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

:root {
    /* 颜色变量 */
    --primary-color: #6366f1;
    --gradient-start: #667eea;
    --gradient-end: #f093fb;
    --dark-bg: #1a1d2e;
    --text-dark: #1f2937;
    --text-gray: #6b7280;
    --text-light: #9ca3af;
    --bg-light: #f9fafb;
    --white: #ffffff;
    
    /* 间距 */
    --container-padding: 80px 20px;
    --section-spacing: 100px;
}

body {
    font-family: "San Francisco", -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: var(--white);
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 40px;
}

/* 小屏幕时减少padding */
@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 20px 0;
    z-index: 1000;
    background: transparent;
    border-bottom: 1px solid transparent;
    transition: background 0.3s ease, backdrop-filter 0.3s ease, border-bottom 0.3s ease;
}

.navbar.fixed {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-dark);
    letter-spacing: 2px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 40px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-size: 16px;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* 移动端导航 */
@media (max-width: 768px) {
    .nav-links {
        gap: 20px;
    }
    
    .logo {
        font-size: 20px;
    }
}

/* ========================================
   Hero 区域
   ======================================== */
.hero {
    padding: var(--container-padding);
    padding-top: 100px; /* 为固定导航栏预留空间 */
    padding-bottom: 200px; /* 底部padding，为视觉呼吸感 */
    /* background: linear-gradient(180deg, rgba(255, 240, 245, 0.3) 0%, rgba(240, 245, 255, 0.3) 100%); */
    background: url(images/hero_bg.png) no-repeat center top/cover;
}

.hero-header {
    text-align: center;
    margin-bottom: 60px;
    padding-top: 40px;
}

.hero-title {
    font-size: 64px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 48px;
    font-weight: 600;
    margin-bottom: 30px;
    color: var(--text-dark);
}

.hero-description {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-gray);
    max-width: 700px;
    margin: 0 auto;
}

/* Hero 产品预览区域 */
.hero-previews-section {
    position: relative;
    z-index: 10;
    margin-top: -200px; /* PC版面向上移动300px，与hero重叠 */
}

/* Hero 产品预览卡片 */
.hero-previews {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

/* 第1、第3个卡片增加顶部间距，形成交错效果 */
.hero-previews .preview-card:nth-child(1),
.hero-previews .preview-card:nth-child(3) {
    margin-top: 50px;
}

.preview-card {
    /* background: url(images/phone-topbar.png) no-repeat center top/100% auto,linear-gradient(0deg, #EFF3FF 0%, #FFFFFF 70%); */
    /* border-radius: 16px; */
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
}


.preview-image {
   display: flex;
   justify-content: center;
   align-items: center;
   aspect-ratio: 375/812;
    overflow: hidden;
}

.preview-image figure {
    width: 100%;
    height: 100%;
    margin: 0;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

/* 为每个figure设置对应的背景图 */
.figure-1 {
    background-image: url('images/hero-1.png');
}

.figure-2 {
    background-image: url('images/hero-2.png');
}

.figure-3 {
    background-image: url('images/hero-3.png');
}

.figure-4 {
    background-image: url('images/hero-4.png');
}

.preview-info {
    padding: 24px;
    display: none;
}

.preview-info h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-dark);
}

.preview-info p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-gray);
    margin-bottom: 16px;
    min-height: 64px;
}

.btn-primary {
    width: 100%;
    padding: 12px 24px;
    background: var(--dark-bg);
    color: var(--white);
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
}

.btn-primary:hover {
    background: #2a2d42;
}

/* Hero 响应式 */
@media (max-width: 1280px) {
    .hero {
        padding-bottom: 100px; /* 平板端调整底部padding */
    }
    
    .hero-previews-section {
        margin-top: -100px; /* 平板端向上移动减少 */
    }
    
    .hero-previews {
        /* grid-template-columns: repeat(2, 1fr); */
        /* width: 70%; */
          margin: 0 auto;
    }
        .hero-previews .preview-card{
          margin-top: 0;
        }
}

@media (max-width: 1024px) {
    .beyond-section {
        padding-top: 60px; /* 平板端调整顶部padding */
    }
}

