:root {
    --bg-color: #ffffff;
    --text-color: #333333;
    --dark-bg-color: #121212;
    --dark-text-color: #e0e0e0;
    --primary-border: #cccccc;
    --primary-hover: #f0f0f0;
    --shadow-color: rgba(0, 0, 0, 0.2);
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'OPPO Sans Medium', Roboto, sans-serif;
    font-weight: 400;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    font-size: 16px;
    line-height: normal;
}

body.dark-mode {
    background-color: var(--dark-bg-color);
    color: var(--dark-text-color);
}

header, footer, nav {
    font-family: 'OPPO Sans Medium', sans-serif;
    font-weight: 300;
    padding: 40px 0;
    text-align: center;
    box-shadow: 0 4px 20px var(--shadow-color);
    border-radius: 0 0 12px 12px;
}

header {
    background-color: var(--primary-hover);
}

body.dark-mode header {
    background-color: #1f1f1f;
}

h1, h2 {
    font-family: 'OPPO Sans Medium', sans-serif;
    font-weight: 300;
    margin: 0;
    transition: transform 0.3s;
}

h1 {
    font-size: 2.5rem;
}

h1:hover {
    transform: translateY(-2px);
}

nav {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 10px;
    border-radius: 12px;
    background-color: var(--primary-hover);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

body.dark-mode nav {
    background-color: #333;
}

nav a {
    color: var(--text-color);
    margin: 0 15px;
    text-decoration: none;
    font-weight: 500;
    padding: 8px 15px;
    position: relative;
    transition: color 0.3s, transform 0.3s;
}

body.dark-mode nav a {
    color: var(--dark-text-color);
}

nav a:hover {
    color: #555;
    transform: translateY(-5px);
}

nav a::after {
    content: '';
    display: block;
    height: 2px;
    width: 0;
    background: #555;
    transition: width 0.3s;
    position: absolute;
    bottom: -5px;
    left: 50%;
    transform: translateX(-50%);
}

body.dark-mode nav a::after {
    background: var(--dark-text-color);
}

nav a:hover::after {
    width: 100%;
}

#toggleButton {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 50%;
    background-color: var(--primary-hover);
    color: var(--text-color);
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
    transition: background-color 0.3s;
    margin-left: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
}


body.dark-mode #toggleButton {
    background-color: #333;
    color: var(--dark-text-color);
}

#toggleButton:hover {
    background-color: #ccc;
}

main {
    flex: 1;
    max-width: auto;
    margin: 20px auto;
    padding: 20px;
    background: var(--bg-color);
    border-radius: 12px;
    box-shadow: 0 4px 20px var(--shadow-color);
}

body.dark-mode main {
    background: #1e1e1e;
}

.post-card, .intro-text {
    margin-bottom: 20px;
    padding: 20px;
    border-radius: 8px;
    background-color: #f9f9f9;
    border: 1px solid #f9f9f9;
    box-shadow: 0 4px 15px var(--shadow-color);
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s, transform 0.3s;
}

body.dark-mode .post-card, body.dark-mode .intro-text {
    border: 1px solid #f0f0f0;
    background-color: #2a2a2a;
}

.post-card:hover, .intro-text:hover {
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
    transform: translateY(-5px);
}

.content {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.8s ease, opacity 0.8s ease;
    margin-top: 10px;
    white-space: pre-wrap;
}

.content.show {
    max-height: 500px;
    opacity: 1;
}

.content img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.meta {
    color: #555555;
    font-size: 0.9em;
}

body.dark-mode .meta {
    color: #e0e0e0;
}


footer {
    text-align: center;
    padding: 15px;
    background-color: #f8f8f8;
    color: var(--text-color);
    border-top: 1px solid #eaeaea;
    border-radius: 12px;
    box-shadow: 0 4px 15px var(--shadow-color);
    margin-top: auto;
    transition: background-color 0.3s, transform 0.3s;
}

body.dark-mode footer {
    background-color: #1f1f1f;
    color: var(--dark-text-color);
}

footer:hover {
    transform: translateY(-5px);
}

footer p {
    margin: 0;
    font-size: 0.9rem;
}

.footer-links, .contact-link {
    margin: 10px 0;
}

.footer-links a, .contact-link {
    margin: 0 10px;
    color: inherit;
    text-decoration: none;
    transition: text-decoration 0.3s;
}

.footer-links a:hover, .contact-link:hover {
    text-decoration: underline;
}

.post-card a {
    text-decoration: underline;
}

.post-card a:hover {
    text-decoration: underline;
}

#introContent {
    margin: 20px 0;
}

@media (max-width: 600px) {
    main {
        margin: 10px;
        padding: 10px;
    }

    header, footer {
        padding: 15px;
    }
}

.rotate {
    transition: transform 0.6s;
    transform: rotate(360deg);
}

button {
    cursor: pointer;
}

button:focus, a:focus {
    outline: none;
}

.pagination {
    display: flex;
    justify-content: center;
    margin-top: 20px;
}

.pagination button {
    margin: 0 5px;
    padding: 10px 15px;
    border: 1px solid var(--primary-border);
    border-radius: 8px;
    background-color: #f9f9f9;
    color: var(--text-color);
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s, transform 0.3s;
    box-shadow: 0 4px 15px var(--shadow-color);
}

body.dark-mode .pagination button {
    background-color: #2a2a2a;
    color: var(--dark-text-color);
    border: 1px solid #f0f0f0;
}

.pagination button:hover {
    background-color: #e0e0e0;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

body.dark-mode .pagination button:hover {
    background-color: #444;
}

.pagination button.active {
    background-color: #444;
    color: #ffffff;
    box-shadow: none;
}

body.dark-mode .pagination button.active {
    background-color: #ffffff;
    color: #444;
}

.pagination button:last-child {
    margin-right: 0;
}