/* CSS Variables - Notion 风格 + 中式简约复古配色 */
:root {
  /* 浅灰色系 */
  --gray-50: #fafafa;
  --gray-100: #f5f5f5;
  --gray-200: #e5e5e5;
  --gray-300: #d4d4d4;
  --gray-400: #a3a3a3;
  --gray-500: #8a8a8a;
  --gray-600: #737373;
  --gray-700: #525252;
  --gray-800: #404040;
  --gray-900: #262626;

  /* 中式米白炭黑配色 */
  --beige-50: #faf9f7;
  --beige-100: #f5f3f0;
  --beige-200: #efebe6;
  --beige-300: #e8e4dd;
  --beige-400: #ddd6ca;
  --beige-500: #d1c7b4;
  --beige-600: #c0b2a0;
  --beige-700: #a99883;
  --beige-800: #8b7d69;
  --beige-900: #6b5f4f;

  /* 炭黑色系 */
  --charcoal-50: #4a4a4a;
  --charcoal-100: #3d3d3d;
  --charcoal-200: #2f2f2f;
  --charcoal-300: #1f1f1f;
  --charcoal-400: #141414;
  --charcoal-500: #0a0a0a;

  /* 强调色 - 深炭黑 */
  --accent-500: #1f1f1f;
  --accent-400: #2f2f2f;
  --accent-300: #3d3d3d;
  --accent-200: #4a4a4a;
  --accent-100: #575757;
  --accent-50: #636363;

  /* 中式朱砂红点缀 */
  --red-accent: #c73e1d;

  /* 字体 */
  --font-primary: 'Source Han Serif SC', 'Noto Serif SC', serif;
  --font-secondary: 'ZCOOL XiaoWei', 'Source Han Serif SC', serif;
  --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', monospace;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);

  /* 边框半径 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  /* 动画 */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
}

/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  background: linear-gradient(135deg, #faf9f7 0%, #f5f3f0 50%, #efebe6 100%);
  color: var(--charcoal-100);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.site-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Navigation */
.nav-container {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: #FFFFFF;
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--beige-300);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.nav-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav-logo {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
}

.brand-text {
  font-family: var(--font-secondary);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--charcoal-200);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  color: var(--charcoal-100);
  text-decoration: none;
  font-weight: 400;
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--charcoal-300);
  transition: width var(--transition-normal);
}

.nav-link:hover {
  color: var(--charcoal-200);
}

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

.cta-button {
  background: var(--charcoal-300);
  color: white;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-lg);
  text-decoration: none;
  font-weight: 500;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

.cta-button:hover {
  background: var(--charcoal-300);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Main Content */
.main-content {
  flex: 1;
  margin-top: 64px;
}

/* Hero Section */
.hero-section {
  padding: 6rem 2rem 4rem;
  background: radial-gradient(ellipse at top, var(--gray-50) 0%, transparent 70%);
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-content {
  animation: fadeInUp 0.8s ease;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--red-accent);
  color: white;
  padding: 0.375rem 1rem;
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.hero-title {
  font-family: var(--font-secondary);
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.2;
  color: var(--charcoal-300);
  margin-bottom: 1.5rem;
}

.highlight {
  background: linear-gradient(135deg, var(--charcoal-300) 0%, var(--charcoal-400) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--charcoal-50);
  margin-bottom: 2rem;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.primary-button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--charcoal-300);
  color: white;
  padding: 0.875rem 1.75rem;
  border-radius: var(--radius-lg);
  text-decoration: none;
  font-weight: 500;
  font-size: 1rem;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-md);
}

.primary-button:hover {
  background: var(--charcoal-300);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.button-arrow {
  transition: transform var(--transition-normal);
}

.primary-button:hover .button-arrow {
  transform: translateX(4px);
}

.secondary-button {
  display: inline-flex;
  align-items: center;
  background: transparent;
  color: var(--charcoal-100);
  padding: 0.875rem 1.75rem;
  border: 2px solid var(--beige-400);
  border-radius: var(--radius-lg);
  text-decoration: none;
  font-weight: 500;
  font-size: 1rem;
  transition: all var(--transition-normal);
}

.secondary-button:hover {
  background: var(--beige-300);
  border-color: var(--beige-500);
  color: var(--charcoal-200);
}

.hero-features {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}


/* Browser Mockup */
.hero-visual {
  animation: fadeInUp 0.8s ease 0.2s both;
}

.browser-mockup {
  background: var(--beige-100);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--beige-400);
  transform: perspective(1000px) rotateY(-5deg) rotateX(5deg);
  transition: transform var(--transition-slow);
}

.browser-mockup:hover {
  transform: perspective(1000px) rotateY(0deg) rotateX(0deg);
}

.browser-header {
  background: var(--beige-200);
  padding: 0.75rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  border-bottom: 1px solid var(--beige-400);
}

.browser-dots {
  display: flex;
  gap: 0.5rem;
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--beige-600);
}

.dot:first-child { background: #ff5f56; }
.dot:nth-child(2) { background: #ffbd2e; }
.dot:nth-child(3) { background: #27ca3f; }

.browser-title {
  flex: 1;
  text-align: center;
  font-size: 0.875rem;
  color: var(--charcoal-100);
  font-weight: 500;
}

.browser-content {
  display: flex;
  height: 300px;
}

.page-content {
  flex: 1;
  padding: 1.5rem;
}

.content-placeholder {
  width: 60%;
  height: 1.5rem;
  background: var(--beige-400);
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
}

.content-line {
  height: 0.875rem;
  background: var(--beige-300);
  border-radius: var(--radius-sm);
  margin-bottom: 0.75rem;
}

