1);
      font-weight: 600;
      color: #4361ee;
    }

    .proportion-examples-table tr:hover {
      background: rgba(247, 37, 133, 0.05);
    }

    .proportion-formula-card {
      background: #f8f9fa;
      border-radius: 16px;
      padding: 1.2rem;
      margin: 1rem 0;
      text-align: center;
      border: 1px solid rgba(67, 97, 238, 0.2);
    }

    .proportion-formula {
      font-family: 'Courier New', monospace;
      font-size: 1.3rem;
      font-weight: 700;
      color: #4361ee;
      background: white;
      display: inline-block;
      padding: 0.5rem 1rem;
      border-radius: 12px;
      margin: 0.5rem 0;
    }

    .proportion-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) {
      .proportion-guide-hero h2 {
        font-size: 2rem;
      }
      .proportion-main-content {
        padding: 1.5rem;
      }
      #proportion-guide-article {
        padding: 1rem;
      }
    }