/* =====================================================
   TechAster LP — style.css
   BOLD STRIKE — Editorial Design System
   VoiceBox base × AI時代を突破するエネルギー
   ===================================================== */

/* ========== 1. CSS カスタムプロパティ ========== */
:root {
    /* Foundation */
    --color-black: #0A0A0A;
    --color-white: #FFFFFF;
    --color-surface: #FFFFFF;
    --color-surface-raised: #FFFFFF;

    /* Text */
    --color-text: #0A0A0A;
    --color-text-secondary: #525252;
    --color-text-tertiary: #A3A3A3;

    /* Borders */
    --color-border-subtle: #E5E5E5;
    --color-border-medium: #D4D4D4;
    --color-border-strong: #0A0A0A;

    /* Accents — 1 viewport 1 accent rule for --color-strike */
    --color-strike: #EF4444;
    /* 人間の意志・決断。見出し強調・ホバー */
    --color-voltage: #00C2FF;
    /* AI/技術次元。暗背景でのデータ表示のみ */

    /* Semantic */
    --color-success: #16A34A;
    --color-error: #EF4444;
    --color-warning: #CA8A04;

    /* Typography */
    --font-display: 'Archivo Black', Impact, 'Arial Black', sans-serif;
    --font-ui: 'Work Sans', -apple-system, 'Segoe UI', Helvetica, sans-serif;
    --font-jp: 'Noto Sans JP', 'ヒラギノ角ゴ Pro', sans-serif;
    --font-en: 'Inter', 'Segoe UI', sans-serif;

    /* Spacing (8px base) */
    --sp-1: 0.25rem;
    --sp-2: 0.5rem;
    --sp-3: 0.75rem;
    --sp-4: 1rem;
    --sp-5: 1.25rem;
    --sp-6: 1.5rem;
    --sp-8: 2rem;
    --sp-10: 2.5rem;
    --sp-12: 3rem;
    --sp-16: 4rem;
    --sp-20: 5rem;
    --sp-24: 6rem;

    /* Border Radius — sharp everywhere */
    --radius: 0px;
    --radius-full: 9999px;

    /* Transitions */
    --dur-fast: 150ms;
    --dur-normal: 250ms;
    --dur-slow: 400ms;
    --ease-out: cubic-bezier(0, 0, 0.2, 1);
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========== 2. リセット & ベース ========== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-jp);
    color: var(--color-text);
    background: var(--color-black);
    line-height: 1.6;
    overflow-x: hidden;
}

img,
svg {
    display: block;
    max-width: 100%;
}

ul,
ol {
    list-style: none;
}

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

button {
    cursor: pointer;
    border: none;
    background: none;
    font: inherit;
}

address {
    font-style: normal;
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

.skip-link:focus {
    left: 1rem;
    top: 1rem;
    width: auto;
    height: auto;
    background: var(--color-white);
    color: var(--color-black);
    padding: 8px 16px;
    z-index: 9999;
    outline: 2px solid var(--color-black);
}

/* ========== 3. スクロール進行バー ========== */
.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    width: 0%;
    background: var(--color-strike);
    z-index: 200;
    transition: width 0.1s linear;
}

/* ========== 4. コンテナ ========== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--sp-8);
}

/* ========== 5. セクションヘッダー ========== */
.section-header {
    margin-bottom: var(--sp-12);
}

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

.section-header--center .section-subtitle {
    margin: 0 auto;
}

.section-overline {
    display: block;
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-strike);
    margin-bottom: var(--sp-3);
}

.section-title {
    font-family: var(--font-jp);
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 900;
    line-height: 1.25;
    color: inherit;
    margin-bottom: var(--sp-4);
}

.section-subtitle {
    font-family: var(--font-jp);
    font-size: 1rem;
    line-height: 1.9;
    color: inherit;
    opacity: 0.65;
    max-width: 560px;
}

/* ========== 6. ボタン ========== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--sp-2);
    padding: 14px 28px;
    font-family: var(--font-ui);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    border: 2px solid;
    transition: background var(--dur-normal), border-color var(--dur-normal), color var(--dur-normal);
    white-space: nowrap;
    line-height: 1;
}

.btn:focus-visible {
    outline: 2px solid var(--color-white);
    outline-offset: 2px;
    box-shadow: 0 0 0 4px var(--color-black);
}

/* 暗い背景用 Primary（白→赤） */
.btn--primary {
    background: var(--color-white);
    color: var(--color-black);
    border-color: var(--color-white);
}

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

/* 明るい背景用 Dark（黒→赤） */
.btn--dark {
    background: var(--color-black);
    color: var(--color-white);
    border-color: var(--color-black);
}

.btn--dark:hover {
    background: var(--color-strike);
    border-color: var(--color-strike);
}

