/* Google Classroom-Style Layout - Premium Modern Redesign */

/* Main Layout Container */
.classroom-layout {
    display: flex;
    min-height: 100vh;
    background-color: var(--color-bg);
    overflow-x: hidden;
    /* Prevent horizontal overflow on course pages */
}

/* Sidebar Navigation */
.classroom-sidebar {
    position: fixed;
    left: 0;
    top: 64px;
    /* Below top bar */
    width: 300px;
    /* Standard width */
    height: calc(100vh - 64px);
    background-color: var(--color-surface);
    border-right: none;
    /* Removed border */
    overflow-y: auto;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 100;
    padding-top: 24px;
    /* More breathing room */
}

.classroom-sidebar.collapsed {
    transform: translateX(-300px);
}

/* Sidebar Navigation Items */
.sidebar-nav {
    padding: 0 16px;
    /* Increased horizontal padding */
}

.sidebar-nav-item {
    display: flex;
    align-items: center;
    padding: 0 24px;
    height: 56px;
    /* Taller for touch/premium feel */
    color: var(--color-text-secondary);
    /* Softer dark gray */
    text-decoration: none;
    font-size: 15px;
    /* Slightly larger */
    font-weight: 500;
    font-family: 'Google Sans', 'Roboto', Arial, sans-serif;
    border-radius: 0 28px 28px 0;
    /* Fully rounded pill right */
    transition: all 0.2s cubic-bezier(0.2, 0, 0, 1);
    cursor: pointer;
    border: none;
    background: none;
    width: 100%;
    /* Full width minus margin if needed */
    text-align: left;
    margin-bottom: 8px;
    /* More space between items */
    letter-spacing: .01em;
}

.sidebar-nav-item:hover {
    background-color: var(--color-surface-variant);
    /* Subtle hover */
    border-radius: 0 24px 24px 0;
}

.sidebar-nav-item.active {
    background-color: var(--color-accent-light, rgba(197, 168, 128, 0.08));
    /* Active state gold */
    color: var(--google-blue-600);
    border-radius: 0 24px 24px 0;
}

.sidebar-nav-item i {
    width: 24px;
    margin-right: 24px;
    /* Spacing between icon and text */
    font-size: 22px;
    /* Larger icons */
    color: var(--color-text-secondary);
    display: flex;
    /* Center icon */
    justify-content: center;
    transition: color 0.2s;
}

.sidebar-nav-item:hover i {
    color: var(--color-text-primary);
}

.sidebar-nav-item.active i {
    color: var(--google-blue-600);
}

/* Top Bar - Floating & Clean */
.classroom-topbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 64px;
    background-color: rgba(255, 255, 255, 0.95);
    /* Glass-ish */
    backdrop-filter: blur(8px);
    border-bottom: none;
    /* Removed border */
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
    /* Very subtle separation */
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    /* Increased padding */
    z-index: 200;
}

.topbar-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.topbar-menu-btn {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: none;
    background: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #5f6368;
    transition: background-color 0.2s;
}

.topbar-menu-btn:hover {
    background-color: rgba(60, 64, 67, 0.08);
}

.topbar-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    margin-left: 8px;
}

.topbar-logo img {
    height: 36px;
    /* Slightly larger logo */
    width: auto;
}

.topbar-logo h1 {
    font-size: 24px;
    font-weight: 400;
    /* Regular weight */
    color: #444746;
    margin: 0;
    font-family: 'Google Sans', 'Product Sans', sans-serif;
    letter-spacing: -0.5px;
}

.topbar-logo h1:hover {
    color: var(--google-blue-600);
    /* Link color on hover */
    text-decoration: none;
}


.topbar-right {
    display: flex;
    align-items: center;
    gap: 12px;
    /* More breathing room */
}

/* App Launcher removed */

/* Account Button */
.account-btn {
    width: 40px;
    /* Larger */
    height: 40px;
    border-radius: 50%;
    border: 2px solid #ffffff;
    /* White ring */
    background: linear-gradient(135deg, #7b1fa2, #9c27b0);
    /* Gradient */
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    font-weight: 500;
    margin-left: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.account-btn:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    transform: scale(1.05);
}

/* Main Content Area */
.classroom-main {
    margin-left: 0;
    margin-top: 64px;
    padding: 32px;
    /* More padding */
    flex: 1;
    min-height: calc(100vh - 64px);
    transition: margin-left 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Floating Action Button (FAB) - Premium */
.fab-container {
    position: fixed;
    bottom: 32px;
    right: 32px;
    z-index: 150;
}

.fab-btn {
    width: 64px;
    /* Larger */
    height: 64px;
    border-radius: 20px;
    /* Squircle/Rounded square modern look */
    background-color: var(--color-surface);
    color: var(--google-blue-600);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1), 0 8px 16px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--color-border);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.fab-btn:hover {
    box-shadow: 0 12px 24px rgba(17, 22, 34, 0.1);
    background-color: var(--color-accent-light, rgba(197, 168, 128, 0.08));
    transform: rotate(90deg) scale(1.05);
    /* Playful interaction */
}

.fab-menu {
    position: absolute;
    bottom: 70px;
    right: 0;
    background-color: #ffffff;
    border-radius: 4px;
    box-shadow: 0 1px 2px 0 rgba(60, 64, 67, 0.30), 0 2px 6px 2px rgba(60, 64, 67, 0.15);
    padding: 8px 0;
    display: none;
    width: 200px;
    z-index: 151;
}

.fab-menu.active {
    display: block;
}

.fab-item {
    display: block;
    padding: 12px 24px;
    color: #3c4043;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
}

.fab-item:hover {
    background-color: #f1f3f4;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .classroom-sidebar {
        transform: translateX(-300px);
        width: 280px;
        top: 56px;
        /* Match smaller mobile header */
        height: calc(100vh - 56px);
        box-shadow: 0 0 24px rgba(0, 0, 0, 0.15);
    }

    .classroom-sidebar.open {
        transform: translateX(0);
    }

    .classroom-topbar {
        height: 56px;
        padding: 0 12px;
    }

    .topbar-logo img {
        height: 30px;
    }

    .classroom-main {
        margin-left: 0;
        padding: 16px;
        margin-top: 56px;
    }

    .topbar-logo h1 {
        display: none;
    }

    .app-launcher-dropdown {
        position: fixed;
        top: 60px;
        left: 12px;
        right: 12px;
        width: auto;
    }
}

@media (max-width: 480px) {
    .classroom-main {
        padding: 12px;
    }
}

/* Overlay for mobile sidebar */
.sidebar-overlay {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(4px);
    z-index: 99;
    display: none;
    transition: opacity 0.3s;
}

.sidebar-overlay.active {
    display: block;
    opacity: 1;
}