@import url('https://fonts.googleapis.com/css2?family=Shippori+Mincho:wght@400;600&family=Yuji+Syuku&family=Zen+Old+Mincho:wght@400;500;700&family=Klee+One:wght@400;600&display=swap');

html {
    overflow: hidden;
    overscroll-behavior: none;
}

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

[hidden] {
    display: none !important;
}

:root {
    --font-mincho: 'Shippori Mincho', 'Hiragino Mincho ProN', 'Yu Mincho', serif;
    --font-rodin: 'FOT-ロダン Pro DB', 'FOT-NewRodin Pro DB', 'Rodin Pro DB', 'Rodin', 'Hiragino Sans', 'Yu Gothic', sans-serif;
    --font-gyosho: 'Yuji Syuku', 'Hiragino Mincho ProN', serif;
    --font-modern: 'Zen Old Mincho', 'Hiragino Mincho ProN', 'Yu Mincho', serif;
    --font-elegant: 'Klee One', 'Hiragino Sans', 'Yu Gothic', sans-serif;
    --active-font-family: var(--font-gyosho);
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background:
        radial-gradient(circle at top, rgba(173, 146, 84, 0.2), transparent 38%),
        linear-gradient(180deg, #2b241d 0%, #120f0c 100%);
    font-family: var(--active-font-family);
    overflow: hidden;
    color: #e8ddc0;
    overscroll-behavior: none;
}

body.font-mincho {
    --active-font-family: var(--font-mincho);
}

body.font-rodin {
    --active-font-family: var(--font-rodin);
}

body.font-gyosho {
    --active-font-family: var(--font-gyosho);
}

body.font-modern {
    --active-font-family: var(--font-modern);
}

body.font-elegant {
    --active-font-family: var(--font-elegant);
}

/* Scene */
.scene {
    perspective: 2000px;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity 2s ease 0.5s;
    position: relative;
    touch-action: none; /* Prevent browser scroll/bounce on the scene */
}

.scene.visible {
    opacity: 1;
}

/* Book Container */
.book {
    position: relative;
    /* Responsive sizing for mobile-first */
    width: 85vw;
    max-width: 480px;
    height: 75vh;
    max-height: 650px;
    transform: translateX(0);
    transition: transform 3s cubic-bezier(0.25, 1, 0.5, 1),
                width 0.6s ease-in-out 0.8s,
                height 0.6s ease-in-out 0.8s,
                max-width 0.6s ease-in-out 0.8s,
                max-height 0.6s ease-in-out 0.8s;
    transform-style: preserve-3d;
}

/* After opening: expand to fill the full viewport */
.book.open {
    width: 100vw;
    max-width: 100vw;
    height: 100vh;
    max-height: 100vh;
    transform: none;
}

@media (min-width: 768px) {
    .book.open {
        transform: none;
    }
}

/* Each page element */
.page-wrapper {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    transform-style: preserve-3d;
}

/* Left Page (The inner text content) */
.page-left {
    background: url('washi.jpg') center/cover, #fdfcf9;
    background-blend-mode: multiply;
    box-shadow: inset -10px 0 20px rgba(0,0,0,0.03), inset 0 0 50px rgba(255,255,255,0.8), -10px 10px 20px rgba(0,0,0,0.15);
    border-radius: 4px 0 0 4px;
    padding: 8vw 6vw;
    display: flex;
    justify-content: flex-end; /* Top/Right origin for vertical text */
    align-items: flex-start;
    position: relative;
    transform-style: flat; /* Prevents children from entering 3D context, fixing iOS touch/click hit-testing */
    border: 1px solid rgba(0,0,0,0.05);
    border-right: none;
    overflow: visible;
    z-index: 1;
}

@media (min-width: 768px) {
    .page-left {
        padding: 50px 40px;
    }
}

.page-left::before {
    content: '';
    position: absolute;
    right: 0; top: 0; bottom: 0; width: 40px;
    background: linear-gradient(to left, rgba(0,0,0,0.08) 0%, rgba(0,0,0,0) 100%);
    pointer-events: none;
}

/* Full-screen state after opening */
.book.open .page-left {
    border-radius: 0;
    border: none;
    box-shadow: none;
}

.book.open .page-left::before {
    display: none;
}

.font-switcher {
    position: absolute;
    top: 16px;
    left: 16px;
    z-index: 30;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: 14px;
    background: rgba(255, 252, 246, 0.9);
    border: 1px solid rgba(173, 138, 45, 0.25);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.12);
    color: #5d4a1e;
    pointer-events: auto;
}

.font-switcher-label {
    font-size: 0.75rem;
    letter-spacing: 0.08em;
    white-space: nowrap;
}

.font-switcher-select {
    appearance: none;
    -webkit-appearance: none;
    border: 1px solid rgba(173, 138, 45, 0.35);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.96);
    color: #4e3b12;
    font: inherit;
    padding: 8px 14px;
    min-width: 116px;
    pointer-events: auto;
    position: relative;
    z-index: 31;
}

