:root {
    --color1: rgb(0, 0, 0);
    --color1b: rgb(0, 0, 0);
    --color2: rgb(255, 255, 255);
    --color3: rgb(250, 250, 250);
    --color4: rgb(100, 100, 100);
    --color5: rgb(230, 230, 230);
    --color6: rgb(210, 210, 210);
    --color7: rgb(80, 80, 80);
    --color8: rgb(200, 200, 200);
    --color9: rgb(240, 240, 240);
    --color10: rgb(220, 220, 220);
    --color11: rgb(150, 150, 150);
    --color12: rgb(180, 180, 180);
    /* 軌跡図鑑用変数 */
    --book-color-border: rgb(60, 60, 60);
    --book-color-scroll-bg: rgb(60, 60, 60);
    --book-color-scroll-hover: rgb(0, 0, 0);
}

body.dark-mode {
    --color1: rgb(200, 200, 200);
    --color1b: rgb(90, 90, 90);
    --color2: rgb(30, 30, 30);
    --color3: rgb(40, 40, 40);
    --color4: rgb(120, 120, 120);
    --color5: rgb(60, 60, 60);
    --color6: rgb(80, 80, 80);
    --color7: rgb(160, 160, 160);
    --color8: rgb(90, 90, 90);
    --color9: rgb(50, 50, 50);
    --color10: rgb(70, 70, 70);
    --color11: rgb(100, 100, 100);
    --color12: rgb(90, 90, 90);
    /* 軌跡図鑑用変数 (ダーク) */
    --book-color-border: rgb(100, 100, 100);
    --book-color-scroll-bg: rgb(100, 100, 100);
    --book-color-scroll-hover: rgb(140, 140, 140);
}

body {
    font-family: sans-serif;
    text-align: left;
    margin: 40px;
    line-height: 1.6;
    font-size: 18px;
    background-color: var(--color2);
    color: var(--color1);
    transition: background-color 0.3s, color 0.3s;
}

h1 {
    font-size: 2.2em;
    margin-bottom: 60px;
    text-align: center;
    position: relative;
}

h2 {
    font-size: 1.6em;
    margin-top: 60px;
    border-bottom: 2px solid var(--color1);
    padding-bottom: 10px;
    padding-left: 1em;
}

/* 軌跡図鑑用 h2 */
body.book-page h2 {
    border-bottom-color: var(--book-color-border);
    padding-bottom: 6px;
    scroll-margin-top: 40px;
    margin-top: 20px;
}

h3 {
    font-size: 1.2em;
    margin-top: 20px;
    cursor: pointer;
    background: var(--color9);
    padding: 8px;
    border: 1px solid var(--color11);
    border-radius: 5px;
    user-select: none;
}

.h2-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 40px;
    border-bottom: 2px solid var(--color1);
    padding-bottom: 6px;
}

.h2-container h2 {
    margin: 0;
    border: none;
    padding: 0;
    padding-left: 1em;
}

.header-ant-icon {
    width: 16px;
    height: 16px;
    cursor: pointer;
    transition: transform 1s ease;
}

.header-ant-icon:hover {
    transform: rotate(720deg) scale(1.2);
}

.footer-ant-icon {
    width: 16px;
    height: 16px;
    display: block;
    margin: 0 auto;
    cursor: pointer;
}

.footer-ant-icon:hover {
    animation: shake 0.8s ease-in-out infinite;
}

@keyframes shake {

    0%,
    50%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-5px) rotate(-16deg);
    }

    75% {
        transform: translateX(5px) rotate(16deg);
    }
}

.dark-mode-toggle {
    position: fixed;
    top: 20px;
    right: 30px;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--color5);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    user-select: none;
    transition: background 0.3s;
}

.dark-mode-toggle:hover {
    background: var(--color6);
}

.toggle-switch {
    width: 50px;
    height: 26px;
    background: var(--color8);
    border-radius: 13px;
    position: relative;
    transition: background 0.3s;
}

.toggle-slider {
    width: 22px;
    height: 22px;
    background: var(--color2);
    border-radius: 50%;
    position: absolute;
    top: 2px;
    left: 2px;
    transition: transform 0.3s;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

body.dark-mode .toggle-slider {
    transform: translateX(24px);
}

body.dark-mode .toggle-switch {
    background: rgb(70, 70, 70);
}

.toggle-arrow {
    font-size: 0.6em;
    margin-right: 6px;
    vertical-align: middle;
    position: relative;
    top: -2px;
}

