/* ============================================
   Shisetsu AI - Main Stylesheet
   ============================================ */

:root {
    --color-bg: #fafafa;
    --color-bg-alt: #f0f0f0;
    --color-text: #1a1a1a;
    --color-text-muted: #666666;
    --color-accent: #000000;
    --color-accent-light: #333333;
    --color-border: #e0e0e0;
    --color-white: #ffffff;
    
    --font-display: 'Space Grotesk', sans-serif;
    --font-body: 'Noto Sans JP', sans-serif;
    
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2.5rem;
    --space-xl: 4rem;
    --space-2xl: 6rem;
    --space-3xl: 10rem;
    
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

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

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

body {
    font-family: var(--font-body);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* Typography */
h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2.5rem, 7vw, 5rem);
}

h2 {
    font-size: clamp(2rem, 5vw, 3.5rem);
}

h3 {
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
}

/* Beta Badge */
.beta-badge {
    display: inline-block;
    padding: 0.15em 0.5em;
    font-size: 0.5em;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    color: var(--color-white);
    border-radius: var(--radius-sm);
    vertical-align: middle;
    margin-left: 0.3em;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-sm) var(--space-lg);
    background: rgba(250, 250, 250, 0.9);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
}

.nav-inner {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    display: flex;
    align-items: center;
}

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

.nav-menu a {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.nav-menu a:hover {
    color: var(--color-text);
}

.nav-cta {
    font-size: 0.9rem;
    padding: var(--space-xs) var(--space-md);
    background: var(--color-accent);
    color: var(--color-white);
    border-radius: var(--radius-xl);
    transition: all var(--transition-fast);
}

.nav-cta:hover {
    background: var(--color-accent-light);
    transform: translateY(-1px);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-sm) var(--space-lg);
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-xl);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
}

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

.btn-primary:hover {
    background: var(--color-accent-light);
    transform: translateY(-2px);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

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

.btn-large {
    padding: var(--space-md) var(--space-xl);
    font-size: 1.125rem;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    align-items: center;
    padding: var(--space-3xl) var(--space-lg);
    max-width: 1400px;
    margin: 0 auto;
}

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

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

.hero-subtitle {
    font-size: clamp(1rem, 1.5vw, 1.25rem);
    color: var(--color-text-muted);
    max-width: 480px;
    margin-bottom: var(--space-lg);
}

.hero-actions {
    display: flex;
    gap: var(--space-sm);
}

.hero-visual {
    display: flex;
    justify-content: center;
    animation: fadeInUp 0.8s ease 0.2s forwards;
    opacity: 0;
}

/* Chat Preview */
.chat-preview {
    width: 100%;
    max-width: 380px;
    background: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    border: 1px solid var(--color-border);
}

.chat-header {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    font-size: 0.875rem;
    font-weight: 500;
}

.chat-status {
    width: 8px;
    height: 8px;
    background: #22c55e;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

.chat-messages {
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    min-height: 300px;
}

.message {
    max-width: 85%;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    line-height: 1.5;
    animation: messageIn 0.4s ease forwards;
}

.message-bot {
    background: var(--color-bg);
    align-self: flex-start;
    border-bottom-left-radius: 4px;
}

.message-user {
    background: var(--color-accent);
    color: var(--color-white);
    align-self: flex-end;
    border-bottom-right-radius: 4px;
}

.message.typing {
    display: flex;
    gap: 4px;
    padding: var(--space-sm) var(--space-md);
}

.message.typing span {
    width: 8px;
    height: 8px;
    background: var(--color-text-muted);
    border-radius: 50%;
    animation: typing 1.4s infinite;
}

.message.typing span:nth-child(2) {
    animation-delay: 0.2s;
}

.message.typing span:nth-child(3) {
    animation-delay: 0.4s;
}

/* Sections */
.section {
    padding: var(--space-3xl) var(--space-lg);
    max-width: 1400px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--space-xl);
}

.section-label {
    display: inline-block;
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-sm);
}

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

.section-description {
    font-size: 1.125rem;
    color: var(--color-text-muted);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.feature-card {
    padding: var(--space-lg);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.08);
    border-color: transparent;
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin-bottom: var(--space-md);
}

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

.feature-card h3 {
    margin-bottom: var(--space-sm);
}

.feature-card p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
}

/* Integration Section */
.section-integration {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
    align-items: start;
}