/* CTAバナー専用 Strike（赤） */
.btn--strike {
    background: var(--color-strike);
    color: var(--color-white);
    border-color: var(--color-strike);
}

.btn--strike:hover {
    background: #DC2626;
    border-color: #DC2626;
}

/* 暗い背景 Outline White */
.btn--outline-white {
    background: transparent;
    color: var(--color-white);
    border-color: rgba(255, 255, 255, 0.5);
}

.btn--outline-white:hover {
    background: var(--color-white);
    color: var(--color-black);
    border-color: var(--color-white);
}

/* 明るい背景 Outline Dark */
.btn--outline-dark {
    background: transparent;
    color: var(--color-black);
    border-color: var(--color-black);
}

.btn--outline-dark:hover {
    background: var(--color-black);
    color: var(--color-white);
}

.btn--full {
    width: 100%;
    justify-content: center;
    padding: 16px 28px;
    font-size: 14px;
}

/* ========== 7. フェードイン ========== */
.fade-in {
    opacity: 0;
    transform: translateY(28px);
    transition:
        opacity var(--dur-slow) var(--ease-out),
        transform var(--dur-slow) var(--ease-out);
    transition-delay: var(--delay, 0s);
}

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

/* ========== 8. ヘッダー & ナビ ========== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    transition: background var(--dur-normal), border-color var(--dur-normal);
    border-bottom: 1px solid transparent;
}

.header--scrolled {
    background: #FFFFFF;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom-color: var(--color-border-subtle);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--sp-5) var(--sp-8);
}

.logo-link {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    color: var(--color-white);
    transition: opacity var(--dur-fast);
}

.logo-link:hover {
    opacity: 0.8;
}

.header--scrolled .logo-link {
    color: var(--color-black);
}

.logo-image {
    display: block;
    width: auto;
    height: 64px;
}

.logo-image--dark,
.logo-image--footer {
    display: block;
}

.logo-image--light {
    display: none;
}

.header--scrolled .logo-image--dark {
    display: none;
}

.header--scrolled .logo-image--light {
    display: block;
}

.logo-mark {
    flex-shrink: 0;
}

.logo-text {
    font-family: var(--font-ui);
    font-size: 1.3125rem;
    letter-spacing: 0.02em;
    line-height: 1;
}

.logo-text__tech {
    color: inherit;
    font-weight: 500;
}

.logo-text__sep {
    margin: 0 3px;
    opacity: 0.4;
    font-weight: 400;
}

.logo-text__aster {
    color: var(--color-strike);
    font-weight: 800;
    letter-spacing: 0.01em;
}

.navbar__menu {
    display: flex;
    align-items: center;
    gap: var(--sp-1);
}

.navbar__menu a {
    font-family: var(--font-ui);
    font-size: 13px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.65);
    padding: var(--sp-2) var(--sp-3);
    transition: color var(--dur-fast);
}

.navbar__menu a:hover,
.navbar__menu a.active {
    color: var(--color-white);
}

.header--scrolled .navbar__menu a {
    color: var(--color-text-secondary);
}

.header--scrolled .navbar__menu a:hover,
.header--scrolled .navbar__menu a.active {
    color: var(--color-black);
}

.nav-cta {
    font-family: var(--font-ui) !important;
    font-size: 12px !important;
    font-weight: 700 !important;
    letter-spacing: 0.06em !important;
    text-transform: uppercase !important;
    background: var(--color-white) !important;
    color: var(--color-black) !important;
    border: 2px solid var(--color-white) !important;
    padding: 8px 18px !important;
    transition: background var(--dur-normal), color var(--dur-normal), border-color var(--dur-normal) !important;
}

.nav-cta:hover {
    background: var(--color-strike) !important;
    border-color: var(--color-strike) !important;
    color: var(--color-white) !important;
}

.header--scrolled .nav-cta {
    background: var(--color-black) !important;
    color: var(--color-white) !important;
    border-color: var(--color-black) !important;
}

.header--scrolled .nav-cta:hover {
    background: var(--color-strike) !important;
    border-color: var(--color-strike) !important;
}

/* ハンバーガー */
.navbar__toggle {
    display: none;
    padding: var(--sp-2);
    color: var(--color-white);
}

.header--scrolled .navbar__toggle {
    color: var(--color-black);
}

.hamburger {
    display: block;
    width: 22px;
    height: 2px;
    background: currentColor;
    position: relative;
    transition: background var(--dur-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 22px;
    height: 2px;
    background: currentColor;
    transition: transform var(--dur-normal) var(--ease-in-out);
}

