/*
 * Boilerplate CSS – dersven.de
 * Version 2.0 · 2026
 *
 * Raster und Klassennamen nach Skeleton 2.0.4 von Dave Gamache (MIT), www.getskeleton.com
 *
 *  1. Variablen
 *  2. Grundlagen
 *  3. Raster
 *  4. Typografie
 *  5. Links
 *  6. Buttons und Pills
 *  7. Formulare
 *  8. Listen
 *  9. Code
 * 10. Tabellen und Akkordeon
 * 11. Bilder und Abschnitte
 * 12. Seitenkopf, Seitenfuß, Hell/Dunkel, Nach oben, Glas-Panel, Toast
 * 13. Symbole und Icons
 * 14. Hilfsklassen
 */


/* 1. Variablen
   ========================================================================== */

/*
 * Stufe          Größe   Zeile    davor   danach
 * h1             34px    39px     –       13px
 * h2             28px    32,5px   32,5px  13px
 * h3             22px    26px     39px    13px
 * h4             20px    26px     39px    13px
 * Fließtext      16px    26px     –       –
 * figcaption     13px    20px     26px    32px
 *
 * Hell und dunkel folgen dem System; <html data-theme="light|dark"> überschreibt.
 */
:root {
	color-scheme: light dark;

	--schrift: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
	--schrift-mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

	--zeile: calc(26rem / 16);
	--halbe-zeile: calc(13rem / 16);

	--rand: 100px;
	--spalten-abstand: 30px;
	--max-breite: 1440px;

	--clr-text: light-dark(#1b1b1b, #fafaf7);
	--clr-text-muted: light-dark(#6e6e73, #9a9a96);
	--clr-background: light-dark(#fafaf7, #1b1b1b);
	--clr-surface: light-dark(#ffffff, #262624);
	--clr-gray-border: light-dark(rgba(0, 0, 0, 0.1), rgba(255, 255, 255, 0.1));
	--clr-gray-bg: light-dark(rgba(0, 0, 0, 0.05), rgba(255, 255, 255, 0.06));
	--clr-stripe: light-dark(rgba(0, 0, 0, 0.025), rgba(255, 255, 255, 0.04));
	--clr-primary: light-dark(rgb(0, 145, 0), rgb(72, 196, 88));
	--clr-primary-accent: light-dark(rgb(0, 100, 0), rgb(120, 214, 132));
	--clr-primary-light: light-dark(rgba(0, 145, 0, 0.14), rgba(72, 196, 88, 0.16));
	--clr-on-primary: light-dark(#ffffff, #1b1b1b);
	--clr-error: #ff263d;
	--clr-error-light: rgba(255, 38, 61, 0.14);
	--clr-switch-off: light-dark(rgba(0, 0, 0, 0.16), rgba(255, 255, 255, 0.22));

	--radius: 2px;
	--radius-pill: 999px;
	--feld-hoehe: 44px;
}

:root[data-theme="light"] { color-scheme: light; }
:root[data-theme="dark"]  { color-scheme: dark; }

@media (max-width: 734px) {
	:root {
		--rand: 30px;
		--spalten-abstand: 20px;
	}
}


/* 2. Grundlagen
   ========================================================================== */

*,
*::before,
*::after {
	box-sizing: border-box;
}

html {
	-webkit-text-size-adjust: 100%;
	text-size-adjust: 100%;
}

body {
	margin: 0;
	font-family: var(--schrift);
	font-size: 1rem;
	line-height: var(--zeile);
	font-weight: 300;
	color: var(--clr-text);
	background: var(--clr-background);
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
	text-rendering: optimizeLegibility;
	overflow-wrap: break-word;
}

hr {
	height: 0;
	margin: var(--zeile) 0;
	border: 0;
	border-top: 1px solid var(--clr-gray-border);
}

::selection {
	background: var(--clr-primary-light);
}


/* 3. Raster
   ========================================================================== */

/*
 * <div class="container">
 *   <div class="row">
 *     <div class="eight columns">…</div>
 *     <div class="four columns">…</div>
 *   </div>
 * </div>
 * Eigene Grids immer mit minmax(0, …) und min-width: 0 an den Kindern,
 * sonst drückt breiter Inhalt die Seite mobil über den Bildschirm.
 */
.container {
	width: 100%;
	max-width: calc(var(--max-breite) + 2 * var(--rand));
	margin: 0 auto;
	padding: 0 var(--rand);
}

.row {
	display: grid;
	grid-template-columns: repeat(12, minmax(0, 1fr));
	column-gap: var(--spalten-abstand);
}