.integration-content .section-label {
    text-align: left;
}

.integration-content .section-title {
    text-align: left;
}

.integration-content .section-description {
    text-align: left;
    margin-bottom: var(--space-lg);
}

.code-block {
    background: var(--color-text);
    border-radius: var(--radius-md);
    overflow: hidden;
    margin-bottom: var(--space-lg);
}

.code-header {
    display: flex;
    gap: 6px;
    padding: var(--space-sm) var(--space-md);
    background: rgba(255, 255, 255, 0.05);
}

.code-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
}

.code-block pre {
    padding: var(--space-md);
    overflow-x: auto;
}

.code-block code {
    font-family: 'SF Mono', 'Consolas', monospace;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.8;
}

.platforms-label {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-sm);
}

.platforms-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
}

.platforms-list span {
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-bg-alt);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

.integration-steps {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
}

.step {
    padding: var(--space-lg);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
}

.step-number {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-bg-alt);
    line-height: 1;
    margin-bottom: var(--space-sm);
}

.step h3 {
    margin-bottom: var(--space-xs);
}

.step p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

/* Pricing Section */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
    align-items: start;
}

.pricing-grid-two {
    grid-template-columns: repeat(2, 1fr);
    max-width: 900px;
    margin: 0 auto;
}

.pricing-card {
    padding: var(--space-lg);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    position: relative;
}

.pricing-card-featured {
    border-color: var(--color-accent);
    transform: scale(1.02);
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.1);
}

.pricing-badge {
    position: absolute;
    top: 0;
    right: var(--space-lg);
    transform: translateY(-50%);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-accent);
    color: var(--color-white);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
}

.pricing-header {
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
}

.pricing-header h3 {
    margin-bottom: var(--space-sm);
}

.pricing-price {
    display: flex;
    align-items: baseline;
    gap: 2px;
}

.pricing-price .currency {
    font-size: 1.25rem;
    font-weight: 600;
}

.pricing-price .amount {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
}

.pricing-price .period {
    font-size: 1rem;
    color: var(--color-text-muted);
}

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

.pricing-features li {
    padding: var(--space-xs) 0;
    font-size: 0.95rem;
    color: var(--color-text-muted);
    position: relative;
    padding-left: var(--space-md);
}

.pricing-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-accent);
}

.pricing-card .btn {
    width: 100%;
}

/* Contact Section */
.section-contact {
    text-align: center;
    padding: var(--space-3xl) var(--space-lg);
    background: var(--color-text);
    color: var(--color-white);
    border-radius: var(--radius-xl);
    margin: var(--space-2xl) var(--space-lg);
    max-width: 1400px;
    margin-left: auto;
    margin-right: auto;
}

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

.section-contact .section-description {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: var(--space-lg);
}

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

.section-contact .btn-primary:hover {
    background: rgba(255, 255, 255, 0.9);
}

/* Footer */
.footer {
    padding: var(--space-2xl) var(--space-lg);
    background: var(--color-bg-alt);
}

.footer-inner {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--space-xl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--color-border);
}

.footer-logo {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    display: flex;
    align-items: center;
}

.footer-brand p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

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

.footer-column h4 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.footer-column a {
    display: block;
    font-size: 0.9rem;
    color: var(--color-text-muted);
    padding: var(--space-xs) 0;
    transition: color var(--transition-fast);
}

.footer-column a:hover {
    color: var(--color-text);
}

.footer-bottom {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-lg);
}

.footer-bottom p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.footer-legal {
    display: flex;
    gap: var(--space-lg);
}

.footer-legal a {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.footer-legal a:hover {
    color: var(--color-text);
}

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

@keyframes messageIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes typing {
    0%, 60%, 100% {
        transform: translateY(0);
    }
    30% {
        transform: translateY(-4px);
    }
}

/* Scroll Animations */
.section {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.section.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 1024px) {
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        padding-top: var(--space-3xl);
    }
    
    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .section-integration {
        grid-template-columns: 1fr;
    }
    
    .pricing-grid,
    .pricing-grid-two {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
    }
    
    .pricing-card-featured {
        transform: none;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .integration-steps {
        grid-template-columns: 1fr;
    }
    
    .footer-inner {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--space-md);
        text-align: center;
    }
}

@media (max-width: 480px) {
    :root {
        --space-lg: 1.5rem;
        --space-xl: 2.5rem;
        --space-2xl: 4rem;
        --space-3xl: 6rem;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }
}