/* ===================================
   KAWA Code - GitHub-inspired Design
   =================================== */

/* CSS Variables */
:root {
    /* Colors - GitHub Dark Theme */
    --color-bg-primary: #0D1117;
    --color-bg-secondary: #161B22;
    --color-bg-tertiary: #1C2128;
    --color-bg-elevated: #21262D;
    
    /* KAWA Brand Colors */
    --color-kawa-blue: #2F81F7;
    --color-kawa-blue-light: #539BFF;
    --color-kawa-blue-dark: #1F6FEB;
    --color-kawa-green: #3FB950;
    --color-kawa-green-light: #56D364;
    
    /* Text Colors */
    --color-text-primary: #E6EDF3;
    --color-text-secondary: #8B949E;
    --color-text-tertiary: #656D76;
    
    /* Accent Colors */
    --color-accent-danger: #F85149;
    --color-accent-warning: #D29922;
    --color-accent-success: #3FB950;
    
    /* Border Colors */
    --color-border-default: #30363D;
    --color-border-muted: #21262D;
    
    /* Shadows */
    --shadow-sm: 0 1px 0 rgba(27, 31, 36, 0.04);
    --shadow-md: 0 3px 6px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.3);
    
    /* Typography */
    --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica', 'Arial', sans-serif;
    --font-family-mono: 'JetBrains Mono', 'Courier New', monospace;
    
    /* Spacing */
    --spacing-unit: 8px;
    
    /* Transitions */
    --transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===================================
   Base Styles
   =================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-base);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    font-size: 16px;
    overflow-x: hidden;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
}

/* ===================================
   Navigation Bar
   =================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(13, 17, 23, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border-default);
    padding: 16px 0;
    z-index: 1000;
    transition: var(--transition-base);
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text-primary);
    text-decoration: none;
    transition: var(--transition-base);
}

.nav-brand:hover {
    opacity: 0.8;
}

.nav-logo {
    width: 32px;
    height: 32px;
    object-fit: contain;
}

.nav-brand i {
    color: var(--color-kawa-blue);
    font-size: 24px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-links a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 14px;
    transition: var(--transition-base);
    padding: 8px 12px;
    border-radius: 6px;
}

.nav-links a:hover {
    color: var(--color-text-primary);
    background-color: var(--color-bg-tertiary);
}

.btn-download-nav {
    background-color: var(--color-kawa-blue) !important;
    color: white !important;
    padding: 8px 16px !important;
    border-radius: 6px;
}

.btn-download-nav:hover {
    background-color: var(--color-kawa-blue-light) !important;
}

/* ===================================
   Hero Section
   =================================== */

.hero {
    padding: 160px 0 120px;
    text-align: center;
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
}

.hero-logo {
    margin-bottom: 32px;
    display: flex;
    justify-content: center;
}

.hero-logo img {
    width: 120px;
    height: 120px;
    object-fit: contain;
    animation: fadeInScale 0.8s ease-out;
}

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

.hero-title {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 32px;
    letter-spacing: -0.02em;
}

.highlight {
    color: var(--color-kawa-blue-light);
    position: relative;
    display: inline-block;
}

.highlight-green {
    color: var(--color-kawa-green-light);
    font-weight: 600;
}

.hero-subtitle {
    font-size: 18px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    margin-bottom: 48px;
}

.hero-subtitle strong {
    color: var(--color-text-primary);
    font-weight: 600;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 64px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-base);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background-color: var(--color-kawa-blue);
    color: white;
    box-shadow: 0 0 0 0 rgba(47, 129, 247, 0.4);
}

.btn-primary:hover {
    background-color: var(--color-kawa-blue-light);
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(47, 129, 247, 0.3);
}

.btn-secondary {
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border-default);
}

.btn-secondary:hover {
    background-color: var(--color-bg-elevated);
    border-color: var(--color-text-tertiary);
}

.btn-large {
    padding: 16px 32px;
    font-size: 18px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 64px;
    flex-wrap: wrap;
}

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

.stat-number {
    font-size: 48px;
    font-weight: 800;
    color: var(--color-kawa-blue-light);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 14px;
    color: var(--color-text-secondary);
}

/* ===================================
   Section Divider
   =================================== */

.section-divider {
    border: none;
    height: 1px;
    background: linear-gradient(
        90deg,
        transparent,
        var(--color-border-default) 50%,
        transparent
    );
    margin: 80px 0;
}

/* ===================================
   Common Section Styles
   =================================== */

section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-title {
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

