* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: #0b141a;
    color: #e9edef;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

#app {
    width: 100%;
    max-width: 450px;
    height: 100vh;
    background-color: #111b21;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
    box-shadow: 0 0 20px rgba(0,255,150,0.1);
}

.screen {
    display: none;
    flex-direction: column;
    height: 100%;
    width: 100%;
}

.screen.active {
    display: flex;
}

/* Header */
.header {
    background-color: #202c33;
    padding: 15px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: bold;
    border-bottom: 1px solid #222d34;
}

/* Forms */
.auth-container {
    padding: 30px 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    justify-content: center;
    height: 100%;
}

.auth-container h2 {
    color: #00a884;
    text-align: center;
    margin-bottom: 10px;
}

.input-group input {
    width: 100%;
    padding: 12px;
    background: #2a3942;
    border: 1px solid #3b4a54;
    border-radius: 8px;
    color: #fff;
    outline: none;
}

.btn {
    background: #00a884;
    color: #111b21;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-weight: bold;
    cursor: pointer;
}

.link {
    color: #00a884;
    text-align: center;
    cursor: pointer;
    font-size: 0.9em;
}

/* User List */
.user-list {
    flex: 1;
    overflow-y: auto;
}

.user-card {
    display: flex;
    align-items: center;
    padding: 12px 15px;
    border-bottom: 1px solid #222d34;
    cursor: pointer;
}

.user-card:hover {
    background: #202c33;
}

.avatar {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background: #00a884;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    margin-right: 12px;
}

.user-info {
    flex: 1;
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #8696a0;
}

.status-dot.online {
    background: #00a884;
}

/* Chat Area */
.chat-messages {
    flex: 1;
    padding: 15px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
    background-color: #0b141a;
}

.msg {
    max-width: 75%;
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 0.95em;
    position: relative;
    word-break: break-word;
}

.msg.sent {
    align-self: flex-end;
    background-color: #005c4b;
}

.msg.received {
    align-self: flex-start;
    background-color: #202c33;
}

.msg img, .msg video {
    max-width: 100%;
    border-radius: 6px;
    margin-top: 5px;
}

.chat-input-area {
    padding: 10px;
    background: #202c33;
    display: flex;
    align-items: center;
    gap: 8px;
}

.chat-input-area input[type="text"] {
    flex: 1;
    padding: 10px;
    background: #2a3942;
    border: none;
    border-radius: 8px;
    color: #fff;
    outline: none;
}

.file-label {
    cursor: pointer;
    font-size: 1.2em;
}

/* Bottom Navigation */
.bottom-nav {
    display: flex;
    background: #202c33;
    border-top: 1px solid #222d34;
    height: 60px;
}

.nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #8696a0;
    cursor: pointer;
    font-size: 0.8em;
}

.nav-item.active {
    color: #00a884;
}

.nav-item i {
    font-size: 1.2em;
    margin-bottom: 2px;
}