/* CSS Variables and Font Definitions */
:root {
  /* Notion风格配色系统 - 极简、优雅、现代 */
  --primary-color: #2f3437;
  --primary-light: #37393d;
  --primary-dark: #191b1d;
  
  /* Notion经典蓝色 - 仅用于重要交互 */
  --notion-blue: #0f7ce1;
  --notion-blue-light: #4b9eff;
  --notion-blue-dark: #0b69c7;
  
  /* 温暖的灰色系统 */
  --gray-50: #fafafa;
  --gray-100: #f5f5f5;
  --gray-200: #eeeeee;
  --gray-300: #e0e0e0;
  --gray-400: #bdbdbd;
  --gray-500: #9e9e9e;
  --gray-600: #757575;
  --gray-700: #616161;
  --gray-800: #424242;
  --gray-900: #212121;
  
  /* 文字颜色 */
  --text-primary: #37352f;
  --text-secondary: #787774;
  --text-tertiary: #9b9a97;
  --text-quaternary: #c7c7c5;
  
  /* 背景色系 */
  --bg-primary: #ffffff;
  --bg-secondary: #fafafa;
  --bg-tertiary: #f7f6f3;
  
  /* Notion风格的微妙阴影 */
  --shadow-color: 15, 15, 15;
  --shadow-light: 0 1px 2px rgba(var(--shadow-color), 0.04);
  --shadow-medium: 0 2px 4px rgba(var(--shadow-color), 0.06), 0 1px 2px rgba(var(--shadow-color), 0.03);
  --shadow-large: 0 4px 8px rgba(var(--shadow-color), 0.08), 0 2px 4px rgba(var(--shadow-color), 0.04);
  --shadow-xl: 0 8px 16px rgba(var(--shadow-color), 0.1), 0 4px 8px rgba(var(--shadow-color), 0.06);
  
  /* Notion风格边框 */
  --border-light: rgba(55, 53, 47, 0.09);
  --border-medium: rgba(55, 53, 47, 0.16);
  
  /* 微妙的渐变 */
  --gradient-hero: linear-gradient(135deg, #fafafa 0%, #f7f6f3 100%);
  --gradient-card: linear-gradient(135deg, #ffffff 0%, #fafafa 100%);
}

@font-face {
  font-family: Unicons;
  src: url("fonts/Unicons.woff2") format("woff2"), url("fonts/Unicons.woff") format("woff");
  font-weight: 400;
  font-style: normal;
  font-display: block
}

@font-face {
  font-family: Custom;
  src: url("fonts/Custom.woff2") format("woff2"), url("fonts/Custom.woff") format("woff");
}

/* Modern CSS Reset and Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.5;
    color: var(--text-primary);
    background: var(--gradient-hero);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container and Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Hero Section - Notion风格的简洁设计 */
.hero-section {
    padding: 100px 0 80px;
    text-align: center;
    background: var(--bg-primary);
    position: relative;
    border-bottom: 1px solid var(--border-light);
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 30% 70%, rgba(15, 124, 225, 0.03) 0%, transparent 60%),
        radial-gradient(circle at 70% 30%, rgba(55, 53, 47, 0.02) 0%, transparent 60%);
    z-index: 0;
}

.hero-content {
    max-width: 720px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    letter-spacing: -0.035em;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-tertiary);
    max-width: 580px;
    margin: 0 auto;
    line-height: 1.6;
    font-weight: 400;
}

/* Apps Section - Notion风格的卡片设计 */
.apps-section {
    padding: 80px 0;
    background: var(--bg-secondary);
    position: relative;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
    letter-spacing: -0.03em;
    line-height: 1.2;
}

.apps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.app-card {
    background: var(--bg-primary);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-medium);
    transition: all 0.2s ease;
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    border: 1px solid var(--border-light);
    position: relative;
}

.app-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-large);
    border-color: var(--border-medium);
}

.app-icon {
    flex-shrink: 0;
}

.app-icon img {
    width: 64px;
    height: 64px;
    border-radius: 8px;
    object-fit: cover;
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-light);
}

.app-card:hover .app-icon img {
    transform: scale(1.02);
}

.app-content {
    flex: 1;
}

.app-title {
    font-size: 1.375rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    letter-spacing: -0.01em;
    line-height: 1.3;
}

.app-description {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
    line-height: 1.6;
    font-weight: 400;
}

.privacy-link {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 0.875rem;
    background: var(--notion-blue);
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.15s ease;
    letter-spacing: 0.01em;
}

.privacy-link:hover {
    background: var(--notion-blue-dark);
    color: white;
    text-decoration: none;
    transform: translateY(-1px);
}

/* Security Section - Notion风格的内容区域 */
.security-section {
    padding: 80px 0;
    background: var(--bg-primary);
    position: relative;
    border-top: 1px solid var(--border-light);
}

.security-section .section-title {
    color: var(--text-primary);
    margin-bottom: 3rem;
}

.security-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.security-card {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 2rem 1.5rem;
    text-align: left;
    box-shadow: var(--shadow-light);
    transition: all 0.15s ease;
    border: 1px solid var(--border-light);
    position: relative;
}

.security-card:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-medium);
    border-color: var(--border-medium);
}

.security-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    opacity: 0.8;
}

.security-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
    letter-spacing: -0.01em;
    line-height: 1.4;
}

.security-card p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
    font-weight: 400;
}

/* Footer - Notion风格的简洁footer */
.footer {
    background: var(--gray-50);
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--border-light);
}

.footer-content {
    max-width: 600px;
    margin: 0 auto;
}

.footer-text {
    color: var(--text-tertiary);
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 400;
}

.footer-contact {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.contact-link {
    color: var(--notion-blue);
    text-decoration: none;
    transition: all 0.15s ease;
    font-weight: 500;
}

.contact-link:hover {
    color: var(--notion-blue-dark);
    text-decoration: none;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.75rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .apps-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .app-card {
        flex-direction: column;
        text-align: center;
        padding: 1.5rem;
    }
    
    .security-grid {
        grid-template-columns: 1fr;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .hero-section,
    .apps-section,
    .security-section {
        padding: 60px 0;
    }
    
    .security-card {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2.25rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .container {
        padding: 0 12px;
    }
    
    .hero-section,
    .apps-section,
    .security-section {
        padding: 50px 0;
    }
}