@media (max-width: 768px) {
    .hero {
        padding-bottom: 60px; /* 移动端减少底部padding */
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 24px;
    }
    
    .hero-description {
        font-size: 14px;
    }
    
    .hero-description br {
        display: none;
    }
    
    .hero-previews-section {
        margin-top: -50px; /* 移动端向上移动很少 */
    }
    
    .hero-previews {
        grid-template-columns: repeat(2,1fr);
        gap: 20px;
    }
    
    /* 移动端移除交错效果 */
    .hero-previews .preview-card:nth-child(1),
    .hero-previews .preview-card:nth-child(3) {
        margin-top: 0;
    }
}

/* ========================================
   Beyond Traditional Note-Taking 区域
   ======================================== */
.beyond-section {
    padding: var(--container-padding);
    padding-top: 80px; /* 减少顶部padding */
    background: var(--white);
    position: relative;
    z-index: 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.section-subtitle {
    font-size: 20px;
    color: var(--text-gray);
    margin-bottom: 8px;
}

.section-description {
    font-size: 18px;
    color: var(--text-gray);
}

/* 特性网格 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.feature-card {
    text-align: center;
    padding: 40px 30px;
    background: linear-gradient(180deg, #F8FAFF 0%, #F0F3FF 100%);
    border-radius: 20px 20px 0 20px;
    border: 1.5px solid #EAEFFF;
    /* border-image: linear-gradient(180deg, #EAEFFF 0%, #D9E3FF 100%) 1.5; */
    transition: transform 0.3s;
    overflow: hidden;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-icon {
    width: 120px;
    height: 120px;
    margin: 0 auto 30px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.feature-card h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.feature-card p {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-gray);
}

/* 特性网格响应式 */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .feature-card {
        padding: 30px 20px;
    }
}

@media (max-width: 768px) {
    .beyond-section {
        padding-top: 60px; /* 移动端减少顶部padding */
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .section-subtitle,
    .section-description {
        font-size: 16px;
    }
}

/* ========================================
   Core Features 区域
   ======================================== */
.core-features {
    padding: 0 20px;
    background: linear-gradient(135deg, rgba(230, 240, 255, 0.5), rgba(255, 240, 250, 0.5));
}

.features-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    align-items: start;
}
.features-left{
  width: 100%;
  height: 100%;
  background: url(images/core-features-left-bg.png) no-repeat center top/cover;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  box-sizing: border-box;
  padding: 40px;
}
.features-left h2 {
    font-size: 38px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.features-tagline {
    font-size: 18px;
}

.features-right {
    display: flex;
    flex-direction: column;
    /* gap: 40px; */
}

.feature-group {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.feature-item {
    /* background: var(--white); */
    padding: 30px;
    /* border-radius: 16px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06); */
}

.feature-item h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-dark);
}

.feature-item > p {
    font-size: 14px;
    color: var(--text-gray);
    margin-bottom: 16px;
}

.feature-tags {
    list-style: none;
}

.feature-tags li {
    font-size: 13px;
    color: var(--primary-color);
    padding: 6px 12px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 6px;
    display: inline-block;
    margin-right: 8px;
    margin-bottom: 8px;
}

/* Core Features 响应式 */
@media (max-width: 1024px) {
    .features-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .features-left h2 {
        font-size: 32px;
    }
    
    .feature-group {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

/* ========================================
   Who Is It For 区域
   ======================================== */
.who-section {
    padding: var(--container-padding);
    background: var(--white);
}

.who-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.who-card {
    border-radius: 16px;
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
    background: var(--white);
}
.who-card-1 {
  background: #E9F5FF;
}
.who-card-2 {
  background: #F0ECFF;
}
.who-card-3 {
  background: #FFF1F4;
}
.who-card-4 {
  background: #FDF1E4;
}

.who-image {
    width: 100%;
    aspect-ratio: 16/9;
    overflow: hidden;
    background: var(--bg-light);
}

.who-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.who-content {
    padding: 30px;
    text-align: center;
}

.who-content h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-dark);
}

.who-content p {
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-gray);
}

/* Who 响应式 */
@media (max-width: 768px) {
    .who-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--dark-bg);
    padding: 60px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-logo {
    max-width: 120px;
}

