:root {
    --header-height: 60px;
    --sidebar-width: 200px;
    --footer-height: 40px;
}

/* Body setup */
html, body {
    height: 100%;
    margin: 0;
    font-size: 16px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    scroll-behavior: smooth;
}

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #000;
    padding: 10px 20px;
    color: white;
    height: var(--header-height);
}

.header-left {
    display: flex;
    align-items: center;
}

    .header-left .hamburger {
        width: 30px;
        height: 22px;
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        cursor: pointer;
        z-index: 1000;
        margin-right: 80px;
    }

.hamburger span {
    height: 3px;
    width: 100%;
    background: white;
    border-radius: 2px;
    transition: all 0.3s ease;
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

.header-left .brand {
    color: white;
    font-weight: bold;
    font-size: 1.5rem;
    text-decoration: none;
}

/* Header nav */
.header-nav {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
    align-items: center;
}

.header-item {
    display: flex;
    align-items: center;
    margin-left: 20px;
}

/* Logout button */
.logout-btn {
    display: flex;
    align-items: center;
    color: white;
    text-decoration: none;
    border: 1.5px solid white;
    padding: 5px 12px;
    border-radius: 4px;
    font-size: 1rem;
    transition: background-color 0.3s, color 0.3s;
}

    .logout-btn:hover {
        background-color: white;
        color: cadetblue;
    }

/* Main layout */
.main-container {
    display: flex;
    height: calc(100vh - var(--header-height));
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: #000;
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    overflow-x: hidden;
    transition: width 0.3s ease;
}

    .sidebar a,
    .sidebar-submenu li a,
    .sidebar-dropdown-toggle {
        display: block;
        padding: 10px 15px;
        text-decoration: none;
        font-size: 16px;
        color: white;
        cursor: pointer;
    }

        .sidebar-submenu li a:hover {
            background-color: purple;
            border-radius: 4px;
        }

        .sidebar-dropdown-toggle,
        .sidebar-dropdown-toggle span.text,
        .sidebar-dropdown-toggle i {
            color: white !important;
        }

/* Hide submenu initially */
.sidebar-submenu {
    display: none;
    padding-left: 15px;
}

    .sidebar-submenu li a {
        transition: background-color 0.3s, padding-left 0.3s;
    }

.sidebar ul {
    list-style-type: none;
    padding-left: 0;
}

.sidebar li {
    margin: 5px 0;
}

.sidebar a i {
    margin-right: 8px;
}

/* Collapsed sidebar */
.sidebar.collapsed {
    width: 50px;
    padding: 0;
}

    .sidebar.collapsed a span.text {
        display: none;
    }

    .sidebar.collapsed a {
        justify-content: center;
    }

/* Sidebar footer */
.sidebar-footer {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding: 10px 15px;
    font-size: 0.85rem;
    text-align: center;
    border-top: 1px solid rgba(255,255,255,0.2);
    width: 100%;
    transition: padding 0.3s ease, font-size 0.3s ease;
}

    .sidebar-footer i {
        font-size: 1rem;
        flex-shrink: 0;
        margin-right: 8px;
        transition: margin 0.3s ease;
    }

    .sidebar-footer span.text {
        display: inline-block;
        transition: opacity 0.3s ease, max-width 0.3s ease;
        overflow: hidden;
        max-width: 200px;
        vertical-align: middle;
        white-space: nowrap;
    }

.sidebar.collapsed .sidebar-footer {
    padding: 10px 0;
    font-size: 1.2rem;
    width: 50px;
    justify-content: center;
}

    .sidebar.collapsed .sidebar-footer span.text {
        opacity: 0;
        max-width: 0;
        pointer-events: none;
        margin: 0;
    }

    .sidebar.collapsed .sidebar-footer i {
        margin-right: 0;
    }

/* Main content */
.main-content {
    flex: 1;
    background: white;
    overflow-y: auto;
    padding: 20px;
}