/* الألوان والمتغيرات */

:root {
    --bg-color: #f0f4f8;
    --calculator-bg: #ffffff;
    --display-bg: #eef3f7;
    --btn-bg: #f5f8fa;
    --operator-btn-bg: #007bff;
    --equals-btn-bg: #28a745;
    --action-btn-bg: #dc3545;
    --text-color: #333;
    --operator-text-color: #fff;
    --equals-text-color: #fff;
    --shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    --hover-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    direction: rtl;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 2rem;
    color: #0056b3;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    animation: fadeInDown 1s ease-in-out;
}

header p {
    font-size: 1.1rem;
    color: #666;
    animation: fadeInUp 1s ease-in-out;
}

.calculator {
    background-color: var(--calculator-bg);
    border-radius: 20px;
    padding: 25px;
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 400px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.calculator:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
}

.display-container {
    background-color: var(--display-bg);
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 20px;
    text-align: right;
    overflow: hidden;
    position: relative;
}

.preview {
    font-size: 1.2rem;
    color: #888;
    min-height: 25px;
    word-wrap: break-word;
    white-space: pre-wrap;
    animation: slideInRight 0.5s ease;
}

.display {
    font-size: 3rem;
    font-weight: bold;
    min-height: 50px;
    word-wrap: break-word;
    white-space: pre-wrap;
    transition: font-size 0.3s ease;
    animation: slideInRight 0.5s ease;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

.buttons button {
    border: none;
    outline: none;
    font-size: 1.5rem;
    padding: 20px 0;
    border-radius: 10px;
    cursor: pointer;
    background-color: var(--btn-bg);
    color: var(--text-color);
    transition: background-color 0.2s ease, transform 0.1s ease, box-shadow 0.2s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.buttons button:active {
    transform: scale(0.95);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
}

.buttons button:hover {
    background-color: #e0e6ec;
}

.operator-btn {
    background-color: var(--operator-btn-bg);
    color: var(--operator-text-color);
}

.operator-btn:hover {
    background-color: #0069d9;
}

.equals-btn {
    background-color: var(--equals-btn-bg);
    color: var(--equals-text-color);
    font-size: 2rem;
}

.equals-btn:hover {
    background-color: #218838;
}

.action-btn {
    color: #fff;
}

.action-btn.clear {
    background-color: #ffc107;
    color: #212529;
}

.action-btn.clear:hover {
    background-color: #e0a800;
}

.action-btn.backspace {
    background-color: var(--action-btn-bg);
}

.action-btn.backspace:hover {
    background-color: #c82333;
}

.btn-zero {
    grid-column: span 2;
}

footer {
    margin-top: 2rem;
    text-align: center;
    width: 100%;
    max-width: 400px;
}

.footer-links {
    display: flex;
    justify-content: space-around;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 10px;
}

.footer-links a {
    text-decoration: none;
    color: #007bff;
    font-size: 0.9rem;
    padding: 8px 12px;
    border-radius: 5px;
    transition: background-color 0.2s ease;
    display: flex;
    align-items: center;
    gap: 5px;
}

.footer-links a:hover {
    background-color: rgba(0, 123, 255, 0.1);
}

.developer-btn {
    background-color: #343a40;
    color: #fff !important;
}

.developer-btn:hover {
    background-color: #1d2124;
}

.copyright {
    color: #6c757d;
    font-size: 0.8rem;
    margin-top: 1rem;
}


/* الأنماط الحركية */

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
    }
    to {
        transform: translateX(0);
    }
}


/* التجاوب مع الأجهزة الصغيرة */

@media (max-width: 480px) {
    .buttons {
        grid-template-columns: repeat(4, 1fr);
        gap: 10px;
    }
    .buttons button {
        font-size: 1.2rem;
        padding: 15px 0;
    }
}