/**
 * GILD Modern Top Page Styles
 * Apple-style sticky scroll design with dramatic animations
 */

/* ========================================
   CSS Custom Properties
   ======================================== */
:root {
    --gild-black: #000000;
    --gild-white: #ffffff;
    --gild-gray-100: #f8f9fa;
    --gild-gray-200: #e9ecef;
    --gild-gray-300: #dee2e6;
    --gild-gray-600: #6c757d;
    --gild-gray-800: #343a40;
    --gild-gray-900: #212529;

    --gild-transition-slow: 0.8s cubic-bezier(0.16, 1, 0.3, 1);
    --gild-transition-medium: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
    --gild-transition-fast: 0.3s cubic-bezier(0.16, 1, 0.3, 1);

    --gild-font-en: 'Helvetica Neue', Arial, sans-serif;
    --gild-font-jp: 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', sans-serif;
}

/* ========================================
   Base Container
   ======================================== */
.gild-modern {
    position: relative;
    width: 100%;
    background: var(--gild-black);
}

/* ========================================
   Particles.js Background
   ======================================== */
.gild-particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    opacity: 0.6;
    pointer-events: none;
}

/* ========================================
   Section Base - Sticky Scroll
   ======================================== */
.gild-section {
    position: relative;
    width: 100%;
    z-index: 2;
}

/* Sticky inner content wrapper */
.gild-section > div:first-child,
.gild-hero__content,
.gild-business__content,
.gild-recruit__content,
.gild-philosophy__content {
    position: sticky;
    top: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

/* ========================================
   Hero Section
   ======================================== */
.gild-hero {
    background: transparent;
    text-align: center;
}

.gild-hero__content {
    position: sticky;
    top: 0;
    width: 100%;
    padding: 0 20px;
    z-index: 10;
    box-sizing: border-box;
}

.gild-hero__tagline {
    font-family: var(--gild-font-jp);
    font-size: clamp(1rem, 3vw, 1.5rem);
    font-weight: 300;
    color: var(--gild-gray-300);
    letter-spacing: 0.3em;
    margin-bottom: 20px;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1s ease, transform 1s ease;
    will-change: transform, opacity;
}

.gild-hero__tagline.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.gild-hero__title {
    font-family: var(--gild-font-jp);
    font-size: clamp(2.5rem, 10vw, 6rem);
    font-weight: 700;
    color: var(--gild-white);
    letter-spacing: 0.1em;
    line-height: 1.2;
    margin: 0;
    opacity: 0;
    transform: translateY(60px);
    transition: opacity 1s ease 0.2s, transform 1s ease 0.2s;
    will-change: transform, opacity;
}

.gild-hero__title.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.gild-hero__scroll {
    position: absolute;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    opacity: 0;
    transition: opacity 0.8s ease;
}

.gild-hero__scroll.is-visible {
    opacity: 1;
}

.gild-hero__scroll-text {
    font-family: var(--gild-font-en);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--gild-gray-600);
    letter-spacing: 0.2em;
    text-transform: uppercase;
}

.gild-hero__scroll-line {
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, var(--gild-gray-600), transparent);
    animation: scrollLine 2s ease-in-out infinite;
}

@keyframes scrollLine {
    0%, 100% { transform: scaleY(1); opacity: 1; }
    50% { transform: scaleY(0.5); opacity: 0.5; }
}

/* ========================================
   Business Section - Sticky with Animations
   ======================================== */
.gild-business {
    background: var(--gild-black);
    overflow: visible;
}

.gild-business--alt {
    background: linear-gradient(180deg, var(--gild-gray-900) 0%, var(--gild-black) 100%);
}

.gild-business__content {
    position: sticky;
    top: 0;
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 40px;
    text-align: center;
    z-index: 10;
    box-sizing: border-box;
}

/* 巨大背景ナンバー */
.gild-business__number {
    position: absolute;
    top: 50%;
    left: 50%;
    font-family: var(--gild-font-en);
    font-size: clamp(20rem, 50vw, 40rem);
    font-weight: 900;
    color: transparent;
    -webkit-text-stroke: 2px rgba(255, 255, 255, 0.06);
    line-height: 1;
    user-select: none;
    pointer-events: none;
    z-index: 1;
    will-change: transform, opacity;
}

/* メインコンテンツ */
.gild-business__main {
    position: relative;
    z-index: 2;
    max-width: 700px;
    margin: 0 auto;
}

.gild-business__title {
    font-family: var(--gild-font-en);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    color: var(--gild-white);
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin: 0 0 30px;
    will-change: transform, opacity;
}

.gild-business__description {
    font-family: var(--gild-font-jp);
    font-size: clamp(0.9rem, 1.5vw, 1.1rem);
    font-weight: 400;
    color: var(--gild-gray-300);
    line-height: 2.2;
    margin: 0 0 50px;
    will-change: transform, opacity;
}

/* ========================================
   Button Styles
   ======================================== */
.gild-btn {
    display: inline-flex;
    align-items: center;
    gap: 16px;
    padding: 18px 40px;
    font-family: var(--gild-font-en);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--gild-white);
    text-decoration: none;
    letter-spacing: 0.15em;
    border: 1px solid rgba(255, 255, 255, 0.4);
    background: transparent;
    transition: all var(--gild-transition-fast);
    position: relative;
    overflow: hidden;
    will-change: transform, opacity;
}

.gild-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 0;
    height: 100%;
    background: var(--gild-white);
    transition: width var(--gild-transition-medium);
    z-index: -1;
}

