:root {
    --primary: #10a37f;
    --primary-dark: #0e8c6b;
    --bg-dark: #212121;
    --bg-darker: #171717;
    --bg-light: #2f2f2f;
    --text-primary: #ececec;
    --text-secondary: #b4b4b4;
    --border-color: #4d4d4d;
    --user-msg-bg: #2b2b2b;
    --assistant-msg-bg: #1e1e1e;
    --shadow: 0 2px 12px rgba(0,0,0,0.3);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-darker);
    color: var(--text-primary);
    min-height: 100vh;
}

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

/* ========== 侧边栏 ========== */
.sidebar {
    width: 280px;
    background: var(--bg-dark);
    padding: 20px;
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
    padding: 8px;
}

.logo i {
    font-size: 32px;
    color: var(--primary);
}

.logo h2 {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), #6ee7b7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.new-chat-btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s ease;
    margin-bottom: 24px;
}

.new-chat-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(16, 163, 127, 0.4);
}

.features-section h3 {
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.features-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.feature-card {
    background: var(--bg-light);
    padding: 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    border: 1px solid transparent;
}

.feature-card:hover {
    background: var(--bg-dark);
    border-color: var(--primary);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 20px;
    color: var(--primary);
    margin-bottom: 6px;
}

.feature-name {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
}

/* ========== 聊天区域 ========== */
.chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--bg-darker);
}

.chat-header {
    padding: 20px 30px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-dark);
}

.chat-header h1 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 4px;
}

.chat-header p {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ========== 消息区域 ========== */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px 30px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.message {
    display: flex;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.message-content {
    display: flex;
    gap: 12px;
    max-width: 80%;
    padding: 16px;
    border-radius: 12px;
    background: var(--bg-light);
}

.message.user .message-content {
    background: var(--user-msg-bg);
    border: 1px solid var(--border-color);
    margin-left: auto;
    flex-direction: row-reverse;
}

.message.assistant .message-content {
    background: var(--assistant-msg-bg);
}

.avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    flex-shrink: 0;
}

.message.user .avatar {
    background: var(--primary);
    color: white;
}

.message.assistant .avatar {
    background: #4a5568;
    color: white;
}

.text {
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-primary);
    word-wrap: break-word;
}

/* ========== 输入区域 ========== */
.chat-input-container {
    padding: 16px 30px 24px;
    border-top: 1px solid var(--border-color);
    background: var(--bg-dark);
}

.input-wrapper {
    display: flex;
    align-items: flex-end;
    gap: 10px;
    background: var(--bg-light);
    border-radius: 12px;
    padding: 8px;
    border: 1px solid var(--border-color);
    transition: border-color 0.3s;
}

.input-wrapper:focus-within {
    border-color: var(--primary);
}

textarea {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 15px;
    font-family: inherit;
    resize: none;
    padding: 8px 12px;
    max-height: 200px;
    line-height: 1.5;
}

textarea::placeholder {
    color: var(--text-secondary);
}

.send-btn {
    background: var(--primary);
    color: white;
    border: none;
    width: 44px;
    height: 44px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.send-btn:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

.input-tools {
    display: flex;
    justify-content: flex-end;
    padding: 8px 4px 0;
}

.tooltip {
    font-size: 12px;
    color: var(--text-secondary);
}

/* ========== 后台管理样式 ========== */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
}

.login-card {
    background: var(--bg-dark);
    padding: 40px;
    border-radius: 16px;
    width: 400px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
    border: 1px solid var(--border-color);
}

.login-header {
    text-align: center;
    margin-bottom: 32px;
}

.login-header i {
    font-size: 48px;
    color: var(--primary);
    margin-bottom: 16px;
}

.login-header h2 {
    font-size: 24px;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 15px;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
}

/* ========== 管理面板 ========== */
.admin-container {
    padding: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.admin-header h1 {
    font-size: 28px;
    color: var(--text-primary);
}

.admin-header h1 i {
    color: var(--primary);
    margin-right: 12px;
}

.admin-actions {
    display: flex;
    gap: 12px;
}

.admin-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.admin-card {
    background: var(--bg-dark);
    border-radius: 12px;
    padding: 24px;
    border: 1px solid var(--border-color);
}

.admin-card h2 {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.admin-card h2 i {
    color: var(--primary);
    margin-right: 8px;
}

.features-editor {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 16px;
}

.feature-row {
    display: flex;
    gap: 10px;
    align-items: flex-start;
}

.feature-row input {
    flex: 1;
    padding: 10px;
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
}

.feature-row textarea {
    flex: 2;
    padding: 10px;
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    font-family: inherit;
    resize: vertical;
    min-height: 40px;
}

.btn-remove {
    background: #e53e3e;
    color: white;
    border: none;
    padding: 10px;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.3s;
}

.btn-remove:hover {
    background: #c53030;
}

.form-actions {
    display: flex;
    gap: 12px;
    margin-top: 16px;
}

.btn-primary {
    background: var(--primary);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--bg-light);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-danger {
    background: #e53e3e;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

.btn-danger:hover {
    background: #c53030;
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

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

.history-stats {
    margin-bottom: 16px;
    color: var(--text-secondary);
}

.history-list {
    max-height: 300px;
    overflow-y: auto;
    margin-bottom: 16px;
}

.history-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
}

.history-item:last-child {
    border-bottom: none;
}

.role-badge {
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
}

.history-item.user .role-badge {
    background: var(--primary);
    color: white;
}

.history-item.assistant .role-badge {
    background: #4a5568;
    color: white;
}

.msg-preview {
    color: var(--text-secondary);
    font-size: 14px;
}

.system-info p {
    padding: 8px 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.system-info p:last-child {
    border-bottom: none;
}

.empty-state {
    color: var(--text-secondary);
    text-align: center;
    padding: 40px 0;
}

.alert {
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-success {
    background: rgba(16, 163, 127, 0.1);
    border: 1px solid var(--primary);
    color: #6ee7b7;
}

.alert-error {
    background: rgba(229, 62, 62, 0.1);
    border: 1px solid #e53e3e;
    color: #fc8181;
}

/* ========== 滚动条 ========== */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    .sidebar {
        display: none;
    }
    
    .admin-grid {
        grid-template-columns: 1fr;
    }
    
    .admin-header {
        flex-direction: column;
        gap: 16px;
    }
    
    .chat-messages {
        padding: 16px;
    }
    
    .message-content {
        max-width: 95%;
    }
}