/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* 色彩方案 */
    --primary-color: #4ECDC4;
    --secondary-color: #FFD93D;
    --danger-color: #FF6B6B;
    --success-color: #51CF66;
    --bg-color: #F7F7F7;
    --text-color: #2D3436;
    --border-color: #DFE6E9;
    --white: #FFFFFF;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "微软雅黑", sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

/* 顶部导航 */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #44B8B3 100%);
    color: var(--white);
    padding: 1rem 2rem;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.avatar {
    font-size: 2.5rem;
    background: var(--white);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 600;
}

.nav {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.nav-btn {
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid transparent;
    color: var(--white);
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: var(--white);
    color: var(--primary-color);
    font-weight: 600;
}

/* 主容器 */
.container {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 2rem;
    max-width: 1400px;
    margin: 2rem auto;
    padding: 0 2rem;
}

/* 侧边栏 */
.sidebar {
    background: var(--white);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    height: fit-content;
    position: sticky;
    top: 100px;
}

.knowledge-menu h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.knowledge-menu ul {
    list-style: none;
}

.knowledge-item {
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.knowledge-item:hover {
    background: var(--bg-color);
    transform: translateX(5px);
}

.knowledge-item .icon {
    font-size: 1.5rem;
}

/* 主内容区 */
.main-content {
    background: var(--white);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow);
    min-height: 600px;
}

.section {
    display: none;
}

.section.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

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

/* 聊天区域 */
.chat-container {
    height: 500px;
    overflow-y: auto;
    margin-bottom: 1rem;
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.welcome-message {
    text-align: center;
    padding: 2rem;
}

.avatar-large {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.welcome-message h2 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.welcome-message p {
    color: #636E72;
    margin-bottom: 1rem;
}

.quick-questions-label {
    font-weight: 600;
    margin-top: 1.5rem;
}

.quick-buttons {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-top: 1rem;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
}

.quick-btn {
    background: var(--bg-color);
    border: 2px solid var(--primary-color);
    color: var(--text-color);
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.quick-btn:hover {
    background: var(--primary-color);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.messages {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.input-area {
    display: flex;
    gap: 1rem;
}

#user-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 25px;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.3s ease;
}

#user-input:focus {
    border-color: var(--primary-color);
}

.send-btn {
    background: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.send-btn:hover {
    background: #44B8B3;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

/* 底部 */
.footer {
    background: var(--white);
    padding: 2rem;
    margin-top: 2rem;
    text-align: center;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.05);
}

.disclaimer-box {
    background: #FFF3CD;
    border: 2px solid #FFD93D;
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1rem;
}

.disclaimer-box.warning {
    background: #FFE5E5;
    border-color: var(--danger-color);
}

.copyright {
    color: #636E72;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 968px) {
    .container {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
    }

    .nav {
        justify-content: center;
    }
}

@media (max-width: 600px) {
    .header {
        padding: 1rem;
    }

    .logo h1 {
        font-size: 1.4rem;
    }

    .nav-btn {
        padding: 0.4rem 1rem;
        font-size: 0.9rem;
    }

    .container {
        margin: 1rem auto;
        padding: 0 1rem;
    }

    .main-content {
        padding: 1rem;
    }

    .chat-container {
        height: 400px;
    }
}

/* 手机横屏模式优化 */
@media (max-width: 968px) and (orientation: landscape) {
    /* 顶部导航优化 - 极度压缩 */
    .header {
        padding: 0.3rem 0.5rem;
        position: fixed;
        width: 100%;
    }

    /* 隐藏logo，只保留导航 */
    .logo {
        display: none;
    }

    .nav {
        gap: 0.3rem;
        flex-wrap: nowrap;
        overflow-x: auto;
        padding: 0;
        margin: 0;
        justify-content: flex-start;
    }

    .nav-btn {
        padding: 0.3rem 0.6rem;
        font-size: 0.7rem;
        white-space: nowrap;
        border-radius: 12px;
    }

    /* 主容器 - 利用横屏宽度 */
    .container {
        display: grid;
        grid-template-columns: 140px 1fr;
        gap: 0.5rem;
        margin: 0;
        padding: 0 0.5rem;
        padding-top: 35px; /* header高度 */
        max-width: 100%;
    }

