html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed, 
figure, figcaption, footer, header, hgroup, 
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
	margin: 0;
	padding: 0;
	border: 0;
	font-size: 100%;
	font-family: 'Inter', sans-serif;
	font: inherit;
	vertical-align: baseline;
}
article, aside, details, figcaption, figure, 
footer, header, hgroup, menu, nav, section {
	display: block;
}
body {
	line-height: 1;
	background: #f7f8fb;
	color: #101828;
	margin: 0;
	min-height: 100vh;
}
.page-shell {
	min-height: 100vh;
	display: flex;
	flex-direction: column;
	justify-content: center;
	align-items: center;
	padding: clamp(24px, 4vw, 64px) clamp(20px, 4vw, 80px);
	box-sizing: border-box;
	gap: clamp(24px, 4vw, 48px);
}
.resistor-row {
	width: 100%;
	display: flex;
	justify-content: center;
	align-items: flex-start;
	gap: clamp(24px, 5vw, 80px);
}
.left, .right {
	display: flex;
	flex-direction: column;
	align-items: center;
	gap: 16px;
}
#band4,
#band5 {
	flex: 1 1 0;
	max-width: 640px;
	width: 45%;
	text-align: center;
	padding: 12px;
	box-sizing: border-box;
	float: none;
}
object {
	width: 100%;
	max-width: 640px;
	height: auto;
}
h2{
	text-align: center;
	font-size: 36px;
	font-family: 'Inter', sans-serif;
	margin: 0 0 16px 0;
	border-bottom: 3px solid #000000;
	display: inline-block;
	color: #000000;
	padding-bottom: 8px;
}
#band4 h2 {
	border-bottom-color: #d9b477;
}
#band5 h2 {
	border-bottom-color: #7bc6b8;
}
.center {
	width: 100%;
	max-width: 640px;
	text-align: center;
	margin: 0 auto;
	padding: 32px 24px 48px;
	box-sizing: border-box;
	clear: both;
	background: #ffffff;
	border-radius: 16px;
	box-shadow: 0 25px 50px rgba(15, 23, 42, 0.08);
}
#btn {
	border: none;
	border-radius: 8px;
	color: #FFFFFF;
	background: #0ca678;
	cursor: pointer;
	display: inline-block;
	font-size: 16px;
	font-weight: 600;
	line-height: 20px;
	margin-top: 12px;
	padding: 10px 24px;
	text-transform: uppercase;
	transition: background 0.2s ease, transform 0.2s ease;
}
#btn:hover {
	background: #0f8d64;
	transform: translateY(-1px);
}
#resistance {
	display: block;
	font-size: 24px;
	color: #0c67a1;
	width: min(520px, 100%);
	margin: 10px auto;
	padding: 12px 14px;
	border-radius: 10px;
	box-shadow: 0 1px 2px rgba(0,0,0,0.2) inset, 0 -1px 0 rgba(0,0,0,0.05) inset;
	border: 1px solid #c8d5e4;
	box-sizing: border-box;
}
#resistance:focus, #resistance:hover {
	border: 1px solid #0f8d64;
	box-shadow: 0 0 0 3px rgba(15,141,100,0.15);
	outline: none;
}
input.correct {
	color: #0d8c5f !important;
}
input.incorrect {
	color: #f15b5d !important;
}
@media (max-width: 900px) {
	.page-shell {
		padding: 32px 24px 48px;
		gap: 32px;
	}
	.resistor-row {
		flex-direction: column;
		width: 100%;
		gap: 20px;
	}
	#band4,
	#band5 {
		width: 100%;
		max-width: none;
	}
	h2 {
		font-size: 28px;
	}
	object {
		max-width: 420px;
	}
}
@media (max-width: 520px) {
	.page-shell {
		padding: 28px 16px 40px;
	}
	h2 {
		font-size: 24px;
	}
	object {
		max-width: 320px;
	}
	.center {
		padding: 24px 16px 32px;
	}
	#resistance {
		font-size: 20px;
	}
}