:root {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #252525;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --accent: #4a9eff;
    --accent-hover: #3a8eef;
    --success: #4caf50;
    --error: #f44336;
    --border: #333;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

#app {
    height: 100vh;
}

.screen {
    height: 100%;
}

.hidden {
    display: none !important;
}

.auth-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    padding: 20px;
}

.auth-container h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--accent);
}

.tagline {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.auth-panel {
    width: 100%;
    max-width: 380px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 20px;
}

.auth-panel h2 {
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.auth-helper {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    line-height: 1.4;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent);
}

.button-group {
    display: flex;
    gap: 0.5rem;
}

.button-group.spaced-top {
    margin-top: 16px;
}

.btn {
    padding: 12px 20px;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.2s;
}

.auth-submit {
    width: 100%;
}

.auth-switch {
    margin-top: 12px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.link-btn {
    background: none;
    border: none;
    color: var(--accent);
    font: inherit;
    cursor: pointer;
    text-decoration: underline;
}

.link-btn:hover {
    color: var(--accent-hover);
}

.btn.primary {
    background: var(--accent);
    color: white;
    flex: 1;
}

.btn.primary:hover {
    background: var(--accent-hover);
}

.btn.secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    flex: 1;
}

.btn.secondary:hover {
    background: var(--border);
}

.btn.small {
    padding: 8px 12px;
    font-size: 0.875rem;
}

.btn-icon {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1rem;
    padding: 4px;
}

.btn-icon:hover {
    color: var(--text-primary);
}

.security-note {
    margin-top: 2rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 6px;
    text-align: center;
    max-width: 320px;
}

.security-note p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

#chat-screen {
    display: flex;
}

.sidebar {
    width: 280px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 16px;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sidebar-header #current-user {
    font-weight: 600;
}

.room-actions {
    padding: 12px;
    display: flex;
    gap: 8px;
}

.room-list {
    flex: 1;
    overflow-y: auto;
}

.room-item {
    padding: 12px 16px;
    cursor: pointer;
    border-bottom: 1px solid var(--border);
    transition: background 0.2s;
}

.room-item:hover {
    background: var(--bg-tertiary);
}

.room-item.active {
    background: var(--accent);
}

.room-item .room-name {
    font-weight: 500;
}

.room-item .room-members {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.placeholder {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

#room-view {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.chat-header {
    padding: 16px 20px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chat-header h2 {
    font-size: 1.25rem;
}

.room-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.room-info span {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.members-bar {
    padding: 8px 20px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

.message {
    margin-bottom: 16px;
}

.message-header {
    display: flex;
    align-items: baseline;
    gap: 8px;
    margin-bottom: 4px;
}

.message-sender {
    font-weight: 600;
    color: var(--accent);
}

.message-time {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.message-content {
    background: var(--bg-secondary);
    padding: 10px 14px;
    border-radius: 12px;
    display: inline-block;
    max-width: 70%;
    word-wrap: break-word;
}

.message.own .message-content {
    background: var(--accent);
}

.system-message {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin: 8px 0;
}

.message-input {
    padding: 16px 20px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    display: flex;
    gap: 12px;
}

.message-input input {
    flex: 1;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
}

.message-input input:focus {
    outline: none;
    border-color: var(--accent);
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.modal-content {
    background: var(--bg-secondary);
    padding: 24px;
    border-radius: 12px;
    width: 100%;
    max-width: 360px;
}

.modal-content h3 {
    margin-bottom: 16px;
}

.encrypted-badge {
    display: inline-block;
    padding: 2px 6px;
    background: var(--success);
    color: white;
    font-size: 0.625rem;
    border-radius: 4px;
    margin-left: 8px;
}

.error-toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--error);
    color: white;
    padding: 12px 20px;
    border-radius: 6px;
    z-index: 200;
}

.error-toast.clickable {
    cursor: pointer;
}

.error-toast.success {
    background: var(--success);
}

.modal-desc {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.error-text {
    color: var(--error);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.security-note .small {
    font-size: 0.75rem;
    margin-top: 0.5rem;
    opacity: 0.8;
}

.security-note .warning {
    color: #ff9800;
    opacity: 1;
}

.invite-code-section {
    padding: 10px 20px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.invite-code-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

#invite-code-display {
    background: var(--bg-primary);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.875rem;
    color: var(--accent);
}

.room-badge {
    display: inline-block;
    padding: 2px 6px;
    font-size: 0.625rem;
    border-radius: 4px;
    margin-left: 8px;
    text-transform: uppercase;
    font-weight: 600;
}

.room-badge.private {
    background: #f44336;
    color: white;
}

.room-badge.public {
    background: #4caf50;
    color: white;
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.checkbox-group span {
    font-size: 0.875rem;
    color: var(--text-primary);
}

.room-actions {
    padding: 12px;
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.room-actions .btn {
    flex: 0 1 auto;
}

.sidebar-header-actions {
    display: flex;
    gap: 4px;
    align-items: center;
}

.settings-modal-content {
    max-width: 420px;
}

.settings-section {
    margin-bottom: 20px;
    padding: 16px;
    background: var(--bg-tertiary);
    border-radius: 8px;
}

.settings-section h4 {
    margin-bottom: 8px;
    font-size: 1rem;
}

.settings-section .modal-desc {
    margin-bottom: 12px;
}

.danger-zone {
    border: 1px solid var(--error);
}

.danger-zone h4 {
    color: var(--error);
}

.btn.danger {
    background: var(--error);
    color: white;
}

.btn.danger:hover {
    background: #d32f2f;
}

@media (max-width: 768px) {
    #chat-screen {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        max-height: 200px;
    }
    
    .chat-area {
        flex: 1;
    }
    
    .room-actions {
        justify-content: center;
    }
    
    .invite-code-section {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .invite-code-section .btn {
        margin-top: 8px;
    }
}