* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Theme variables */
body.light-mode {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --panel-bg: #0070f3;
    --panel-text: #ffffff;
    --status-bg: #f3f4f6;
    --status-text: #6b7280;
    --chat-bg: #f8fafc;
    --msg-received-bg: #e4e6eb;
    --msg-received-text: #050505;
    --msg-sent-bg: #0070f3;
    --msg-sent-text: #ffffff;
    --input-panel-bg: #ffffff;
    --border-color: #e5e7eb;
}

body.dark-mode {
    --bg-color: #0f172a;
    --container-bg: #1e293b;
    --panel-bg: #1e1b4b;
    --panel-text: #f8fafc;
    --status-bg: #111827;
    --status-text: #9ca3af;
    --chat-bg: #0f172a;
    --msg-received-bg: #334155;
    --msg-received-text: #f8fafc;
    --msg-sent-bg: #4f46e5;
    --msg-sent-text: #ffffff;
    --input-panel-bg: #1e293b;
    --border-color: #334155;
}

body {
    background-color: var(--bg-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.chat-container {
    width: 100%;
    max-width: 600px;
    height: 90vh;
    background: var(--container-bg);
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Connection Header */
.connection-panel {
    background: var(--panel-bg);
    color: var(--panel-text);
    padding: 15px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    border-bottom: 1px solid var(--border-color);
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.id-display {
    font-size: 0.95rem;
    font-weight: 500;
}

.connect-form {
    display: flex;
    gap: 8px;
}

input {
    flex: 1;
    padding: 10px 14px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
    outline: none;
    background: var(--container-bg);
    color: var(--msg-received-text);
}

button {
    padding: 10px 16px;
    background: #22c55e;
    color: white;
    border: none;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, opacity 0.2s;
}

button:hover {
    background: #16a34a;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.secondary-btn {
    background: rgba(255, 255, 255, 0.2);
    font-size: 0.85rem;
    padding: 6px 12px;
}

.secondary-btn:hover {
    background: rgba(255, 255, 255, 0.3);
}

.icon-btn {
    background: transparent;
    padding: 6px;
    font-size: 1.2rem;
}
.icon-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.danger-btn {
    background: #ef4444;
}
.danger-btn:hover {
    background: #dc2626;
}

/* Status Banner */
.status-banner {
    background: var(--status-bg);
    padding: 6px 15px;
    font-size: 0.8rem;
    color: var(--status-text);
    border-bottom: 1px solid var(--border-color);
    text-align: center;
}

/* Message Area */
.messages-box {
    flex: 1;
    padding: 15px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
    background: var(--chat-bg);
}

.message {
    max-width: 75%;
    padding: 10px 14px;
    border-radius: 12px;
    font-size: 0.95rem;
    line-height: 1.4;
    word-break: break-word;
    position: relative;
}

.timestamp {
    display: block;
    font-size: 0.7rem;
    margin-top: 4px;
    opacity: 0.6;
    text-align: right;
}

.message.system {
    align-self: center;
    background: var(--status-bg);
    color: var(--msg-received-text);
    font-size: 0.8rem;
    border-radius: 6px;
    border: 1px solid var(--border-color);
}

.message.sent {
    align-self: flex-end;
    background: var(--msg-sent-bg);
    color: var(--msg-sent-text);
    border-bottom-right-radius: 2px;
}

.message.received {
    align-self: flex-start;
    background: var(--msg-received-bg);
    color: var(--msg-received-text);
    border-bottom-left-radius: 2px;
}

/* Footer Input */
.input-panel {
    padding: 15px;
    background: var(--input-panel-bg);
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 10px;
}