/* --- Root Variables and Dark/Light Mode --- */
:root {
    /* Dark Mode (Default) */
    --bg-color: #121212; 
    --text-color: #e0e0e0;
    --primary-color: #0c61e4; /* Vibrant Blue */
    --user-bubble: #0c61e4; 
    --ai-bubble: #2c2c2c; 
    --input-bg: #1e1e1e;
    --border-color: #333333;
    --transition-duration: 0.35s; 
}

.light-mode {
    --bg-color: #ffffff; 
    --text-color: #1a1a1a;
    --user-bubble: #0c61e4; 
    --ai-bubble: #f0f2f5; 
    --input-bg: #e5e7eb;
    --border-color: #d1d5db;
}

/* --- Global Reset and Body --- */
* {
    box-sizing: border-box;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color var(--transition-duration), color var(--transition-duration);
}

.chat-container {
    width: 100%;
    max-width: 600px;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-color);
    border-left: 1px solid var(--border-color); 
    border-right: 1px solid var(--border-color);
    transition: border-color var(--transition-duration), background-color var(--transition-duration);
}

.hidden { display: none; }

/* --- Splash Screen --- */
.splash-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-color);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 1;
    transition: opacity 0.8s ease-out;
}
.splash-screen.fade-out {
    opacity: 0;
    pointer-events: none;
}
.logo-m {
    font-size: 8rem;
    font-weight: 800;
    color: var(--primary-color);
    text-shadow: 0 0 20px rgba(12, 97, 228, 0.5);
}
@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}
.logo-m-container {
    animation: bounce 1.5s infinite ease-in-out;
}
.loading-text {
    margin-top: 20px;
    font-size: 1.2rem;
    color: #aaa;
}


/* --- Header and Settings Menu --- */
.chat-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    padding: 15px 20px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 10;
}
.settings-btn {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 10px;
    border-radius: 50%;
    transition: background-color 0.2s;
}
.settings-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}
.settings-menu {
    position: absolute;
    top: 100%;
    right: 5px;
    background-color: var(--input-bg);
    border-radius: 8px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    opacity: 0;
    transform: translateY(-10px);
    pointer-events: none;
    transition: opacity 0.3s, transform 0.3s;
    z-index: 100;
}
.settings-menu.active {
    opacity: 1;
    transform: translateY(0);
    pointer-events: all;
}
.settings-menu a {
    display: block;
    padding: 12px 20px;
    color: var(--text-color);
    text-decoration: none;
    font-size: 0.95rem;
    transition: background-color 0.2s;
    white-space: nowrap;
}
.settings-menu a:hover {
    background-color: #2a2a2a;
}
.settings-menu a i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
}

/* --- Chat History and Messages --- */
.chat-history {
    flex-grow: 1;
    padding: 20px;
    overflow-y: auto;
    scroll-behavior: smooth;
}
@keyframes fadeInSlideUp {
    0% { opacity: 0; transform: translateY(15px); }
    100% { opacity: 1; transform: translateY(0); }
}
.message {
    display: flex;
    margin-bottom: 15px;
    opacity: 0;
    transform: translateY(15px);
    animation: fadeInSlideUp 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}
.message-bubble {
    padding: 12px 18px;
    border-radius: 18px;
    max-width: 80%;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
    line-height: 1.5;
    transition: background-color var(--transition-duration), color var(--transition-duration);
}
.user-message { justify-content: flex-end; }
.user-message .message-bubble { background-color: var(--user-bubble); color: var(--text-color); }
.ai-message { justify-content: flex-start; }
.ai-message .message-bubble { background-color: var(--ai-bubble); color: var(--text-color); }

/* --- Input Area --- */
.chat-input-area {
    display: flex;
    padding: 15px;
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-color);
}
#message-input {
    flex-grow: 1;
    background: none;
    border: 2px solid var(--border-color);
    resize: none;
    padding: 12px 18px;
    border-radius: 25px;
    color: var(--text-color);
    font-size: 16px;
    transition: border-color 0.2s, background-color 0.2s;
    overflow: hidden; 
    min-height: 20px;
    max-height: 120px; /* Max 6 lines */
    line-height: 20px;
}
#message-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(12, 97, 228, 0.2);
}
#send-btn {
    background-color: var(--primary-color);
    color: var(--text-color);
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    margin-left: 10px;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background-color var(--transition-duration), transform 0.1s;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}
#send-btn:hover { background-color: #0c7bfa; }
#send-btn:active { transform: scale(0.92); }
#send-btn i { font-size: 1.2rem; }

/* --- Modal Styles --- */
.modal {
    display: none; 
    position: fixed; 
    z-index: 200; 
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.6); 
    justify-content: center;
    align-items: center;
    backdrop-filter: blur(4px);
}
.modal-content {
    background-color: var(--input-bg);
    margin: auto;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    width: 80%;
    max-width: 400px;
    color: var(--text-color);
    animation: modalPop 0.3s ease-out;
}
@keyframes modalPop {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}
.close-btn {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.2s;
}
.close-btn:hover, .close-btn:focus {
    color: var(--primary-color);
    text-decoration: none;
}