:root{
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #212529;
    --navbar-brand-text: var(--text-color);
    --navbar-bg: #0d6efd; /* keep existing blue for light */
    --border-color: #dee2e6;
    --muted: #6c757d;
    --landing-navbar-bg: #ffffff;
    --landing-hero-bg: #f8fafc;
    --landing-section-bg: #ffffff;
    --landing-info-bg: #f1f5f9;
    --landing-card-bg: #ffffff;
    --landing-border-color: #e2e8f0;
    --landing-muted: #6c757d;
    --landing-shadow: 0 28px 80px rgba(13, 110, 253, 0.12);
    --landing-cta-bg: linear-gradient(135deg, #2563eb, #1d4ed8);
}

html[data-theme="dark"]{
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-color: #f1f1f1;
    --navbar-brand-text: #f8fafc;
    --navbar-bg: #0d1117;
    --border-color: #30363d;
    --muted: #9aa4b2;
    --landing-navbar-bg: #1e293b;
    --landing-hero-bg: #0f172a;
    --landing-section-bg: #0f172a;
    --landing-info-bg: #1e293b;
    --landing-card-bg: #1e293b;
    --landing-border-color: #334155;
    --landing-muted: #94a3b8;
    --landing-shadow: 0 28px 80px rgba(0, 0, 0, 0.45);
    --landing-cta-bg: linear-gradient(135deg, #2563eb, #1d4ed8);
}

/* Smooth transitions */
.transition-theme{
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body, .card, .table, .modal-content, .form-control, .form-select, .list-group-item {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body{
    background-color: var(--bg-color) !important;
    color: var(--text-color) !important;
}

.navbar.bg-primary{
    background-color: var(--navbar-bg) !important;
}
.navbar .navbar-brand, .navbar .nav-link{
    color: rgba(255,255,255,0.95) !important;
}

.card{
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
    border: 1px solid var(--border-color) !important;
}

.bg-card{ background-color: var(--card-bg) !important; color: var(--text-color) !important }

/* Override Bootstrap utility that uses white or light background so it's theme-aware */
.bg-white, .bg-light{ background-color: var(--card-bg) !important; color: var(--text-color) !important }
.text-bg-light{ background-color: var(--card-bg) !important; color: var(--text-color) !important }

.table, .table th, .table td{
    background-color: transparent;
    color: var(--text-color) !important;
    border-color: var(--border-color) !important;
}

.form-control, .form-select, .form-floating > label{
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
    border: 1px solid var(--border-color) !important;
}

.form-control::placeholder,
.form-select::placeholder,
textarea::placeholder {
    color: var(--muted) !important;
    opacity: 1 !important;
}

.form-control:focus,
.form-select:focus,
textarea:focus {
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
    border-color: var(--border-color) !important;
    box-shadow: 0 0 0 0.25rem rgba(13,110,253,0.15);
}

.modal-content{
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
    border-color: var(--border-color) !important;
}

/* Tweak btn-outline-light for dark mode so it remains visible */
html[data-theme="dark"] .btn-outline-light{
    color: var(--text-color) !important;
    border-color: rgba(255,255,255,0.2) !important;
}

/* Ensure text utility classes adapt */
.text-black{ color: var(--text-color) !important }
.text-muted{ color: var(--muted) !important }

/* Theme Toggle icon sizing */
#themeIcon svg{ width: 18px; height: 18px; display:block }

/* Alerts should follow theme */
.alert{
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
    border: 1px solid var(--border-color) !important;
}
.alert-light{
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
    border-color: var(--border-color) !important;
}

/* Sidebar layout */
.app-shell{
    min-height: 100vh;
    display: flex;
    background-color: var(--bg-color);
}

.sidebar{
    width: 260px;
    min-width: 260px;
    background-color: var(--navbar-bg);
    color: #ffffff;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    overflow-y: auto;
    z-index: 1030;
    transition: transform 0.3s ease;
}

.sidebar-scroll{
    overflow-y: auto;
    padding-right: 0.5rem;
}

.sidebar-brand{
    padding: 1rem 1.25rem;
    border-bottom: 1px solid rgba(255,255,255,0.15);
}

.sidebar-brand .brand-text{
    font-weight: 600;
    color: #fff;
}

.sidebar-heading{
    color: rgba(255,255,255,0.88);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.sidebar-section + .sidebar-section{
    margin-top: 1rem;
}

.sidebar-link{
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: rgba(255,255,255,0.95);
    padding: 0.75rem 1rem;
    border-radius: 0.75rem;
    text-decoration: none;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.sidebar-link:hover,
.sidebar-link.active{
        background-color: rgba(255,255,255,0.18);
        color: #ffffff;
    }

    .sidebar-link.active{
        font-weight: 600;
        border-left: 4px solid #0d6efd;
        background-color: rgba(13,110,253,0.16);
        box-shadow: inset 0 0 0 1px rgba(255,255,255,0.08);
    }

