/* 全局样式重置和基础设置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f9f7f7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 温馨治愈色调系统 */
:root {
    --primary-color: #ffb6c1;    /* 淡粉色 - 温暖关怀 */
    --secondary-color: #b5e8d3;  /* 薄荷绿 - 清新自然 */
    --accent-color: #ffd166;     /* 暖黄色 - 积极向上 */
    --tertiary-color: #a8d8ea;   /* 天蓝色 - 宁静平和 */
    --text-color: #4a4a4a;       /* 深灰色 - 清晰可读 */
    --light-text: #666;          /* 中灰色 - 辅助文字 */
    --light-bg: #fff9f9;         /* 浅背景 - 柔和舒适 */
    --card-bg: #ffffff;          /* 卡片背景 - 纯净白色 */
    --shadow-light: 0 4px 6px rgba(0, 0, 0, 0.05);
    --shadow-medium: 0 8px 15px rgba(0, 0, 0, 0.1);
    --shadow-heavy: 0 15px 30px rgba(0, 0, 0, 0.15);
    --border-radius: 15px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 导航栏样式 - 专业而友好 */
header {
    background-color: var(--card-bg);
    box-shadow: var(--shadow-light);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
    max-width: 1200px;
    margin: 0 auto;
    padding-left: 20px;
    padding-right: 20px;
}

.logo {
    display: flex;
    align-items: center;
    cursor: pointer;
    transition: var(--transition);
}

.logo:hover {
    transform: scale(1.05);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 18px;
    margin-right: 10px;
}

.logo h1 {
    font-size: 24px;
    color: var(--primary-color);
    font-weight: 600;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    font-size: 16px;
    transition: var(--transition);
    position: relative;
    padding: 5px 0;
}

.nav-links a:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

.auth-buttons {
    display: flex;
    gap: 10px;
}

.btn {
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-login {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

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

.btn-register {
    background-color: var(--primary-color);
    color: white;
}

.btn-register:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

/* 页面内容基础样式 */
.page {
    display: none;
    flex: 1;
    padding: 40px 0;
}

.page.active {
    display: block;
}

/* 首页英雄区域 - 温暖欢迎 */
.journey-hero {
    min-height: 80vh;
    background: linear-gradient(135deg, var(--light-bg) 0%, #f0f9ff 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding: 60px 20px;
}

.journey-hero::before {
    content: "";
    position: absolute;
    top: -50px;
    right: -50px;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, var(--accent-color) 0%, transparent 70%);
    border-radius: 50%;
    opacity: 0.1;
    animation: float 6s ease-in-out infinite;
}

.journey-hero::after {
    content: "";
    position: absolute;
    bottom: -100px;
    left: -100px;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--secondary-color) 0%, transparent 70%);
    border-radius: 50%;
    opacity: 0.1;
    animation: float 8s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(180deg); }
}

.journey-content {
    text-align: left;
    max-width: 600px;
    padding: 40px;
    position: relative;
    z-index: 2;
}

.journey-hero h2 {
    font-size: 42px;
    margin-bottom: 20px;
    color: var(--text-color);
    line-height: 1.2;
    font-weight: 700;
}

.journey-hero p {
    font-size: 18px;
    margin-bottom: 30px;
    color: var(--light-text);
    line-height: 1.8;
}

.journey-btn {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: white;
    padding: 14px 35px;
    font-size: 18px;
    border-radius: 30px;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 5px 15px rgba(255, 182, 193, 0.3);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.journey-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(255, 182, 193, 0.4);
    background: linear-gradient(135deg, var(--accent-color) 0%, var(--primary-color) 100%);
}

/* 平台特色页面 - 心形卡片设计 */
.features-page {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
}

.section-title h2 {
    font-size: 32px;
    color: var(--text-color);
    margin-bottom: 15px;
    font-weight: 700;
    position: relative;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

.section-title p {
    color: var(--light-text);
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
}

.heart-notes {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
    margin-top: 50px;
}

.heart-note {
    width: 280px;
    height: 280px;
    background-color: white;
    border-radius: 50% 50% 50% 0;
    transform: rotate(-45deg);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-medium);
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.heart-note::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.1;
    transition: var(--transition);
}

.heart-note:hover::before {
    opacity: 0.2;
}

.heart-note:nth-child(1)::before { background: linear-gradient(135deg, var(--primary-color), transparent); }
.heart-note:nth-child(2)::before { background: linear-gradient(135deg, var(--secondary-color), transparent); }
.heart-note:nth-child(3)::before { background: linear-gradient(135deg, var(--accent-color), transparent); }
.heart-note:nth-child(4)::before { background: linear-gradient(135deg, var(--tertiary-color), transparent); }

