/* ===== I18N LOADING STATE ===== */
/* Hide content during Chinese language initialization to prevent flash of English content */
html.i18n-loading body {
    visibility: hidden;
}

html.i18n-loading .nav {
    visibility: visible; /* Keep navigation visible for better UX */
}

/* ===== CSS RESET & BASE STYLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: 'Inter', 'SF Pro Display', 'Helvetica Neue', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background-color: #FEFEFE;
    color: #1A1A1A;
    line-height: 1.6;
    font-weight: 400;
    overflow-x: hidden;
}

/* ===== CSS CUSTOM PROPERTIES ===== */
:root {
    /* Colors */
    --color-primary: #2B5CE6;
    --color-primary-hover: #1E4BC7;
    --color-success: #22C55E;
    --color-text-primary: #1A1A1A;
    --color-text-secondary: #666666;
    --color-text-light: #999999;
    --color-background: #FEFEFE;
    --color-background-alt: #FBFBFB;
    --color-background-input: #F8F8F8;
    --color-border: #F0F0F0;
    --color-border-input: #E8E8E8;
    --color-white: #FFFFFF;
    
    /* Typography */
    --font-size-h1: clamp(32px, 4vw, 48px);
    --font-size-h2: clamp(24px, 3vw, 36px);
    --font-size-h3: clamp(20px, 2.5vw, 24px);
    --font-size-body-large: 18px;
    --font-size-body: 16px;
    --font-size-body-small: 14px;
    --font-size-caption: 12px;
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    
    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;
    --space-4xl: 96px;
    --space-5xl: 128px;
    
    /* Container */
    --container-max-width: 1200px;
    --container-padding: max(5vw, 40px);
    --content-max-width: 680px;
    --title-max-width: 800px;
    
    /* Shadows */
    --shadow-level-1: 0 1px 3px rgba(0,0,0,0.04);
    --shadow-level-2: 0 4px 12px rgba(0,0,0,0.06);
    --shadow-level-3: 0 8px 24px rgba(0,0,0,0.08);
    --shadow-focus: 0 0 0 3px rgba(43, 92, 230, 0.1);
    --shadow-hover: 0 2px 8px rgba(0,0,0,0.08);
    
    /* Transitions */
    --transition-fast: 150ms ease-out;
    --transition-normal: 250ms ease-out;
    --transition-slow: 400ms ease-out;
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    margin-bottom: var(--space-lg);
    color: var(--color-text-primary);
}

/* Display headings (Hero, major sections) */
h1 {
    font-family: var(--font-family-display);
    font-size: var(--font-size-h1);
    font-weight: var(--font-weight-medium);
    letter-spacing: -0.03em;
    line-height: 1.15;
}

/* Section headings */
h2 {
    font-family: var(--font-family-display);
    font-size: var(--font-size-h2);
    font-weight: var(--font-weight-normal);
    letter-spacing: -0.02em;
    line-height: 1.25;
}

/* Subsection headings */
h3 {
    font-family: var(--font-family-heading);
    font-size: var(--font-size-h3);
    font-weight: var(--font-weight-medium);
    letter-spacing: -0.01em;
    line-height: 1.3;
}

/* Minor headings */
h4 {
    font-family: var(--font-family-heading);
    font-size: var(--font-size-h4);
    font-weight: var(--font-weight-semibold);
    letter-spacing: normal;
    line-height: 1.4;
}

/* Body text */
p {
    font-family: var(--font-family-body);
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-normal);
    line-height: 1.7;
    margin-bottom: var(--space-lg);
    color: var(--color-text-secondary);
}

/* Large body text (intro paragraphs, important content) */
.text-large,
.hero-subtitle,
.paradigm-intro {
    font-family: var(--font-family-body);
    font-size: var(--font-size-body-large);
    line-height: 1.6;
    font-weight: var(--font-weight-light);
}

/* Small text (captions, metadata) */
.text-small,
.caption,
.meta {
    font-family: var(--font-family-body);
    font-size: var(--font-size-body-small);
    line-height: 1.5;
    color: var(--color-text-light);
}

