/* 
  Modern Design System for ST9.5 Landing Page
  Colors: Pale Green & Pale Blue
*/

:root {
    --color-bg-light: #ffffff;
    --color-pale-blue: #F0F8FF;
    --color-pale-green: #F2FAF5;
    --color-primary-blue: #4A90E2;
    --color-primary-green: #52B788;
    --color-accent-blue: #0077B6;
    --color-accent-green: #2D6A4F;
    --color-text-main: #2D3436;
    --color-text-sub: #636E72;
    --color-white: #ffffff;
    --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
    --border-radius: 12px;
    --container-width: 1100px;
    --nav-height: 80px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Noto Sans JP', 'Inter', sans-serif;
    color: var(--color-text-main);
    line-height: 1.8;
    overflow-x: hidden;
    background-color: var(--color-bg-light);
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

/* Scroll Smoothing */
html {
    scroll-behavior: smooth;
}

/* --- Layout Components --- */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 15px;
    background: linear-gradient(90deg, var(--color-accent-blue), var(--color-accent-green));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.section-title p {
    color: var(--color-text-sub);
    font-size: 1.1rem;
}

/* --- Navigation --- */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    transition: var(--transition);
}

header.scrolled {
    height: 70px;
    background: rgba(255, 255, 255, 0.95);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-weight: 900;
    font-size: 1.5rem;
    color: var(--color-accent-blue);
}

.nav-links {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-links a {
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
}

.nav-links a:after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: var(--color-primary-green);
    transition: var(--transition);
}

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

.header-cta {
    background: linear-gradient(135deg, var(--color-primary-blue), var(--color-primary-green));
    color: white !important;
    padding: 10px 24px;
    border-radius: 50px;
    font-weight: 700;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.3);
}

.header-cta:after {
    display: none;
}

.header-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.5);
}

/* Hamburger */
.hamburger {
    display: none;
    cursor: pointer;
    flex-direction: column;
    gap: 6px;
    z-index: 1002;
    position: relative;
}

.hamburger span {
    width: 30px;
    height: 3px;
    background-color: var(--color-text-main);
    border-radius: 3px;
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
}

/* --- Buttons --- */
.btn {
    display: inline-block;
    padding: 16px 40px;
    border-radius: 50px;
    font-weight: 700;
    text-align: center;
    cursor: pointer;
    border: none;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary-blue), var(--color-primary-green));
    color: white;
    box-shadow: 0 10px 25px rgba(74, 144, 226, 0.2);
}

.btn-primary:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 15px 35px rgba(74, 144, 226, 0.4);
}

.btn-white:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 15px 35px rgba(255, 255, 255, 0.3);
}

/* --- Sections --- */

/* Hero */
.hero {
    padding-top: calc(var(--nav-height) + 60px);
    background: linear-gradient(rgba(240, 248, 255, 0.8), rgba(255, 255, 255, 0.8)), url('../img/heroback.jpg');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    text-align: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    color: #1a1a1a;
}

.hero-tagline {
    font-size: 1.25rem;
    color: var(--color-text-sub);
    margin-bottom: 40px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* Benefit Cards */
.benefit-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 25px;
    margin-top: 50px;
}

.benefit-card {
    background: white;
    padding: 40px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border-bottom: 4px solid transparent;
    transition: var(--transition);
    height: 100%;
}

.benefit-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-md);
    border-bottom-color: var(--color-primary-green);
}

.benefit-icon {
    width: 80px;
    height: 80px;
    background: var(--color-pale-blue);
    border-radius: 20px;
    margin: 0 auto 25px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent-blue);
}

/* Benefit Icon Color Themes (Hero Section) */
.hero .benefit-card:nth-child(1) .benefit-icon {
    background-color: #EBF5FF;
    color: #4A90E2;
}

.hero .benefit-card:nth-child(2) .benefit-icon {
    background-color: #F0FAF5;
    color: #52B788;
}

.hero .benefit-card:nth-child(3) .benefit-icon {
    background-color: #FFF9E6;
    color: #F59E0B;
}