.row > .column,
.row > .columns {
	grid-column: 1 / -1;
	min-width: 0;
}

@media (min-width: 735px) {
	.one.column,
	.one.columns     { grid-column: span 1; }
	.two.columns     { grid-column: span 2; }
	.three.columns   { grid-column: span 3; }
	.four.columns    { grid-column: span 4; }
	.five.columns    { grid-column: span 5; }
	.six.columns     { grid-column: span 6; }
	.seven.columns   { grid-column: span 7; }
	.eight.columns   { grid-column: span 8; }
	.nine.columns    { grid-column: span 9; }
	.ten.columns     { grid-column: span 10; }
	.eleven.columns  { grid-column: span 11; }
	.twelve.columns  { grid-column: span 12; }

	.one-third.column  { grid-column: span 4; }
	.two-thirds.column { grid-column: span 8; }
	.one-half.column   { grid-column: span 6; }
}


/* 4. Typografie
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
	margin: 0;
	font-weight: 700;
	letter-spacing: -0.01em;
	text-wrap: balance;
}

h1 {
	font-size: calc(34rem / 16);
	line-height: calc(39rem / 16);
	margin-bottom: var(--halbe-zeile);
	font-weight: 800;
	letter-spacing: -0.02em;
}

h2 {
	font-size: calc(28rem / 16);
	line-height: calc(32.5rem / 16);
	margin-top: calc(32.5rem / 16);
	margin-bottom: var(--halbe-zeile);
}

h3 {
	font-size: calc(22rem / 16);
	line-height: var(--zeile);
	margin-top: calc(39rem / 16);
	margin-bottom: var(--halbe-zeile);
}

h4, h5, h6 {
	font-size: calc(20rem / 16);
	line-height: var(--zeile);
	margin-top: calc(39rem / 16);
	margin-bottom: var(--halbe-zeile);
	font-weight: 600;
	letter-spacing: 0;
}

:is(h1, h2, h3, h4, h5, h6):first-child {
	margin-top: 0;
}

p {
	margin: 0 0 var(--zeile);
	text-wrap: pretty;
}

p,
ul,
ol,
dl,
blockquote {
	max-width: 36em;
}

.lead {
	font-size: calc(20rem / 16);
	line-height: var(--zeile);
	color: var(--clr-text-muted);
}

small,
figcaption,
.klein {
	font-size: calc(13rem / 16);
	line-height: calc(20rem / 16);
}

.versal {
	font-size: calc(12rem / 16);
	line-height: calc(20rem / 16);
	font-weight: 600;
	letter-spacing: 0.1em;
	text-transform: uppercase;
}

figcaption {
	display: block;
	margin-top: calc(6rem / 16);
	color: var(--clr-text-muted);
}

strong, b {
	font-weight: 600;
}

:lang(de) q {
	quotes: "\201E" "\201C" "\201A" "\2018";
}

blockquote {
	position: relative;
	margin: 0 0 var(--zeile);
	padding-left: calc(44rem / 16);
}

blockquote::before {
	content: "\201C";
	position: absolute;
	left: 0;
	top: -0.08em;
	font-size: calc(68rem / 16);
	font-weight: 700;
	line-height: 1;
	color: var(--clr-primary);
}

blockquote p {
	font-size: calc(22rem / 16);
	line-height: calc(32.5rem / 16);
	font-style: italic;
}

blockquote p:last-of-type {
	margin-bottom: 0;
}

blockquote cite {
	display: block;
	margin-top: calc(4rem / 16);
	font-size: 1rem;
	line-height: var(--zeile);
	font-style: normal;
	font-variant-caps: all-small-caps;
	letter-spacing: 0.06em;
	color: var(--clr-text-muted);
}


/* 5. Links
   ========================================================================== */

a {
	color: var(--clr-text);
	text-decoration: underline;
	text-decoration-thickness: 1px;
	text-underline-offset: 0.18em;
	text-decoration-skip-ink: auto;
	transition: color 0.15s ease;
}

a:hover {
	color: var(--clr-primary);
}

:focus-visible {
	outline: 2px solid var(--clr-primary);
	outline-offset: 2px;
}


/* 6. Buttons und Pills
   ==========================================================================

   .button          grüner Rahmen
   .button-primary  grün gefüllt
   .button-neutral  Rahmen in Textfarbe */

