:root {
    --bg-color: #0D1117;
    --surface-color: #161B22;
    --border-color: #30363d;
    --primary-gradient-start: #38BDF8;
    --primary-gradient-end: #818CF8;
    --accent-color: #F59E0B;
    --text-primary: #E6EDF3;
    --text-secondary: #7D8590;
    --font-family-sans-serif: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-family-sans-serif);
    min-height: 100vh;
}

.navbar {
    background-color: transparent;
    padding: 1rem 0;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    background: linear-gradient(45deg, var(--primary-gradient-start), var(--primary-gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: transparent;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s ease-in-out;
}

.nav-link:hover, .nav-link.active {
    color: var(--text-primary);
}

.navbar-toggler {
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
}
.navbar-toggler:focus {
    box-shadow: none;
}

.hero-section {
    padding: 8rem 0;
    animation: fadeIn 1s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.hero-title {
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -1.5px;
}

.hero-subtitle {
    color: var(--text-secondary);
    max-width: 600px;
    margin: 1.5rem auto;
}

.btn-primary {
    background: linear-gradient(45deg, var(--primary-gradient-start), var(--primary-gradient-end));
    border: none;
    padding: 0.75rem 2rem;
    font-weight: 500;
    transition: transform 0.2s ease-out, box-shadow 0.2s ease-out;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

/* Chat Widget */
#chat-widget-container {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 1050;
}

#chat-toggle-button {
    width: 60px;
    height: 60px;
    font-size: 1.8rem;
    background: linear-gradient(45deg, var(--primary-gradient-start), var(--primary-gradient-end));
    color: white;
    border: none;
    display: flex;
    justify-content: center;
    align-items: center;
}

#chat-window {
    display: none;
    width: 370px;
    height: 70vh;
    max-height: 600px;
    flex-direction: column;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    position: absolute;
    bottom: 0;
    right: 0;
}

#chat-window.open {
    display: flex;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from { transform: translateY(30px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

#chat-window .card-header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
}
#chat-window .card-header .ai-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: linear-gradient(45deg, var(--primary-gradient-start), var(--primary-gradient-end));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

#chat-window .card-footer {
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
}

#chat-messages {
    flex-grow: 1;
    overflow-y: auto;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.message {
    max-width: 85%;
    padding: 0.5rem 1rem;
    border-radius: 1.25rem;
    display: inline-block;
}

.message.received {
    background-color: #21262d;
    align-self: flex-start;
    border-bottom-left-radius: 0.25rem;
}
.message.sent {
    background: linear-gradient(45deg, var(--primary-gradient-start), var(--primary-gradient-end));
    color: white;
    align-self: flex-end;
    border-bottom-right-radius: 0.25rem;
}
.message .message-content {
    margin: 0;
    word-wrap: break-word;
}
.message.typing {
    color: var(--text-secondary);
    font-style: italic;
    align-self: flex-start;
}

#chat-input {
    background-color: #0D1117;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}
#chat-input:focus {
    background-color: #0D1117;
    color: var(--text-primary);
    box-shadow: none;
    border-color: var(--primary-gradient-end);
}