.hero .benefit-card:nth-child(4) .benefit-icon {
    background-color: #F3E8FF;
    color: #8B5CF6;
}


.benefit-card h3 {
    font-size: 1.25rem;
    margin-bottom: 15px;
}


/* Problem Section */
.problem-section {
    background-color: #fafbfc;
}

.problem-list {
    max-width: 700px;
    margin: 0 auto;
}

.problem-item {
    display: flex;
    align-items: center;
    gap: 15px;
    background: white;
    padding: 20px 30px;
    margin-bottom: 15px;
    border-radius: 50px;
    box-shadow: var(--shadow-sm);
}

.problem-note {
    max-width: 700px;
    margin: 50px auto 0;
    background-color: var(--color-pale-blue);
    padding: 35px;
    border-radius: var(--border-radius);
    border: 1px dashed var(--color-primary-blue);
    position: relative;
}

.problem-note h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--color-accent-blue);
    display: flex;
    align-items: center;
    gap: 10px;
}

.problem-note ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.problem-note li {
    font-size: 0.95rem;
    color: var(--color-text-main);
    padding-left: 20px;
    position: relative;
}

.problem-note li::before {
    content: '•';
    color: var(--color-primary-blue);
    position: absolute;
    left: 0;
    font-weight: bold;
}


.problem-item svg {
    color: #ff6b6b;
    flex-shrink: 0;
}

/* Comparison Table */
.comparison-wrapper {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

th,
td {
    padding: 25px;
    text-align: center;
    border-bottom: 1px solid #eee;
    vertical-align: middle;
}

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

.cell-item-label {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    color: var(--color-text-sub);
}

.cell-item-label svg {
    flex-shrink: 0;
}


.cell-with-icon svg {
    color: var(--color-accent-green);
}

th {
    background: #f8f9fa;
    font-weight: 700;
}

.highlight-col {
    background: var(--color-pale-green);
    font-weight: 700;
    color: var(--color-accent-green);
}

@media (max-width: 768px) {
    .comparison-wrapper {
        margin: 0 -20px;
        padding: 0 20px;
    }

    table {
        min-width: 650px;
        /* Prevent squashing */
    }

    th,
    td {
        padding: 15px 10px;
        font-size: 0.9rem;
    }

    .cell-with-icon img {
        height: 24px !important;
        /* Smaller icon on mobile */
    }

    .cell-item-label {
        gap: 5px;
    }
}


/* Use Case Section */
.usecase-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.usecase-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.usecase-image {
    height: 200px;
    background-size: cover;
    background-position: center;
}

.usecase-body {
    padding: 25px;
}

/* FAQ Section */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.faq-item {
    background: white;
    padding: 30px;
    border-radius: var(--border-radius);
    border: 1px solid #edf2f7;
}

.faq-q {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 10px;
    display: flex;
    gap: 10px;
    color: var(--color-accent-blue);
}

.faq-q::before {
    content: 'Q';
    color: var(--color-primary-blue);
    font-weight: 900;
}

.faq-a {
    color: var(--color-text-sub);
    display: flex;
    gap: 10px;
}

.faq-a::before {
    content: 'A';
    color: var(--color-primary-green);
    font-weight: 900;
}

/* Suitable Uses Check List */
.check-list-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
}

.check-item {
    display: flex;
    align-items: center;
    gap: 12px;
    background: #f8fafc;
    padding: 15px 20px;
    border-radius: 50px;
    font-weight: 700;
    color: var(--color-accent-blue);
}

/* Usecase Tag */
.usecase-tag {
    display: inline-block;
    padding: 6px 15px;
    background: var(--color-pale-blue);
    color: var(--color-accent-blue);
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 700;
    margin-top: 10px;
}

/* Tech Fields Grid */
.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 30px;
}

.tech-card {
    background: white;
    padding: 40px 30px;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border-top: 4px solid var(--color-primary-blue);
    transition: var(--transition);
}