/* Emphasized text */
strong, b {
    font-weight: var(--font-weight-semibold);
}

em, i {
    font-style: italic;
}

/* Quotes and citations */
blockquote {
    font-family: var(--font-family-display);
    font-style: italic;
    font-size: var(--font-size-body-large);
    line-height: 1.6;
    color: var(--color-text-secondary);
    border-left: 3px solid var(--color-primary);
    padding-left: var(--space-lg);
    margin: var(--space-xl) 0;
}

/* Code and technical content */
code, pre {
    font-family: var(--font-family-mono);
    font-size: 0.9em;
    background: var(--color-background-input);
    padding: 2px 6px;
    border-radius: 4px;
}

pre {
    padding: var(--space-md);
    overflow-x: auto;
    line-height: 1.5;
}

.text-large {
    font-size: var(--font-size-body-large);
    line-height: 1.6;
}

.text-small {
    font-size: var(--font-size-body-small);
    line-height: 1.5;
}

.text-caption {
    font-size: var(--font-size-caption);
    line-height: 1.4;
}

/* ===== LAYOUT COMPONENTS ===== */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding-left: var(--container-padding);
    padding-right: var(--container-padding);
}

.section {
    padding: var(--space-4xl) 0;
}

.section-title {
    font-family: var(--font-family-display);
    font-size: var(--font-size-h2);
    font-weight: var(--font-weight-normal);
    text-align: center;
    margin-bottom: var(--space-3xl);
    max-width: var(--title-max-width);
    margin-left: auto;
    margin-right: auto;
    letter-spacing: -0.02em;
    line-height: 1.25;
}

.section-title.coming-soon {
    color: var(--color-text-secondary);
    position: relative;
}

.section-title.coming-soon::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 1px;
    background: var(--color-text-light);
}

/* ===== NAVIGATION ===== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(254, 254, 254, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: var(--transition-normal);
}

.nav-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

.nav-logo .logo-link {
    font-size: var(--font-size-body-large);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-primary);
    text-decoration: none;
    transition: var(--transition-fast);
}

.nav-logo .logo-link:hover {
    color: var(--color-primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
}

.nav-link {
    font-family: var(--font-family-heading);
    font-size: var(--font-size-body-small);
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.01em;
    transition: var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--color-text-primary);
    font-weight: var(--font-weight-medium);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--color-primary);
    transition: var(--transition-fast);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
    gap: var(--space-xs);
}

.hamburger-line {
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    transition: var(--transition-normal);
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-family: var(--font-family-heading);
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.02em;
    border-radius: 6px;
    text-decoration: none;
    transition: var(--transition-fast);
    cursor: pointer;
    border: none;
    min-height: 44px;
    min-width: 44px;
}

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

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

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
    padding: 11px 23px;
}

.btn-secondary:hover {
    background: rgba(43, 92, 230, 0.05);
}

.btn-text {
    background: transparent;
    color: var(--color-primary);
    padding: var(--space-sm) var(--space-md);
    text-decoration: underline;
    text-underline-offset: 4px;
}

.btn-text:hover {
    background: rgba(43, 92, 230, 0.05);
    text-decoration: none;
}

.btn:focus {
    outline: none;
    box-shadow: var(--shadow-focus);
}

/* ===== HERO SECTION ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding-top: 80px;
    overflow: hidden;
}

.hero-container {
    position: relative;
    z-index: 2;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
    display: flex;
    align-items: center;
    gap: var(--space-4xl);
}

.hero-content {
    flex: 1;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    margin-bottom: var(--space-lg);
    animation: fadeInUp 0.8s ease-out;
}

.hero-subtitle {
    font-family: var(--font-family-body);
    font-size: var(--font-size-body-large);
    font-weight: var(--font-weight-light);
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-cta {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease-out 0.6s both;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1;
    opacity: 0.3;
}