@media (max-width: 767px) {
    .font-switcher {
        top: 10px;
        left: 10px;
        gap: 8px;
        padding: 8px 10px;
    }

    .font-switcher-label {
        font-size: 0.68rem;
    }

    .font-switcher-select {
        min-width: 96px;
        padding: 7px 12px;
        font-size: 0.8rem;
    }
}

/* Cover Wrapper */
.cover-wrapper {
    transform-origin: right center; /* Hinge on the right edge */
    transition: transform 3s cubic-bezier(0.25, 1, 0.5, 1);
    cursor: pointer;
    box-shadow: -10px 10px 20px rgba(0,0,0,0.2);
    z-index: 2;
}

.cover-wrapper:hover {
    box-shadow: -12px 12px 25px rgba(0,0,0,0.25);
    transform: rotateY(3deg); /* Hint that it opens */
}

.cover-wrapper.open {
    transform: rotateY(175deg); /* Open nearly flat */
    box-shadow: 10px 10px 20px rgba(0,0,0,0.1);
    cursor: default;
    pointer-events: none;
    z-index: 0;
}

.cover-wrapper.open .cover-face {
    pointer-events: none;
}

/* Common Cover Face */
.cover-face {
    position: absolute;
    width: 100%; height: 100%;
    backface-visibility: hidden;
    border-radius: 4px 0 0 4px;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

/* Front Cover Layout */
.cover-front {
    background: 
        radial-gradient(circle at top left, rgba(255, 255, 255, 0.12), transparent 28%),
        linear-gradient(160deg, rgba(8, 8, 8, 0.05), rgba(0, 0, 0, 0.72)),
        url('black-leather-texture.jpg') center/cover;
    background-blend-mode: screen, multiply, normal;
    border: 1px solid rgba(196, 148, 46, 0.9);
    z-index: 2;
    box-shadow:
        inset 0 0 50px rgba(0, 0, 0, 0.45),
        inset 0 0 18px rgba(212, 175, 55, 0.08);
}

.cover-front::before {
    content: '';
    position: absolute;
    top: 20px; left: 20px; right: 20px; bottom: 20px;
    border: 1px solid rgba(212, 175, 55, 0.85);
    box-shadow: 0 0 15px rgba(212, 175, 55, 0.2), inset 0 0 15px rgba(212, 175, 55, 0.12);
    pointer-events: none;
}

/* Extra inner border for more gold decoration */
.cover-front::after {
    content: '';
    position: absolute;
    top: 26px; left: 26px; right: 26px; bottom: 26px;
    border: 1px solid rgba(111, 85, 20, 0.7);
    pointer-events: none;
}

.title-box {
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.22), rgba(0, 0, 0, 0.38));
    backdrop-filter: blur(2px);
    border: 1px solid rgba(212, 175, 55, 0.8);
    padding: 8vw 6vw;
    box-shadow: 0 18px 40px rgba(0,0,0,0.28), inset 0 0 18px rgba(212, 175, 55, 0.12);
    
    writing-mode: vertical-rl;
    text-orientation: upright;
    color: #d9b45b;
    text-shadow: 0 1px 0 rgba(65, 42, 4, 0.65), 0 0 12px rgba(212, 175, 55, 0.12);
}

@media (min-width: 768px) {
    .title-box {
        padding: 50px 40px;
    }
}

.sender-company {
    font-size: 4vw;
    letter-spacing: 0.3em;
    margin-left: 3vw;
    color: #f1dd9c;
}

.sender-title {
    font-size: 3vw;
    letter-spacing: 0.2em;
    padding-top: 6vw;
    margin-left: 3vw;
    color: #d9b45b;
}

.sender-name {
    font-size: 6vw;
    letter-spacing: 0.4em;
    font-weight: 400;
    margin: 0;
    padding-top: 18vw;
    color: #f3d480;
}

@media (min-width: 768px) {
    .sender-company { font-size: 1.1rem; margin-left: 15px; }
    .sender-title { font-size: 0.9rem; padding-top: 30px; margin-left: 15px; }
    .sender-name { font-size: 2rem; padding-top: 90px; }
}


.cover-logo {
    position: absolute;
    left: 50%;
    bottom: 76px;
    transform: translateX(-50%);
    width: min(30vw, 150px);
    height: auto;
    opacity: 0.95;
    filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.45));
}

.open-instruction {
    position: absolute;
    bottom: 30px;
    background: rgba(212, 175, 55, 0.12);
    color: #f0d78a;
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 3.5vw;
    letter-spacing: 0.1em;
    animation: pulse 2.5s infinite ease-in-out;
    border: 1px solid rgba(212, 175, 55, 0.6);
    font-weight: 600;
    box-shadow: inset 0 0 10px rgba(212, 175, 55, 0.12);
}

@media (min-width: 768px) {
    .open-instruction {
        font-size: 0.9rem;
        bottom: 40px;
    }
}

@keyframes pulse {
    0%, 100% { opacity: 0.6; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.05); }
}