.center-area {
    text-align: center;
    margin-top: 30px;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    width: 360px;
    margin-left: auto;
    margin-right: auto;
}

button {
    font-size: 1.2em;
    padding: 10px 20px;
    margin: 0px 24px;
    border: none;
    cursor: pointer;
    border: 2px solid var(--color1b);
    border-radius: 8px;
    background: var(--color5);
    color: var(--color1);
    transition: background 0.3s;
}

button:hover {
    background: var(--color6);
}

ul {
    margin-left: 16px;
}

.reference-list {
    margin-top: 40px;
}

.reference-list ul {
    padding-left: 20px;
    margin-top: 8px;
    list-style-position: outside;
}

.reference-list li {
    margin-bottom: 0.6rem;
    line-height: 1.5;
}

.reference-list a {
    color: var(--color1);
}

.collapsible-content {
    display: none;
    margin: 10px 0 20px 0;
    padding: 10px;
    border-left: 3px solid var(--color4);
    background: var(--color3);
}

.active {
    display: block;
}

.ui-btn {
    font-size: 14px;
    padding: 2px 7px;
    margin: 2px;
    border: 1px solid var(--color1b);
    background: var(--color9);
    cursor: default;
    pointer-events: none;
    border-radius: 4px;
}

.mode-btn {
    width: 100%;
    text-align: center;
    flex: 0 0 auto;
    margin: 0;
    padding: 18px 12px;
    font-size: 1.6em;
    background: var(--color5);
    border: 3px solid var(--color1b);
    border-radius: 8px;
    cursor: pointer;
    box-sizing: border-box;
    height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.carousel-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    margin-top: 10px;
    width: 100%;
    box-sizing: border-box;
}

.carousel {
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
    padding: 8px 8px;
    gap: 8px;
    max-height: 302px;
    width: 360px;
    box-sizing: border-box;
    background: transparent;
    border-radius: 6px;
}

.carousel::-webkit-scrollbar {
    width: 12px;
}

.carousel::-webkit-scrollbar-thumb {
    background: rgba(0, 0, 0, 0.2);
    border-radius: 6px;
}

body.dark-mode .carousel::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
}

.carousel::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 0, 0, 0.3);
}

body.dark-mode .carousel::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

.arrow {
    background: none;
    border: none;
    font-size: 30px;
    cursor: pointer;
    user-select: none;
    padding: 6px 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 240px;
}

.kiseki-box {
    position: absolute;
    left: calc(100% + 80px);
    top: 30%;
    transform: translateY(-50%);
    margin-top: 0;
    z-index: 10;
}

.kiseki-btn {
    width: 260px;
    text-align: center;
    display: inline-block;
    border: 3px solid var(--color1b);
    border-radius: 8px;
    padding: 18px 18px;
    font-size: 1.6em;
    cursor: pointer;
    white-space: nowrap;
    background: var(--color5);
}

.mobile-box {
    position: absolute;
    right: calc(100% + 80px);
    top: 30%;
    transform: translateY(-50%);
    z-index: 10;
}

.mobile-btn {
    width: 260px;
    text-align: center;
    display: inline-block;
    border: 3px solid var(--color1b);
    border-radius: 8px;
    padding: 18px 18px;
    font-size: 1.5em;
    cursor: pointer;
    white-space: nowrap;
    background: var(--color5);
}

.mobile-btn.active,
.mode-btn.mobile {
    position: relative;
    border-radius: 8px;
    border: 4px solid transparent;
    background:
        linear-gradient(var(--color5)) padding-box,
        linear-gradient(90deg, rgb(180, 90, 160), rgb(90, 140, 160)) border-box;
    box-sizing: border-box;
}

.mobile-btn.active:hover,
.mode-btn.mobile:hover {
    filter: brightness(0.9);
}

.tuto-box {
    position: absolute;
    right: 4%;
    transform: translateY(-140%);
    z-index: 60;
}

.tuto-btn {
    width: 200px;
    text-align: center;
    display: inline-block;
    border: 2px solid var(--color1b);
    border-radius: 6px;
    padding: 10px 0px;
    font-size: 1.1em;
    cursor: pointer;
    white-space: nowrap;
    background: var(--color5);
}

