/* General Styles */
body {
    font-family: 'Roboto', sans-serif;
    margin: 0;
    background-color: #f4f4f9;
    color: #333;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%239C92AC' fill-opacity='0.1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

/* Header */
header {
    background-color: #4a90e2;
    color: white;
    padding: 1rem;
    display: flex;
    align-items: center;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1), 0 2px 4px rgba(0,0,0,0.1);
}

#menu-toggle {
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    margin-right: 1rem;
    border-radius: 8px;
    padding: 0.5rem;
    transition: background-color 0.3s, box-shadow 0.3s;
}

#menu-toggle:hover {
    background: rgba(255,255,255,0.2);
    box-shadow: 0 0 10px rgba(255,255,255,0.5);
}

header h1 {
    margin: 0;
    font-size: 2rem;
    text-align: center;
    flex-grow: 1;
}

/* Main Content */
main {
    display: flex;
    padding: 1rem;
}

/* Category List */
#category-list {
    position: fixed;
    top: 0;
    left: 0;
    width: 250px;
    height: 100%;
    background-color: #fff;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%239C92AC' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    box-shadow: 4px 0 15px rgba(0,0,0,0.2), 2px 0 5px rgba(0,0,0,0.1);
    transform: translateX(-100%);
    transition: transform 0.3s ease-in-out;
    z-index: 1000;
}

#category-list.show {
    transform: translateX(0);
}

#category-list h2 {
    font-size: 1.5rem;
    margin: 1rem;
    color: #4a90e2;
}

#category-list ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

#category-list li {
    padding: 1rem;
    cursor: pointer;
    border-bottom: 1px solid #eee;
    transition: background-color 0.3s, color 0.3s, box-shadow 0.3s;
}

#category-list li:hover {
    background-color: #4a90e2;
    color: white;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.1);
}

#category-list li.active {
    background-color: #4a90e2;
    color: white;
    font-weight: bold;
    box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
}

/* Menu Overlay */
#menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.6);
    z-index: 999;
}

.hidden {
    display: none;
}

/* Notes Container */
#notes-container {
    flex-grow: 1;
    padding-left: 1rem;
}

#notes-container h2 {
    font-size: 1.5rem;
    margin-top: 0;
}

#notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1rem;
}

/* Note Card Custom Element */
note-card {
    display: block;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1), 0 2px 4px rgba(0,0,0,0.1);
    padding: 1rem;
    transition: box-shadow 0.3s;
}

note-card:hover {
    box-shadow: 0 8px 16px rgba(0,0,0,0.2), 0 4px 8px rgba(0,0,0,0.1);
}