:root {
            --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            --secondary-bg: #f3f4f6;
            --card-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
            --hover-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
        }

        body {
            font-family: 'Poppins', sans-serif;
            background-color: #ebedef;
            background-image: radial-gradient(#d7dadd 1px, transparent 1px);
            background-size: 20px 20px;
            color: #495057;
        }

        /* Navbar Design */
        .navbar-custom {
            background: var(--primary-gradient);
          /*  box-shadow: 0 4px 15px rgba(118, 75, 162, 0.3);*/
            padding: 15px 0;
        }

        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            letter-spacing: 1px;
        }

        /* Card Design */
        .card-custom {
            /*border: none;*/
           /* border-radius: 20px; */
          /*  background: #ffffff; */
           /* box-shadow: var(--card-shadow);*/
           /* transition: transform 0.3s ease, box-shadow 0.3s ease;*/
            overflow: hidden;
        }

      /*  .card-custom:hover {
            transform: translateY(-5px);
            box-shadow: var(--hover-shadow);
        }
*/
        .card-header-custom {
            background: #fff;
            border-bottom: 1px solid #eee;
            padding: 20px 25px;
            font-weight: 600;
            color: #333;
            font-size: 1.1rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .card-header-custom i {
            color: #764ba2;
        }

        /* Toolbar Buttons */
        .toolbar-btn {
            border-radius: 50px;
            padding: 5px 10px;
            font-size: 0.8rem;
            border: 1px solid #e0e0e0;
            background: #f8f9fa;
            color: #555;
            transition: all 0.2s;
            margin-right: 5px;
            margin-bottom: 5px;
        }

        .toolbar-btn:hover {
            background: #e2e6ea;
            border-color: #dbe2e8;
            transform: scale(1.05);
        }

        /* Math Field */
        math-field {
            border: 2px solid #e9ecef;
           /* border-radius: 15px;*/
            padding: 15px;
            background: #fff;
           /* box-shadow: inset 0 2px 5px rgba(0, 0, 0, 0.02);*/
            transition: border-color 0.3s;
            min-height: 220px !important;
        }

        math-field:focus-within {
            border-color: #764ba2;
            outline: none;
        }

        /* Preview Area */
        .preview-box {
            background: #f8f9fa;
            border: 1px dashed #ced4da;
            border-radius: 15px;
            min-height: 150px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #666;
            overflow: auto;
        }

        /* Custom Buttons */
        .btn-gradient-primary {
            background: var(--primary-gradient);
            border: none;
            color: white;
            padding: 10px 20px;
            border-radius: 12px;
            font-weight: 500;
            box-shadow: 0 4px 10px rgba(118, 75, 162, 0.2);
        }

        .btn-gradient-primary:hover {
            opacity: 0.9;
            color: white;
            box-shadow: 0 6px 15px rgba(118, 75, 162, 0.3);
        }

        /* Calculator Styles */
        .calc-input {
           /* border-radius: 12px;*/
            padding: 12px;
            border: 2px solid #e9ecef;
        }

        .calc-input:focus {
            border-color: #667eea;
            box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
        }

        .result-box {
            background: linear-gradient(to right, #d4fc79, #96e6a1);
            color: #155724;
            border: none;
            border-radius: 12px;
        }
        
        .btn-gradient-danger {
    background: linear-gradient(45deg, #ff4b5c, #d90429);
    color: #fff !important;
    border: none;
}
.btn-gradient-danger:hover {
    background: linear-gradient(45deg, #ff6b81, #ef233c);
}



/* এক্টিভ বাটন বোঝানোর জন্য স্টাইল */
.btn-active-tool {
    background: #764ba2 !important;
    color: #fff !important;
    border-color: #764ba2 !important;
}


  /* Mathfield internal styles */
     
        .ML__content{ overflow: auto; }

        /* Copy Button Style */
        .copy-btn-overlay {
            position: absolute;
            top: 5px;
            right: 5px;
            z-index: 10;
        }

        /* Footer Links Hover */
        .footer-link {
            color: #adb5bd;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer-link:hover {
            color: #fff;
        }
        
        /* Feature Icon Box */
        .feature-icon {
            width: 50px;
            height: 50px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            margin-bottom: 15px;
        }
        


/* Feature Icons (Colorful Boxes) */
.feature-icon-box {
    width: 55px;
    height: 55px;
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

/* Gradient Colors for icons */
.icon-purple { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); }
.icon-blue   { background: linear-gradient(135deg, #89f7fe 0%, #66a6ff 100%); }
.icon-orange { background: linear-gradient(135deg, #f6d365 0%, #fda085 100%); }

.feature-icon-box:hover {
    transform: translateY(-5px); /* Hover animation */
}

/* Footer Styling */
.footer-custom {
    background-color: #1a1a2e; /* Dark Navy Background */
    color: #b8b8d1;
    padding-top: 60px;
    padding-bottom: 20px;
    margin-top: 80px;
    border-top: 5px solid #764ba2; /* Top colored border */
}

.footer-title {
    color: #fff;
    font-weight: 600;
    margin-bottom: 20px;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-link {
    color: #b8b8d1;
    text-decoration: none;
    display: block;
    margin-bottom: 12px;
    transition: all 0.2s;
    font-size: 0.8rem;
}

.footer-link:hover {
    color: #fff;
    padding-left: 8px; /* Slide effect on hover */
}

.footer-social-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    margin-right: 10px;
    text-decoration: none;
    transition: 0.3s;
}

.footer-social-btn:hover {
    background: #764ba2;
    transform: scale(1.1);
}






/* Calculator Grid System - Compact Version */


/* Calculator Grid System - Compact Version */
.calc-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr); /* 4 columns */
    gap: 3px; /* Reduced gap (was 8px) */
}

.calc-grid button {
    height: 35px; /* Reduced height (was 45px) */
    font-size: 13px; /* Smaller text */
    padding: 0px; /* Remove extra padding */
    transition: all 0.2s;
}

.calc-grid button:hover {
    transform: translateY(-1px); 
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.calc-grid button:active {
    transform: translateY(0px);
}