/* Inside Front Cover (Right side when open) */
.cover-back {
    background:
        linear-gradient(180deg, rgba(34, 28, 22, 0.88), rgba(10, 9, 8, 0.92)),
        url('black-leather-texture.jpg') center/cover;
    background-blend-mode: multiply;
    transform: rotateY(180deg);
    border-radius: 0 4px 4px 0;
    box-shadow: inset 10px 0 20px rgba(0,0,0,0.18);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.cover-back::before {
    content: '';
    position: absolute;
    left: 0; top: 0; bottom: 0; width: 40px;
    background: linear-gradient(to right, rgba(0,0,0,0.08) 0%, rgba(0,0,0,0) 100%);
}

.stamp {
    width: 25vw;
    height: 25vw;
    max-width: 140px;
    max-height: 140px;
    border: 3px solid rgba(212, 175, 55, 0.72);
    border-radius: 8px; /* Square stamp */
    display: flex;
    justify-content: center;
    align-items: center;
    color: rgba(241, 221, 156, 0.95);
    font-size: 8vw;
    font-weight: 600;
    margin-bottom: 5vw;
}

@media (min-width: 768px) {
    .stamp {
        font-size: 2.5rem;
        margin-bottom: 30px;
    }
}

.stamp-text {
    writing-mode: vertical-rl;
    text-orientation: upright;
    font-size: 3.8vw;
    line-height: 1.8;
    color: rgba(232, 214, 163, 0.82);
    letter-spacing: 0.3em;
    margin-top: 2vw;
}

@media (min-width: 768px) {
    .stamp-text {
        font-size: 1.1rem;
        margin-top: 20px;
    }
}

.text-container {
    width: 100%;
    height: 100%;
    overflow: hidden; /* Hide scrollbars, we do custom translate */
    position: relative;
    z-index: 1;
    cursor: default;
    /* Prevent text selection while dragging */
    -webkit-user-select: none;
    user-select: none;
    -webkit-touch-callout: none;
    overscroll-behavior: none;
    touch-action: none; /* Crucial for custom touch handling */
    opacity: 0; /* Hidden until book fully expands */
}

/* Reveal animation: starts as background expansion finishes (0.8s delay + 0.6s duration = 1.4s) */
.text-container.show {
    animation: textReveal 1.8s cubic-bezier(0.25, 0.46, 0.45, 0.94) 1.4s both;
}

@keyframes textReveal {
    0%   { opacity: 0; transform: translateX(30px); }
    100% { opacity: 1; transform: translateX(0); }
}

.text-container.manual-ready {
    cursor: grab;
}

.text-container:active {
    cursor: grabbing;
}
@media (max-width: 767px) {
    .cover-logo {
        bottom: 72px;
        width: min(34vw, 132px);
    }
}

/* Main Text Content */
.vertical-text {
    position: absolute;
    right: 0;
    top: 0;
    width: max-content; /* Allow it to grow as much as needed horizontally */
    min-width: 100%;
    height: 100%;
    writing-mode: vertical-rl;
    text-orientation: upright;
    line-height: 2.2;
    font-size: 3.8vw;
    color: #2c3138;
    font-weight: 400;
    padding-bottom: 2vw;
    will-change: transform; /* Hint for GPU hardware acceleration equivalent to WebGL */
    line-break: strict; /* 日本語禁則処理（行頭・行末禁則文字を自動制御） */
    overflow-wrap: break-word;
}

@media (min-width: 768px) {
    .vertical-text {
        font-size: 1.15rem;
        line-height: 2.5;
        margin-right: 15px;
        padding-bottom: 10px;
    }
}

/* (show class was moved to .text-container for proper animation sequencing) */

/* Hide scrollbar for the vertical text container but keep functionality */
.vertical-text::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
.vertical-text::-webkit-scrollbar-thumb {
    background-color: rgba(0,0,0,0.1);
    border-radius: 3px;
}

/* Profile Image Styling */

.profile-aside {
    display: inline-flex;
    writing-mode: horizontal-tb;
    flex-direction: row;
    align-items: center;
    gap: 6vw;
    height: 100%;
    margin-right: 6vw;
}

.profile-image-wrapper {
    display: inline-block;
    padding: 1vw;
    background: #fffdf9;
    border: 1px solid rgba(212, 175, 55, 0.4);
    box-shadow: 2px 2px 10px rgba(0,0,0,0.08);
    border-radius: 2px;
}

.profile-image {
    display: block;
    width: 50vw;
    height: auto;
}

.profile-signature-text {
    display: inline-flex;
    writing-mode: horizontal-tb;
    flex-direction: row-reverse;
    align-items: flex-end;
    gap: 2.2vw;
}

.profile-signature-title,
.profile-signature-name {
    white-space: nowrap;
    line-height: 1.8;
    font-size: 4.4vw;
    color: #4f3c1f;
    writing-mode: vertical-rl;
    text-orientation: upright;
}

@media (min-width: 768px) {
    .profile-aside {
        gap: 28px;
        margin-right: 32px;
    }
    .profile-image-wrapper {
        padding: 6px;
    }
    .profile-image {
        width: 50vw;
    }
    .profile-signature-title,
    .profile-signature-name {
        font-size: 1.35rem;
    }
}