:root {
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --primary: #10b981; /* Emerald Green */
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    overflow-x: hidden;
}

/* --- Layout --- */
.app-container {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 260px;
    background: var(--bg-card);
    border-right: 1px solid rgba(255,255,255,0.1);
    display: flex;
    flex-direction: column;
    padding: 1rem;
    transition: 0.3s;
}

.brand-logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-btn {
    width: 100%;
    text-align: left;
    background: transparent;
    color: var(--text-muted);
    border: none;
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 5px;
    transition: 0.2s;
}

.nav-btn:hover, .nav-btn.active {
    background: rgba(16, 185, 129, 0.1);
    color: var(--primary);
}

/* Main Chat Area */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
}

.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
    padding-bottom: 150px; /* Space for input */
}

/* Chat Bubbles */
.message {
    max-width: 80%;
    margin-bottom: 1.5rem;
    padding: 1rem;
    border-radius: 12px;
    line-height: 1.6;
}

.message.user {
    background: var(--primary);
    color: #fff;
    margin-left: auto; /* Kanan */
    border-bottom-right-radius: 2px;
}

.message.ai {
    background: var(--bg-card);
    border: 1px solid rgba(255,255,255,0.1);
    margin-right: auto; /* Kiri */
    border-bottom-left-radius: 2px;
}

/* Input Area */
.input-area {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 2rem;
    background: linear-gradient(to top, var(--bg-dark) 80%, transparent);
}

.input-box {
    background: var(--bg-card);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 15px;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.input-box textarea {
    background: transparent;
    border: none;
    color: white;
    width: 100%;
    resize: none;
    padding: 10px;
    outline: none;
    height: 50px;
}

/* Special Components: SLIDE & QUIZ */
.slide-card {
    background: linear-gradient(135deg, #1e293b, #0f172a);
    border: 1px solid var(--primary);
    padding: 20px;
    margin: 10px 0;
    border-radius: 10px;
}

.quiz-option {
    display: block;
    width: 100%;
    padding: 10px;
    margin: 5px 0;
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    color: white;
    text-align: left;
    border-radius: 8px;
    transition: 0.2s;
}
.quiz-option:hover { background: rgba(16, 185, 129, 0.2); }

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -100%;
        height: 100%;
        z-index: 1000;
    }
    .sidebar.open { left: 0; }
    .chat-container { padding: 1rem; }
}