.content-line.short { width: 40%; }
.content-line.medium { width: 70%; }
.content-line.long { width: 90%; }

.chat-sidebar {
  width: 280px;
  background: white;
  border-left: 1px solid var(--beige-400);
  display: flex;
  flex-direction: column;
}

.chat-header {
  padding: 1rem;
  border-bottom: 1px solid var(--beige-300);
  background: var(--beige-100);
}

.chat-title {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--charcoal-200);
}

.chat-messages {
  flex: 1;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.message {
  padding: 0.75rem;
  border-radius: var(--radius-md);
  max-width: 85%;
  font-size: 0.875rem;
  line-height: 1.4;
}

.message.user {
  background: var(--charcoal-300);
  color: #FFFFFF;
  align-self: flex-end;
}

.message.ai {
  background: var(--beige-200);
  color: var(--charcoal-100);
  align-self: flex-start;
}

/* Section Styles */
section {
  padding: 4rem 2rem;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
  animation: fadeInUp 0.6s ease;
}

.section-title {
  font-family: 'Noto Serif SC', serif, 'Source Han Serif SC', 'Source Han Serif CN', serif;
  font-size: 2.5rem;
  font-weight: 600;
  color: var(--charcoal-300);
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--charcoal-50);
  max-width: 600px;
  margin: 0 auto;
}

/* Features Section */
.features-section {
  background: linear-gradient(135deg, var(--gray-100) 0%, var(--gray-50) 100%);
}

.features-layout {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
}

.features-image {
  text-align: center;
  width: 100%;
  height: auto;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.features-img {
  width: 100%;
  max-width: 1100px;
  height: auto;
  border-radius: 0;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
  object-fit: cover;
  transition: all var(--transition-normal);
  background: #FFFFFF;
}

.features-img:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.15);
}


.feature-title {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--charcoal-300);
  margin-bottom: 0;
  line-height: 1.3;
}



/* Download Section */
.download-section {
  background: linear-gradient(135deg, var(--charcoal-300) 0%, var(--charcoal-400) 100%);
  color: white;
}

.download-container {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.download-content {
  animation: fadeInUp 0.6s ease;
}

.download-title {
  font-family: var(--font-secondary);
  font-size: 2.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.download-description {
  font-size: 1.125rem;
  margin-bottom: 2rem;
  opacity: 0.9;
}

.download-steps {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 3rem;
  text-align: left;
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background: rgba(255, 255, 255, 0.1);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  backdrop-filter: blur(10px);
}

.step-number {
  width: 32px;
  height: 32px;
  background: white;
  color: var(--charcoal-200);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 1rem;
  flex-shrink: 0;
}

.step-content h4 {
  font-family: var(--font-secondary);
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.step-content p {
  opacity: 0.9;
  font-size: 0.875rem;
}

.download-actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.download-button {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: white;
  color: var(--charcoal-200);
  padding: 1rem 2rem;
  border-radius: var(--radius-lg);
  text-decoration: none;
  font-weight: 600;
  font-size: 1.125rem;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-lg);
}

.download-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.download-icon {
  font-size: 1.25rem;
}

.download-note {
  font-size: 0.875rem;
  opacity: 0.8;
}

/* Footer */
.footer {
  background: var(--charcoal-500);
  color: var(--beige-300);
  padding: 3rem 2rem 1.5rem;
  margin-top: auto;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.footer-logo {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
}

.footer-brand-text {
  font-family: var(--font-secondary);
  font-size: 1.125rem;
  font-weight: 500;
}

.footer-info {
  text-align: center;
}

.footer-description {
  margin-bottom: 1rem;
  opacity: 0.8;
}

.footer-links {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-link {
  color: var(--beige-300);
  text-decoration: none;
  transition: color var(--transition-fast);
  font-size: 0.875rem;
}

.footer-link:hover {
  color: white;
}

.footer-copyright {
  padding-top: 2rem;
  border-top: 1px solid var(--charcoal-400);
  font-size: 0.875rem;
  opacity: 0.6;
  text-align: center;
}

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

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInFromLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .hero-container {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-features {
    justify-content: center;
  }

  .browser-mockup {
    transform: none;
    max-width: 100%;
  }

  .nav-content {
    padding: 1rem;
  }

  .nav-actions {
    gap: 1rem;
  }

  .nav-link:not(.cta-button) {
    display: none;
  }

  .features-layout {
    grid-template-columns: 1fr;
    gap: 3rem;
    text-align: center;
    max-width: 100%;
  }

  .features-image {
    height: auto;
    margin-bottom: 2rem;
  }

  .features-img {
    max-width: 600px;
  }

  .features-list {
    gap: 2rem;
  }

  .feature-item:hover {
    padding-left: 0;
    background: transparent;
    margin-left: 0;
    padding-right: 0;
    margin-right: 0;
    border-radius: 0;
  }

  
  .download-steps {
    gap: 1rem;
  }

  .step {
    flex-direction: column;
    text-align: center;
  }

  .section-title {
    font-size: 2rem;
  }

  .footer-links {
    gap: 1rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

  .hero-description {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .download-title {
    font-size: 2rem;
  }

  .feature-card,
  .step {
    padding: 1.5rem;
  }

  section {
    padding: 3rem 1rem;
  }

  .hero-section {
    padding: 4rem 1rem 3rem;
  }
}

/* Scroll animations */
.scroll-animate {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.6s ease;
}

.scroll-animate.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Focus and accessibility */
*:focus {
  outline: 2px solid var(--charcoal-300);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}