/* Corners Layout and Sidebar Styles */
:root {
    --student-primary: #667eea;
    --student-secondary: #764ba2;
    --teacher-primary: #667eea;
    --teacher-secondary: #764ba2;
    --sidebar-bg: #1e293b;
    /* Darker professional sidebar */
    --sidebar-text: #cbd5e1;
    --sidebar-active: #ffffff;
    --content-bg: #f1f5f9;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --card-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
    --sidebar-width: 280px;
}

body.corner-body {
    background-color: var(--content-bg);
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

.corner-layout {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Styling - Full Height */
.corner-sidebar {
    width: var(--sidebar-width);
    flex-shrink: 0;
    background: var(--sidebar-bg);
    padding: 30px 0;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    z-index: 100;
    transition: all 0.3s ease;
}

.sidebar-header {
    padding: 0 25px 30px 25px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 20px;
}

.sidebar-header h3 {
    font-size: 20px;
    font-weight: 800;
    margin: 0;
    color: #fff;
    letter-spacing: 0.5px;
}

.teacher-corner-page .sidebar-header h3 {
    background: linear-gradient(135deg, var(--teacher-primary), var(--teacher-secondary));
}

.sidebar-menu {
    list-style: none;
    padding: 0 15px;
    margin: 0;
    flex-grow: 1;
}

.sidebar-menu li {
    margin-bottom: 5px;
}

.sidebar-menu a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 15px;
    text-decoration: none !important;
    color: var(--sidebar-text);
    font-weight: 500;
    border-radius: 10px;
    transition: all 0.2s ease;
    font-size: 14px;
}

.sidebar-menu a i {
    font-size: 18px;
    width: 24px;
    text-align: center;
    opacity: 0.8;
}

.sidebar-menu a:hover {
    background: rgba(255, 255, 255, 0.05);
    color: #fff;
    transform: translateX(4px);
}

.sidebar-menu li.active a {
    background: var(--student-primary);
    color: #fff;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.teacher-corner-page .sidebar-menu li.active a {
    background: var(--teacher-primary);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.sidebar-footer {
    padding: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-footer a {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--sidebar-text);
    text-decoration: none;
    font-size: 14px;
    padding: 10px;
    border-radius: 8px;
    transition: background 0.3s;
}

.sidebar-footer a:hover {
    background: rgba(255, 255, 255, 0.05);
    color: #fff;
}

/* Main Content Area */
.corner-content {
    flex-grow: 1;
    margin-left: var(--sidebar-width);
    padding: 40px;
    width: calc(100% - var(--sidebar-width));
}

.content-card {
    background: #fff;
    border-radius: 20px;
    padding: 35px;
    box-shadow: var(--card-shadow);
    margin-bottom: 30px;
    border: 1px solid rgba(0, 0, 0, 0.03);
}

.content-header {
    margin-bottom: 35px;
}

.content-header h1 {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 8px;
    color: #0f172a;
}

.content-header p {
    color: var(--text-muted);
    font-size: 15px;
}

/* Resource Grid */
.resource-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 25px;
}

.resource-card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    padding: 25px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    text-align: center;
}

.resource-card:hover {
    border-color: transparent;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    transform: translateY(-8px);
}

.resource-card i {
    font-size: 36px;
    margin-bottom: 18px;
    display: inline-block;
    padding: 15px;
    border-radius: 12px;
}

.student-corner-page .resource-card i {
    background: #f0f4ff;
    color: var(--student-primary);
}

.teacher-corner-page .resource-card i {
    background: #f0f4ff;
    color: var(--teacher-primary);
}

.resource-card h4 {
    font-size: 17px;
    font-weight: 700;
    margin-bottom: 10px;
    color: #1e293b;
}

.resource-card p {
    font-size: 13.5px;
    color: var(--text-muted);
    line-height: 1.6;
    margin: 0;
}

@media (max-width: 992px) {
    .corner-sidebar {
        width: 80px;
        padding: 20px 0;
    }

    .sidebar-header h3,
    .sidebar-menu a span,
    .sidebar-footer a span {
        display: none;
    }

    .corner-content {
        margin-left: 80px;
        width: calc(100% - 80px);
    }

    .sidebar-menu {
        padding: 0 10px;
    }

    .sidebar-menu a {
        justify-content: center;
        padding: 15px;
    }

    .sidebar-menu a i {
        margin: 0;
        font-size: 22px;
    }
}