.hero-pattern {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Hero pattern CSS replacement */
.hero-pattern-css {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: radial-gradient(circle, rgba(43, 92, 230, 0.1) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.5;
    pointer-events: none;
}

/* Captain-Ship Diagram CSS */
.captain-ship-diagram-css {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-lg);
    padding: var(--space-xl) var(--space-lg);
    min-height: 200px;
    flex-wrap: wrap;
}

.diagram-captain,
.diagram-ship,
.diagram-phantom {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
}

.captain-icon,
.ship-icon,
.phantom-icon {
    font-size: 48px;
    line-height: 1;
}

.captain-text,
.phantom-text {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.captain-label,
.ship-label,
.phantom-label {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-primary);
}

.captain-desc,
.phantom-desc {
    font-size: 12px;
    color: var(--color-text-secondary);
}

.diagram-arrow {
    font-size: 32px;
    color: var(--color-text-secondary);
    opacity: 0.5;
}

/* Founder Avatar Placeholder */
.founder-avatar-placeholder {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    border: 2px solid var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    font-weight: 600;
    color: var(--color-primary);
    background: rgba(43, 92, 230, 0.05);
}

/* Product Hero Specific */
.product-hero .hero-container {
    align-items: center;
    text-align: left;
}

.product-hero .hero-content {
    text-align: left;
    flex: 1;
}

.product-hero .hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.product-diagram {
    max-width: 100%;
    height: auto;
}

.platform-info {
    font-size: var(--font-size-body-small);
    color: var(--color-text-light);
    margin-bottom: var(--space-lg);
}

.platform-item {
    display: inline-block;
}

.platform-divider {
    margin: 0 var(--space-sm);
}

/* ===== HIGHLIGHT TEXT & TOOLTIPS ===== */
.highlight-text {
    color: var(--color-primary);
    cursor: help;
    position: relative;
    text-decoration: underline;
    text-decoration-color: transparent;
    transition: var(--transition-fast);
}

.highlight-text:hover {
    text-decoration-color: var(--color-primary);
}

.tooltip-trigger {
    color: var(--color-primary);
    cursor: help;
    text-decoration: underline;
    text-decoration-style: dotted;
}

.tooltip {
    position: absolute;
    background: var(--color-text-primary);
    color: var(--color-white);
    padding: var(--space-sm) var(--space-md);
    border-radius: 4px;
    font-size: var(--font-size-body-small);
    max-width: 280px;
    z-index: 1001;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition-fast);
    box-shadow: var(--shadow-level-2);
}

.tooltip.show {
    opacity: 1;
}

.tooltip::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 6px solid transparent;
    border-top-color: var(--color-text-primary);
}

/* ===== PHILOSOPHY SECTION ===== */
.philosophy {
    background: var(--color-background-alt);
}

.philosophy-content {
    max-width: var(--content-max-width);
    margin: 0 auto;
}

.philosophy-text {
    text-align: center;
}

.philosophy-subtitle {
    text-align: left;
    margin-top: var(--space-xl);
    margin-bottom: var(--space-lg);
}

.philosophy-list {
    list-style: none;
    margin-bottom: var(--space-lg);
}

.philosophy-list li {
    padding: var(--space-sm) 0;
    position: relative;
    padding-left: var(--space-lg);
}

.philosophy-list li::before {
    content: '•';
    color: var(--color-primary);
    position: absolute;
    left: 0;
    font-weight: var(--font-weight-semibold);
}

/* ===== CORE PROBLEM SECTION ===== */
.core-problem {
    background: var(--color-text-primary);
    color: var(--color-white);
}

.core-problem .section-title {
    color: var(--color-white);
}

.problem-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4xl);
    align-items: center;
}

.problem-visualization {
    display: flex;
    justify-content: center;
}

.captain-ship-diagram {
    width: 100%;
    max-width: 800px;
    height: auto;
}

