:root {
    --dark-bg: #1a1a1a;
    --primary-green: #00ff00;
    --primary-cyan: #00ffff;
    --text-color: #e0e0e0;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --border-color: rgba(0, 255, 255, 0.2);
}

body {
    background-color: var(--dark-bg);
    color: var(--text-color);
    font-family: 'Arial', sans-serif;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

#particle-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.particle {
    position: absolute;
    background-color: var(--primary-green);
    width: 10px;
    height: 10px;
    opacity: 0;
    animation: float 20s infinite linear;
}

@keyframes float {
    0% { transform: translateY(100vh) rotate(0deg); opacity: 1; }
    100% { transform: translateY(-10vh) rotate(720deg); opacity: 0; }
}

header {
    padding: 20px 50px;
}

nav .logo {
    font-family: 'Press Start 2P', cursive;
    font-size: 24px;
    color: var(--primary-green);
    text-shadow: 0 0 10px var(--primary-green);
}

main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 120px);
    text-align: center;
    padding: 20px;
}

.hero {
    max-width: 800px;
}

.hero h1 {
    font-size: 3rem;
    color: var(--text-color);
    text-shadow: 0 0 15px var(--primary-cyan);
}

#start-chat-btn {
    background: linear-gradient(45deg, var(--primary-green), var(--primary-cyan));
    border: none;
    color: var(--dark-bg);
    padding: 15px 30px;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    border-radius: 5px;
    margin-top: 20px;
    transition: all 0.3s ease;
    box-shadow: 0 0 20px var(--primary-green);
}

#start-chat-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 0 30px var(--primary-cyan);
}

#chat-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
    z-index: 1000;
}

#chat-container:not(.hidden) {
    opacity: 1;
    visibility: visible;
}

.chat-window {
    width: 90%;
    max-width: 800px;
    height: 80vh;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    box-shadow: 0 0 30px rgba(0, 255, 255, 0.1);
}

.chat-header {
    background: rgba(0, 255, 255, 0.1);
    padding: 15px;
    font-size: 1.2rem;
    font-weight: bold;
    border-bottom: 1px solid var(--border-color);
    text-shadow: 0 0 5px var(--primary-cyan);
}

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

.message {
    margin-bottom: 15px;
    display: flex;
    flex-direction: column;
    opacity: 0;
    transform: translateY(20px);
    animation: slide-in 0.5s forwards;
}

@keyframes slide-in {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.user {
    align-items: flex-end;
}

.message.ai {
    align-items: flex-start;
}

.message .content {
    max-width: 80%;
    padding: 10px 15px;
    border-radius: 10px;
    line-height: 1.6;
}

.message.user .content {
    background-color: var(--primary-green);
    color: var(--dark-bg);
}

.message.ai .content {
    background-color: rgba(0, 255, 255, 0.2);
}

.typing-indicator {
    padding: 0 20px 10px;
    color: var(--primary-cyan);
    display: none;
}

.chat-input {
    display: flex;
    padding: 20px;
    border-top: 1px solid var(--border-color);
}

#user-input {
    flex-grow: 1;
    background: var(--glass-bg);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 10px;
    color: var(--text-color);
    font-size: 1rem;
}

#send-btn {
    background: var(--primary-cyan);
    border: none;
    color: var(--dark-bg);
    padding: 10px 20px;
    margin-left: 10px;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    transition: background 0.3s ease;
}

#send-btn:hover {
    background: #00dddd;
}

.quick-topics {
    position: fixed;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.topic-btn {
    background: var(--glass-bg);
    border: 1px solid var(--border-color);
    color: var(--primary-cyan);
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(5px);
}

.topic-btn:hover {
    background: rgba(0, 255, 255, 0.2);
    box-shadow: 0 0 10px var(--primary-cyan);
}

footer {
    text-align: center;
    padding: 20px;
    font-size: 0.9rem;
    color: #666;
}

.hidden {
    display: none !important;
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }

    .quick-topics {
        position: static;
        transform: none;
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
        margin-top: 30px;
    }

    .chat-window {
        width: 100%;
        height: 100vh;
        border-radius: 0;
    }
}