.hamburger::before {
    top: -7px;
}

.hamburger::after {
    top: 7px;
}

.navbar--open .hamburger {
    background: transparent;
}

.navbar--open .hamburger::before {
    transform: translateY(7px) rotate(45deg);
}

.navbar--open .hamburger::after {
    transform: translateY(-7px) rotate(-45deg);
}

/* ========== 9. Hero Section（黒） ========== */
.hero-section {
    position: relative;
    min-height: 100vh;
    background: var(--color-black);
    display: flex;
    align-items: center;
    padding: 100px 0 var(--sp-20);
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
    background-size: 64px 64px;
    pointer-events: none;
}

.hero-section__inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-16);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-section__overline {
    display: block;
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-strike);
    margin-bottom: var(--sp-5);
}

.hero-section__title {
    font-family: var(--font-jp);
    font-size: clamp(2.25rem, 5vw, 3.5rem);
    font-weight: 900;
    line-height: 1.15;
    color: var(--color-white);
    margin-bottom: var(--sp-6);
    letter-spacing: -0.03em;
}

.title-line {
    display: block;
}

.title-line--accent {
    position: relative;
    display: inline-block;
}

.title-line--accent::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 100%;
    height: 4px;
    background: var(--color-strike);
}

.hero-section__subtitle {
    font-family: var(--font-jp);
    font-size: 1.0625rem;
    line-height: 1.95;
    color: rgba(250, 250, 250, 0.62);
    margin-bottom: var(--sp-10);
    max-width: 480px;
}

.hero-section__cta {
    display: flex;
    gap: var(--sp-4);
    flex-wrap: wrap;
}

/* 右カラム：エディトリアル数値ブロック */
.hero-section__trust {
    border: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    flex-direction: column;
}

.trust-item {
    padding: var(--sp-8) var(--sp-10);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.trust-item:last-child {
    border-bottom: none;
}

.trust-num-wrap {
    display: flex;
    align-items: baseline;
    gap: var(--sp-1);
    line-height: 1;
    margin-bottom: var(--sp-2);
}

.trust-num {
    font-family: var(--font-display);
    font-size: clamp(3rem, 5.5vw, 5rem);
    font-weight: 400;
    color: var(--color-white);
    line-height: 1;
}

.trust-suffix {
    font-family: var(--font-display);
    font-size: clamp(1.5rem, 2.5vw, 2.25rem);
    color: var(--color-voltage);
    font-weight: 400;
    line-height: 1;
}

.trust-label {
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: rgba(250, 250, 250, 0.4);
}

/* スクロールインジケーター */
.hero-section__scroll {
    position: absolute;
    bottom: var(--sp-8);
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.scroll-indicator {
    width: 24px;
    height: 40px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    display: flex;
    justify-content: center;
    padding-top: 7px;
}

.scroll-dot {
    width: 3px;
    height: 7px;
    background: var(--color-white);
    animation: scrollDot 2s ease-in-out infinite;
}

@keyframes scrollDot {
    0% {
        opacity: 1;
        transform: translateY(0);
    }

    100% {
        opacity: 0;
        transform: translateY(12px);
    }
}

/* ========== 10. Stats Section（白） ========== */
.stats-section {
    background: var(--color-white);
    padding: var(--sp-16) 0;
    border-bottom: 1px solid var(--color-border-subtle);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
}

.stat-item {
    padding: var(--sp-8) var(--sp-6);
    border-right: 1px solid var(--color-border-subtle);
    text-align: center;
}

.stat-item:last-child {
    border-right: none;
}

.stat-item__num {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 400;
    color: var(--color-black);
    line-height: 1;
    margin-bottom: var(--sp-3);
}

.stat-suffix {
    color: var(--color-strike);
}

.stat-item__label {
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
}

.stats-note {
    margin-top: var(--sp-6);
    text-align: center;
    font-family: var(--font-ui);
    font-size: 0.72rem;
    color: var(--color-text-secondary);
    letter-spacing: 0.02em;
}

/* ========== 11. AI Services Section（黒） ========== */
.ai-services-section {
    background: var(--color-black);
    padding: var(--sp-24) 0;
    color: var(--color-white);
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.ai-services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.ai-card {
    padding: var(--sp-8) var(--sp-6);
    border-right: 1px solid rgba(255, 255, 255, 0.1);
    transition: background var(--dur-normal);
    position: relative;
}

.ai-card:last-child {
    border-right: none;
}

.ai-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--color-strike);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--dur-normal) var(--ease-out);
}

.ai-card:hover {
    background: rgba(255, 255, 255, 0.04);
}

.ai-card:hover::before {
    transform: scaleX(1);
}

.ai-card__num {
    display: block;
    font-family: var(--font-display);
    font-size: 3rem;
    color: rgba(255, 255, 255, 0.05);
    line-height: 1;
    margin-bottom: var(--sp-4);
    user-select: none;
}

