/* ============================================
   葉桜ラボ — Design System
   ============================================ */

/* --- CSS Custom Properties --- */
:root {
    /* 色彩: 桜×新緑×静寂 */
    --sakura-100: #fff5f7;
    --sakura-200: #ffe0e6;
    --sakura-300: #ffb8c6;
    --sakura-400: #f7879a;
    --sakura-500: #e8587a;
    --green-100: #f0f8f0;
    --green-200: #d4edda;
    --green-300: #90c695;
    --green-400: #5a9e5f;
    --green-500: #3d7a41;
    --warm-50: #fefcfa;
    --warm-100: #faf6f0;
    --warm-200: #f0e8dc;
    --warm-300: #ddd0be;
    --ink-900: #1a1a2e;
    --ink-800: #2d2d44;
    --ink-700: #454563;
    --ink-600: #5e5e7a;
    --ink-500: #7a7a94;
    --ink-400: #9e9eb4;
    --ink-300: #c4c4d4;
    --ink-200: #e2e2ec;
    --ink-100: #f2f2f7;

    /* タイポグラフィ */
    --font-serif: 'Noto Serif JP', 'Yu Mincho', 'Hiragino Mincho ProN', serif;
    --font-sans: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', sans-serif;

    /* 間 (spacing) */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 6rem;
    --space-2xl: 10rem;

    /* 動き */
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
    --duration-slow: 0.8s;
    --duration-normal: 0.5s;
    --duration-fast: 0.3s;
}

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

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

body {
    font-family: var(--font-sans);
    color: var(--ink-800);
    background: var(--warm-50);
    line-height: 1.8;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

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

/* --- Sakura Canvas --- */
#sakura-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
}

/* --- Navigation --- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1.2rem 2rem;
    transition: all var(--duration-normal) var(--ease-out-expo);
}

.nav.scrolled {
    background: rgba(254, 252, 250, 0.85);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    box-shadow: 0 1px 20px rgba(0, 0, 0, 0.06);
    padding: 0.8rem 2rem;
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 1.25rem;
    color: var(--ink-800);
    letter-spacing: 0.1em;
    transition: opacity var(--duration-fast) ease;
}

.nav-logo:hover {
    opacity: 0.7;
}

.logo-icon {
    font-size: 1.5rem;
    animation: bloom 3s ease-in-out infinite;
}

@keyframes bloom {
    0%, 100% { transform: scale(1) rotate(0deg); }
    50% { transform: scale(1.1) rotate(5deg); }
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2.5rem;
}

.nav-links a {
    font-family: var(--font-serif);
    font-size: 0.9rem;
    font-weight: 400;
    letter-spacing: 0.3em;
    color: var(--ink-600);
    position: relative;
    padding-bottom: 4px;
    transition: color var(--duration-fast) ease;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--sakura-400);
    transition: width var(--duration-normal) var(--ease-out-expo);
}

.nav-links a:hover {
    color: var(--sakura-500);
}

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

/* --- Hero Section --- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: flex-end;
    overflow: hidden;
    background: linear-gradient(180deg, #e8f0e0 0%, #f5ede0 40%, var(--warm-50) 100%);
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(
        180deg,
        rgba(255,255,255,0) 0%,
        rgba(255,255,255,0) 40%,
        rgba(254, 252, 250, 0.6) 70%,
        rgba(254, 252, 250, 1) 100%
    );
    z-index: 2;
}

.hero-image-container {
    position: absolute;
    inset: 0;
    z-index: 1;
}

.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center 30%;
    opacity: 0;
    transition: opacity 1.5s var(--ease-out-expo);
}

.hero-image.loaded {
    opacity: 1;
}

.hero-content {
    position: relative;
    z-index: 3;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    padding-bottom: 6rem;
    width: 100%;
}

.hero-kana {
    font-family: var(--font-serif);
    font-size: 0.85rem;
    letter-spacing: 0.5em;
    color: var(--sakura-500);
    margin-bottom: var(--space-sm);
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 1s var(--ease-out-expo) 0.5s forwards;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 600;
    line-height: 1.5;
    color: var(--ink-900);
    margin-bottom: var(--space-md);
}

.title-line {
    display: block;
    opacity: 0;
    transform: translateY(30px);
    animation: fadeUp 1s var(--ease-out-expo) forwards;
}

