/* ========================================
   AINIX Labs - Modern, Balanced Design System
   ======================================== */

/* ========================================
   1. CSS Variables & Design Tokens
   ======================================== */
:root {
    /* Color Palette - 로고와 조화로운 모던 컬러 */
    --color-primary: #1a2847;        /* Deep Navy - 로고 기본색 */
    --color-primary-light: #2d3e5f;  /* Lighter Navy */
    --color-primary-dark: #0f1a2e;   /* Darker Navy */
    
    --color-accent: #00d4ff;         /* Bright Cyan - 로고 포인트 */
    --color-accent-soft: #4de2ff;    /* Soft Cyan */
    --color-accent-glow: rgba(0, 212, 255, 0.3);
    
    --color-secondary: #ff6b6b;      /* Coral - 따뜻한 포인트 */
    --color-tertiary: #4ecdc4;       /* Teal - 부드러운 그라데이션 */
    
    /* Neutral Colors */
    --color-white: #ffffff;
    --color-light: #f8f9fb;
    --color-light-gray: #e5e9f0;
    --color-gray: #8892a6;
    --color-dark-gray: #4a5568;
    --color-text: #2d3748;
    
    /* Gradient */
    --gradient-primary: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    --gradient-accent: linear-gradient(135deg, var(--color-accent) 0%, var(--color-tertiary) 100%);
    --gradient-overlay: linear-gradient(180deg, rgba(26, 40, 71, 0.05) 0%, rgba(26, 40, 71, 0) 100%);
    
    /* Typography Scale - 균형잡힌 타이포그래피 */
    --font-primary: 'Inter', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    
    --font-size-hero: clamp(2.5rem, 5vw, 4rem);        /* 40-64px */
    --font-size-h1: clamp(2rem, 4vw, 3rem);            /* 32-48px */
    --font-size-h2: clamp(1.5rem, 3vw, 2.25rem);       /* 24-36px */
    --font-size-h3: clamp(1.25rem, 2.5vw, 1.75rem);    /* 20-28px */
    --font-size-h4: clamp(1.125rem, 2vw, 1.375rem);    /* 18-22px */
    --font-size-body: clamp(1rem, 1.5vw, 1.125rem);    /* 16-18px */
    --font-size-small: clamp(0.875rem, 1.25vw, 1rem);  /* 14-16px */
    --font-size-tiny: 0.8125rem;                        /* 13px */
    
    --font-weight-light: 300;
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-extrabold: 800;
    
    --line-height-tight: 1.2;
    --line-height-normal: 1.6;
    --line-height-relaxed: 1.8;
    
    /* Spacing Scale */
    --spacing-xs: 0.5rem;    /* 8px */
    --spacing-sm: 1rem;      /* 16px */
    --spacing-md: 1.5rem;    /* 24px */
    --spacing-lg: 2rem;      /* 32px */
    --spacing-xl: 3rem;      /* 48px */
    --spacing-2xl: 4rem;     /* 64px */
    --spacing-3xl: 6rem;     /* 96px */
    --spacing-4xl: 8rem;     /* 128px */
    
    /* Layout */
    --container-width: 1200px;
    --section-padding: var(--spacing-4xl);
    --border-radius: 16px;
    --border-radius-sm: 8px;
    --border-radius-lg: 24px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.15);
}

/* ========================================
   2. Global Reset & Base Styles
   ======================================== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-primary);
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-regular);
    line-height: var(--line-height-normal);
    color: var(--color-text);
    background-color: var(--color-white);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ========================================
   3. Navigation
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 80px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    box-shadow: 0 2px 16px rgba(0, 0, 0, 0.04);
    z-index: 1000;
    transition: all var(--transition-base);
    opacity: 0;
    pointer-events: none;
}

.navbar.visible {
    opacity: 1;
    pointer-events: auto;
}

.navbar.scrolled {
    height: 70px;
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: var(--container-width);
    height: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo img {
    height: 60px;
    transition: transform var(--transition-base);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-xl);
}

.nav-link {
    position: relative;
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-medium);
    color: var(--color-primary);
    text-decoration: none;
    padding: var(--spacing-xs) 0;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-accent);
    transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-accent);
}

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

.language-switcher {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-left: var(--spacing-lg);
}

.lang-link {
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-semibold);
    color: var(--color-gray);
    text-decoration: none;
    padding: 6px 12px;
    border-radius: 6px;
    transition: all var(--transition-fast);
}

.lang-link:hover {
    color: var(--color-primary);
    background: rgba(0, 212, 255, 0.1);
}

.lang-link.active {
    color: var(--color-white);
    background: var(--gradient-accent);
    box-shadow: 0 2px 8px var(--color-accent-glow);
}

.lang-divider {
    color: var(--color-light-gray);
    font-weight: var(--font-weight-light);
}

