:root {
    --bg: #f9fafb;
    --navbar-bg: rgba(255, 255, 255, 0.8);
    --navbar-bg-hover: rgba(255, 255, 255, 1);
    --navbar-shadow: rgba(0, 0, 0, 0.1);
    --navbar-shadow-hover: rgba(0, 0, 0, 0.3);
    --navbar-border: #e11d48;
    --navbar-content: #e11d48;
    --navbar-content-hover: #790e25;
    --footer-bg: #f1f5f9;
    --footer-content: #4b5563;
    --footer-border: #e5e7eb;
    --inline-code-content: #ff4d4d;
    --multiline-code-bg: #1e1e1e;
    --multiline-code-content: white;
    --multiline-code-shadow: rgba(255, 77, 77, 0.8);
    --copy-prompt-success-content: #39FF14;
    --copy-prompt-success-shadow1: white;
    --copy-prompt-success-shadow2: #39FF14;
    --copy-prompt-fail-content: rgb(255, 77, 77);
    --copy-prompt-fail-shadow1: white;
    --copy-prompt-fail-shadow2: rgb(255, 77, 77);
    --main-content-bg: #fefefee3;
    --section-border: #e5e7eb;
    --normal-content: #4b5563;
    --header-content: #1f2937;
    --remark-content: #1f2937;
    --link: #e11d48;
    --link-hover: #790e25;
    --theme-selector-shadow1: rgba(0, 0, 0, 0.2);
    --theme-selector-shadow2: rgba(0, 0, 0, 0.5);
    --particle-color-1: #e11d48;
    --particle-color-2: #cbd5e1;
}

* {
    /* css reset */
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Noto Sans JP', 'Noto Sans TC', sans-serif;
    background: var(--bg);
    overflow-x: hidden;
    color: var(--normal-content);
    scroll-behavior: smooth;
}

#bg-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.navbar {
    position: fixed;
    top: 0; left: 0;
    width: 100%;
    height: 7vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--navbar-bg);
    backdrop-filter: blur(8px);
    box-shadow: 0 4px 8px var(--navbar-shadow);
    z-index: 10;
    border-bottom: 2px solid var(--navbar-border);
    border-radius: 8px 8px 0 0;
    opacity: 1;
    transition: box-shadow 0.3s ease, opacity 0.3s ease;
}

.navbar.scrolled {
    opacity: 0.1;
}

.navbar:hover {
    background-color: var(--navbar-bg-hover);
    box-shadow: 0 4px 8px var(--navbar-shadow-hover);
    opacity: 1;
}

.navbar ul {
    list-style: none;
    display: flex;
    width: 75vw;
    max-width: 800px;
    margin-left: auto; margin-right: auto;
    justify-content: center;
}

.navbar li {
    width: 25%;
    margin-left: auto; margin-right: auto;
    text-align: center;
}

.navbar a {
    text-decoration: none;
    color: var(--navbar-content);
    font-weight: bold;
    font-size: 1.5 vh;
    transition: color 0.3s ease;
}

.navbar a:hover {
    color: var(--navbar-content-hover);
}

.content {
    padding: 14vh 2em 4vh 2em;
    margin: 0 auto;
    width: 75vw;
    max-width: 800px;
    z-index: 0;
    background-color: var(--main-content-bg);

}

.content a {
    color: var(--link);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}
.content a:hover {
    color: var(--link-hover);
}
section {
    margin-bottom: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid var(--section-border);
}

h1, h2, h3, h4 {
    margin: 20px 0;
    color: var(--header-content);
}

h1 {
    font-size: 2em;
}

h2 {
    font-size: 1.5em;
}

h3 {
    font-size: 1.3em;
}

h4 {
    font-size: 1.1em;
}

code {
    font-family: 'Courier New', monospace;
    font-size: 1em;
    background-color: transparent;
    color: var(--inline-code-content);
    padding: 0 4px;
}

pre {
    position: relative;
    margin: 20px 0;
}

pre code {
    display: block;
    padding: 1em;
    background-color: var(--multiline-code-bg);
    color: var(--multiline-code-content);
    border-radius: .5em;
    overflow-x: auto;
    font-size: 1.1em;
    line-height: 1.6;
    box-shadow: 0 4px 12px var(--multiline-code-shadow);  /* 紅色陰影 */
}