.section-title i {
    color: var(--color-kawa-blue);
}

.section-subtitle {
    font-size: 18px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    max-width: 800px;
    margin: 0 auto;
}

.section-subtitle strong {
    color: var(--color-text-primary);
}

/* ===================================
   Governance Section
   =================================== */

.problem-solution {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 32px;
    margin-bottom: 64px;
}

.problem-card,
.solution-card {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: 12px;
    padding: 32px;
}

.card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
}

.card-header i {
    font-size: 28px;
}

.problem-card .card-header i {
    color: var(--color-accent-danger);
}

.solution-card .card-header i {
    color: var(--color-kawa-green);
}

.card-header h3 {
    font-size: 24px;
    font-weight: 700;
}

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

.problem-list li {
    padding: 12px 0;
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--color-text-secondary);
    border-bottom: 1px solid var(--color-border-muted);
}

.problem-list li:last-child {
    border-bottom: none;
}

.problem-list i {
    color: var(--color-accent-danger);
    font-size: 18px;
}

.solution-features {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.feature-item {
    display: flex;
    gap: 16px;
}

.feature-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-kawa-blue);
    font-size: 20px;
}

.feature-content h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--color-text-primary);
}

.feature-content p {
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Audit Visualization */

.audit-visualization {
    max-width: 800px;
    margin: 0 auto;
}

.code-audit {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: 12px;
    overflow: hidden;
}

.audit-header {
    background-color: var(--color-bg-tertiary);
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--color-border-default);
}

.audit-badge {
    background-color: var(--color-kawa-blue);
    color: white;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}

.audit-timestamp {
    font-family: var(--font-family-mono);
    font-size: 12px;
    color: var(--color-text-tertiary);
}

.audit-body {
    padding: 24px;
}

.audit-row {
    display: flex;
    padding: 12px 0;
    border-bottom: 1px solid var(--color-border-muted);
}

.audit-row:last-child {
    border-bottom: none;
}

.audit-key {
    flex: 0 0 140px;
    font-weight: 600;
    color: var(--color-text-tertiary);
    font-size: 14px;
}

.audit-value {
    flex: 1;
    color: var(--color-text-primary);
    font-family: var(--font-family-mono);
    font-size: 14px;
}

.audit-status {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 600;
}

.audit-status.approved {
    background-color: rgba(63, 185, 80, 0.15);
    color: var(--color-kawa-green);
}

/* ===================================
   Universal Programming Section
   =================================== */

.universal-concept {
    margin-bottom: 64px;
}

.concept-diagram {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 32px;
    flex-wrap: wrap;
    padding: 48px 0;
}

.concept-step {
    text-align: center;
    flex: 0 0 200px;
}

.step-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--color-kawa-blue), var(--color-kawa-blue-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    color: white;
    box-shadow: 0 8px 16px rgba(47, 129, 247, 0.3);
}

.concept-step h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
}

.concept-step p {
    font-size: 14px;
    color: var(--color-text-secondary);
}

.concept-arrow {
    color: var(--color-kawa-blue);
    font-size: 32px;
}

/* Code Split View */

.code-split-view {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: 12px;
    padding: 32px;
}

.split-view-title {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.split-view-title i {
    color: var(--color-kawa-blue);
}

.split-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 24px;
    margin-bottom: 24px;
}

.split-pane {
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: 8px;
    overflow: hidden;
}

.pane-header {
    background-color: var(--color-bg-elevated);
    padding: 12px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--color-border-default);
}

.pane-title {
    font-size: 14px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.split-left .pane-title {
    color: var(--color-kawa-green);
}

.split-right .pane-title {
    color: var(--color-kawa-blue);
}

.pane-label {
    font-size: 12px;
    color: var(--color-text-tertiary);
    font-family: var(--font-family-mono);
}

.code-block {
    margin: 0;
    padding: 16px;
    overflow-x: auto;
}

.code-block code {
    font-family: var(--font-family-mono);
    font-size: 13px;
    line-height: 1.6;
    color: var(--color-text-primary);
}

.split-benefits {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
    padding: 24px;
    background-color: var(--color-bg-tertiary);
    border-radius: 8px;
}

.benefit-item {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--color-text-secondary);
}

.benefit-item i {
    color: var(--color-kawa-green);
    font-size: 18px;
}

.benefit-item strong {
    color: var(--color-kawa-green-light);
}

/* ===================================
   Collaboration Section
   =================================== */

.collaboration-features {
    display: flex;
    flex-direction: column;
    gap: 48px;
}