.nav-toggle {
    display: none;
    font-size: 1.5rem;
    color: var(--color-primary);
    cursor: pointer;
}

/* ========================================
   4. Intro Section (첫 페이지)
   ======================================== */
.intro-section {
    position: relative;
    width: 100%;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.intro-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.intro-background img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.intro-content {
    position: relative;
    z-index: 2;
    text-align: center;
    animation: fadeIn 2s ease-out;
}

.intro-logo {
    margin-bottom: var(--spacing-2xl);
    animation: zoomIn 1.5s ease-out;
}

.intro-logo img {
    height: 400px;
    max-width: 90vw;
    object-fit: contain;
    filter: drop-shadow(0 8px 24px rgba(0, 0, 0, 0.06));
    animation: float 6s ease-in-out infinite;
}

.intro-tagline {
    font-size: var(--font-size-h4);
    font-weight: var(--font-weight-regular);
    color: var(--color-dark-gray);
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-3xl);
    animation: fadeInUp 1.5s ease-out 0.8s both;
}

.intro-scroll {
    animation: fadeInUp 1.5s ease-out 1.2s both;
}

.scroll-link {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-accent);
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-semibold);
    text-decoration: none;
    transition: all var(--transition-base);
    padding: var(--spacing-md);
}

.scroll-link:hover {
    transform: translateY(-4px);
    color: var(--color-primary);
}

.scroll-link i {
    font-size: 1.5rem;
    animation: bounce 2s ease-in-out infinite;
}

/* ========================================
   5. Hero Section
   ======================================== */
.hero-section {
    position: relative;
    min-height: calc(100vh - 80px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-4xl) var(--spacing-lg);
    padding-top: 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.hero-background img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, 
        rgba(26, 40, 71, 0.85) 0%, 
        rgba(26, 40, 71, 0.75) 50%,
        rgba(0, 212, 255, 0.15) 100%);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 1000px;
}

.hero-divider {
    width: 80px;
    height: 3px;
    background: var(--gradient-accent);
    margin: 0 auto var(--spacing-xl);
    border-radius: 3px;
    box-shadow: 0 0 20px var(--color-accent-glow);
    animation: fadeIn 1s ease-out 0.5s both;
}

.hero-title {
    font-size: var(--font-size-h2);
    font-weight: var(--font-weight-semibold);
    color: var(--color-accent);
    line-height: var(--line-height-tight);
    margin-bottom: var(--spacing-sm);
    letter-spacing: 0.05em;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease-out 0.3s both;
}

.hero-subtitle {
    font-size: var(--font-size-h4);
    font-weight: var(--font-weight-regular);
    color: rgba(255, 255, 255, 0.9);
    line-height: var(--line-height-relaxed);
    margin-bottom: var(--spacing-3xl);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease-out 0.5s both;
}

.hero-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-top: var(--spacing-2xl);
    animation: fadeInUp 1s ease-out 0.6s both;
}

.flow-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.flow-icon {
    width: 72px;
    height: 72px;
    background: var(--gradient-accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-white);
    font-size: 2rem;
    box-shadow: 0 8px 32px var(--color-accent-glow);
    transition: transform var(--transition-base);
}

.flow-item:hover .flow-icon {
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 12px 40px var(--color-accent-glow);
}

.flow-item span {
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-semibold);
    color: var(--color-white);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.flow-arrow {
    width: 60px;
    height: 20px;
    color: var(--color-accent);
    opacity: 0.8;
}

.hero-cta {
    margin-top: var(--spacing-3xl);
    animation: fadeInUp 1s ease-out 0.9s both;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(12px);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50px;
    color: var(--color-white);
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-semibold);
    text-decoration: none;
    transition: all var(--transition-base);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.cta-button:hover {
    background: rgba(0, 212, 255, 0.2);
    border-color: var(--color-accent);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 212, 255, 0.4);
}

.cta-button i {
    font-size: 1rem;
    animation: bounce 2s ease-in-out infinite;
}

/* ========================================
   6. Section Header (공통 섹션 헤더)
   ======================================== */
.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-3xl);
}

.section-tag {
    display: inline-block;
    font-size: var(--font-size-tiny);
    font-weight: var(--font-weight-semibold);
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(0, 212, 255, 0.1);
    border-radius: 100px;
    margin-bottom: var(--spacing-md);
}

.section-title {
    font-size: var(--font-size-h1);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    line-height: var(--line-height-tight);
    margin-bottom: var(--spacing-md);
}

.section-desc {
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-regular);
    color: var(--color-dark-gray);
    line-height: var(--line-height-relaxed);
}

/* ========================================
   7. Technology Section
   ======================================== */
.tech-section {
    padding: var(--section-padding) 0;
    background: linear-gradient(180deg, #ffffff 0%, #f8f9fb 50%, #ffffff 100%);
}