    .sidebar-link{
        transition: transform 0.2s ease, background-color 0.2s ease;
    }

    .sidebar-link:hover{
        transform: translateX(2px);
    }

    .sidebar-group-toggle{
        justify-content: space-between;
        font-weight: 600;
        color: rgba(255,255,255,0.95);
        background: transparent;
        border: none;
        width: 100%;
        text-align: left;
        padding: 0.75rem 1rem;
    }

    .sidebar-group-toggle i.bi-chevron-down{
        transition: transform 0.2s ease;
    }

    .collapse.show + .sidebar-link,
    .sidebar-link.active + .sidebar-link{
        margin-left: 0;
    }

    .sidebar-group-toggle[aria-expanded="true"] i.bi-chevron-down{
        transform: rotate(180deg);
    }

    .sidebar-section .collapse .sidebar-link{
        padding-left: 2.5rem;
    }

    .sidebar-section .collapse .sidebar-link.active{
        background-color: rgba(13,110,253,0.18);
    }

.sidebar-close{
    border: none;
}

.main-content{
    margin-left: 260px;
    width: calc(100% - 260px);
    min-width: 0;
    min-height: 100vh;
    transition: margin-left 0.3s ease, width 0.3s ease;
}

}

.topbar{
    border-bottom: 1px solid rgba(255,255,255,0.12);
}

.chart-container{
    position: relative;
    height: 320px;
    width: 100%;
}

.chart-container canvas{
    width: 100% !important;
    height: 100% !important;
}


.content-wrapper{
    min-height: calc(100vh - 64px);
    padding-top: 1rem;
}

body.sidebar-show .sidebar{
    transform: translateX(0);
}

body.sidebar-collapsed .sidebar{
    transform: translateX(-260px);
}

body.sidebar-collapsed .main-content{
    margin-left: 0;
    width: 100%;
}

.sidebar-backdrop{
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.35);
    z-index: 1020;
}

body.sidebar-show .sidebar-backdrop{
    display: block;
}

@media (max-width: 991.98px) {
    .sidebar{
        width: 100%;
        min-width: 0;
        transform: translateX(-100%);
        position: fixed;
    }

    .main-content{
        margin-left: 0;
        width: 100%;
    }

    body.sidebar-show .sidebar{
        transform: translateX(0);
    }
}

/* List groups and their items */
.list-group{
    background-color: transparent !important;
}
.list-group-item{
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
    border: 1px solid var(--border-color) !important;
}

.card-kpi{
    border-radius: 1rem;
    overflow: hidden;
}

.card-kpi .card-body{
    padding: 1.2rem 1.25rem;
}

.kpi-icon{
    width: 52px;
    height: 52px;
    min-width: 52px;
    border-radius: 0.9rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    color: #fff !important;
}

.bg-purple{background-color: #6f42c1 !important;}
.bg-purple.bg-opacity-15{background-color: rgba(111,66,193,0.15) !important;}

.chart-card{
    border-radius: 1rem;
    overflow: hidden;
}

.card-overview{
    border-radius: 1rem;
}

.overview-metric{
    background-color: var(--bg-color);
}

.card-hover{
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card-hover:hover{
    transform: translateY(-3px);
    box-shadow: 0 16px 40px rgba(0,0,0,0.06);
}

.chart-card canvas{
    width: 100% !important;
}

.card-kpi:hover,
.card-overview:hover,
.chart-card:hover{
    box-shadow: 0 14px 30px rgba(0,0,0,0.08);
}

/* Card footers used as action bars */
.card-footer{
    background-color: var(--card-bg) !important;
    border-top: 1px solid var(--border-color) !important;
    color: var(--text-color) !important;
}

/* Progress background tweak for dark */
.progress{
    background-color: rgba(255,255,255,0.06) !important;
}

/* Reduced spacing for specific student nav items */
.navbar .nav-item.nav-tight .nav-link{
    padding-left: 0.25rem !important;
    padding-right: 0.25rem !important;
    white-space: nowrap;
}
.navbar .nav-item.nav-tight{
    margin-right: 0.35rem;
}

@media (min-width: 768px) {
    /* Keep navbar items on a single line on md+ viewports */
    .navbar-nav {
        flex-wrap: nowrap !important;
    }
}

/* Authentication page styles */
.auth-page{
    min-height: 100vh;
    background-color: var(--bg-color);
}
.auth-header{
    background: var(--card-bg);
}

/* Ensure auth header brand text stays readable in dark mode */
html[data-theme="dark"] .auth-header a.text-dark,
html[data-theme="dark"] .auth-header a.text-dark span {
    color: var(--navbar-brand-text) !important;
}
.auth-main{
    min-height: calc(100vh - 72px);
}
.auth-page .card{
    border-radius: 1rem;
}