.problem-text {
    color: #CCCCCC;
}

.problem-text p {
    color: #CCCCCC;
}

.problem-list {
    list-style: none;
    margin-bottom: var(--space-lg);
}

.problem-list li {
    padding: var(--space-sm) 0;
    color: #CCCCCC;
}

.problem-list strong {
    color: var(--color-white);
}

/* ===== PARADIGM SECTION ===== */
.paradigm-intro {
    text-align: center;
    font-size: var(--font-size-body-large);
    margin-bottom: var(--space-3xl);
    max-width: var(--content-max-width);
    margin-left: auto;
    margin-right: auto;
}

.paradigm-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-3xl);
    margin-bottom: var(--space-4xl);
}

.paradigm-step {
    text-align: center;
    padding: var(--space-2xl);
    background: var(--color-white);
    border-radius: 12px;
    border: 1px solid var(--color-border-input);
    box-shadow: var(--shadow-level-1);
    transition: var(--transition-normal);
}

.paradigm-step:hover {
    box-shadow: var(--shadow-level-2);
    transform: translateY(-4px);
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: var(--color-white);
    border-radius: 50%;
    font-size: var(--font-size-h3);
    font-weight: var(--font-weight-light);
    margin-bottom: var(--space-lg);
}

.step-title {
    margin-bottom: var(--space-md);
}

.step-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.step-method {
    font-size: var(--font-size-body-small);
    color: var(--color-primary);
    font-weight: var(--font-weight-medium);
    background: rgba(43, 92, 230, 0.1);
    padding: var(--space-xs) var(--space-md);
    border-radius: 16px;
    display: inline-block;
}

.methods-explanation h3 {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.methods-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
}

.method-card {
    padding: var(--space-lg);
    background: var(--color-background-alt);
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.method-card h4 {
    color: var(--color-primary);
    margin-bottom: var(--space-md);
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-medium);
}

.method-card p {
    margin-bottom: 0;
    color: var(--color-text-secondary);
    font-size: var(--font-size-body-small);
}

/* ===== PRODUCT SECTION ===== */
.product {
    background: linear-gradient(to bottom, var(--color-background-alt), var(--color-white));
}

.product-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--space-4xl);
    align-items: start;
}

.product-card {
    background: var(--color-white);
    padding: var(--space-2xl);
    border-radius: 12px;
    border: 1px solid var(--color-border-input);
    box-shadow: var(--shadow-level-1);
}

.product-card.featured {
    box-shadow: var(--shadow-level-2);
    border-color: var(--color-primary);
}

.product-title {
    font-family: var(--font-family-heading);
    font-size: var(--font-size-h3);
    font-weight: var(--font-weight-semibold);
    color: var(--color-primary);
    margin-bottom: var(--space-md);
    letter-spacing: -0.01em;
}

.product-tagline {
    font-size: var(--font-size-body-large);
    font-weight: var(--font-weight-medium);
    margin-bottom: var(--space-lg);
    color: var(--color-text-primary);
}

.product-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.product-features {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
}

.feature-tag {
    background: rgba(43, 92, 230, 0.1);
    color: var(--color-primary);
    padding: var(--space-xs) var(--space-md);
    border-radius: 16px;
    font-family: var(--font-family-heading);
    font-size: var(--font-size-body-small);
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.01em;
}

.future-title {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.future-list {
    list-style: none;
}

.future-list li {
    padding: var(--space-sm) 0;
    color: var(--color-text-secondary);
    position: relative;
    padding-left: var(--space-lg);
    opacity: 0.8;
}

.future-list li::before {
    content: '→';
    color: var(--color-text-light);
    position: absolute;
    left: 0;
}

/* ===== MISSION SECTION ===== */
.mission {
    background: var(--color-background-alt);
}

.mission-content {
    max-width: var(--content-max-width);
    margin: 0 auto;
    text-align: center;
}

.mission-text {
    font-size: var(--font-size-body-large);
    margin-bottom: var(--space-xl);
}

.mission-quote {
    font-size: var(--font-size-h3);
    font-weight: var(--font-weight-light);
    color: var(--color-primary);
    font-style: italic;
    margin-bottom: 0;
}