.title-line:nth-child(1) { animation-delay: 0.7s; }
.title-line:nth-child(2) { animation-delay: 0.9s; }
.title-line:nth-child(3) { animation-delay: 1.1s; }

.title-accent {
    background: linear-gradient(135deg, var(--sakura-500), var(--green-400));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-family: var(--font-serif);
    font-size: 1rem;
    line-height: 2;
    color: var(--ink-600);
    letter-spacing: 0.1em;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 1s var(--ease-out-expo) 1.4s forwards;
}

.hero-scroll-hint {
    position: absolute;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    opacity: 0;
    animation: fadeUp 1s var(--ease-out-expo) 2s forwards;
}

.scroll-text {
    font-family: var(--font-sans);
    font-size: 0.7rem;
    letter-spacing: 0.2em;
    color: var(--ink-400);
    text-transform: uppercase;
    writing-mode: vertical-rl;
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: var(--ink-300);
    position: relative;
    overflow: hidden;
}

.scroll-line::after {
    content: '';
    position: absolute;
    top: -100%;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--sakura-400);
    animation: scrollDown 2s ease-in-out infinite;
}

@keyframes scrollDown {
    0% { top: -100%; }
    100% { top: 100%; }
}

@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* --- Sections Common --- */
.section {
    padding: var(--space-2xl) 0;
    position: relative;
}

.section-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.section-label {
    display: inline-block;
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.3em;
    color: var(--sakura-400);
    text-transform: uppercase;
    margin-bottom: var(--space-sm);
    position: relative;
    padding: 0 2rem;
}

.section-label::before,
.section-label::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 1.5rem;
    height: 1px;
    background: var(--sakura-300);
}

.section-label::before { left: 0; }
.section-label::after { right: 0; }

.section-title {
    font-family: var(--font-serif);
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    font-weight: 600;
    color: var(--ink-900);
    letter-spacing: 0.15em;
    margin-bottom: var(--space-md);
}

.section-desc {
    font-family: var(--font-serif);
    font-size: 0.95rem;
    line-height: 2;
    color: var(--ink-500);
    letter-spacing: 0.05em;
}

/* --- Philosophy Section --- */
.section-philosophy {
    background: var(--warm-50);
}

.philosophy-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.philosophy-card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    border: 1px solid var(--ink-200);
    border-radius: 20px;
    padding: 3rem 2rem;
    text-align: center;
    transition: all var(--duration-normal) var(--ease-out-expo);
    opacity: 0;
    transform: translateY(40px);
}

.philosophy-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.philosophy-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.06);
    border-color: var(--sakura-200);
}

.card-icon-wrap {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--space-md);
    border-radius: 50%;
    background: linear-gradient(135deg, var(--sakura-100), var(--green-100));
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--duration-normal) var(--ease-out-expo);
}

.philosophy-card:hover .card-icon-wrap {
    transform: scale(1.1) rotate(5deg);
}

.card-icon {
    font-family: var(--font-serif);
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--sakura-500), var(--green-400));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.card-title {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--ink-800);
    margin-bottom: 0.3rem;
    letter-spacing: 0.1em;
}

.card-subtitle {
    font-family: var(--font-serif);
    font-size: 0.8rem;
    color: var(--sakura-400);
    letter-spacing: 0.2em;
    margin-bottom: var(--space-sm);
}

.card-text {
    font-size: 0.9rem;
    color: var(--ink-600);
    line-height: 1.9;
}

/* --- Library / Book Section --- */
.section-library {
    background: linear-gradient(180deg, var(--warm-50) 0%, var(--sakura-100) 50%, var(--warm-50) 100%);
}

.book-showcase {
    display: grid;
    grid-template-columns: 1fr 1.3fr;
    gap: 4rem;
    align-items: center;
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.8s var(--ease-out-expo);
}

.book-showcase.visible {
    opacity: 1;
    transform: translateY(0);
}

.book-visual {
    display: flex;
    justify-content: center;
    perspective: 1000px;
}

.book-3d {
    position: relative;
    width: 260px;
    height: 380px;
    transform-style: preserve-3d;
    transform: rotateY(-15deg);
    transition: transform 0.6s var(--ease-out-expo);
}