.ai-card__icon {
    color: var(--color-voltage);
    margin-bottom: var(--sp-5);
}

.ai-card__title {
    font-family: var(--font-jp);
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: var(--sp-3);
    line-height: 1.4;
}

.ai-card__desc {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: rgba(250, 250, 250, 0.58);
    line-height: 1.85;
    margin-bottom: var(--sp-5);
}

.ai-card__list {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: var(--sp-4);
    margin-bottom: var(--sp-6);
}

.ai-card__list li {
    font-family: var(--font-jp);
    font-size: 0.8125rem;
    color: rgba(250, 250, 250, 0.48);
    padding: var(--sp-2) 0 var(--sp-2) var(--sp-4);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    position: relative;
}

.ai-card__list li:last-child {
    border-bottom: none;
}

.ai-card__list li::before {
    content: '—';
    position: absolute;
    left: 0;
    top: var(--sp-2);
    color: var(--color-strike);
    font-size: 11px;
}

.ai-card__link {
    font-family: var(--font-ui);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-strike);
    display: inline-flex;
    align-items: center;
    gap: var(--sp-2);
    border-bottom: 1px solid transparent;
    padding-bottom: 2px;
    transition: gap var(--dur-fast), border-color var(--dur-fast);
}

.ai-card__link:hover {
    gap: var(--sp-3);
    border-bottom-color: var(--color-strike);
}

/* ========== 12. About Section（白） ========== */
.about-section {
    background: var(--color-white);
    padding: var(--sp-24) 0;
    color: var(--color-black);
}

.about-section__grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-16);
    align-items: center;
}

/* 左：エディトリアルビジュアルブロック（黒背景） */
.about-editorial {
    background: var(--color-black);
    color: var(--color-white);
    padding: var(--sp-10);
}

.about-editorial__overline {
    display: block;
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-strike);
    margin-bottom: var(--sp-6);
}

.about-editorial__quote {
    font-family: var(--font-jp);
    font-size: clamp(1.5rem, 3vw, 2.125rem);
    font-weight: 900;
    line-height: 1.5;
    border-left: 4px solid var(--color-strike);
    padding-left: var(--sp-6);
    margin-bottom: var(--sp-10);
    letter-spacing: -0.01em;
}

.about-editorial__stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--sp-4);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--sp-6);
}

.ae-stat__num {
    display: block;
    font-family: var(--font-display);
    font-size: 1.75rem;
    color: var(--color-white);
    line-height: 1;
    margin-bottom: var(--sp-2);
}

.ae-stat__label {
    font-family: var(--font-ui);
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: rgba(250, 250, 250, 0.38);
}

/* 右：テキストコンテンツ */
.about-lead {
    font-family: var(--font-jp);
    font-size: 1.0625rem;
    line-height: 1.95;
    color: var(--color-text-secondary);
    margin-bottom: var(--sp-10);
}

.about-strengths {
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--color-border-subtle);
    margin-bottom: var(--sp-10);
}

.strength-item {
    display: flex;
    gap: var(--sp-5);
    align-items: flex-start;
    padding: var(--sp-5) 0;
    border-bottom: 1px solid var(--color-border-subtle);
}

.strength-item__icon {
    width: 40px;
    height: 40px;
    border: 2px solid var(--color-border-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--color-black);
}

.strength-item__body {
    flex: 1;
}

.strength-item__title {
    font-family: var(--font-jp);
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-black);
    margin-bottom: var(--sp-1);
}

.strength-item__text {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

/* ========== 13. Services Section（薄灰） ========== */
.services-section {
    background: var(--color-surface);
    padding: var(--sp-24) 0;
    color: var(--color-black);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    border: 1px solid var(--color-border-subtle);
}

.service-card {
    background: var(--color-white);
    padding: var(--sp-10) var(--sp-8);
    border-right: 1px solid var(--color-border-subtle);
    position: relative;
    transition: background var(--dur-normal);
}

.service-card:last-child {
    border-right: none;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--color-strike);
}

.service-card:hover {
    background: var(--color-surface);
}

.service-card__num {
    display: block;
    font-family: var(--font-display);
    font-size: 4rem;
    color: var(--color-surface-raised);
    line-height: 1;
    margin-bottom: var(--sp-4);
    user-select: none;
}

.service-card__icon {
    width: 44px;
    height: 44px;
    border: 2px solid var(--color-border-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-black);
    margin-bottom: var(--sp-5);
}

.service-card__title {
    font-family: var(--font-jp);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-black);
    margin-bottom: var(--sp-4);
    line-height: 1.4;
}