#copyable:hover {
    cursor: pointer;
}

#copyable.suc_def::before {
    content: 'copied';
    display: block;
    position: absolute;
    top: 0%; left: 50%;
    transform: translateX(-50%);
    color: transparent;
    text-shadow: none;
    font-size: 1.1em;
    transition: color .3s ease, top .3s ease, text-shadow .3s ease;
}

#copyable.suc::before {
    content: 'copied';
    display: block;
    position: absolute;
    top: 25%; left: 50%;
    transform: translateX(-50%);
    color: var(--copy-prompt-success-content);
    text-shadow: 0 0 10px var(--copy-prompt-success-shadow1), 0 0 20px var(--copy-prompt-success-shadow2);
    font-size: 1.1em;
    transition: none;
}

#copyable.fail_def::before {
    content: 'failed';
    display: block;
    position: absolute;
    top: 0%; left: 50%;
    transform: translateX(-50%);
    color: transparent;
    text-shadow: none;
    font-size: 1.1em;
    transition: color .3s ease, top .3s ease, text-shadow .3s ease;
}

#copyable.fail::before {
    content: 'failed';
    display: block;
    position: absolute;
    top: 25%; left: 50%;
    transform: translateX(-50%);
    color: var(--copy-prompt-fail-content);
    text-shadow: 0 0 10px var(--copy-prompt-fail-shadow1), 0 0 20px var(--copy-prompt-fail-shadow2);
    font-size: 1.1em;
    transition: none;
}

.warning {
    animation: rainbow 5s infinite linear;
}

@keyframes rainbow {
    0% { color: red; }
    14% { color: orange; }
    28% { color: yellow; }
    42% { color: green; }
    56% { color: rgb(0, 157, 255); }
    70% { color: rgb(0, 4, 255); }
    84% { color: purple; }
    100% { color: red; }
}

p {
    font-size: 1.1em;
    line-height: 1.8;
}

.content ol, .content ul{
    padding: 0.5em 0 0.5em 2.2em;
}


.content ol li, .content ul li{
    padding: 0.1em 0;
    font-size: 1em;
}

.remark {
    color: var(--remark-content);
    font-weight: bold;
}

footer {
    padding: 20px;
    background-color: var(--footer-bg);
    text-align: center;
    font-size: 1.1em;
    color: var(--footer-content);
    border-top: 1px solid var(--footer-border);
    margin-top: 40px;
}

footer a {
    color: #e11d48;
    text-decoration: none;
}

footer a:hover {
    color: #be123c;
}

.main-particles {
    display: none;
    color: var(--particle-color-1);
}

.side-particles {
    display: none;
    color: var(--particle-color-2);
}


.theme-switcher {
    position: fixed;
    bottom: 4vh;
    right: 2vw;
    display: none;
    flex-direction: column;
    align-items: center;
    z-index: 1000;
}

.theme-color {
    width: 1.5em;
    height: 1.5em;
    margin: .5em 0;
    cursor: pointer;
    border-radius: 50%;
    box-shadow: 0 0px 1em var(--theme-selector-shadow1);
    transform: rotate(0deg) scale(1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.theme-color:hover {
    transform: rotate(180deg) scale(1.1);
    box-shadow: 0 0px 2em var(--theme-selector-shadow2);
}

.theme-color.selected {
    transform: rotate(180deg);
    box-shadow: 0 0px 2em var(--theme-selector-shadow2);
}

@media (min-width: 768px) {
    .theme-switcher {
        display: flex;
    }
}