.book-3d:hover {
    transform: rotateY(-5deg) scale(1.05);
}

.book-cover {
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 4px 16px 16px 4px;
    background: linear-gradient(
        135deg,
        #2d1b4e 0%,
        #3d2b5e 20%,
        #e8587a 50%,
        #f7879a 70%,
        #ffb8c6 100%
    );
    box-shadow:
        -5px 5px 20px rgba(0, 0, 0, 0.2),
        inset 0 0 60px rgba(255, 255, 255, 0.1);
    overflow: hidden;
}

.book-cover::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 30% 20%, rgba(255,255,255,0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 80%, rgba(255,184,198,0.2) 0%, transparent 50%);
}

.book-cover-inner {
    position: relative;
    z-index: 1;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    text-align: center;
}

.book-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.65rem;
    color: white;
    letter-spacing: 0.1em;
}

.book-title-display {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: 700;
    color: white;
    line-height: 1.5;
    margin-bottom: 0.8rem;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.book-volume {
    font-size: 0.75rem;
    color: rgba(255,255,255,0.8);
    letter-spacing: 0.1em;
    margin-bottom: 1.5rem;
}

.book-authors {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.2rem;
    font-size: 0.75rem;
    color: rgba(255,255,255,0.7);
    letter-spacing: 0.1em;
}

.book-spine {
    position: absolute;
    left: 0;
    top: 0;
    width: 30px;
    height: 100%;
    background: linear-gradient(90deg, #1a0e33, #2d1b4e);
    border-radius: 4px 0 0 4px;
    transform: translateX(-29px) rotateY(90deg);
    transform-origin: right;
}

/* Book info */
.book-info {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.book-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.meta-tag {
    font-size: 0.8rem;
    color: var(--ink-500);
    background: rgba(255,255,255,0.7);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    border: 1px solid var(--ink-200);
}

.book-info-title {
    font-family: var(--font-serif);
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--ink-900);
    letter-spacing: 0.1em;
}

.book-info-subtitle {
    font-size: 0.9rem;
    color: var(--ink-500);
    letter-spacing: 0.1em;
    margin-top: -0.5rem;
}

.book-description {
    font-size: 0.95rem;
    color: var(--ink-600);
    line-height: 2;
}

.book-price {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.6rem;
    padding: 1rem 0;
    border-top: 1px solid var(--ink-200);
    border-bottom: 1px solid var(--ink-200);
}

.price-label {
    font-size: 0.75rem;
    font-weight: 500;
    color: white;
    background: linear-gradient(135deg, var(--sakura-400), var(--sakura-500));
    padding: 0.3rem 0.8rem;
    border-radius: 4px;
}

.price-value {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--sakura-500);
}

.price-or {
    font-size: 0.8rem;
    color: var(--ink-400);
}

.price-buy {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--ink-800);
}

.book-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--ink-900), var(--ink-800));
    color: white;
    border-radius: 12px;
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    transition: all var(--duration-normal) var(--ease-out-expo);
    position: relative;
    overflow: hidden;
    align-self: flex-start;
}

.book-cta::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--sakura-500), var(--sakura-400));
    opacity: 0;
    transition: opacity var(--duration-normal) ease;
}

.book-cta:hover::before {
    opacity: 1;
}

.book-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(232, 88, 122, 0.3);
}

.book-cta > * {
    position: relative;
    z-index: 1;
}

.cta-arrow {
    transition: transform var(--duration-fast) ease;
}

.book-cta:hover .cta-arrow {
    transform: translateX(4px);
}

/* --- Vision Section --- */
.section-vision {
    background: var(--warm-50);
}

.vision-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.vision-card {
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(10px);
    border: 1px solid var(--ink-200);
    border-radius: 20px;
    padding: 2.5rem;
    transition: all var(--duration-normal) var(--ease-out-expo);
    opacity: 0;
    transform: translateY(30px);
}

.vision-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.vision-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.05);
    border-color: var(--sakura-200);
    background: rgba(255, 255, 255, 0.8);
}

.vision-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    display: inline-block;
    transition: transform var(--duration-normal) var(--ease-out-expo);
}

.vision-card:hover .vision-icon {
    transform: scale(1.2);
}

.vision-card h3 {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--ink-800);
    letter-spacing: 0.05em;
}

.vision-jp {
    font-family: var(--font-serif);
    font-size: 0.8rem;
    color: var(--sakura-400);
    letter-spacing: 0.2em;
    margin-bottom: 0.8rem;
}