.service-card__desc {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.9;
    margin-bottom: var(--sp-6);
}

.service-card__list {
    border-top: 1px solid var(--color-border-subtle);
    padding-top: var(--sp-5);
    margin-bottom: var(--sp-8);
}

.service-card__list li {
    font-family: var(--font-jp);
    font-size: 0.8125rem;
    color: var(--color-text-secondary);
    padding: var(--sp-2) 0 var(--sp-2) var(--sp-4);
    border-bottom: 1px solid var(--color-border-subtle);
    position: relative;
}

.service-card__list li:last-child {
    border-bottom: none;
}

.service-card__list li::before {
    content: '–';
    position: absolute;
    left: 0;
    color: var(--color-strike);
    font-weight: 700;
}

.service-card__link {
    font-family: var(--font-ui);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-black);
    display: inline-flex;
    align-items: center;
    gap: var(--sp-2);
    border-bottom: 2px solid var(--color-black);
    padding-bottom: 2px;
    transition: color var(--dur-fast), border-color var(--dur-fast), gap var(--dur-fast);
}

.service-card__link:hover {
    color: var(--color-strike);
    border-color: var(--color-strike);
    gap: var(--sp-3);
}

/* ========== 14. Industries Section（黒） ========== */
.industries-section {
    background: var(--color-black);
    padding: var(--sp-24) 0;
    color: var(--color-white);
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.industries-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.industry-card {
    padding: var(--sp-8) var(--sp-5);
    text-align: center;
    border-right: 1px solid rgba(255, 255, 255, 0.1);
    transition: background var(--dur-normal);
}

.industry-card:last-child {
    border-right: none;
}

.industry-card:hover {
    background: rgba(255, 255, 255, 0.04);
}

.industry-card:hover .industry-card__icon {
    color: var(--color-voltage);
}

.industry-card__icon {
    color: rgba(255, 255, 255, 0.35);
    margin: 0 auto var(--sp-5);
    transition: color var(--dur-normal);
}

.industry-card__title {
    font-family: var(--font-jp);
    font-size: 0.9375rem;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: var(--sp-3);
}

.industry-card__text {
    font-family: var(--font-jp);
    font-size: 0.8125rem;
    color: rgba(250, 250, 250, 0.42);
    line-height: 1.8;
}

/* ========== 15. Case Studies Section（白） ========== */
.case-studies-section {
    background: var(--color-white);
    padding: var(--sp-24) 0;
    color: var(--color-black);
}

.case-filter {
    display: flex;
    gap: var(--sp-2);
    flex-wrap: wrap;
    margin-bottom: var(--sp-10);
}

.filter-btn {
    font-family: var(--font-ui);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-text-secondary);
    background: transparent;
    border: 2px solid var(--color-border-medium);
    padding: 6px 14px;
    transition: all var(--dur-normal);
}

.filter-btn:hover,
.filter-btn--active {
    background: var(--color-black);
    color: var(--color-white);
    border-color: var(--color-black);
}

.case-studies-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    border: 1px solid var(--color-border-subtle);
}

.case-card {
    background: var(--color-white);
    border-right: 1px solid var(--color-border-subtle);
    border-bottom: 1px solid var(--color-border-subtle);
    overflow: hidden;
    transition: background var(--dur-normal);
}

.case-card:nth-child(3n) {
    border-right: none;
}

.case-card:hover {
    background: var(--color-surface);
}

.case-card.hidden {
    display: none;
}

.case-card__header {
    background: var(--color-surface);
    padding: var(--sp-5) var(--sp-6);
    border-bottom: 1px solid var(--color-border-subtle);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.case-card__badge {
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-black);
    border: 2px solid var(--color-border-medium);
    padding: 3px 10px;
}

.case-card__icon {
    width: 40px;
    height: 40px;
    border: 2px solid var(--color-border-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-black);
}

.case-card__body {
    padding: var(--sp-6);
}

.case-card__title {
    font-family: var(--font-jp);
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-black);
    margin-bottom: var(--sp-2);
    line-height: 1.5;
}

.case-card__client {
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-text-tertiary);
    margin-bottom: var(--sp-4);
}

.case-card__desc {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--sp-5);
}

.case-card__results {
    display: flex;
    flex-wrap: wrap;
    gap: var(--sp-2);
    border-top: 1px solid var(--color-border-subtle);
    padding-top: var(--sp-4);
}

.result-pill {
    display: inline-flex;
    align-items: center;
    gap: var(--sp-1);
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.04em;
    color: var(--color-success);
    border: 2px solid var(--color-success);
    padding: 3px 10px;
}