.tech-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-md);
}

.tech-icon {
    width: 120px;
    height: 120px;
    margin: 0 auto 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary-blue);
}


.tech-card h4 {
    font-size: 1.1rem;
    margin-bottom: 15px;
    line-height: 1.4;
}

.tech-card p {
    font-size: 0.9rem;
    color: var(--color-text-sub);
    line-height: 1.6;
}

/* Advanced Potential */
.advanced-container {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 50px;
    align-items: center;
}

.advanced-list {
    list-style: none;
    margin-bottom: 30px;
}

.advanced-list li {
    position: relative;
    padding-left: 25px;
    margin-bottom: 15px;
    font-weight: 500;
}

.advanced-list li::before {
    content: '・';
    position: absolute;
    left: 0;
    color: var(--color-primary-blue);
    font-weight: 900;
}

.advanced-note {
    font-size: 0.85rem;
    color: var(--color-text-sub);
    opacity: 0.8;
}

.advanced-image img {
    width: 100%;
    display: block;
}

/* Flow Steps */
.flow-steps {
    display: flex;
    justify-content: space-between;
    align-items: stretch;
    /* Height unification */
    max-width: 1000px;
    margin: 0 auto;
    gap: 10px;
}

.flow-step {
    background: white;
    padding: 35px 20px 20px;
    border-radius: 12px;
    text-align: center;
    flex: 1;
    font-weight: 700;
    color: var(--color-text-main);
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    border: 1px solid #e2e8f0;
}

.step-num {
    position: absolute;
    top: 10px;
    left: 15px;
    font-size: 0.75rem;
    color: var(--color-primary-blue);
    font-weight: 900;
    letter-spacing: 0.05em;
}

.flow-step.highlight .step-num {
    color: rgba(255, 255, 255, 0.8);
}


.flow-step.highlight {
    background: var(--color-primary-blue);
    color: white;
}

.flow-arrow {
    width: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--color-primary-blue);
    position: relative;
    margin: 0 5px;
}

.flow-arrow::after {
    content: '→';
}


/* Responsive Flow */
@media (max-width: 768px) {
    .advanced-container {
        grid-template-columns: 1fr;
    }

    .flow-steps {
        flex-direction: column;
        gap: 20px;
        align-items: center;
        /* Center cards and arrows */
    }

    .flow-step {
        width: 100%;
        /* Full width cards on mobile */
        max-width: 400px;
    }

    .flow-arrow {
        transform: rotate(90deg);
        margin: 5px 0;
        width: 100%;
        height: 30px;
    }

    .footer-nav {
        flex-wrap: wrap;
        gap: 15px 20px;
        padding: 0 20px;
    }
}


/* Footer (Existing) */
footer {
    background: #2D3436;

    color: white;
    padding: 60px 0;
    text-align: center;
}

.footer-nav {
    margin-bottom: 30px;
    display: flex;
    justify-content: center;
    gap: 20px;
}

.footer-nav a:hover {
    text-decoration: underline;
}

/* --- Responsive --- */
@media (max-width: 992px) {
    .nav-links {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }
}

/* Mobile Nav Open state */
.nav-mobile {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 300px;
    height: 100vh;
    background: white;
    z-index: 1001;
    box-shadow: -5px 0 20px rgba(0, 0, 0, 0.1);
    padding: 80px 40px;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.mobile-close {
    position: absolute;
    top: 20px;
    right: 20px;
    cursor: pointer;
    color: var(--color-text-sub);
    transition: var(--transition);
}

.mobile-close:hover {
    color: var(--color-text-main);
}


.nav-mobile.active {
    right: 0;
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    display: none;
}

.overlay.active {
    display: block;
}

/* Animation Initial State - Prevents jumping from final position to start position */
.hero h1,
.hero .hero-tagline,
.hero .benefit-card,
.hero .btn,
.section-title,
.problem-item,
.usecase-card,
.problem-note,
.check-item,
.tech-card,
.advanced-container,
.flow-step,
.faq-item {
    opacity: 0;
    transform: translateY(30px);
    will-change: opacity, transform;
}