/* ===== FEATURES SECTION ===== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-2xl);
}

.feature-card {
    background: var(--color-white);
    padding: var(--space-2xl);
    border-radius: 8px;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-level-1);
    transition: var(--transition-normal);
    text-align: center;
}

.feature-card:hover {
    box-shadow: var(--shadow-level-2);
    transform: translateY(-4px);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--space-lg);
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-title {
    margin-bottom: var(--space-md);
}

.feature-description {
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* ===== ADVANCED FEATURES SECTION ===== */
.advanced-features {
    background: var(--color-background-alt);
}

.advanced-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-2xl);
}

.advanced-category {
    background: var(--color-white);
    padding: var(--space-xl);
    border-radius: 8px;
    border: 1px solid var(--color-border);
    opacity: 0.8;
}

.advanced-category h3 {
    color: var(--color-text-secondary);
    font-size: var(--font-size-body);
    margin-bottom: var(--space-md);
}

.advanced-category ul {
    list-style: none;
}

.advanced-category li {
    padding: var(--space-xs) 0;
    color: var(--color-text-secondary);
    font-size: var(--font-size-body-small);
    position: relative;
    padding-left: var(--space-md);
}

.advanced-category li::before {
    content: '·';
    color: var(--color-text-light);
    position: absolute;
    left: 0;
}

/* ===== WHY SECTION ===== */
.why-section {
    background: var(--color-text-primary);
    color: var(--color-white);
}

.why-section .section-title {
    color: var(--color-white);
}

.why-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
    max-width: var(--content-max-width);
    margin: 0 auto;
}

.why-item {
    display: flex;
    align-items: flex-start;
    gap: var(--space-lg);
}

.why-icon {
    width: 24px;
    height: 24px;
    background: var(--color-success);
    color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--font-weight-semibold);
    flex-shrink: 0;
    margin-top: 2px;
}

.why-content h3 {
    color: var(--color-white);
    margin-bottom: var(--space-sm);
    font-size: var(--font-size-body);
}

.why-content p {
    color: #CCCCCC;
    margin-bottom: 0;
    font-size: var(--font-size-body-small);
}

/* ===== TARGET USERS SECTION ===== */
.users-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.user-card {
    text-align: center;
    padding: var(--space-xl);
    background: var(--color-white);
    border-radius: 8px;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-level-1);
    transition: var(--transition-normal);
}

.user-card:hover {
    box-shadow: var(--shadow-level-2);
    transform: translateY(-4px);
}

.user-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--space-lg);
}

.user-icon svg {
    width: 100%;
    height: 100%;
}

.user-card h3 {
    margin-bottom: var(--space-sm);
    color: var(--color-primary);
}

.user-card p {
    color: var(--color-text-secondary);
    margin-bottom: 0;
    font-size: var(--font-size-body-small);
}

/* ===== PRIVACY SECTION ===== */
.privacy {
    background: var(--color-background-alt);
}

.privacy-content {
    max-width: var(--content-max-width);
    margin: 0 auto;
    text-align: center;
}

.privacy-subtitle {
    color: var(--color-primary);
    margin-bottom: var(--space-lg);
}

.privacy-intro {
    font-size: var(--font-size-body-large);
    margin-bottom: var(--space-2xl);
}

.privacy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-2xl);
}

.privacy-card {
    background: var(--color-white);
    padding: var(--space-lg);
    border-radius: 8px;
    border: 1px solid var(--color-border);
    text-align: center;
}

.privacy-card h4 {
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
    font-size: var(--font-size-body-small);
    font-weight: var(--font-weight-medium);
}

.privacy-card p {
    color: var(--color-text-secondary);
    margin-bottom: 0;
    font-size: var(--font-size-caption);
}

.privacy-note {
    color: var(--color-text-secondary);
    font-style: italic;
    margin-bottom: 0;
}

/* ===== GET STARTED SECTION ===== */
.get-started {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
    color: var(--color-white);
}