/* ========== 16. Why Us Section（黒） ========== */
.why-us-section {
    background: var(--color-black);
    padding: var(--sp-24) 0;
    color: var(--color-white);
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.why-us-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.why-card {
    padding: var(--sp-10) var(--sp-5);
    text-align: center;
    border-right: 1px solid rgba(255, 255, 255, 0.1);
    transition: background var(--dur-normal);
    position: relative;
}

.why-card:last-child {
    border-right: none;
}

.why-card:hover {
    background: rgba(255, 255, 255, 0.04);
}

.why-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: var(--color-strike);
    transition: width var(--dur-normal) var(--ease-out);
}

.why-card:hover::after {
    width: 60%;
}

.why-card__number {
    display: block;
    font-family: var(--font-display);
    font-size: 3.5rem;
    color: rgba(255, 255, 255, 0.05);
    line-height: 1;
    margin-bottom: var(--sp-4);
    user-select: none;
    transition: color var(--dur-normal);
}

.why-card:hover .why-card__number {
    color: rgba(255, 255, 255, 0.1);
}

.why-card__icon {
    color: rgba(255, 255, 255, 0.3);
    margin: 0 auto var(--sp-4);
    transition: color var(--dur-normal);
}

.why-card:hover .why-card__icon {
    color: var(--color-voltage);
}

.why-card__title {
    font-family: var(--font-jp);
    font-size: 0.9375rem;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: var(--sp-3);
}

.why-card__text {
    font-family: var(--font-jp);
    font-size: 0.8125rem;
    color: rgba(250, 250, 250, 0.42);
    line-height: 1.8;
}

/* ========== 17. CTA バナー（黒・赤ボーダー） ========== */
.cta-banner {
    background: var(--color-black);
    border-top: 4px solid var(--color-strike);
    padding: var(--sp-20) 0;
    color: var(--color-white);
}

.cta-banner__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--sp-12);
}

.cta-banner__title {
    font-family: var(--font-jp);
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 900;
    color: var(--color-white);
    margin-bottom: var(--sp-3);
    line-height: 1.25;
}

.cta-banner__subtitle {
    font-family: var(--font-jp);
    font-size: 0.9375rem;
    color: rgba(250, 250, 250, 0.58);
    line-height: 1.9;
    max-width: 480px;
}

.cta-banner__actions {
    display: flex;
    align-items: center;
    gap: var(--sp-6);
    flex-shrink: 0;
}

.cta-phone {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    font-family: var(--font-ui);
    font-size: 1.125rem;
    font-weight: 700;
    color: rgba(250, 250, 250, 0.65);
    transition: color var(--dur-fast);
}

.cta-phone:hover {
    color: var(--color-white);
}

/* ========== 18. Contact Section（薄灰） ========== */
.contact-section {
    background: var(--color-surface);
    padding: var(--sp-24) 0;
    color: var(--color-black);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.4fr;
    gap: var(--sp-16);
    align-items: start;
}

.contact-info .section-header {
    margin-bottom: var(--sp-8);
}

.contact-info__lead {
    font-family: var(--font-jp);
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    line-height: 1.9;
    margin-bottom: var(--sp-8);
}

.contact-info__items {
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--color-border-subtle);
    margin-bottom: var(--sp-8);
}

.contact-info-item {
    display: flex;
    align-items: flex-start;
    gap: var(--sp-4);
    padding: var(--sp-5) 0;
    border-bottom: 1px solid var(--color-border-subtle);
}

.contact-info-item__icon {
    width: 36px;
    height: 36px;
    border: 2px solid var(--color-border-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--color-black);
}

.contact-info-item__label {
    font-family: var(--font-ui);
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-text-tertiary);
    margin-bottom: var(--sp-1);
}

.contact-info-item__value {
    font-family: var(--font-jp);
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-black);
    transition: color var(--dur-fast);
}

a.contact-info-item__value:hover {
    color: var(--color-strike);
}

.contact-response {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    border: 2px solid var(--color-border-medium);
    padding: var(--sp-4) var(--sp-5);
}

.contact-response__icon {
    font-size: 1.25rem;
}

.contact-response__text {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.contact-response__text strong {
    color: var(--color-success);
}

/* フォーム */
.contact-form-wrap {
    background: var(--color-white);
    border: 1px solid var(--color-border-subtle);
    padding: var(--sp-10);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--sp-5);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-5);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--sp-2);
}

.form-label {
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-black);
}

.form-required {
    color: var(--color-strike);
    margin-left: var(--sp-1);
    font-weight: 400;
}

.form-input,
.form-select,
.form-textarea {
    font-family: var(--font-jp);
    font-size: 0.9375rem;
    color: var(--color-black);
    background: var(--color-surface);
    border: 2px solid var(--color-border-medium);
    padding: 12px 14px;
    transition: border-color var(--dur-normal), background var(--dur-normal);
    width: 100%;
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--color-text-tertiary);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-black);
    background: var(--color-white);
    box-shadow: 0 0 0 2px var(--color-white), 0 0 0 4px var(--color-black);
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

