/* Reset và nền tối */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #121212;
    color: #e0e0e0;
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    max-width: 1000px;
    width: 100%;
    background-color: #1e1e1e;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.6);
    border: 1px solid #333;
}

h1 {
    text-align: center;
    color: #bb86fc;
    margin-bottom: 25px;
    font-weight: 400;
    letter-spacing: 1px;
}

/* Hộp tìm kiếm */
.search-box {
    display: flex;
    gap: 12px;
    margin-bottom: 30px;
    justify-content: center;
}

#searchInput {
    flex: 1;
    padding: 14px 20px;
    background-color: #2c2c2c;
    border: 1px solid #444;
    border-radius: 10px;
    font-size: 16px;
    color: #f0f0f0;
    transition: border-color 0.3s, box-shadow 0.3s;
}

#searchInput:focus {
    border-color: #bb86fc;
    outline: none;
    box-shadow: 0 0 0 3px rgba(187, 134, 252, 0.3);
}

#searchInput::placeholder {
    color: #888;
}

#searchBtn {
    padding: 14px 30px;
    background-color: #bb86fc;
    color: #121212;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.1s;
}

#searchBtn:hover {
    background-color: #9f6fdf;
}

#searchBtn:active {
    transform: scale(0.97);
}

/* Khu vực kết quả */
#result {
    background-color: #252525;
    padding: 20px 24px;
    border-radius: 12px;
    margin-bottom: 30px;
    min-height: 120px;
    line-height: 1.7;
    border-left: 4px solid #bb86fc;
}

#result h2 {
    margin-top: 0;
    color: #e0e0e0;
    border-bottom: 1px solid #3a3a3a;
    padding-bottom: 10px;
    font-weight: 400;
}

#result p {
    margin: 10px 0;
}

#result strong {
    color: #bb86fc;
}

/* Danh sách nguyên tố dạng lưới */
#elementList {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 14px;
}

.element-item {
    background-color: #2a2a2a;
    padding: 14px 10px;
    border-radius: 10px;
    text-align: center;
    border: 1px solid #3a3a3a;
    cursor: pointer;
    transition: transform 0.2s, background-color 0.2s, box-shadow 0.2s;
}

.element-item:hover {
    transform: translateY(-4px);
    background-color: #333;
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.4);
    border-color: #bb86fc;
}

.element-item .symbol {
    font-size: 1.8em;
    font-weight: bold;
    color: #bb86fc;
}

.element-item .number {
    font-size: 0.85em;
    color: #888;
    margin-top: 4px;
}

.element-item .name {
    font-size: 0.95em;
    color: #ccc;
    margin-top: 2px;
}

/* Responsive nhỏ */
@media (max-width: 600px) {
    .container {
        padding: 16px;
    }
    #elementList {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    }
    .search-box {
        flex-direction: column;
    }
    #searchBtn {
        width: 100%;
    }
}