.get-started .section-title {
    color: var(--color-white);
}

.start-content {
    max-width: var(--content-max-width);
    margin: 0 auto;
    text-align: center;
}

.start-subtitle {
    color: var(--color-white);
    margin-bottom: var(--space-xl);
}

.start-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-2xl);
}

.start-feature {
    padding: var(--space-md);
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    font-size: var(--font-size-body-small);
}

.start-cta {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

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

.start-cta .btn-primary:hover {
    background: var(--color-background-alt);
    transform: translateY(-2px);
}

.start-cta .btn-secondary {
    border-color: var(--color-white);
    color: var(--color-white);
}

.start-cta .btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
}

.start-cta .btn-text {
    color: var(--color-white);
}

/* ===== FOUNDERS SECTION ===== */
.founders-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--space-2xl);
}

.founder-card {
    background: var(--color-white);
    padding: var(--space-2xl);
    border-radius: 12px;
    border: 1px solid var(--color-border-input);
    box-shadow: var(--shadow-level-1);
    text-align: center;
    transition: var(--transition-normal);
}

.founder-card:hover {
    box-shadow: var(--shadow-level-2);
    transform: translateY(-4px);
}

.founder-avatar {
    width: 100px;
    height: 100px;
    margin: 0 auto var(--space-lg);
}

.founder-avatar svg {
    width: 100%;
    height: 100%;
}

.founder-name {
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
}

.founder-title {
    color: var(--color-text-secondary);
    font-size: var(--font-size-body-small);
    margin-bottom: var(--space-lg);
}

.founder-details {
    list-style: none;
    text-align: left;
}

.founder-details li {
    padding: var(--space-xs) 0;
    font-size: var(--font-size-body-small);
    color: var(--color-text-secondary);
    position: relative;
    padding-left: var(--space-md);
}

.founder-details li::before {
    content: '•';
    color: var(--color-primary);
    position: absolute;
    left: 0;
}

/* ===== FOOTER ===== */
.footer {
    background: var(--color-background-input);
    padding: var(--space-2xl) 0 var(--space-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-2xl);
    margin-bottom: var(--space-xl);
}

.footer-title {
    color: var(--color-text-primary);
    margin-bottom: var(--space-md);
    font-size: var(--font-size-body);
}

.footer-main h4,
.footer-links h4,
.footer-social h4 {
    color: var(--color-text-secondary);
    font-size: var(--font-size-body-small);
    font-weight: var(--font-weight-medium);
    margin-bottom: var(--space-md);
}

.footer-contact,
.footer-location {
    color: var(--color-text-secondary);
    font-size: var(--font-size-body-small);
    margin-bottom: var(--space-sm);
}

.footer-links a,
.footer-social a {
    display: block;
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: var(--font-size-body-small);
    margin-bottom: var(--space-sm);
    transition: var(--transition-fast);
}

.footer-links a:hover,
.footer-social a:hover {
    color: var(--color-primary);
}

.footer-bottom {
    border-top: 1px solid var(--color-border);
    padding-top: var(--space-lg);
    text-align: center;
}

.footer-bottom p {
    color: var(--color-text-light);
    font-size: var(--font-size-caption);
    margin-bottom: 0;
}

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

.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: var(--transition-slow);
}

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

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 991px) {
    :root {
        --container-padding: 32px;
    }
    
    .nav-container {
        height: 70px;
    }
    
    .hero {
        padding-top: 70px;
    }
    
    .problem-content {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
        text-align: center;
    }
    
    .product-content {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
    
    .product-hero .hero-container {
        flex-direction: column;
        text-align: center;
    }
    
    .product-hero .hero-content {
        text-align: center;
    }
}

@media (max-width: 767px) {
    :root {
        --container-padding: 20px;
        --space-4xl: 64px;
        --space-5xl: 96px;
    }
    
    .nav-container {
        height: 60px;
    }
    
    .nav-menu {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--color-white);
        flex-direction: column;
        gap: 0;
        padding: var(--space-lg);
        border-bottom: 1px solid var(--color-border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition-normal);
    }
    
