:root {
    --primary-color: #1a73e8;
    --success-color: #34a853;
    --background-color: #f0f2f5;
    --surface-color: #ffffff;
    --text-primary: #202124;
    --text-secondary: #5f6368;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    margin: 0;
    padding: 20px;
    color: var(--text-primary);
}

.container {
    max-width: 400px;
    margin: 2rem auto;
    background: var(--surface-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    animation: fadeIn 1s ease-in-out;
}

.header {
    text-align: center;
    margin-bottom: 2rem;
    background: linear-gradient(135deg, #1a73e8 0%, #0052cc 100%);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(26, 115, 232, 0.2);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.8rem;
    transition: all 0.3s ease;
    animation: slideDown 1s ease-in-out;
}

.logo {
    width: 130px;
    height: auto;
    border-radius: 10px;
    padding: 12px;
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: transform 0.3s ease;
    animation: pulse 2s infinite;
}

.logo:hover {
    transform: scale(1.02);
}

h1 {
    color: white;
    font-size: 1.8rem;
    font-weight: 600;
    margin: 0.5rem 0;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    letter-spacing: 0.5px;
}

.toggle-section {
    margin-bottom: 1.5rem;
}

.switch {
    display: flex;
    align-items: center;
    cursor: pointer;
}

.switch input {
    margin-right: 8px;
}

.input-group {
    margin-bottom: 1rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 0.9rem;
    transition: border-color 0.2s;
}

input[type="text"]:focus,
input[type="password"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.button-group {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

button {
    flex: 1;
    padding: 0.75rem 1rem;
    border: none;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 1s ease-in-out;
}

#login-button {
    background-color: var(--primary-color);
    color: white;
}

#contact-admin {
    background-color: var(--success-color);
    color: white;
}

button:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.tg-icon {
    width: 16px;
    height: 16px;
    margin-right: 8px;
    fill: currentColor;
}

.response-area {
    margin-top: 1.5rem;
    padding: 1rem;
    border-radius: 6px;
    background-color: #f8f9fa;
    border: 1px solid #e0e0e0;
    font-size: 0.9rem;
    display: none;
}

.popup {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    animation: fadeIn 0.5s ease-in-out;
}

.popup-content {
    background-color: var(--surface-color);
    padding: 2rem;
    border-radius: 12px;
    max-width: 500px;
    width: 90%;
    max-height: 90%; /* Limits the height of the popup content */
    overflow-y: auto; /* Enables vertical scrolling */
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    animation: slideUp 0.5s ease-in-out;
    color: var(--text-primary);
}

.popup-content h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.popup-content ul {
    margin: 1rem 0;
    padding-left: 1.5rem;
}

.popup-content button {
    margin-top: 1rem;
    width: 100%;
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}

.popup-content button:hover {
    background-color: #0052cc;
}

.popup-content a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: bold;
}

.popup-content a:hover {
    text-decoration: underline;
}

.footer {
    text-align: center;
    padding: 1rem;
    background-color: var(--surface-color);
    border-top: 1px solid #ddd;
    margin-top: 2rem;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.08);
    font-size: 0.9rem;
    color: var(--text-secondary);
    animation: fadeIn 1s ease-in-out;
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: bold;
}

.footer a:hover {
    text-decoration: underline;
}

.admin-credit {
    background: linear-gradient(45deg, #007bff, #046cdc);
    color: white; /* White text color */
    padding: 0.5rem 1rem; /* Padding around the text */
    border-radius: 12px; /* Rounded corners */
    display: inline-block; /* Inline block to fit content */
    margin-top: 0.1rem; /* Margin on top */
    font-size: 1.1rem; /* Slightly larger font size */
    font-weight: 600; /* Semi-bold text */
    text-align: center; /* Center text */
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15); /* Enhanced shadow */
    transition: transform 0.3s ease, box-shadow 0.3s ease; /* Smooth hover effect */
    animation: pulse 2s infinite;
}

.admin-credit a {
    color: #3cff00; /* White link color */
    text-decoration: none; /* Remove underline */
}

.admin-credit a:hover {
    text-decoration: underline; /* Underline on hover */
}

.admin-credit:hover {
    transform: translateY(-2px); /* Slight lift on hover */
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2); /* Stronger shadow on hover */
}

.animate-container {
    animation: fadeIn 1s ease-in-out, slideDown 1s ease-in-out;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
    }
    to {
        transform: translateY(0);
    }
}

@keyframes slideUp {
    from {
        transform: translateY(100%);
    }
    to {
        transform: translateY(0);
    }
}

.topic-section {
    border: 1px solid #dee2e6;
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1rem;
}

.topic-section h5 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.class-topics, .notes-topics {
    max-height: 300px;
    overflow-y: auto;
    padding-right: 10px;
}

.form-check {
    margin-bottom: 0.5rem;
}

.hidden {
    display: none;
}