.form-group--checkbox {
    flex-direction: row;
    align-items: center;
    gap: var(--sp-3);
}

.form-group--checkbox input[type="checkbox"] {
    width: 18px;
    height: 18px;
    border: 2px solid var(--color-black);
    accent-color: var(--color-black);
    flex-shrink: 0;
    cursor: pointer;
}

.form-label-checkbox {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    cursor: pointer;
}

.form-label-checkbox .link {
    color: var(--color-black);
    text-decoration: underline;
}

.form-message {
    margin-top: var(--sp-4);
    padding: var(--sp-4) var(--sp-5);
    font-family: var(--font-jp);
    font-size: 0.875rem;
    font-weight: 600;
    border: 2px solid;
}

.form-message.success {
    border-color: var(--color-success);
    color: var(--color-success);
}

.form-message.error {
    border-color: var(--color-error);
    color: var(--color-error);
}

/* ========== 19. フッター（黒） ========== */
.footer {
    background: var(--color-black);
    color: var(--color-white);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer__top {
    padding: var(--sp-16) 0 var(--sp-12);
}

.footer__grid {
    display: grid;
    grid-template-columns: 1.8fr 1fr 1fr 1.2fr;
    gap: var(--sp-12);
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    margin-bottom: var(--sp-4);
    width: fit-content;
    color: var(--color-white);
    transition: opacity var(--dur-fast);
}

.footer__logo:hover {
    opacity: 0.8;
}

.footer__logo .logo-image {
    height: 64px;
}

.footer__logo .logo-text {
    color: var(--color-white);
}

.footer__tagline {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: rgba(250, 250, 250, 0.48);
    line-height: 1.9;
    margin-bottom: var(--sp-6);
}

.footer__social {
    display: flex;
    gap: var(--sp-2);
}

.social-link {
    width: 36px;
    height: 36px;
    border: 2px solid rgba(255, 255, 255, 0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    color: rgba(250, 250, 250, 0.38);
    transition: border-color var(--dur-normal), color var(--dur-normal);
}

.social-link:hover {
    border-color: var(--color-white);
    color: var(--color-white);
}

.footer__nav-title {
    font-family: var(--font-ui);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-white);
    margin-bottom: var(--sp-5);
}

.footer__nav-list {
    display: flex;
    flex-direction: column;
    gap: var(--sp-3);
}

.footer__nav-list a {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: rgba(250, 250, 250, 0.48);
    transition: color var(--dur-fast);
}

.footer__nav-list a:hover {
    color: var(--color-white);
}

.footer__contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--sp-3);
    margin-bottom: var(--sp-5);
}

.footer__contact-info p {
    font-family: var(--font-jp);
    font-size: 0.875rem;
    color: rgba(250, 250, 250, 0.48);
    margin: 0;
}

.footer__contact-info a {
    transition: color var(--dur-fast);
}

.footer__contact-info a:hover {
    color: var(--color-white);
}

.footer__hours {
    font-size: 0.8125rem;
}

.footer__bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding: var(--sp-5) 0;
}

.footer__bottom-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer__copyright {
    font-family: var(--font-ui);
    font-size: 12px;
    color: rgba(250, 250, 250, 0.32);
}

.footer__legal {
    display: flex;
    gap: var(--sp-6);
}

.footer__legal a {
    font-family: var(--font-ui);
    font-size: 12px;
    color: rgba(250, 250, 250, 0.32);
    transition: color var(--dur-fast);
}

.footer__legal a:hover {
    color: var(--color-white);
}

/* ========== 20. フローティングCTA ========== */
.floating-cta {
    position: fixed;
    bottom: var(--sp-8);
    right: var(--sp-8);
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    background: var(--color-black);
    color: var(--color-white);
    font-family: var(--font-ui);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    padding: var(--sp-3) var(--sp-5);
    border: 2px solid var(--color-black);
    z-index: 90;
    opacity: 0;
    transform: translateY(20px);
    transition: all var(--dur-normal) var(--ease-out);
    pointer-events: none;
}

.floating-cta.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.floating-cta:hover {
    background: var(--color-strike);
    border-color: var(--color-strike);
    color: var(--color-white);
}

/* ========== 21. レスポンシブ ========== */
@media (max-width: 1100px) {
    .ai-services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .ai-card:nth-child(2) {
        border-right: none;
    }

    .ai-card:nth-child(3) {
        border-right: 1px solid rgba(255, 255, 255, 0.1);
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .ai-card:nth-child(4) {
        border-right: none;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .industries-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .industry-card:nth-child(3) {
        border-right: none;
    }