.vision-text {
    font-size: 0.9rem;
    color: var(--ink-600);
    line-height: 1.9;
}

/* --- Quote Section --- */
.section-quote {
    background: linear-gradient(180deg, var(--warm-50), var(--warm-100), var(--warm-50));
    padding: var(--space-xl) 0;
    text-align: center;
}

.quote-block {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s var(--ease-out-expo);
}

.quote-block.visible {
    opacity: 1;
    transform: translateY(0);
}

.quote-text {
    font-family: var(--font-serif);
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    font-weight: 300;
    line-height: 2;
    color: var(--ink-800);
    letter-spacing: 0.3em;
}

.quote-cite {
    display: block;
    font-family: var(--font-serif);
    font-style: normal;
    font-size: 0.9rem;
    color: var(--ink-500);
    margin-top: var(--space-md);
    letter-spacing: 0.2em;
}

.quote-commentary {
    font-family: var(--font-serif);
    font-size: 0.9rem;
    color: var(--ink-500);
    margin-top: var(--space-md);
    letter-spacing: 0.1em;
}

/* --- Contact Section --- */
.section-contact {
    background: linear-gradient(
        180deg,
        var(--warm-50) 0%,
        var(--sakura-100) 50%,
        var(--ink-900) 100%
    );
    padding-bottom: 0;
}

.contact-content {
    text-align: center;
    padding: var(--space-xl) 0;
}

.contact-title {
    font-family: var(--font-serif);
    font-size: clamp(1.5rem, 3.5vw, 2.2rem);
    font-weight: 600;
    color: var(--ink-900);
    line-height: 1.6;
    margin: var(--space-md) 0;
    letter-spacing: 0.1em;
}

.contact-text {
    font-family: var(--font-serif);
    font-size: 0.95rem;
    line-height: 2.2;
    color: var(--ink-600);
    margin-bottom: var(--space-lg);
}

.contact-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    padding: 1.2rem 3rem;
    background: transparent;
    color: var(--ink-800);
    border: 2px solid var(--ink-800);
    border-radius: 60px;
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    transition: all var(--duration-normal) var(--ease-out-expo);
}

.contact-cta:hover {
    background: var(--ink-900);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(26, 26, 46, 0.2);
}

.contact-cta:hover .cta-arrow {
    transform: translateX(4px);
}

/* --- Footer --- */
.footer {
    background: var(--ink-900);
    color: var(--ink-300);
    padding: var(--space-lg) 0 var(--space-md);
}

.footer-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.footer .footer-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    margin-bottom: var(--space-sm);
}

.footer .logo-text {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--ink-300);
    letter-spacing: 0.15em;
}

.footer-philosophy {
    font-family: var(--font-serif);
    font-size: 0.8rem;
    color: var(--ink-500);
    letter-spacing: 0.1em;
    margin-bottom: var(--space-lg);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    padding-top: var(--space-md);
}

.footer-copy {
    font-size: 0.75rem;
    color: var(--ink-500);
    letter-spacing: 0.05em;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 900px) {
    .philosophy-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .book-showcase {
        grid-template-columns: 1fr;
        gap: 3rem;
    }

    .book-visual {
        order: -1;
    }

    .book-3d {
        width: 220px;
        height: 320px;
    }

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

    .nav-links {
        gap: 1.5rem;
    }

    .nav-links a {
        font-size: 0.8rem;
        letter-spacing: 0.15em;
    }
}

@media (max-width: 600px) {
    html {
        font-size: 15px;
    }

    .nav {
        padding: 1rem 1.2rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .nav-links a {
        font-size: 0.75rem;
        letter-spacing: 0.1em;
    }

    .section {
        padding: var(--space-xl) 0;
    }

    .section-inner {
        padding: 0 1.2rem;
    }

    .hero-content {
        padding: 0 1.2rem;
        padding-bottom: 4rem;
    }

    .hero-scroll-hint {
        right: 1rem;
    }

    .philosophy-card {
        padding: 2rem 1.5rem;
    }

    .book-3d {
        width: 200px;
        height: 290px;
    }

    .book-title-display {
        font-size: 1.3rem;
    }

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

    .vision-card {
        padding: 2rem 1.5rem;
    }

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