    .nav-menu.open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        padding: var(--space-md) 0;
        border-bottom: 1px solid var(--color-border);
        text-align: center;
        width: 100%;
    }
    
    .nav-link:last-child {
        border-bottom: none;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero {
        min-height: 100vh;
        padding-top: 60px;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-cta .btn {
        width: 100%;
        max-width: 280px;
    }
    
    .paradigm-steps {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }
    
    .advanced-grid {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }
    
    .users-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: var(--space-lg);
    }
    
    .privacy-grid {
        grid-template-columns: 1fr;
        gap: var(--space-md);
    }
    
    .founders-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
        text-align: center;
    }
    
    .start-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .start-cta .btn {
        width: 100%;
        max-width: 280px;
    }
    
    .language-selector-container {
        margin-left: var(--space-md);
    }
}

/* ===== LANGUAGE SELECTOR STYLES ===== */
.language-selector-container {
    position: relative;
    display: flex;
    align-items: center;
    margin-left: var(--space-lg);
}

.language-selector-btn {
    background: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 8px 12px;
    font-size: var(--font-size-body-small);
    font-family: inherit;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 100px;
    outline: none;
    display: flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
}

.language-selector-btn:hover {
    border-color: var(--color-primary);
    background: var(--color-background-alt);
}

.language-selector-btn:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(43, 92, 230, 0.15);
}

.language-selector-btn[aria-expanded="true"] {
    border-color: var(--color-primary);
    background: var(--color-background-alt);
}

.language-selector-btn[aria-expanded="true"] .chevron-icon {
    transform: rotate(180deg);
}

.globe-icon {
    flex-shrink: 0;
    color: var(--color-text-secondary);
}

.language-text {
    font-weight: var(--font-weight-medium);
    min-width: 20px;
}

.chevron-icon {
    margin-left: auto;
    flex-shrink: 0;
    transition: transform 0.2s ease;
    color: var(--color-text-light);
}

.language-dropdown {
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    box-shadow: var(--shadow-level-2);
    min-width: 120px;
    padding: 4px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s ease;
    z-index: 1000;
}

.language-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.language-option {
    display: block;
    width: 100%;
    padding: 8px 12px;
    text-align: left;
    background: transparent;
    border: none;
    border-radius: 4px;
    font-family: inherit;
    font-size: var(--font-size-body-small);
    color: var(--color-text-primary);
    cursor: pointer;
    transition: background 0.15s ease;
}

.language-option:hover {
    background: var(--color-background-alt);
}

.language-option.active {
    background: var(--color-primary);
    color: var(--color-white);
}

/* Responsive adjustments for language selector */
@media (max-width: 768px) {
    .language-selector-container {
        position: absolute;
        top: 50%;
        right: 60px; /* Position to the right of nav toggle */
        transform: translateY(-50%);
        margin-left: 0;
        margin-right: 0;
    }
    
    .language-selector-btn {
        font-size: var(--font-size-caption);
        padding: 6px 8px;
        min-width: 80px;
        gap: 4px;
    }
    
    .globe-icon {
        width: 14px;
        height: 14px;
    }
    
    .chevron-icon {
        width: 10px;
        height: 10px;
    }
    
    .language-dropdown {
        min-width: 100px;
    }
}

@media (max-width: 480px) {
    .language-selector-container {
        right: 50px; /* Adjust for smaller screens */
    }
    
    .language-selector-btn {
        padding: 4px 6px;
        min-width: 65px;
        font-size: 11px;
    }
    
    .globe-icon {
        width: 12px;
        height: 12px;
    }
    
    .language-text {
        font-size: 11px;
    }
}

/* ===== PRINT STYLES ===== */
@media print {
    .nav,
    .hero-background,
    .tooltip,
    .btn {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
    