.collab-feature {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
    align-items: center;
}

.feature-visual {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: 12px;
    padding: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Conflict Detection Visual */

.conflict-detection {
    display: flex;
    align-items: center;
    gap: 24px;
}

.dev-icon {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.dev-icon i {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--color-kawa-blue), var(--color-kawa-blue-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
}

.dev-icon span {
    font-size: 12px;
    color: var(--color-text-secondary);
}

.conflict-alert {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    animation: pulse 2s infinite;
}

.conflict-alert i {
    font-size: 32px;
    color: var(--color-accent-warning);
}

.conflict-alert span {
    font-size: 12px;
    color: var(--color-accent-warning);
    font-weight: 600;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(1.05);
    }
}

/* P2P Sync Visual */

.p2p-sync {
    display: flex;
    align-items: center;
    gap: 32px;
}

.sync-node i {
    font-size: 48px;
    color: var(--color-kawa-blue);
}

.sync-line {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    position: relative;
}

.sync-line::before {
    content: '';
    position: absolute;
    top: 50%;
    left: -32px;
    right: -32px;
    height: 2px;
    background: linear-gradient(90deg, var(--color-kawa-blue), var(--color-kawa-green));
    z-index: -1;
}

.sync-line i {
    font-size: 24px;
    color: var(--color-kawa-green);
}

.sync-line span {
    font-size: 11px;
    color: var(--color-text-tertiary);
    font-weight: 600;
}

.feature-description h3 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.feature-description h3 i {
    color: var(--color-kawa-blue);
}

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

.feature-description strong {
    color: var(--color-text-primary);
    font-weight: 600;
}

/* ===================================
   ROI Section
   =================================== */

.roi-calculator {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: 12px;
    padding: 48px;
    margin-bottom: 64px;
}

.calculator-inputs {
    margin-bottom: 48px;
}

.calculator-inputs h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.calculator-inputs h3 i {
    color: var(--color-kawa-blue);
}

.input-group {
    margin-bottom: 24px;
}

.input-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--color-text-secondary);
}

.input-group input {
    width: 100%;
    max-width: 400px;
    padding: 12px 16px;
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: 6px;
    color: var(--color-text-primary);
    font-size: 16px;
    font-family: var(--font-family-base);
    transition: var(--transition-base);
}

.input-group input:focus {
    outline: none;
    border-color: var(--color-kawa-blue);
    box-shadow: 0 0 0 3px rgba(47, 129, 247, 0.1);
}

#calculateBtn {
    margin-top: 24px;
}

.calculator-results {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
    margin-bottom: 48px;
}

.result-card {
    flex: 1;
    min-width: 280px;
    background-color: var(--color-bg-tertiary);
    border: 2px solid var(--color-border-default);
    border-radius: 12px;
    padding: 32px;
    text-align: center;
}

.result-card.current {
    border-color: var(--color-accent-danger);
}

.result-card.improved {
    border-color: var(--color-kawa-green);
}

.result-card h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.result-card.current h4 {
    color: var(--color-accent-danger);
}

.result-card.improved h4 {
    color: var(--color-kawa-green);
}

.result-amount {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 12px;
    font-family: var(--font-family-mono);
}

.result-card.current .result-amount {
    color: var(--color-accent-danger);
}

.result-card.improved .result-amount.saving {
    color: var(--color-kawa-green);
}

.result-label {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
}

.result-detail {
    padding-top: 16px;
    border-top: 1px solid var(--color-border-default);
    font-size: 14px;
    color: var(--color-text-secondary);
}

.result-detail strong {
    color: var(--color-text-primary);
    font-weight: 600;
}

.result-arrow {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--color-kawa-blue);
}

.result-arrow i {
    font-size: 32px;
}

.result-arrow span {
    font-size: 12px;
    font-weight: 600;
}

.roi-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    padding: 32px;
    background-color: var(--color-bg-tertiary);
    border-radius: 12px;
}

.summary-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.summary-item i {
    font-size: 32px;
    color: var(--color-kawa-blue);
    margin-top: 4px;
}

.summary-item strong {
    display: block;
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--color-text-primary);
}

.summary-item p {
    font-size: 14px;
    color: var(--color-text-secondary);
}

.summary-item span {
    color: var(--color-kawa-green-light);
    font-weight: 700;
}

/* Case Study */

.case-study {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: 12px;
    padding: 48px;
}

.case-study h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 32px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.case-study h3 i {
    color: var(--color-kawa-blue);
}