    .industry-card:nth-child(4),
    .industry-card:nth-child(5) {
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .industry-card:nth-child(5) {
        border-right: none;
    }

    .why-us-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .why-card:nth-child(3) {
        border-right: none;
    }

    .why-card:nth-child(4) {
        border-right: 1px solid rgba(255, 255, 255, 0.1);
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .why-card:nth-child(5) {
        border-right: none;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .footer__grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--sp-10);
    }
}

@media (max-width: 900px) {
    .hero-section__inner {
        grid-template-columns: 1fr;
        gap: var(--sp-10);
    }

    .hero-section__trust {
        flex-direction: row;
        flex-wrap: wrap;
        border: none;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
        padding-top: 0;
    }

    .trust-item {
        flex: 1 1 30%;
        padding: var(--sp-5) var(--sp-4);
        border-bottom: none;
        border-right: 1px solid rgba(255, 255, 255, 0.1);
        text-align: center;
    }

    .trust-item:last-child {
        border-right: none;
    }

    .trust-num-wrap {
        justify-content: center;
    }

    .about-section__grid {
        grid-template-columns: 1fr;
        gap: var(--sp-10);
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

    .service-card {
        border-right: none;
        border-bottom: 1px solid var(--color-border-subtle);
    }

    .service-card:last-child {
        border-bottom: none;
    }

    .case-studies-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .case-card:nth-child(2n) {
        border-right: none;
    }

    .case-card:nth-child(odd) {
        border-right: 1px solid var(--color-border-subtle);
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .cta-banner__inner {
        flex-direction: column;
        text-align: center;
    }

    .cta-banner__subtitle {
        margin: 0 auto;
    }

    .navbar__toggle {
        display: flex;
        align-items: center;
    }

    .navbar__menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(10, 10, 10, 0.98);
        flex-direction: column;
        gap: 0;
        padding: var(--sp-4);
        border-top: 1px solid rgba(255, 255, 255, 0.08);
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        backdrop-filter: blur(16px);
    }

    .header--scrolled .navbar__menu {
        background: #FFFFFF;
        border-top-color: var(--color-border-subtle);
        border-bottom-color: var(--color-border-subtle);
    }

    .navbar__menu li {
        width: 100%;
    }

    .navbar__menu a {
        display: block;
        padding: var(--sp-3) var(--sp-4);
        text-align: center;
    }

    .navbar--open .navbar__menu {
        display: flex;
    }
}

@media (max-width: 640px) {
    .container {
        padding: 0 var(--sp-5);
    }

    .navbar {
        padding: var(--sp-4) var(--sp-5);
    }

    .hero-section__title {
        font-size: clamp(2rem, 9vw, 3rem);
    }

    .hero-section__trust {
        flex-direction: column;
    }

    .trust-item {
        flex: unset;
        border-right: none;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        text-align: left;
    }

    .trust-item:last-child {
        border-bottom: none;
    }

    .trust-num-wrap {
        justify-content: flex-start;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .stat-item:nth-child(2n) {
        border-right: none;
    }

    .stat-item:nth-child(n+3) {
        border-top: 1px solid var(--color-border-subtle);
    }

    .ai-services-grid {
        grid-template-columns: 1fr;
    }

    .ai-card {
        border-right: none;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .ai-card:first-child {
        border-top: none;
    }

    .industries-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .industry-card:nth-child(2n) {
        border-right: none;
    }

    .industry-card:nth-child(n+3) {
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .industry-card:nth-child(5) {
        grid-column: 1 / -1;
        border-right: none;
    }

    .case-studies-grid {
        grid-template-columns: 1fr;
    }

    .case-card {
        border-right: none !important;
    }

    .why-us-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .why-card:nth-child(2n) {
        border-right: none;
    }

    .why-card:nth-child(n+3) {
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    .why-card:nth-child(5) {
        grid-column: 1 / -1;
        border-right: none;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .footer__grid {
        grid-template-columns: 1fr;
        gap: var(--sp-8);
    }

    .footer__bottom-inner {
        flex-direction: column;
        gap: var(--sp-3);
        text-align: center;
    }

    .cta-banner__actions {
        flex-direction: column;
        width: 100%;
    }

    .cta-banner__actions .btn {
        width: 100%;
        justify-content: center;
    }

    .about-editorial__quote {
        font-size: 1.375rem;
    }

    .about-editorial__stats {
        grid-template-columns: repeat(3, 1fr);
    }

    .floating-cta span {
        display: none;
    }

    .floating-cta {
        padding: var(--sp-3);
        width: 50px;
        height: 50px;
        justify-content: center;
    }
}