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

body {
    font-family: Arial, sans-serif;
    height: 100vh;
    overflow: hidden;
    background: #f0f2f5;
}

.container {
    display: flex;
    height: 100vh;
}

.chat-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: white;
}

.chat-header {
    background: #4a76a8;
    color: white;
    padding: 15px 20px;
    font-size: 18px;
    font-weight: bold;
}

.messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.message {
    max-width: 70%;
    padding: 10px 15px;
    border-radius: 10px;
    word-wrap: break-word;
}

.message.sent {
    align-self: flex-end;
    background: #4a76a8;
    color: white;
}

.message.received {
    align-self: flex-start;
    background: #e4e6eb;
    color: #050505;
}

.message-time {
    font-size: 11px;
    opacity: 0.7;
    margin-top: 5px;
}

.input-area {
    padding: 15px 20px;
    background: #f0f2f5;
    display: flex;
    gap: 10px;
    border-top: 1px solid #ddd;
}

.input-area input {
    flex: 1;
    padding: 10px 15px;
    border: 1px solid #ddd;
    border-radius: 20px;
    outline: none;
    font-size: 14px;
}

.input-area button {
    padding: 10px 25px;
    background: #4a76a8;
    color: white;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
}

.input-area button:hover {
    background: #3d6291;
}

.users-sidebar {
    width: 250px;
    background: #f8f9fa;
    border-left: 1px solid #ddd;
    display: flex;
    flex-direction: column;
}

.users-header {
    background: #4a76a8;
    color: white;
    padding: 15px 20px;
    font-size: 16px;
    font-weight: bold;
}

.users-list {
    padding: 10px;
    overflow-y: auto;
}

.user-item {
    padding: 12px 15px;
    margin-bottom: 5px;
    background: white;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    transition: background 0.2s;
}

.user-item:hover {
    background: #e9ecef;
}

.user-status {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #28a745;
}

.user-status.offline {
    background: #6c757d;
}

.notification-popup {
    position: fixed;
    bottom: 100px;
    left: 85vw;
    width: 300px;
    height: 200px;
    background: white;
    border: 2px solid #4a76a8;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    overflow: hidden;
}

.notification-popup iframe {
    width: 100%;
    height: 100%;
    border: none;
}