@import url('https://fonts.googleapis.com/css2?family=Gluten:wght@100..900&family=Grandstander:ital,wght@0,100..900;1,100..900&family=Potta+One&display=swap');

:root {
font-size: 1.125em;
color-scheme: light dark;
accent-color: teal;
}

body {
color: black;
font-family: "Grandstander", sans-serif;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
}

* { 
	box-sizing: border-box;
	margin: 0;
	padding: 0;
	scrollbar-color: cadetblue gainsboro;
	overscroll-behavior: none;
}

ul {
	padding: 0px 10px 0px 20px;
	margin: 0px;
	text-align: left;
}

.grid-container {
  display: grid;
  grid-template-columns: repeat(4, 1fr); /* 4 equal columns */
  grid-template-rows: repeat(2, auto);   /* 2 rows */
  gap: 0px;                             /* space between boxes */
  padding: 10px;
  max-width: 1200px;
  margin: auto;                          /* center grid on page */
}

.iframe-container {
  display: flex;
  justify-content: center;  /* căn giữa ngang */
  align-items: center;      /* căn giữa dọc (nếu có chiều cao xác định) */
  height: 100vh;            /* tùy chọn: chiếm toàn màn hình */
}
.strike {
  position: relative;
  color: #555;
}
.strike::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  background: rgba(0,0,0,0.3);
  transform: rotate(-1deg);
}

iframe {
  border: none; /* bỏ khung nếu muốn */
}
.grid-item {
  background-color: transparent;
  border: 1px;
  padding: 15px;
  border-radius: 10px;
  text-align: justify;                   /* neat paragraph text */
}

.grid-item p {
  margin: 0;
  font-family: 'Grandstander', sans-serif; /* example Google font */
}

.border { /* .rope from https://maxbittker.github.io/broider/ */

   
    border-image:  url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAFQAAABUCAYAAAAcaxDBAAAAAXNSR0IArs4c6QAAAS9JREFUeF7t3TEKgDAUBcGf+x9a0VpTLVg4OcAK4wuWrpk5xskEFtDM8g4BbT2Bxp6PoNdqnXeB7Tfn6coD3c8JaHzdgAKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchQKNBeKchX4NGj//Xzm/rojfN1CgsUCcs1CgsUCcs1CgsUCcOwEsZJwBnQvBGwAAAABJRU5ErkJggg==') 28 /  28px / 0 round;
    border-width:  20px;
    border-style:  solid; 
	background-color: rgb(255, 255, 255, 75%);
	padding: 5px 36px;
}	
a.border:hover, a.border:focus { 
    border-image:  url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACoAAAAqCAYAAADFw8lbAAAAAXNSR0IArs4c6QAAAMBJREFUWEftlmEKgCAMhfUA3v+gHqAIEmIha9tDHL3+Cfn2+TmtWpI8NQlnISh6p2iURtEG0HnsURpFG0DnqT3aWjvQRa+83rta+1lXfTkdqNXAbBfGwq15n41ag5eBzrY8Cgw3uj2oXLE2tt4IMKMamLfQWJB3/uswEfRWusyotSfl+/8DlU0/xtH7E36Y0oFGDSz7hKYFjZ52Od/a85//nrYHRQN681Sj3mD0PILSKNoAOo89SqNoA+g89ija6AkKGqgruOVHVgAAAABJRU5ErkJggg==') 16 /  16px / 0 round;
}
	
.clearfix::after {
	content: "";
	clear: both;
	display: table;
}

hr {
	border: none;
	border-top: 1px solid;
}

h3, h2, h1 { font-weight: normal; }

h3 { font-family: "Potta One", system-ui !important; font-size: 1.25rem; line-height: 1; font-style: italic; }
h2 { font-family: "Potta One", system-ui !important; font-size: 1.45rem; line-height: 1; }
h1 { font-family: "Potta One", system-ui !important; font-size: 2.75rem; line-height: 1; }
		 
p, ol, ul, dl, code, details { font-size: 1rem; line-height: 1.3; }
		 
h1, h2, h3, h4, h5, h6, p, table, details, cite, blockquote, hr {
	margin: 18px 0;
}

ul, dl {
	margin: 18px 0 18px 18px;
}

ol { margin: 18px 0 18px 54px; }
ol ol { margin: 0 0 0 54px; }

ul ul, dd { 
	margin: 0 0 0 18px;
}

details p { margin: 18px 0 18px 36px; }

summary { cursor: pointer; }

/* Add a custom symbol before the summary text */
summary::before {
  content: "➤"; /* your new symbol */
  display: inline-block;
  margin-right: 0.2em; margin-bottom: 1em;
  transition: transform 0.2s; /* optional for rotation effect */
}

/* Optional: rotate symbol when open */
details[open] summary::before {
  transform: rotate(90deg);
}
ul { list-style-type: square; }

code {
	background-color: lightgrey;
	font-family: 'Courier New', monospace; 
	padding: 1px 4px;
	
}

pre {
	background-color: lightgrey;
	overflow-x: auto;
	padding: 1px 4px;
}

table {	border: 1px solid; }
tr, td, th { border: 1px dotted; }
td, th { padding: 5px; }

textarea {
	padding: 2px;
}

cite { 
	display: block;
	text-align: right;
}

blockquote { border-left: 1px solid; padding-left: 14px; }

details > summary {
    list-style-type: '';
}

details[open] > summary {
    list-style-type:;
}

a {
	color: teal;
	padding: 1px;
}

a:hover, a:focus {
	background-color: teal;
	color: white;
}

button, input, textarea {	
	font-family: "Grandstander", sans-serif, "Courier New"
}

img { max-width: 100%; }
	
.new { 
	text-transform: uppercase;
	text-shadow: 0 -1px yellow, 1px 0 yellow, 0 1px yellow, -1px 0 yellow;
}

::selection {
	color: white;
	background-color: teal;
}

@media screen and (max-width: 600px){
	
	h1, h2, h3, h4, h5, h6, p, table, details, cite, blockquote, hr {
		margin: 16px 0;
	}

	ul, dl {
		margin: 16px 0 16px 16px;
	}

	ol { margin: 16px 0 16px 48px; }
	ol ol { margin: 0 0 0 48px; }

	ul ul, dd { 
		margin: 0 0 0 16px;
	}

	details p { margin: 16px 0 16px 32px; }
	
	p, ol, ul, dl, code, details, table, figcaption { font-size: 0.9rem; }
}

@media (prefers-color-scheme: dark) {
	* { scrollbar-color: cadetblue darkslategrey; }
	body { color: white; }
	img { filter: brightness(.9); }
	.border { background-color: rgb(0,20,20,75%); border-color: darkslategrey; }
	.new, code { color: black; }
	a { color: #b2d7c1; }
	a:hover, a:focus { color: darkslategrey; background-color: #b2d7c1; }
	a.border:hover, a.border:focus { border-image:  url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABUAAAAVCAYAAACpF6WWAAAAtklEQVQ4T7VV2xHAIAjTzToao3Wz9vigFyMoZ7V/VIghPKzlwFcPYJYG9BJ57JJbpKKNl+uZ2uxvPh+oOpgzBuA/CzIw9jd7CBoBWhZbQJGhl1nH1NOINWXmU00N1EvZ6xBkyhp3mnpFmIEyIbdQrNcW0IwUqUKNnKKpY12X+xQviFqs0VQDcARXOkExhrPvsYp2AxKYjmnUYr8KFbXXMihqHBUIN1dq9nkf8E5Nzf6uV+DIc/ICR9UIJTV+2f0AAAAASUVORK5CYII=") 7 /  7px / 0 round;
	}
}