:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --border-color: #30363d;
    --accent-color: #58a6ff;
    --hover-bg: #1c2128;
    --message-user-bg: #238636;
    --message-assistant-bg: #161b22;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

/* 모달 스타일 */
.modal {
    display: flex;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--bg-secondary);
    padding: 2.5rem;
    border-radius: 16px;
    width: 90%;
    max-width: 400px;
    border: 1px solid var(--border-color);
}

.modal-content h2 {
    margin-bottom: 1.5rem;
    text-align: center;
}

.modal-content input {
    width: 100%;
    padding: 0.875rem;
    margin-bottom: 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
}

.modal-content button {
    width: 100%;
    padding: 0.875rem;
    background: var(--accent-color);
    border: none;
    border-radius: 8px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

.modal-content button:hover {
    opacity: 0.9;
}

.auth-toggle {
    text-align: center;
    margin-top: 1rem;
    color: var(--text-secondary);
}

.auth-toggle a {
    color: var(--accent-color);
    text-decoration: none;
}

.error-message {
    color: #f85149;
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

/* 채팅 앱 레이아웃 */
#chatApp {
    display: flex;
    height: 100vh;
}

/* 사이드바 */
.sidebar {
    width: 280px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
}

.sidebar-header {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.new-chat-btn {
    width: 100%;
    padding: 0.75rem;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: background 0.2s;
    font-size: 0.95rem;
}

.new-chat-btn:hover {
    background: var(--hover-bg);
}

.conversations-list {
    flex: 1;
    overflow-y: auto;
    padding: 0.5rem;
}

.conversation-item {
    padding: 0.75rem;
    margin-bottom: 0.25rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.2s;
    position: relative;
}

.conversation-item:hover {
    background: var(--hover-bg);
}

.conversation-item.active {
    background: var(--bg-tertiary);
}

.conversation-title {
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.conversation-preview {
    font-size: 0.75rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.conversation-delete {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.2s;
    padding: 0.25rem;
}

.conversation-item:hover .conversation-delete {
    opacity: 1;
}

.sidebar-footer {
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

.user-info {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.logout-btn {
    width: 100%;
    padding: 0.625rem;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    cursor: pointer;
    transition: background 0.2s;
}

.logout-btn:hover {
    background: var(--hover-bg);
}

/* 채팅 영역 */
.chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.chat-header {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chat-header h1 {
    font-size: 1.25rem;
    font-weight: 600;
}

.model-select {
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    cursor: pointer;
}

.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 2rem 1rem;
}

.messages-container::after {
    content: "";
    display: table;
    clear: both;
}

.welcome-message {
    text-align: center;
    margin-top: 20vh;
}

.welcome-message h2 {
    margin-bottom: 0.5rem;
    font-size: 2rem;
}

.welcome-message p {
    color: var(--text-secondary);
}

.message {
    max-width: 70%;
    margin-bottom: 1.5rem;
    padding: 1rem 1.25rem;
    border-radius: 16px;
    animation: fadeIn 0.3s;
    clear: both;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.user {
    background: transparent;
    margin-left: auto;
    margin-right: 1rem;
    float: right;
    clear: both;
}

.message.assistant {
    background: var(--message-assistant-bg);
    border: 1px solid var(--border-color);
    margin-right: auto;
    margin-left: 1rem;
    float: left;
    clear: both;
}

.message-role {
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    opacity: 0.8;
}

.message-content {
    line-height: 1.6;
}

.message-content p {
    margin-bottom: 0.75rem;
}

.message-content pre {
    background: var(--bg-tertiary);
    padding: 1rem;
    border-radius: 6px;
    overflow-x: auto;
    margin: 0.75rem 0;
}

.message-content code {
    background: var(--bg-tertiary);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-size: 0.9em;
}

/* 코드 블록 래퍼 */
.code-block-wrapper {
    position: relative;
    margin: 0.75rem 0;
}

.code-block-wrapper code {
    background: transparent !important;
    padding: 0 !important;
}

/* 복사 버튼 */
.copy-code-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.375rem 0.625rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 0.75rem;
    cursor: pointer;
    opacity: 0;
    transition: all 0.2s;
}

.code-block-wrapper:hover .copy-code-btn {
    opacity: 1;
}

.copy-code-btn:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

.copy-code-btn.copied {
    color: #3fb950;
    border-color: #3fb950;
}

.copy-code-btn svg {
    flex-shrink: 0;
}

.typing-indicator {
    display: inline-block;
    padding: 0.5rem;
}

.typing-indicator span {
    display: inline-block;
    width: 8px;
    height: 8px;
    background: var(--text-secondary);
    border-radius: 50%;
    margin: 0 2px;
    animation: typing 1.4s infinite;
}

.typing-indicator span:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {

    0%,
    60%,
    100% {
        opacity: 0.3;
    }

    30% {
        opacity: 1;
    }
}

/* 입력 영역 */
.input-area {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    background: var(--bg-secondary);
}

.input-area form {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    gap: 0.75rem;
    align-items: flex-end;
}

.input-area textarea {
    flex: 1;
    padding: 0.875rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    resize: none;
    max-height: 200px;
    font-family: inherit;
}

.input-area button {
    padding: 0.875rem;
    background: var(--accent-color);
    border: none;
    border-radius: 12px;
    color: white;
    cursor: pointer;
    transition: opacity 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.input-area button:hover {
    opacity: 0.9;
}

.input-area button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* 스크롤바 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-color);
}

/* 강의영상 등록 영역 */
.lecture-area {
    width: 400px;
    background: var(--bg-secondary);
    border-left: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.lecture-header {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.lecture-header h2 {
    font-size: 1.125rem;
    font-weight: 600;
}

.lecture-content {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
}

.upload-section {
    margin-bottom: 2rem;
}

.upload-box {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s;
    cursor: pointer;
}

.upload-box:hover {
    border-color: var(--accent-color);
    background: var(--hover-bg);
}

.upload-box.dragover {
    border-color: var(--accent-color);
    background: var(--bg-tertiary);
}

.upload-box svg {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.upload-box p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

.upload-btn {
    padding: 0.625rem 1.25rem;
    background: var(--accent-color);
    border: none;
    border-radius: 8px;
    color: white;
    cursor: pointer;
    font-weight: 500;
    transition: opacity 0.2s;
}

.upload-btn:hover {
    opacity: 0.9;
}

.video-info {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-top: 1rem;
}

.video-info p {
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
}

.video-info strong {
    color: var(--text-secondary);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--bg-primary);
    border-radius: 4px;
    overflow: hidden;
    margin-top: 1rem;
}

.progress-fill {
    height: 100%;
    background: var(--accent-color);
    transition: width 0.3s;
    width: 0%;
}

.results-section {
    margin-top: 2rem;
}

.results-section h3 {
    font-size: 1rem;
    margin-bottom: 1rem;
}

.result-box {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1rem;
}

.result-box h4 {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.result-content {
    color: var(--text-primary);
    line-height: 1.6;
    font-size: 0.875rem;
    white-space: pre-wrap;
    word-break: break-word;
}

/* 반응형 */
@media (max-width: 1200px) {
    .lecture-area {
        width: 350px;
    }
}

@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100%;
        z-index: 100;
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .lecture-area {
        display: none;
    }
}