.footer-logo img {
    width: 100%;
    height: auto;
}

.contact-info {
    display: flex;
    align-items: center;
    gap: 20px;
}

.contact-icon {
    width: 48px;
    height: 48px;
    flex-shrink: 0;
}

.contact-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.contact-text h4 {
    font-size: 16px;
    color: var(--white);
    margin-bottom: 8px;
}

.contact-text p {
    font-size: 14px;
    color: var(--text-light);
}
.contact-text a{
  text-decoration: none;
  color: #C4C2FF;
}
.contact-text a:hover {
  text-decoration: underline;
}

/* 页脚响应式 */
@media (max-width: 768px) {
  .footer {
    padding: 40px 0;
  }
    .footer-content {
        flex-direction: column;
        gap: 30px;
        text-align: center;
    }
    
    .contact-info {
        flex-direction: column;
        gap: 15px;
    }
}

/* ========================================
   通用动画
   ======================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 选中文字颜色 */
::selection {
    background: rgba(99, 102, 241, 0.2);
    color: var(--text-dark);
}

/* ========================================
   1920px 宽屏适配
   ======================================== */
@media (min-width: 1920px) {
    /* 容器宽度调整 */
    .container {
        max-width: 1600px;
        padding: 0 60px;
    }
    
    /* Hero 区域 */
    .hero {
        padding-top: 120px;
        padding-bottom: 240px;
    }
    
    .hero-title {
        font-size: 72px;
    }
    
    .hero-subtitle {
        font-size: 56px;
    }
    
    .hero-description {
        font-size: 18px;
        max-width: 800px;
    }
    
    /* Hero Previews */
    .hero-previews-section {
        margin-top: -240px;
    }
    
    .hero-previews {
        gap: 30px;
    }
    
    .hero-previews .preview-card:nth-child(1),
    .hero-previews .preview-card:nth-child(3) {
        margin-top: 60px;
    }
    
    .preview-info {
        padding: 30px;
    }
    
    .preview-info h3 {
        font-size: 20px;
    }
    
    .preview-info p {
        font-size: 15px;
    }
    
    /* Beyond Section */
    .beyond-section {
        padding-top: 100px;
        padding-bottom: 100px;
    }
    
    .section-title {
        font-size: 56px;
    }
    
    .section-subtitle,
    .section-description {
        font-size: 22px;
    }
    
    .features-grid {
        gap: 50px;
    }
    
    .feature-card {
        padding: 50px 40px;
    }
    
    .feature-icon {
        width: 140px;
        height: 140px;
        margin-bottom: 40px;
    }
    
    .feature-card h3 {
        font-size: 28px;
        margin-bottom: 20px;
    }
    
    .feature-card p {
        font-size: 18px;
    }
    
    /* Core Features */
    .core-features {
        padding: 100px 60px;
    }
    
    .features-content {
        gap: 80px;
    }
    
    .features-left {
        padding: 60px;
    }
    
    .features-left h2 {
        font-size: 48px;
    }
    
    .features-tagline {
        font-size: 20px;
    }
    
    .feature-group {
        gap: 40px;
    }
    
    .feature-item {
        padding: 40px;
    }
    
    .feature-item h3 {
        font-size: 24px;
    }
    
    .feature-item > p {
        font-size: 16px;
    }
    
    .feature-tags li {
        font-size: 14px;
        padding: 8px 16px;
    }
    
    /* Who Section */
    .who-section {
        padding-top: 100px;
        padding-bottom: 100px;
    }
    
    .who-grid {
        gap: 50px;
    }
    
    .who-content {
        padding: 40px;
    }
    
    .who-content h3 {
        font-size: 28px;
        margin-bottom: 16px;
    }
    
    .who-content p {
        font-size: 18px;
    }
    
    /* Footer */
    .footer {
        padding: 80px 0;
    }
    
    .footer-logo {
        max-width: 150px;
    }
    
    .contact-icon {
        width: 56px;
        height: 56px;
    }
    
    .contact-text h4 {
        font-size: 18px;
    }
    
    .contact-text p {
        font-size: 16px;
    }
}