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

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --text: #f1f5f9;
    --text-muted: #94a3b8;
    --border: #334155;
    --success: #10b981;
    --warning: #f59e0b;
}

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

/* Header */
header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--text);
}

/* Chat Container */
.chat-container {
    flex: 1;
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    padding: 2rem;
}

.chat-header {
    text-align: center;
    margin-bottom: 2rem;
}

.chat-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.chat-header p {
    color: var(--text-muted);
}

/* Messages */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-card);
    border-radius: 12px;
    border: 1px solid var(--border);
    min-height: 400px;
    max-height: 60vh;
}

.message {
    display: flex;
    gap: 0.75rem;
    max-width: 85%;
}

.message.user {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.message.assistant {
    align-self: flex-start;
}

.message-content {
    padding: 1rem 1.25rem;
    border-radius: 16px;
    line-height: 1.6;
}

.message.user .message-content {
    background: var(--primary);
    color: white;
    border-bottom-right-radius: 4px;
}

.message.assistant .message-content {
    background: var(--bg-dark);
    border: 1px solid var(--border);
    border-bottom-left-radius: 4px;
}

.message-content ul {
    margin: 0.75rem 0;
    padding-left: 1.5rem;
}

.message-content code {
    background: rgba(0,0,0,0.3);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
}

/* Quick Actions */
.quick-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.quick-actions button {
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.quick-actions button:hover {
    background: var(--primary);
    border-color: var(--primary);
}

/* Input */
.chat-input-container {
    margin-top: 1rem;
}

.chat-input {
    display: flex;
    gap: 0.75rem;
}

.chat-input input {
    flex: 1;
    padding: 1rem 1.25rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s;
}

.chat-input input:focus {
    border-color: var(--primary);
}

.chat-input button {
    padding: 1rem 2rem;
    background: var(--primary);
    border: none;
    border-radius: 12px;
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.chat-input button:hover {
    background: var(--primary-dark);
}

/* Loading */
.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 1rem;
}

.typing-indicator span {
    width: 8px;
    height: 8px;
    background: var(--text-muted);
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out;
}

.typing-indicator span:nth-child(1) { animation-delay: -0.32s; }
.typing-indicator span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

/* Simulados Page */
.page-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
}

.page-header {
    text-align: center;
    margin-bottom: 2rem;
}

.page-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1rem;
}

.card h3 {
    margin-bottom: 1rem;
    color: var(--primary);
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group select,
.form-group input {
    width: 100%;
    padding: 0.75rem;
    background: var(--bg-dark);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 1rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    background: var(--primary);
    border: none;
    border-radius: 8px;
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

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

.btn-secondary {
    background: var(--bg-dark);
    border: 1px solid var(--border);
}

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

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
        font-size: 0.875rem;
    }
    
    .chat-container {
        padding: 1rem;
    }
    
    .message {
        max-width: 95%;
    }
}