    /* 侧边栏紧凑显示 */
    .sidebar {
        padding: 0.4rem;
        top: 35px;
        max-height: calc(100vh - 40px);
        overflow-y: auto;
    }

    .knowledge-menu h3 {
        font-size: 0.8rem;
        margin-bottom: 0.3rem;
    }

    .knowledge-item {
        padding: 0.3rem;
        margin-bottom: 0.2rem;
        font-size: 0.7rem;
    }

    .knowledge-item .icon {
        font-size: 1rem;
    }

    /* 主内容区优化 */
    .main-content {
        padding: 0.5rem;
        min-height: calc(100vh - 50px);
    }

    /* 聊天区域 - 充分利用横屏高度 */
    .chat-container {
        height: calc(100vh - 140px);
        min-height: 200px;
        margin-bottom: 0.5rem;
        padding: 0.5rem;
    }

    .welcome-message {
        padding: 0.5rem;
    }

    .avatar-large {
        font-size: 1.8rem;
        margin-bottom: 0.3rem;
    }

    .welcome-message h2 {
        font-size: 1rem;
        margin-bottom: 0.2rem;
    }

    .welcome-message p {
        font-size: 0.75rem;
        margin-bottom: 0.3rem;
    }

    .quick-questions-label {
        font-size: 0.8rem;
        margin-top: 0.5rem;
    }

    .quick-buttons {
        flex-direction: row;
        flex-wrap: wrap;
        max-width: 100%;
        gap: 0.4rem;
    }

    .quick-btn {
        flex: 1 1 calc(50% - 0.2rem);
        min-width: 150px;
        padding: 0.4rem 0.6rem;
        font-size: 0.7rem;
    }

    /* 输入区域 */
    .input-area {
        gap: 0.4rem;
    }

    #user-input {
        padding: 0.4rem 0.7rem;
        font-size: 0.8rem;
        border-radius: 15px;
    }

    .send-btn {
        padding: 0.4rem 1rem;
        font-size: 0.8rem;
        border-radius: 15px;
    }

    /* 隐藏底部以节省空间 */
    .footer {
        display: none;
    }
}

/* 小屏幕横屏模式 (手机横屏) - 更极致的压缩 */
@media (max-width: 850px) and (max-height: 450px) and (orientation: landscape) {
    .header {
        padding: 0.2rem 0.4rem;
    }

    .nav-btn {
        padding: 0.25rem 0.5rem;
        font-size: 0.65rem;
    }

    .container {
        grid-template-columns: 110px 1fr;
        gap: 0.4rem;
        padding: 0 0.4rem;
        padding-top: 30px;
    }

    .sidebar {
        padding: 0.3rem;
        top: 30px;
    }

    .knowledge-menu h3 {
        font-size: 0.7rem;
        margin-bottom: 0.2rem;
    }

    .knowledge-item {
        padding: 0.25rem;
        font-size: 0.65rem;
    }

    .knowledge-item .icon {
        font-size: 0.9rem;
    }

    .main-content {
        padding: 0.4rem;
    }

    .chat-container {
        height: calc(100vh - 110px);
        min-height: 150px;
        padding: 0.4rem;
    }

    .welcome-message {
        padding: 0.3rem;
    }

    .avatar-large {
        font-size: 1.5rem;
        margin-bottom: 0.2rem;
    }

    .welcome-message h2 {
        font-size: 0.9rem;
        margin-bottom: 0.1rem;
    }

    .welcome-message p {
        font-size: 0.7rem;
        margin-bottom: 0.2rem;
    }

    .quick-questions-label {
        font-size: 0.7rem;
        margin-top: 0.3rem;
    }

    .quick-btn {
        padding: 0.3rem 0.5rem;
        font-size: 0.65rem;
        min-width: 120px;
    }

    #user-input {
        padding: 0.3rem 0.6rem;
        font-size: 0.75rem;
    }

    .send-btn {
        padding: 0.3rem 0.8rem;
        font-size: 0.75rem;
    }
}