/* --- CSS Variables & Reset --- */
:root {
    --header-height: 60px;
    --sidebar-width: 250px;
    --sidebar-width-narrow: 80px;
    --primary-bg: #2c3e50;
    --secondary-bg: #34495e;
    --text-color: #ecf0f1;
    --accent-color: #337ab7; /*#3498db;*/
    --body-bg: #f4f6f7;
    --topbar-bg: #ffffff;
    --topbar-text: #333333;
    --main-text: #333333;
}

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

html, body {
/*    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; */
    font-size: 14px;
}

body {
    background-color: var(--body-bg);
    color: var(--main-text);
    display: flex;
    flex-direction: column;
    height: 100vh;
}


/* --- Top Bar --- */
.top-bar {
    width: 100%;
    height: var(--header-height);
    background-color: var(--topbar-bg);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    z-index: 1000;
    .btn {
        display: flex;
        gap: 10px;
        align-items: center;
        padding: 20px;
        border: none;
        border-radius: 0;
        box-shadow: none;
        background-color: var(--topbar-bg);
    }
    .left-section {
        display: flex;
        align-items: center;
        gap: 15px;
    }
    .hamburger {
        display: block;
        background: none;
        border: none;
        font-size: 24px;
        cursor: pointer;
        color: var(--topbar-text);
    }
    a.app-logo {
        font-size: 1.8rem;
        font-weight: bold;
        color: var(--topbar-text);
        text-decoration: none;
    }
    .right-section {
        display: flex;
        align-items: center;
        .dropdown-menu {
            right: 0;
            left: auto;
        }
    }
}

/* --- Navigation sidebar --- */
.nav-sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--header-height));
    background-color: var(--primary-bg);
    color: var(--text-color);
    overflow-y: auto;
    transition: transform 0.3s ease-in-out;
    z-index: 999;
    a:focus, a:hover {
        text-decoration: none;
        color: var(--text-color);
    }
    i.link-icon {
        width: 14px;
    }
    .nav-list {
        list-style: none;
    }
    .nav-item {
        border-bottom: 1px solid rgba(255,255,255,0.05);

        &.open .sub-menu {
            max-height: 500px;
        }

        /* Arrow Icon Animation */
        .arrow {
            font-size: 12px;
            transition: transform 0.3s;
        }
        &.open .arrow {
            transform: rotate(180deg);
        }
    }

    /* Links and Toggle Headers */
    .nav-link {
        display: flex;
        align-items: center;
        padding: 15px 20px;
        color: var(--text-color);
        text-decoration: none;
        cursor: pointer;
        transition: background 0.2s;
        user-select: none;
        gap: 15px;
        &:hover {
            background-color: var(--secondary-bg);
        }
        &.active {
            background-color: var(--accent-color);
            color: #fff;
        }
        .link-text {
            flex-grow: 1;
        }
    }

    /* Collapsible Sub-menus */
    .sub-menu {
        list-style: none;
        background-color: rgba(0,0,0,0.2);
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease-out;
        li a {
            display: block;
            padding: 12px 20px 12px 40px; /* Indented */
            color: #bdc3c7;
            text-decoration: none;
            font-size: 0.95em;
            &:hover {
                color: #fff;
                background-color: rgba(255,255,255,0.05);
            }
            &.active {
                background-color: var(--accent-color);
                color: #fff;
            }
        }
    }

}

/* --- Narrow Mode (Desktop) --- */
body.narrow {
    .main-content, footer {
        margin-left: var(--sidebar-width-narrow);
    }
    .nav-sidebar {
        width: var(--sidebar-width-narrow);
        overflow: visible;
        .nav-link {
            flex-direction: column;
            text-align: center;
            padding: 15px 5px;
            gap: 5px;
        }
        .link-text {
            font-size: 0.85em;
            width: 100%;
            /* white-space: nowrap; */
            overflow: hidden;
            text-overflow: ellipsis;
        }
        .arrow {
            display: none;
        }

        /* Floating submenus in narrow mode */
        .nav-item {
            position: relative;
        }

        .sub-menu {
            position: absolute;
            left: 100%;
            top: 0;
            width: 200px;
            background-color: var(--primary-bg);
            box-shadow: 2px 2px 5px rgba(0,0,0,0.2);
            display: none;
            max-height: none;
            overflow: visible;
        }

        .nav-item.open .sub-menu {
            display: block;
            max-height: none;
        }

        .nav-item.has-active-child .nav-link {
            background-color: var(--accent-color);
            color: #fff;
        }
    }
}

/* --- Main Content --- */
.main-content {
    margin-left: var(--sidebar-width);
    padding: 20px;
    transition: margin-left 0.3s ease-in-out;
    overflow: auto;
}
@media (max-width: 768px) {
    .main-content {
        padding: 5px;
    }

}
.main-container {
    .page-header {
        margin: 0;
    }
}

footer {
    display: flex;
    height: var(--header-height);
    margin-top: 20px;
    align-items: center;
    .footer-left {
        width: 50%;
        display: flex;
        justify-content: center;
        .footer-image {}
    }
    .footer-right {
        width: 50%;
        display: flex;
        justify-content: center;
        .footer-contact {}
    }
}

.page-content {
    background-color: white;
    padding: 20px;
}

.view-container {
    display: flex;
    gap: 50px;
    .sidebar {
        width: 25%;
        max-width: fit-content;
    }
    .view-body {
        flex-grow: 1;
    }
}

/* --- Responsive Design (Small Screens) --- */
@media (max-width: 768px) {
    .nav-sidebar {
        transform: translateX(-100%); /* Hide sidebar off-screen */
    }

    .nav-sidebar.active {
        transform: translateX(0); /* Slide sidebar in */
    }

    .main-content, footer {
        margin-left: 0; /* Content takes full width */
    }
}

/* --- Breadcrumb --- */
.breadcrumb {
    margin-bottom: 20px;
    padding: 0;
    font-size: 0.9rem;
    color: var(--main-text);
    opacity: 0.7;
}

/* --- Loading Spinner --- */
.loading-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0);
    z-index: 3000;
    justify-content: center;
    align-items: center;
}

.loading-overlay.active {
    display: flex;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid rgba(128, 128, 128, 0.2);
    border-top: 5px solid var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}