/* DM Serif Display - Regular */
@font-face {
  font-family: 'DMSerifDisplay';
  src: url('fonts/DMSerifDisplay-Regular.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

/* DM Serif Display - Italic */
@font-face {
  font-family: 'DMSerifDisplay';
  src: url('fonts/DMSerifDisplay-Italic.ttf') format('truetype');
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

:root {
    --bg-color: #f5f5dc;
    --text-color: #111111;
    --nav-bg: #e8e8cc;
    --link-color: #0055cc;
    --card-bg: #fffff0;
}

[data-theme="dark"] {
    --bg-color: #1e1e1e;
    --text-color: #f5f5dc;
    --nav-bg: #2a2a2a;
    --link-color: #66b3ff;
    --card-bg: #2d2d2d;
}

body {
    /* font-family: "Times New Roman", Times, serif; */
    font-family: 'DMSerifDisplay', 'Times New Roman', Times, serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-color);
    background-image:
        linear-gradient(rgba(137, 16, 16, 0.1), rgba(114, 182, 59, 0.1)),
        url("Untitled design (1).png");
    background-repeat: repeat;
    background-size: 800px auto;
    background-position: top left;
    color: var(--text-color);
    margin: 0;
    padding: 0;
    text-align: center;
    transition: color 0.3s ease, background-color 0.3s ease;
}

[data-theme="dark"] body {
    background-image:
        linear-gradient(rgba(30, 30, 30, 0.1), rgba(30, 30, 30, 0.1)),
        url("Untitled design (1).png");
}

nav {
    position: sticky;
    top: 0;
    background-color: var(--nav-bg);
    padding: 15px 70px 15px 15px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 15px;
}

nav a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: bold;
    font-size: 1.1rem;
}

nav a:hover {
    text-decoration: underline;
}

.theme-switch-wrapper {
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
}

.theme-switch {
    position: relative;
    display: inline-block;
    width: 54px;
    height: 28px;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #d1d1b5;
    transition: 0.4s;
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "☀️";
    font-size: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 22px;
    width: 22px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: 0.4s;
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

input:checked + .slider {
    background-color: #555;
}

input:checked + .slider:before {
    transform: translateX(26px);
    content: "🌙";
    background-color: #222;
}

header,
section,
.theorem-container,
.quote-container {
    background-color: var(--card-bg);
    border-radius: 30px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

header {
    max-width: 900px;
    box-sizing: border-box;
    margin: 40px auto;
    padding: 30px;
}

main {
    flex: 1;
    width: 100%;
    box-sizing: border-box;
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

section {
    margin: 40px 0;
    padding: 30px;
}

h1,
h2,
h3 {
    margin-top: 0;
}

ul {
    display: inline-block;
    text-align: left;
    margin: 0 auto;
}

li {
    margin-bottom: 10px;
}

a {
    color: var(--link-color);
}

.theorem-container {
    padding: 20px 30px;
    margin: 20px auto 40px;
    text-align: left;
}

.theorem-title {
    font-size: 1.2rem;
    margin-bottom: 10px;
    display: block;
    font-weight: bold;
}

.theorem-statement {
    font-size: 1.1rem;
    line-height: 1.5;
    font-style: italic;
}

details {
    background-color: rgba(0, 0, 0, 0.03);
    padding: 10px 15px;
    margin-bottom: 15px;
    border-radius: 30px;
    border: 1px solid rgba(0, 0, 0, 0.05);
    text-align: left;
    transition: background-color 0.3s ease;
}

[data-theme="dark"] details {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.1);
}

summary {
    cursor: pointer;
    font-weight: bold;
    font-size: 1.1rem;
    outline: none;
    padding: 5px 0;
}

summary:hover {
    color: var(--link-color);
}

details > p,
details > ul {
    margin-top: 10px;
    line-height: 1.6;
}

.poster-img {
    max-width: 100%;
    height: auto;
    border: 1px solid var(--text-color);
    margin-top: 15px;
    border-radius: 30px;
}

.btn {
    background-color: var(--text-color);
    color: var(--bg-color);
    border: none;
    padding: 10px 15px;
    cursor: pointer;
    font-family: inherit;
    font-size: 1rem;
    border-radius: 30px;
    text-decoration: none;
    display: inline-block;
}

.btn:hover {
    opacity: 0.8;
}

.quote-container {
    font-size: 1.2rem;
    font-style: italic;
    margin: 40px 0;
    padding: 30px;
}

.quote-author {
    display: block;
    margin-top: 15px;
    font-weight: bold;
    font-style: normal;
    font-size: 1rem;
}

footer {
    background-color: var(--nav-bg);
    padding: 20px;
    margin-top: 50px;
}

#about p {
    text-align: left;
}

@media (max-width: 700px) {
    nav {
        padding-right: 15px;
    }

    .theme-switch-wrapper {
        position: static;
        transform: none;
    }

    header,
    section {
        margin-left: 10px;
        margin-right: 10px;
        padding: 24px 20px;
    }
}