.comment-box {
    margin-top: 40px;
}

.comment-form {
    margin-top: 20px;
}

.comment-form input,
.comment-form textarea {
    width: 100%;
    padding: 10px 0px;
    margin-bottom: 12px;
    border: 1px solid var(--color8);
    border-radius: 4px;
    font-size: 1em;
    background: var(--color2);
    color: var(--color1);
}

.comment-form button {
    padding: 6px 18px;
    background: var(--color5);
    color: var(--color1);
    border: 0px solid var(--color1b);
    border-radius: 8px;
    cursor: pointer;
}

.comment-form button:hover {
    background: var(--color6);
}

.comment-form button:active,
.mode-btn:active,
.kiseki-btn:active,
.mobile-btn:active,
.tuto-btn:active {
    transform: scale(0.9);
}

.comment-list {
    margin-top: 30px;
    padding: 12px;
    background: var(--color3);
    border-radius: 8px;
}

.comment-list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.comment-list-header h3 {
    margin: 0 20px;
    background: none;
    border: none;
    cursor: default;
    padding: 0;
    font-size: 1.3em;
}

.sort-toggle {
    font-size: 0.9em;
    color: var(--color7);
    cursor: pointer;
    user-select: none;
}

.sort-toggle input {
    vertical-align: middle;
    margin-right: 4px;
}

#comments-container {
    max-height: 240px;
    overflow-y: auto;
    padding-right: 16px;
    box-sizing: border-box;
}

.comment-item {
    padding: 12px;
    margin-bottom: 12px;
    background: var(--color2);
    border-radius: 6px;
}

.comment-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 1em;
    color: var(--color4);
}

.comment-name {
    font-weight: bold;
    color: var(--color1);
}

.comment-date {
    font-style: italic;
    color: var(--color4);
}

.comment-message {
    line-height: 1.6;
    white-space: pre-wrap;
    text-align: left;
    word-wrap: break-word;
    color: var(--color1);
}

#comments-container::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

#comments-container::-webkit-scrollbar-thumb {
    background: var(--color12);
    border-radius: 6px;
}

.form-actions {
    display: flex;
    align-items: center;
    gap: 50px;
    flex-wrap: wrap;
}

.comment-form .form-actions button {
    margin: 0;
}

.comment-form-options {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.9em;
    user-select: none;
    cursor: pointer;
    white-space: nowrap;
}

.comment-form-options input[type="checkbox"] {
    vertical-align: middle;
    position: relative;
    top: 0;
    margin: 0;
    width: 18px;
    height: 18px;
}

.loading-message {
    text-align: center;
    padding: 20px;
    color: var(--color4);
}

.error-message {
    text-align: center;
    padding: 20px;
    color: rgb(200, 20, 20);
}

.no-comments {
    text-align: center;
    padding: 20px;
    color: var(--color7);
}

.faq-item {
    margin: 10px 0;
    padding: 8px 12px;
    border: 1px solid var(--color8);
    border-radius: 6px;
    cursor: pointer;
    background: var(--color2);
}

.faq-item:hover {
    background: var(--color9);
}

.faq-item .a {
    display: none;
    margin-left: 1em;
    margin-top: 6px;
    padding-left: 10px;
    color: var(--color7);
}

.faq-item.active .a {
    display: block;
}

a:hover {
    color: rgb(40, 160, 240);
}

.English-link {
    position: absolute;
    top: 40px;
    left: 80px;
    z-index: 1000;
    cursor: pointer;
    user-select: none;
    font-size: 1.1em;
    color: var(--color7);
}

.thank-you {
    position: fixed;
    top: -60px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color5);
    color: var(--color1);
    padding: 20px 32px;
    border-radius: 6px;
    font-size: 1.6em;
    z-index: 1000;
    opacity: 0;
    transition: all 1.0s ease;
}

.thank-you.show {
    top: 20px;
    opacity: 1;
}

.history-container {
    margin-top: 10px;
}

.history-list {
    list-style: disc;
    margin: 10px 0 0 30px;
    padding-left: 0;
    max-height: 1.6em;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.history-list.expanded {
    max-height: 500px;
    transition: max-height 0.3s ease-in;
}

.history-item {
    font-size: 1em;
    line-height: 1.6;
    margin-bottom: 2px;
}