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

.gild-btn:hover::before {
    width: 100%;
}

.gild-btn__arrow {
    width: 20px;
    height: 20px;
    transition: transform var(--gild-transition-fast);
}

.gild-btn:hover .gild-btn__arrow {
    transform: translateX(5px);
}

.gild-btn--large {
    padding: 24px 56px;
    font-size: 1rem;
}

/* ========================================
   Recruit Section
   ======================================== */
.gild-recruit {
    background: var(--gild-white);
    color: var(--gild-black);
}

.gild-recruit__content {
    position: sticky;
    top: 0;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 40px;
    z-index: 10;
    box-sizing: border-box;
}

.gild-recruit__header {
    text-align: center;
    margin-bottom: 60px;
    will-change: transform, opacity;
}

.gild-recruit__label {
    display: block;
    font-family: var(--gild-font-en);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--gild-gray-600);
    letter-spacing: 0.3em;
    text-transform: uppercase;
    margin-bottom: 16px;
}

.gild-recruit__title {
    font-family: var(--gild-font-en);
    font-size: clamp(3rem, 10vw, 7rem);
    font-weight: 700;
    color: var(--gild-black);
    letter-spacing: -0.03em;
    margin: 0 0 16px;
}

.gild-recruit__subtitle {
    font-family: var(--gild-font-jp);
    font-size: 1.125rem;
    font-weight: 400;
    color: var(--gild-gray-600);
    margin: 0;
}

.gild-recruit__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.gild-recruit__card {
    display: flex;
    flex-direction: column;
    padding: 48px 36px;
    background: var(--gild-gray-100);
    text-decoration: none;
    color: var(--gild-black);
    transition: all var(--gild-transition-medium);
    position: relative;
    overflow: hidden;
    will-change: transform, opacity;
}

.gild-recruit__card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--gild-black);
    transform: translateY(100%);
    transition: transform var(--gild-transition-medium);
    z-index: 0;
}

.gild-recruit__card:hover::before {
    transform: translateY(0);
}

.gild-recruit__card > * {
    position: relative;
    z-index: 1;
    transition: color var(--gild-transition-medium);
}

.gild-recruit__card:hover > * {
    color: var(--gild-white);
}

.gild-recruit__card-en {
    font-family: var(--gild-font-en);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--gild-gray-600);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.gild-recruit__card-type {
    font-family: var(--gild-font-jp);
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0 0 16px;
}

.gild-recruit__card-desc {
    font-family: var(--gild-font-jp);
    font-size: 0.875rem;
    color: var(--gild-gray-600);
    line-height: 1.8;
    margin: 0;
    flex-grow: 1;
}

.gild-recruit__card-arrow {
    display: flex;
    justify-content: flex-end;
    margin-top: 24px;
}

.gild-recruit__card-arrow svg {
    width: 24px;
    height: 24px;
    transition: transform var(--gild-transition-fast);
}

.gild-recruit__card:hover .gild-recruit__card-arrow svg {
    transform: translateX(8px);
}

/* ========================================
   Philosophy Section
   ======================================== */
.gild-philosophy {
    background: var(--gild-black);
    text-align: center;
}

.gild-philosophy__content {
    position: sticky;
    top: 0;
    width: 100%;
    padding: 0 40px;
    max-width: 900px;
    margin: 0 auto;
    z-index: 10;
    box-sizing: border-box;
}

.gild-philosophy__quote {
    font-family: var(--gild-font-jp);
    font-size: clamp(1.25rem, 3vw, 2.25rem);
    font-weight: 300;
    color: var(--gild-white);
    line-height: 2.4;
    margin: 0 0 60px;
    letter-spacing: 0.1em;
    will-change: transform, opacity;
}

.gild-philosophy__quote strong {
    font-weight: 700;
    color: var(--gild-white);
    position: relative;
}

.gild-philosophy__quote strong::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--gild-white);
}

/* ========================================
   Responsive: Tablet
   ======================================== */
@media (max-width: 1024px) {
    .gild-business__content {
        padding: 0 30px;
    }

    .gild-business__number {
        font-size: clamp(12rem, 40vw, 25rem);
        -webkit-text-stroke-width: 1.5px;
    }

    .gild-recruit__grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }
}

/* ========================================
   Responsive: Mobile
   ======================================== */
@media (max-width: 768px) {
    .gild-hero__scroll {
        bottom: 60px;
    }

    .gild-business__content {
        padding: 0 24px;
    }

    .gild-business__number {
        font-size: clamp(8rem, 35vw, 15rem);
        -webkit-text-stroke-width: 1px;
    }

    .gild-business__title {
        font-size: clamp(2rem, 8vw, 3rem);
    }

    .gild-business__description {
        font-size: 0.9rem;
        line-height: 2;
    }

    .gild-recruit__content {
        padding: 0 24px;
    }

    .gild-recruit__header {
        margin-bottom: 40px;
    }

    .gild-recruit__card {
        padding: 36px 28px;
    }

    .gild-philosophy__content {
        padding: 0 24px;
    }

    .gild-btn {
        padding: 16px 32px;
        font-size: 0.85rem;
    }

    .gild-btn--large {
        padding: 20px 40px;
    }
}

/* ========================================
   Responsive: Small Mobile
   ======================================== */
@media (max-width: 480px) {
    .gild-hero__tagline {
        letter-spacing: 0.15em;
    }

    .gild-business__number {
        font-size: 6rem;
        -webkit-text-stroke-width: 0.5px;
    }

    .gild-recruit__card-type {
        font-size: 1.5rem;
    }

    .gild-philosophy__quote {
        line-height: 2.2;
    }
}