    .section {
        padding: 20pt 0;
        break-inside: avoid;
    }
    
    .section-title {
        break-after: avoid;
    }
}

/* ===== FONT UTILITY CLASSES ===== */
.font-display {
    font-family: var(--font-family-display) !important;
}

.font-heading {
    font-family: var(--font-family-heading) !important;
}

.font-body {
    font-family: var(--font-family-body) !important;
}

.font-mono {
    font-family: var(--font-family-mono) !important;
}

.text-light {
    font-weight: var(--font-weight-light) !important;
}

.text-normal {
    font-weight: var(--font-weight-normal) !important;
}

.text-medium {
    font-weight: var(--font-weight-medium) !important;
}

.text-semibold {
    font-weight: var(--font-weight-semibold) !important;
}

.text-bold {
    font-weight: var(--font-weight-bold) !important;
}

/* ===== ACCESSIBILITY IMPROVEMENTS ===== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

@media (prefers-color-scheme: dark) {
    /* Dark mode styles can be added here if needed */
}

/* ===== FOCUS STYLES ===== */
button:focus,
a:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ===== HIGH CONTRAST MODE ===== */
@media (prefers-contrast: high) {
    :root {
        --color-text-secondary: #000000;
        --color-border: #000000;
    }
}

/* ===== COMPETITOR COMPARISON STYLES ===== */
.competitor-comparison {
    background-color: var(--color-background-alt);
}

.comparison-table-wrapper {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: var(--space-sm);
    box-shadow: var(--shadow-level-1);
}

.comparison-table {
    width: 100%;
    min-width: 600px;
    border-collapse: collapse;
    background-color: var(--color-white);
    font-size: var(--font-size-body-small);
}

.comparison-table th,
.comparison-table td {
    padding: var(--space-md);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
    vertical-align: top;
}

.comparison-table th {
    background-color: var(--color-background-alt);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-primary);
    border-bottom: 2px solid var(--color-border);
}

.comparison-table th:first-child {
    border-top-left-radius: var(--space-sm);
}

.comparison-table th:last-child {
    border-top-right-radius: var(--space-sm);
}

.comparison-table tbody tr:last-child td {
    border-bottom: none;
}

.comparison-table tbody tr:last-child td:first-child {
    border-bottom-left-radius: var(--space-sm);
}

.comparison-table tbody tr:last-child td:last-child {
    border-bottom-right-radius: var(--space-sm);
}

.comparison-table tbody tr:hover {
    background-color: rgba(43, 92, 230, 0.02);
}

.comparison-table .feature-highlight {
    background-color: rgba(43, 92, 230, 0.08);
    color: var(--color-primary);
    font-weight: var(--font-weight-medium);
}

.comparison-table .feature-coming {
    color: var(--color-text-secondary);
    font-style: italic;
}

/* ===== PRIVACY CARD PRIORITY STYLES ===== */
.privacy-card.priority {
    border: 2px solid var(--color-primary);
    background-color: rgba(43, 92, 230, 0.03);
    position: relative;
}

.privacy-card.priority::before {
    content: "优先";
    position: absolute;
    top: var(--space-sm);
    right: var(--space-sm);
    background-color: var(--color-primary);
    color: var(--color-white);
    font-size: var(--font-size-caption);
    font-weight: var(--font-weight-medium);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--space-xs);
}

/* ===== MOBILE RESPONSIVE FOR COMPARISON TABLE ===== */
@media (max-width: 768px) {
    .comparison-table {
        font-size: var(--font-size-caption);
    }
    
    .comparison-table th,
    .comparison-table td {
        padding: var(--space-sm);
    }
    
    .comparison-table th:nth-child(n+4),
    .comparison-table td:nth-child(n+4) {
        display: none;
    }
}

@media (max-width: 480px) {
    .comparison-table th:nth-child(n+3),
    .comparison-table td:nth-child(n+3) {
        display: none;
    }
}

/* ===== MISC UTILITY CLASSES ===== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

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

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.mb-0 {
    margin-bottom: 0 !important;
}

.mt-0 {
    margin-top: 0 !important;
}