:root {
    --primary: #ff6b6b;
    --secondary: #4ecdc4;
    --accent: #ffe66d;
    --bg: #f7fff7;
    --text: #2f3542;
    --card-bg: rgba(255, 255, 255, 0.8);
}

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

body {
    font-family: 'Cairo', sans-serif;
    background: linear-gradient(135deg, #a1c4fd 0%, #c2e9fb 100%);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow-x: hidden;
}

.screen {
    width: 100%;
    max-width: 1200px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.screen.hidden {
    opacity: 0;
    pointer-events: none;
    position: absolute;
    transform: scale(0.9);
}

.screen.active {
    opacity: 1;
    pointer-events: all;
    position: relative;
    transform: scale(1);
}

.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    text-align: center;
    max-width: 500px;
    width: 100%;
    border: 2px solid white;
}

.glass-card h1 {
    color: var(--primary);
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.input-group {
    margin: 30px 0;
    text-align: right;
}

.input-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 700;
    color: var(--secondary);
    font-size: 1.2rem;
}

.input-group input {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--secondary);
    border-radius: 10px;
    font-size: 1.2rem;
    font-family: 'Cairo', sans-serif;
    outline: none;
    transition: box-shadow 0.3s ease;
}

.input-group input:focus {
    box-shadow: 0 0 15px rgba(78, 205, 196, 0.5);
}

.btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: 1.5rem;
    font-weight: 900;
    border-radius: 50px;
    cursor: pointer;
    font-family: 'Cairo', sans-serif;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 5px 15px rgba(255, 107, 107, 0.4);
}

.btn:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 20px rgba(255, 107, 107, 0.6);
}

.btn:active {
    transform: translateY(2px);
}

/* Lesson Screen */
header {
    text-align: center;
    margin-bottom: 40px;
    animation: slideDown 0.5s ease;
}

header h1 {
    color: var(--primary);
    font-size: 3rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
}

header h2 {
    color: var(--text);
    font-size: 1.8rem;
    background: var(--accent);
    display: inline-block;
    padding: 5px 20px;
    border-radius: 20px;
    margin-top: 10px;
    transform: rotate(-2deg);
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    width: 100%;
}

.part-card {
    background: white;
    border-radius: 15px;
    padding: 20px;
    text-align: center;
    cursor: pointer;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s, box-shadow 0.3s;
    border: 3px solid transparent;
    position: relative;
    overflow: hidden;
}

.part-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    border-color: var(--secondary);
}

.part-card::before {
    content: '';
    position: absolute;
    top: -50%; left: -50%;
    width: 200%; height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.8) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

.part-card:hover::before {
    opacity: 1;
}

.part-card .ar-text {
    font-size: 2rem;
    font-weight: 900;
    color: var(--primary);
    margin-bottom: 10px;
    display: block;
}

.part-card .en-text {
    font-family: 'Nunito', sans-serif;
    font-size: 1.2rem;
    color: #747d8c;
    font-weight: 700;
}

.part-card .icon-container {
    height: 60px;
    margin-bottom: 15px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.part-card .part-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.part-card .icon {
    font-size: 3rem;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-30px); }
    to { opacity: 1; transform: translateY(0); }
}