.tech-pipeline {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-3xl);
}

.pipeline-stage {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
    padding: var(--spacing-xl);
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.pipeline-stage:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.pipeline-stage:nth-child(even) .stage-visual {
    order: 2;
}

.pipeline-stage:nth-child(even) .stage-content {
    order: 1;
}

.stage-number {
    position: absolute;
    top: var(--spacing-lg);
    left: var(--spacing-lg);
    width: 48px;
    height: 48px;
    background: var(--gradient-accent);
    color: var(--color-white);
    font-size: var(--font-size-h4);
    font-weight: var(--font-weight-bold);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 16px var(--color-accent-glow);
    z-index: 10;
}

.stage-visual {
    position: relative;
    border-radius: var(--border-radius);
    overflow: hidden;
    aspect-ratio: 16 / 10;
}

.stage-visual img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.pipeline-stage:hover .stage-visual img {
    transform: scale(1.05);
}

.stage-content {
    padding: var(--spacing-md);
}

.stage-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.1) 0%, rgba(78, 205, 196, 0.1) 100%);
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
    font-size: 1.75rem;
    margin-bottom: var(--spacing-md);
}

.stage-title {
    font-size: var(--font-size-h3);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    line-height: var(--line-height-tight);
    margin-bottom: var(--spacing-sm);
}

.stage-desc {
    font-size: var(--font-size-small);
    font-weight: var(--font-weight-regular);
    color: var(--color-dark-gray);
    line-height: var(--line-height-relaxed);
    margin-bottom: var(--spacing-md);
}

.stage-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.stage-tags span {
    font-size: var(--font-size-tiny);
    font-weight: var(--font-weight-medium);
    color: var(--color-accent);
    background: rgba(0, 212, 255, 0.08);
    padding: 6px 12px;
    border-radius: 6px;
    border: 1px solid rgba(0, 212, 255, 0.2);
    transition: all var(--transition-fast);
}

.stage-tags span:hover {
    background: rgba(0, 212, 255, 0.15);
    border-color: var(--color-accent);
    transform: translateY(-2px);
}

/* Technology Advantages */
.tech-advantages {
    margin-top: var(--spacing-3xl);
    padding: var(--spacing-2xl);
    background: linear-gradient(135deg, rgba(26, 40, 71, 0.03) 0%, rgba(0, 212, 255, 0.03) 100%);
    border-radius: var(--border-radius-lg);
}

.advantages-title {
    font-size: var(--font-size-h2);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.advantage-card {
    padding: var(--spacing-xl);
    background: var(--color-white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: all var(--transition-base);
}

.advantage-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.advantage-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-md);
    background: var(--gradient-accent);
    color: var(--color-white);
    font-size: 2rem;
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 24px var(--color-accent-glow);
}

.advantage-card h4 {
    font-size: var(--font-size-h4);
    font-weight: var(--font-weight-semibold);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.advantage-card p {
    font-size: var(--font-size-small);
    color: var(--color-dark-gray);
    line-height: var(--line-height-relaxed);
}

/* ========================================
   8. Projects Section
   ======================================== */
.projects-section {
    padding: var(--section-padding) 0;
    background: var(--color-white);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.project-card {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.project-image {
    position: relative;
    aspect-ratio: 16 / 10;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.project-card:hover .project-image img {
    transform: scale(1.08);
}

.project-badge {
    position: absolute;
    top: var(--spacing-md);
    left: var(--spacing-md);
    font-size: var(--font-size-tiny);
    font-weight: var(--font-weight-semibold);
    color: var(--color-white);
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    padding: 6px 14px;
    border-radius: 100px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.project-body {
    padding: var(--spacing-xl);
}

.project-body h3 {
    font-size: var(--font-size-h3);
    font-weight: var(--font-weight-semibold);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    line-height: var(--line-height-tight);
}

.project-body p {
    font-size: var(--font-size-small);
    color: var(--color-dark-gray);
    line-height: var(--line-height-relaxed);
    margin-bottom: var(--spacing-md);
}

.project-tech {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-light-gray);
}

.tech-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    font-size: var(--font-size-small);
    color: var(--color-dark-gray);
    line-height: var(--line-height-normal);
}

.tech-item i {
    flex-shrink: 0;
    width: 20px;
    color: var(--color-accent);
    font-size: 1rem;
    margin-top: 2px;
}

/* ========================================
   9. Footer
   ======================================== */
.footer {
    background: var(--gradient-primary);
    color: var(--color-white);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: var(--spacing-lg);
}

.footer-contact {
    display: flex;
    justify-content: center;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.9);
    font-size: var(--font-size-small);
}

.contact-item i {
    color: var(--color-accent);
}

.contact-item a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

.contact-item a:hover {
    color: var(--color-accent);
}

.footer-bottom {
    padding-top: var(--spacing-md);
}

.footer-divider {
    border: none;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin: 0 0 var(--spacing-md) 0;
}