.case-details {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.case-item {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.case-icon {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
}

.case-icon.loss {
    background-color: rgba(248, 81, 73, 0.15);
    color: var(--color-accent-danger);
}

.case-icon.gain {
    background-color: rgba(63, 185, 80, 0.15);
    color: var(--color-kawa-green);
}

.case-content h4 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}

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

.case-content strong {
    color: var(--color-text-primary);
    font-weight: 700;
}

/* ===================================
   FAQ Section
   =================================== */

.setup-guide,
.faq-list {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border-default);
    border-radius: 12px;
    padding: 48px;
    margin-bottom: 32px;
}

.setup-guide h3,
.faq-list h3 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 32px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.setup-guide h3 i,
.faq-list h3 i {
    color: var(--color-kawa-blue);
}

.setup-steps {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.setup-step {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.step-number {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-kawa-blue), var(--color-kawa-blue-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 700;
    color: white;
}

.step-content h4 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}

.step-content p {
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
}

.download-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.download-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: 6px;
    color: var(--color-text-primary);
    text-decoration: none;
    transition: var(--transition-base);
    font-family: var(--font-family-mono);
    font-size: 14px;
}

.download-link:hover {
    background-color: var(--color-bg-elevated);
    border-color: var(--color-kawa-blue);
}

.download-link i {
    color: var(--color-kawa-blue);
}

.link-external {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--color-kawa-blue);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-base);
}

.link-external:hover {
    color: var(--color-kawa-blue-light);
}

/* FAQ Items */

.faq-items {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.faq-item {
    background-color: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-default);
    border-radius: 8px;
    overflow: hidden;
    transition: var(--transition-base);
}

.faq-item:hover {
    border-color: var(--color-kawa-blue);
}

.faq-question {
    padding: 20px 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    user-select: none;
}

.faq-question i {
    color: var(--color-kawa-blue);
    font-size: 14px;
    transition: var(--transition-base);
}

.faq-item.active .faq-question i {
    transform: rotate(90deg);
}

.faq-question h4 {
    font-size: 18px;
    font-weight: 600;
    flex: 1;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 24px 20px 48px;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

/* ===================================
   Footer
   =================================== */

.footer {
    padding: 120px 0 60px;
    text-align: center;
    background: linear-gradient(180deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 100%);
}

.footer-content {
    max-width: 800px;
    margin: 0 auto 60px;
}

.footer-title {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.3;
    margin-bottom: 24px;
}

.footer-subtitle {
    font-size: 18px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    margin-bottom: 48px;
}

.footer-downloads {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 32px;
    flex-wrap: wrap;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
}

.footer-links a {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition-base);
}

.footer-links a:hover {
    color: var(--color-kawa-blue);
}

.footer-bottom {
    padding-top: 48px;
    border-top: 1px solid var(--color-border-default);
}

.footer-bottom p {
    color: var(--color-text-tertiary);
    font-size: 14px;
    margin-bottom: 8px;
}

.footer-note {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 16px !important;
}

.footer-note i {
    color: var(--color-kawa-blue);
}

/* ===================================
   Animations
   =================================== */

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 1024px) {
    .hero-title {
        font-size: 44px;
    }
    
    .section-title {
        font-size: 36px;
    }
    
    .split-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .nav-logo {
        width: 28px;
        height: 28px;
    }
    
    .hero {
        padding: 120px 0 80px;
    }
    
    .hero-logo img {
        width: 80px;
        height: 80px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .hero-stats {
        gap: 32px;
    }
    
    .stat-number {
        font-size: 36px;
    }
    
    .section-title {
        font-size: 28px;
        flex-direction: column;
    }
    
    .problem-solution {
        grid-template-columns: 1fr;
    }
    
    .concept-diagram {
        flex-direction: column;
    }
    
    .concept-arrow {
        transform: rotate(90deg);
    }
    
    .split-container {
        grid-template-columns: 1fr;
    }
    
    .collab-feature {
        grid-template-columns: 1fr;
    }
    
    .calculator-results {
        flex-direction: column;
    }
    
    .result-arrow {
        transform: rotate(90deg);
    }
    
    .footer-title {
        font-size: 32px;
    }
    
    .footer-downloads {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .nav-logo {
        width: 24px;
        height: 24px;
    }
    
    .hero-logo img {
        width: 64px;
        height: 64px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .stat-number {
        font-size: 28px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .roi-calculator,
    .setup-guide,
    .faq-list,
    .case-study {
        padding: 24px;
    }
}