:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --accent: #3b82f6;
    --text-main: #f8fafc;
    --text-sec: #94a3b8;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 250px;
    background-color: var(--card-bg);
    padding: 20px;
    display: flex;
    flex-direction: column;
    border-right: 1px solid #334155;
}

.logo { font-size: 24px; font-weight: bold; margin-bottom: 40px; color: var(--accent); }

.nav-btn {
    background: none;
    border: none;
    color: var(--text-sec);
    padding: 15px;
    text-align: left;
    cursor: pointer;
    font-size: 16px;
    transition: 0.3s;
    border-radius: 8px;
    margin-bottom: 10px;
}

.nav-btn:hover, .nav-btn.active {
    background-color: var(--accent);
    color: white;
}

/* Main Content */
.main {
    flex: 1;
    padding: 40px;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.chat-box {
    flex: 1;
    background: #131c2e;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    overflow-y: auto;
    border: 1px solid #334155;
}

.input-area { display: flex; gap: 10px; }

textarea {
    flex: 1;
    background: var(--card-bg);
    border: 1px solid #334155;
    color: white;
    padding: 15px;
    border-radius: 8px;
    resize: none;
    height: 50px;
    font-family: inherit;
}

button.send-btn {
    background-color: var(--accent);
    color: white;
    border: none;
    padding: 0 30px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
}

button.send-btn:hover { background-color: #2563eb; }

/* Mensajes */
.msg { margin-bottom: 20px; padding: 15px; border-radius: 8px; max-width: 80%; }
.msg.user { background-color: #334155; align-self: flex-end; margin-left: auto; }
.msg.ai { background-color: var(--card-bg); border-left: 4px solid var(--accent); }
.msg img { max-width: 100%; border-radius: 8px; margin-top: 10px; }
pre { background: #000; padding: 10px; border-radius: 5px; overflow-x: auto; }