.heart-note:hover {
    transform: rotate(-45deg) scale(1.05) translateY(-10px);
    box-shadow: var(--shadow-heavy);
}

.heart-note-content {
    transform: rotate(45deg);
    text-align: center;
    padding: 30px;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.heart-note h3 {
    margin-bottom: 15px;
    color: var(--text-color);
    font-size: 20px;
    font-weight: 600;
    z-index: 1;
    position: relative;
}

.heart-note p {
    color: var(--light-text);
    font-size: 14px;
    line-height: 1.6;
    z-index: 1;
    position: relative;
    text-align: center;
    padding: 0 20px;
}

/* 知识科普页面 - 卡片网格布局 */
.knowledge-page {
    padding: 40px 0;
}

.knowledge-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.knowledge-card {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border: 1px solid #f0f0f0;
    position: relative;
    overflow: hidden;
}

.knowledge-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    transform: scaleY(0);
    transition: var(--transition);
}

.knowledge-card:hover::before {
    transform: scaleY(1);
}

.knowledge-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-heavy);
}

.knowledge-icon {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 15px;
    display: block;
}

.knowledge-card h3 {
    margin-bottom: 15px;
    color: var(--text-color);
    font-size: 1.3rem;
    font-weight: 600;
    line-height: 1.4;
}

.knowledge-card p {
    color: var(--light-text);
    margin-bottom: 20px;
    line-height: 1.6;
    min-height: 80px;
}

.knowledge-btn {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
    width: 100%;
    font-weight: 500;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.knowledge-btn:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 182, 193, 0.3);
}
/* 新增交互卡片样式 */
.knowledge-card[data-type="bookshelf"] .knowledge-btn {
    background-color: #90caf9; /* 蓝色变体 */
}

.knowledge-card[data-type="movie-gallery"] .knowledge-btn {
    background-color: #f48fb1; /* 粉色变体 */
}

.knowledge-card[data-type="letter"] .knowledge-btn {
    background-color: #a5d6a7; /* 绿色变体 */
}

/* 核心功能模块 - 简洁现代 */
.features {
    padding: 80px 0;
    background-color: var(--card-bg);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: var(--light-bg);
    border-radius: var(--border-radius);
    padding: 30px;
    text-align: center;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    cursor: pointer;
    border: 1px solid #f5f5f5;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-medium);
}

.feature-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    font-weight: bold;
    transition: var(--transition);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.feature-card h3 {
    margin-bottom: 15px;
    color: var(--text-color);
    font-size: 1.2rem;
    font-weight: 600;
}

.feature-card p {
    color: var(--light-text);
    line-height: 1.6;
}

.audio-player {
    width: 100%;
    padding: 20px 0;
}

.audio-player::-webkit-media-controls-panel {
    background-color: #f0f0f0;
    border-radius: 10px;
}

/* 用户画像统计 - 数据可视化 */
.user-profile {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.profile-stats {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    margin-top: 40px;
    gap: 20px;
}

.stat-item {
    text-align: center;
    margin: 20px;
    flex: 1;
    min-width: 150px;
    max-width: 200px;
}

.stat-value {
    font-size: 36px;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 10px;
    font-family: 'Arial', sans-serif;
}

.stat-label {
    color: var(--light-text);
    font-size: 16px;
    font-weight: 500;
}

/* 响应式设计 - 移动端友好 */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        padding: 20px 0;
        gap: 20px;
    }
    
    .nav-links {
        margin: 20px 0;
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }
    
    .nav-links a {
        font-size: 14px;
        padding: 8px 12px;
    }
    
    .auth-buttons {
        justify-content: center;
        width: 100%;
    }
    
    .journey-hero h2 {
        font-size: 32px;
    }
    
    .journey-hero p {
        font-size: 16px;
    }
    
    .heart-note {
        width: 250px;
        height: 250px;
    }
    
    .section-title h2 {
        font-size: 28px;
    }
    
    .profile-stats {
        flex-direction: column;
        align-items: center;
    }
    
    .stat-item {
        margin: 10px 0;
    }
    
    .features-grid,
    .knowledge-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .feature-card,
    .knowledge-card {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .journey-hero {
        padding: 40px 15px;
    }
    
    .journey-content {
        padding: 20px;
    }
    
    .journey-hero h2 {
        font-size: 28px;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: 10px;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }
    
    .heart-note {
        width: 220px;
        height: 220px;
    }
    
    .knowledge-grid {
        grid-template-columns: 1fr;
    }
    
    .feature-card,
    .knowledge-card {
        padding: 15px;
    }
}

/* 动画增强用户体验 */
.fade-in {
    animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.slide-up {
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 滚动条美化 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
}