/* Enhanced, Theme-Aware Back Button CSS */
.back-button {
    /* Positioning: Fixed position for persistent visibility */
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 50; /* Ensures it stays on top of content */
    
    /* Styling based on CSS variables from the theme */
    padding: 8px 16px; /* Refined padding for a pill shape */
    font-size: 14px;
    font-weight: 600; /* Bolder text for clarity */
    cursor: pointer;
    
    /* Use theme-aware colors and borders */
    border: 1px solid var(--color-border);
    border-radius: 9999px; /* Full rounded corners (pill shape) */
    background-color: var(--color-bg-card); /* Matches the general card background */
    color: var(--color-text-primary); /* Primary text color */
    
    /* Animation and effect */
    transition: all 0.3s ease-in-out;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.05); /* Subtle initial shadow */
    
    /* Better alignment for the arrow and text */
    display: flex;
    align-items: center;
    gap: 4px; 
}

.back-button:hover {
    /* Accent hover effect for a clear action signal */
    background-color: var(--color-accent);
    border-color: var(--color-accent);
    color: var(--color-accent-text); /* White/accent text on hover */
    transform: translateY(-2px); /* Slight lift effect */
    /* Dynamic shadow on hover, similar to .card:hover */
    box-shadow: var(--color-shadow); 
}

/* Style for the disabled state, using theme variables for a muted look */
.back-button:disabled {
    cursor: not-allowed;
    background-color: var(--color-border); /* Muted background */
    border-color: var(--color-border);
    opacity: 0.6;
    color: var(--color-text-secondary); /* Secondary/muted text color */
    transform: none;
    box-shadow: none;
}

/* Ensure the button is properly positioned on smaller screens */
@media (max-width: 768px) {
    .back-button {
        top: 10px;
        left: 10px;
    }
}







:root {
    /* Auto-calculates sidebar: 280px on PC, 100% width on small phones */
    --sidebar-width: min(280px, 80vw);
    --primary-gradient: linear-gradient(135deg, #00d2ff 0%, #3a7bd5 100%);
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    
    /* Auto-scaling font: Minimum 1.5rem, grows with screen, max 3rem */
    --fluid-title: clamp(1.8rem, 5vw, 3rem);
}

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

body {
    font-family: 'Poppins', sans-serif;
    background: #0f172a;
    color: #f8fafc;
    overflow-x: hidden; /* Prevents horizontal scrolling on mobile */
}

/* Sidebar: Using transforms for better mobile performance */
.sidebar {
    width: var(--sidebar-width);
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(20px);
    z-index: 1000;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar.active {
    transform: translateX(0);
}

/* Main Wrapper: Automatic padding adjustment */
.main-wrapper {
    width: 100%;
    padding: clamp(1rem, 5vw, 3rem);
    padding-top: 80px;
    transition: margin 0.3s ease;
}

/* Automatic Title Resizing */
.title {
    font-size: var(--fluid-title);
    font-weight: 800;
    line-height: 1.2;
}

/* THE "AUTO" GRID: No media queries needed here! 
   It automatically fits as many 300px cards as it can. */
.notifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
    gap: 1.5rem;
}

/* Header: Auto-stacks on small screens */
.header-content {
    display: flex;
    flex-wrap: wrap; /* Allows items to wrap to next line if no space */
    align-items: center;
    gap: 20px;
    margin-bottom: 2rem;
}

.header-logo {
    width: clamp(100px, 15vw, 180px);
    height: clamp(100px, 15vw, 180px);
    border-radius: 50%;
    object-fit: cover;
}

/* Buttons and Cards */
.teacher-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
}

.menu-toggle {
    position: fixed;
    top: 15px;
    left: 15px;
    z-index: 1100;
    width: 45px;
    height: 45px;
    border-radius: 10px;
    background: var(--primary-gradient);
    border: none;
    color: white;
    cursor: pointer;
}


:root {
    --sidebar-width: min(280px, 85vw);
    --primary-gradient: linear-gradient(135deg, #00d2ff 0%, #3a7bd5 100%);
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --text-dim: #94a3b8;
    --transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* Navigation Toggle Button */
.menu-toggle {
    position: fixed;
    top: 15px;
    left: 15px;
    z-index: 1100;
    background: var(--primary-gradient);
    border: none;
    color: white;
    width: 48px;
    height: 48px;
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

/* Sidebar Styling */
.sidebar {
    width: var(--sidebar-width);
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(25px);
    -webkit-backdrop-filter: blur(25px);
    border-right: 1px solid var(--glass-border);
    height: 100vh;
    position: fixed;
    left: calc(-1.1 * var(--sidebar-width)); /* Hidden by default */
    top: 0;
    display: flex;
    flex-direction: column;
    padding: 80px 1.2rem 2rem;
    transition: var(--transition);
    z-index: 1050;
    overflow-y: auto;
}

.sidebar.active {
    left: 0; /* Shown when active */
}

/* Sidebar Links */
.nav-link {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 12px 18px;
    color: var(--text-dim);
    text-decoration: none;
    border-radius: 14px;
    margin-bottom: 8px;
    transition: 0.3s;
    font-size: 0.95rem;
}

.nav-link:hover, .nav-link.active {
    background: var(--glass-bg);
    color: #00d2ff;
    box-shadow: inset 0 0 10px rgba(0, 210, 255, 0.1);
}

/* Main Content Shifting Logic */
.main-wrapper {
    transition: var(--transition);
}

@media (min-width: 1024px) {
    .main-wrapper.shifted {
        margin-left: var(--sidebar-width);
    }
}

@media (max-width: 768px) {
    .main-wrapper.shifted { 
        margin-left: 0; 
        filter: blur(5px); /* Adds a blur effect on mobile when sidebar is open */
    }
}