.footer-info {
    margin-bottom: var(--spacing-md);
}

.footer-address,
.footer-email {
    font-size: var(--font-size-small);
    color: rgba(255, 255, 255, 0.7);
    margin: var(--spacing-xs) 0;
    line-height: 1.6;
}

.footer-email a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-base);
}

.footer-email a:hover {
    color: var(--color-accent);
}

.footer-copyright {
    font-size: var(--font-size-small);
    color: rgba(255, 255, 255, 0.5);
    margin: 0;
}

.footer-tagline {
    font-weight: var(--font-weight-medium);
    color: rgba(255, 255, 255, 0.6);
    font-size: var(--font-size-small);
    margin: var(--spacing-xs) 0 0 0;
}

/* ========================================
   10. Back to Top Button
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 56px;
    height: 56px;
    background: var(--gradient-accent);
    color: var(--color-white);
    border: none;
    border-radius: 50%;
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
    box-shadow: 0 8px 24px var(--color-accent-glow);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px var(--color-accent-glow);
}

/* ========================================
   11. Animations
   ======================================== */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes zoomIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-8px);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        filter: drop-shadow(0 8px 32px rgba(0, 0, 0, 0.3));
    }
    50% {
        transform: scale(1.05);
        filter: drop-shadow(0 12px 40px rgba(0, 212, 255, 0.5));
    }
}

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

/* ========================================
   12. Responsive Design
   ======================================== */

/* Tablet (768px ~ 1024px) */
@media (max-width: 1024px) {
    :root {
        --section-padding: var(--spacing-3xl);
    }
    
    .intro-logo img {
        height: 320px;
    }
    
    .pipeline-stage {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .pipeline-stage:nth-child(even) .stage-visual,
    .pipeline-stage:nth-child(even) .stage-content {
        order: initial;
    }
    
    .stage-number {
        top: var(--spacing-md);
        left: var(--spacing-md);
        width: 40px;
        height: 40px;
        font-size: var(--font-size-body);
    }
    
    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .project-tech {
        gap: var(--spacing-xs);
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-lg);
        text-align: center;
    }
    
    .footer-contact {
        flex-direction: column;
        gap: var(--spacing-md);
        align-items: center;
    }
}

/* Mobile (< 768px) */
@media (max-width: 768px) {
    :root {
        --section-padding: var(--spacing-2xl);
    }
    
    .navbar {
        height: 70px;
    }
    
    .intro-logo img {
        height: 260px;
    }
    
    .intro-tagline {
        font-size: var(--font-size-small);
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--color-white);
        flex-direction: column;
        align-items: center;
        justify-content: flex-start;
        padding: var(--spacing-xl) 0;
        gap: var(--spacing-lg);
        box-shadow: var(--shadow-lg);
        transition: left var(--transition-base);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .language-switcher {
        position: fixed;
        top: 15px;
        right: 70px;
        z-index: 1001;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .intro-logo img {
        height: 200px;
    }
    
    .intro-tagline {
        font-size: var(--font-size-tiny);
    }
    
    .hero-company {
        font-size: clamp(1.5rem, 3vw, 2rem);
    }
    
    .hero-flow {
        gap: var(--spacing-sm);
    }
    
    .flow-icon {
        width: 56px;
        height: 56px;
        font-size: 1.5rem;
    }
    
    .flow-arrow {
        width: 40px;
    }
    
    .cta-button {
        padding: var(--spacing-sm) var(--spacing-lg);
        font-size: var(--font-size-small);
    }
    
    .section-header {
        margin-bottom: var(--spacing-2xl);
    }
    
    .tech-pipeline {
        gap: var(--spacing-xl);
    }
    
    .pipeline-stage {
        padding: var(--spacing-md);
    }
    
    .advantages-grid {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .project-tech {
        font-size: var(--font-size-tiny);
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .back-to-top {
        width: 48px;
        height: 48px;
        bottom: var(--spacing-lg);
        right: var(--spacing-lg);
    }
}

/* Small Mobile (< 480px) */
@media (max-width: 480px) {
    .hero-section {
        padding: var(--spacing-2xl) var(--spacing-md);
    }
    
    .hero-brand-logo {
        height: 60px;
    }
    
    .hero-company {
        font-size: 1.25rem;
        letter-spacing: 0.1em;
    }
    
    .hero-divider {
        width: 60px;
        height: 2px;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .nav-container {
        padding: 0 var(--spacing-md);
    }
    
    .flow-item {
        flex: 1 1 auto;
    }
    
    .flow-arrow {
        display: none;
    }
    
    .cta-button {
        padding: var(--spacing-sm) var(--spacing-md);
    }
}

/* ========================================
   13. Utility Classes
   ======================================== */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}