:root {
            --primary: #1a4731;
            --secondary: #2d6a4f;
            --accent: #40916c;
            --gold: #d4a373;
            --cream: #faf6f1;
            --dark: #1b4332;
            --background: #f8f9fa;
            --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            --card-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            --text-tertiary: var(--gold);
        }
        
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, var(--cream) 0%, var(--background) 100%);
            min-height: 100vh;
            padding: 60px 10px 20px;
            display: flex;
            flex-direction: column;
            align-items: center;
            position: relative;
        }
        
        .language-selector {
            position: fixed;
            top: 15px;
            right: 15px;
            z-index: 1000;
            background: var(--cream);
            border-radius: 25px;
            padding: 5px;
            box-shadow: var(--shadow);
            border: 2px solid var(--gold);
        }
        
        .language-selector select {
            border: none;
            background: transparent;
            color: var(--dark);
            font-weight: 600;
            font-size: 0.8rem;
            padding: 5px 10px;
            border-radius: 20px;
            cursor: pointer;
            outline: none;
        }
        
        .home-button {
            position: fixed;
            bottom: 20px;
            right: 20px;
            width: 60px;
            height: 60px;
            background: linear-gradient(145deg, var(--primary), var(--secondary));
            border: none;
            border-radius: 50%;
            color: white;
            font-size: 1.5rem;
            cursor: pointer;
            box-shadow: var(--card-shadow);
            transition: var(--transition);
            z-index: 1000;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        .home-button:hover {
            transform: scale(1.1);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        
        .calculator {
            background: linear-gradient(145deg, var(--cream), white);
            border-radius: 25px;
            box-shadow: var(--card-shadow);
            max-width: 380px;
            width: 100%;
            margin: 0 auto;
            padding: 20px;
            border: 3px solid var(--gold);
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            min-height: calc(100vh - 80px);
        }
        
        .calculator-header {
            text-align: center;
            margin-bottom: 15px;
        }
        
        .calculator-header h1 {
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            font-size: 1.6rem;
            font-weight: 700;
            margin-bottom: 5px;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }
        
        .calculator-header p {
            color: var(--gold);
            font-size: 0.85rem;
            font-weight: 500;
        }
        
        .display {
            background: linear-gradient(135deg, var(--background), var(--cream));
            border-radius: 20px;
            padding: 15px;
            box-shadow: inset 0 3px 10px rgba(0, 0, 0, 0.08);
            border: 2px solid var(--accent);
            flex-grow: 1;
            margin-bottom: 15px;
        }
        
        .input-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
            margin-bottom: 15px;
        }
        
        .input-group {
            display: flex;
            flex-direction: column;
        }
        
        .input-group.full-width {
            grid-column: 1 / -1;
        }
        
        .input-group label {
            font-size: 0.85rem;
            color: var(--dark);
            font-weight: 600;
            margin-bottom: 5px;
            text-align: center;
        }
        
        .input-group input,
        .input-group select {
            padding: 12px;
            border: 2px solid var(--accent);
            border-radius: 15px;
            text-align: center;
            font-size: 0.9rem;
            font-weight: 500;
            background: white;
            color: var(--dark);
            transition: var(--transition);
        }
        
        .input-group input:focus,
        .input-group select:focus {
            outline: none;
            border-color: var(--gold);
            box-shadow: 0 0 0 3px rgba(212, 163, 115, 0.2);
            transform: scale(1.02);
        }
        
        .results-section {
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            border-radius: 15px;
            padding: 12px;
            margin: 15px 0;
            color: white;
        }
        
        .result {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin: 8px 0;
            padding: 8px;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 10px;
            backdrop-filter: blur(10px);
        }
        
        .result-label {
            font-weight: 600;
            font-size: 0.85rem;
        }
        
        .result-value {
            font-weight: 700;
            font-size: 1.1rem;
            color: var(--gold);
            text-shadow: 1px 1px 2px rgba(0,0,0,0.3);
        }
        
        .buttons {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
        }
        
        .btn {
            padding: 15px;
            border: none;
            border-radius: 20px;
            font-size: 0.9rem;
            font-weight: 700;
            cursor: pointer;
            transition: var(--transition);
            text-transform: uppercase;
            letter-spacing: 0.5px;
            position: relative;
            overflow: hidden;
        }
        
        .btn::before {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            width: 0;
            height: 0;
            background: rgba(255, 255, 255, 0.2);
            border-radius: 50%;
            transform: translate(-50%, -50%);
            transition: width 0.3s, height 0.3s;
        }
        
        .btn:active::before {
            width: 300px;
            height: 300px;
        }
        
        .calculate-btn {
            background: linear-gradient(145deg, var(--accent), var(--secondary));
            color: white;
            box-shadow: var(--shadow);
        }
        
        .calculate-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 15px rgba(64, 145, 108, 0.3);
        }
        
        .reset-btn {
            background: linear-gradient(145deg, var(--gold), #b8905a);
            color: white;
            box-shadow: var(--shadow);
        }
        
        .reset-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 15px rgba(212, 163, 115, 0.3);
        }
        
        .footer {
            text-align: center;
            font-size: 0.7rem;
            color: var(--text-tertiary);
            font-weight: 500;
            margin-top: 10px;
        }

        .faq-container {
            max-width: 700px;
            width: 100%;
            margin: 40px auto;
            padding: 0 10px;
        }

        .faq-title {
            text-align: center;
            font-size: 2rem;
            color: var(--dark);
            margin-bottom: 25px;
            font-weight: 700;
        }

        .faq-accordion .faq-item {
            background-color: #fff;
            border-radius: 15px;
            margin-bottom: 15px;
            box-shadow: var(--card-shadow);
            border: 1px solid var(--cream);
            transition: var(--transition);
        }

        .faq-accordion .faq-item:hover {
            transform: translateY(-2px);
            box-shadow: 0 12px 25px rgba(0,0,0,0.08);
        }

        .faq-question {
            background-color: transparent;
            border: none;
            width: 100%;
            text-align: left;
            padding: 20px;
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--primary);
            cursor: pointer;
            position: relative;
            outline: none;
        }
        
        html[lang="ar"] .faq-question {
            text-align: right;
        }

        .faq-question::after {
            content: '+';
            font-family: monospace;
            font-size: 1.8rem;
            position: absolute;
            right: 20px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--gold);
            transition: transform 0.3s ease;
        }
        
        html[lang="ar"] .faq-question::after {
            right: auto;
            left: 20px;
        }

        .faq-question.active::after {
            transform: translateY(-50%) rotate(45deg);
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), padding 0.4s ease;
            color: var(--secondary);
            font-size: 0.95rem;
            line-height: 1.6;
        }

        .faq-answer p, .faq-answer ul {
            padding: 0 20px 20px 20px;
        }
        
        .faq-answer ul {
            padding-left: 40px;
        }
        
        html[lang="ar"] .faq-answer ul {
             padding-left: 20px;
             padding-right: 40px;
        }
        
        html[lang="ar"] body {
            direction: rtl;
        }
        
        html[lang="ar"] .language-selector {
            right: auto;
            left: 15px;
        }
        
        html[lang="ar"] .home-button {
            right: auto;
            left: 20px;
        }
        
        @media (max-height: 700px) {
            .calculator {
                padding: 15px;
                min-height: auto;
            }
            .calculator-header h1 {
                font-size: 1.4rem;
                margin-bottom: 3px;
            }
            .display {
                padding: 12px;
            }
            .input-grid {
                gap: 10px;
                margin-bottom: 12px;
            }
            .results-section {
                margin: 12px 0;
                padding: 10px;
            }
        }