:root {
    --bg-main: #1a1a1d;
    --bg-surface: #252528;
    --bg-inset: #111113;
    --primary: #4a90e2;
    --primary-light: #6aa7ff;
    --text-light: #f4f4f5;
    --text-medium: #a8a8b3;
    --text-dark: #6c6c74;
    --border-color: #3a3a40;
    --shadow-color: rgba(0, 0, 0, 0.5);

    --cell-size: 16px;
    --grid-gap: 1px;
    --transition-speed: 0.3s;
}

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

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-light);
    overflow: hidden;
    height: 100vh;
    width: 100vw;
}

/* Loader */
#loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-main);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    transition: opacity 0.5s ease;
}
.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid var(--border-color);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Main App Layout */
#app-container {
    width: 100%;
    height: 100%;
    position: relative;
}
header {
    position: absolute;
    top: 20px;
    left: 20px;
    z-index: 10;
    background: var(--bg-surface);
    padding: 8px 16px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 12px var(--shadow-color);
}
header h1 {
    font-size: 1.2rem;
    font-weight: 600;
}
header p {
    font-size: 0.8rem;
    color: var(--text-medium);
}

/* Grid */
#grid-viewport {
    width: 100%;
    height: 100%;
    overflow: hidden; /* Panning is handled by JS */
    cursor: grab;
}
#grid-viewport:active {
    cursor: grabbing;
}
#grid {
    display: grid;
    grid-template-columns: repeat(100, var(--cell-size));
    grid-template-rows: repeat(100, var(--cell-size));
    gap: var(--grid-gap);
    background-color: var(--border-color);
    padding: var(--grid-gap);
    width: fit-content;
    transform-origin: 0 0;
}
.cell {
    background-color: #fff;
    transition: transform 0.1s ease-out, box-shadow 0.1s ease-out;
}
.cell:hover {
    transform: scale(1.5);
    z-index: 5;
    box-shadow: 0 0 8px var(--shadow-color);
    cursor: pointer;
}

/* Toolbar */
#toolbar {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 16px;
    background-color: var(--bg-surface);
    padding: 10px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 20px var(--shadow-color);
    z-index: 10;
}
.tool-section {
    display: flex;
    align-items: center;
    gap: 10px;
}
#color-preview {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2px solid var(--border-color);
    background-color: #fff;
}
#colorPicker {
    opacity: 0;
    width: 32px;
    height: 32px;
    position: absolute;
    cursor: pointer;
}
#toolbar button {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-medium);
    border-radius: 8px;
    height: 36px;
    padding: 0 15px;
    font-size: 1rem;
    font-weight: 500;
    font-family: 'Poppins', sans-serif;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
}
#toolbar button:hover {
    background-color: var(--primary);
    border-color: var(--primary-light);
    color: var(--text-light);
}
.zoom-controls span {
    color: var(--text-light);
    font-weight: 500;
    width: 50px;
    text-align: center;
}
.zoom-controls button {
    width: 36px;
    padding: 0;
}

/* Chat Sidebar */
#chat-sidebar {
    position: fixed;
    top: 0;
    right: 0;
    height: 100vh;
    width: 340px;
    background-color: var(--bg-surface);
    display: flex;
    flex-direction: column;
    border-left: 1px solid var(--border-color);
    transform: translateX(100%);
    transition: transform var(--transition-speed) ease-in-out;
    z-index: 20;
}
#chat-sidebar.open {
    transform: translateX(0);
    box-shadow: -5px 0 30px var(--shadow-color);
}
.chat-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}
.chat-header h3 {
    font-weight: 600;
    text-align: center;
}
#chat-messages {
    flex-grow: 1;
    overflow-y: auto;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.chat-message {
    display: flex;
    flex-direction: column;
    max-width: 85%;
    word-wrap: break-word;
}
.chat-message-content {
    padding: 8px 12px;
    border-radius: 12px;
    font-size: 0.9rem;
}
.chat-message .author {
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--primary-light);
}
.chat-message.self {
    align-self: flex-end;
    align-items: flex-end;
}
.chat-message.self .chat-message-content {
    background-color: var(--primary);
}
.chat-message.other {
    align-self: flex-start;
    align-items: flex-start;
}
.chat-message.other .chat-message-content {
    background-color: var(--bg-inset);
    border: 1px solid var(--border-color);
}
#chat-form {
    display: flex;
    padding: 16px;
    gap: 10px;
    border-top: 1px solid var(--border-color);
}
#chat-input {
    flex-grow: 1;
    background-color: var(--bg-inset);
    border: 1px solid var(--border-color);
    color: var(--text-light);
    border-radius: 8px;
    padding: 10px 14px;
    font-family: 'Poppins', sans-serif;
}
#chat-send-btn {
    width: 44px;
    height: 44px;
    border: none;
    background-color: var(--primary);
    color: white;
    font-size: 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color var(--transition-speed) ease;
}
#chat-send-btn:hover {
    background-color: var(--primary-light);
}
/* Custom Scrollbars */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-surface);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-dark);
}