.history-toggle {
    display: block;
    margin-top: 6px;
    text-align: left;
    color: var(--color7);
    cursor: pointer;
    text-decoration: underline;
    font-size: 0.9em;
    user-select: none;
    padding-left: 36px;
}

@media (max-width: 640px) {
    body {
        margin: 16px;
        font-size: 0.9em
    }

    .h1 {
        margin-top: 60px;
        font-size: 2em;
    }

    .center-area {
        width: 100%;
    }

    .carousel-container {
        margin-top: 60px;
        margin-bottom: 60px;
    }

    .carousel {
        width: 100%;
        max-height: 260px;
    }

    .tuto-btn {
        font-size: 1em;
        width: 160px;
        padding: 3px 0px;
    }

    .tuto-box {
        position: absolute;
        right: 2%;
        transform: translateY(-120%);
    }

    .mobile-box {
        left: 8%;
        top: 4%;
    }

    .kiseki-box {
        left: 8%;
        top: 98%;
    }

    .dark-mode-toggle {
        right: 10px;
        top: 76px;
        padding: 6px 8px;
        position: absolute;
    }

    .English-link {
        left: 12px;
        top: 76px;
        padding: 6px 10px;
        font-size: 1.1em;
    }

    .mode-btn {
        font-size: 2em;
        padding: 6px 4px;
    }

    #comments-container {
        max-height: 200px;
        padding: 0;
    }
}

/* 軌跡図鑑用追加 */
.image-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 100px 30px;
    margin: 60px 12px;
}

.image-grid img {
    width: 600px;
    border: 3px solid var(--color1);
    cursor: pointer;
    transition: transform 1s;
    background: transparent;
}

.image-grid img:hover {
    transform: scale(1.05);
}

.image-grid figure {
    margin: 0;
    text-align: center;
}

.image-grid figcaption {
    margin-top: 8px;
    font-size: 16px;
    color: var(--color1);
}

.toc {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.toc ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.toc li {
    margin-bottom: 6px;
}

.toc a {
    display: block;
    text-decoration: none;
    color: var(--color1);
    padding: 8px 0px;
    font-size: 20px;
    border-radius: 6px;
    transition: background 0.18s, transform 0.12s;
}

.toc a:hover {
    background: var(--color5);
    transform: translateY(-2px);
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
}

.modal img {
    max-width: 92%;
    border: 5px solid rgb(255, 255, 255);
}

.modal.show {
    display: flex;
}

.hide-captions figcaption,
.hide-captions h2+p {
    display: none;
}

#caption {
    position: absolute;
    right: 60px;
    top: 20px;
    width: 120px;
    padding: 6px 12px;
    font-size: 14px;
    cursor: pointer;
    border: 1px solid var(--book-color-border);
    background: var(--color5);
    border-radius: 8px;
    transition: background 0.2s, transform 0.12s;
    color: var(--color1);
}

#back {
    position: absolute;
    top: 30px;
    left: 30px;
    padding: 6px 8px;
    font-size: 16px;
    background: var(--color5);
    border: 1px solid var(--book-color-border);
    border-radius: 8px;
    text-decoration: none;
    color: var(--color1);
    z-index: 500;
    transition: background 0.2s, color 0.2s;
}

#scrollToTop,
#scrollToBottom {
    position: fixed;
    bottom: 40px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--book-color-scroll-bg);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s, background 0.3s, transform 0.2s;
    z-index: 20;
}

#scrollToTop.show,
#scrollToBottom.show {
    opacity: 1;
    visibility: visible;
}

#scrollToTop:hover,
#scrollToBottom:hover {
    background: var(--book-color-scroll-hover);
    transform: translateY(-3px);
}

#scrollToTop::before {
    content: '';
    width: 0;
    height: 0;
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-bottom: 14px solid var(--color2);
}

#scrollToBottom::before {
    content: '';
    width: 0;
    height: 0;
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: 14px solid var(--color2);
}

@media (max-width: 800px) {
    .image-grid {
        grid-template-columns: 1fr;
        gap: 40px;
        margin: 30px 8px;
    }

    .image-grid img {
        width: 100%;
        max-width: 720px;
    }

    #caption {
        right: 16px;
        width: auto;
        padding: 6px 10px;
        font-size: 13px;
    }
}