.button,
button,
input[type="submit"],
input[type="reset"],
input[type="button"] {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: 0.5em;
	min-height: var(--feld-hoehe);
	margin: 0 calc(6rem / 16) var(--halbe-zeile) 0;
	padding: 0 calc(20rem / 16);
	font: inherit;
	font-weight: 500;
	line-height: 1.2;
	color: var(--clr-primary);
	text-align: center;
	text-decoration: none;
	white-space: nowrap;
	background: transparent;
	border: 1px solid var(--clr-primary);
	border-radius: var(--radius);
	cursor: pointer;
	-webkit-appearance: none;
	appearance: none;
	transition: color 0.15s ease, background-color 0.15s ease, border-color 0.15s ease, gap 0.2s ease;
}

.button:hover,
button:hover,
input[type="submit"]:hover,
input[type="reset"]:hover,
input[type="button"]:hover {
	color: var(--clr-on-primary);
	text-decoration: none;
	background: var(--clr-primary);
}

.button-primary,
.button-primary:is(button, input) {
	color: var(--clr-on-primary);
	background: var(--clr-primary);
	border-color: var(--clr-primary);
}

.button-primary:hover,
.button-primary:is(button, input):hover {
	color: var(--clr-on-primary);
	background: var(--clr-primary-accent);
	border-color: var(--clr-primary-accent);
}

.button-neutral,
.button-neutral:is(button, input) {
	color: var(--clr-text);
	background: transparent;
	border-color: var(--clr-text);
}

.button-neutral:hover,
.button-neutral:is(button, input):hover {
	color: var(--clr-background);
	background: var(--clr-text);
	border-color: var(--clr-text);
}

.button-pfeil::before {
	content: "";
	flex: none;
	width: 8px;
	height: 14px;
	background: currentColor;
	-webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 14'%3E%3Cpath d='m1 1 6 6-6 6' fill='none' stroke='%23000' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat center / contain;
	mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 14'%3E%3Cpath d='m1 1 6 6-6 6' fill='none' stroke='%23000' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat center / contain;
	transition: transform 0.2s ease;
}

.button-pfeil {
	justify-content: flex-start;
	padding-right: calc(20rem / 16 + 0.3em);
	transition: color 0.15s ease, background-color 0.15s ease, border-color 0.15s ease, gap 0.2s ease, padding 0.2s ease;
}

.button-pfeil:hover {
	gap: 0.8em;
	padding-right: calc(20rem / 16);
}

.button-pfeil:hover::before {
	transform: translateX(0.15em);
}

.button-klein {
	min-height: 32px;
	padding: 0 calc(12rem / 16);
	font-size: calc(13rem / 16);
}

.button-gross {
	min-height: 52px;
	padding: 0 calc(28rem / 16);
	font-size: calc(20rem / 16);
}

/* <button class="pill" aria-pressed="true">Alle</button> */
.pill,
.pill:is(button, a) {
	display: inline-flex;
	align-items: center;
	min-height: 32px;
	margin: 0;
	padding: 0 calc(12rem / 16);
	font: inherit;
	font-size: calc(14rem / 16);
	font-weight: 500;
	color: var(--clr-text);
	text-decoration: none;
	white-space: nowrap;
	background: none;
	border: 1px solid currentColor;
	border-radius: var(--radius-pill);
	cursor: pointer;
}

.pill:hover {
	color: var(--clr-primary);
	background: none;
}

.pill:is([aria-pressed="true"], [aria-selected="true"], [aria-current]) {
	color: var(--clr-background);
	background: var(--clr-text);
	border-color: var(--clr-text);
}

@media (prefers-reduced-motion: reduce) {
	.button-pfeil,
	.button-pfeil::before {
		transition: none;
	}
}


/* 7. Formulare
   ========================================================================== */

input[type="email"],
input[type="number"],
input[type="search"],
input[type="text"],
input[type="tel"],
input[type="url"],
input[type="password"],
input[type="date"],
textarea,
select {
	display: block;
	width: 100%;
	min-height: var(--feld-hoehe);
	margin: 0 0 var(--zeile);
	padding: calc(8rem / 16) calc(12rem / 16);
	font: inherit;
	color: var(--clr-text);
	background: transparent;
	border: 1px solid var(--clr-text-muted);
	border-radius: var(--radius);
	-webkit-appearance: none;
	appearance: none;
}

@media (min-width: 735px) {
	:where(input[type="email"], input[type="number"], input[type="search"], input[type="text"],
	input[type="tel"], input[type="url"], input[type="password"], input[type="date"], textarea, select) {
		max-width: min(calc(100% - 100px), 32em);
	}
}

/* <input type="text" class="feld-linie"> */
:is(input, textarea, select).feld-linie {
	padding-left: 0;
	padding-right: 0;
	border-width: 0 0 1px;
	border-color: currentColor;
	border-radius: 0;
}

:is(input, textarea, select).feld-linie:focus {
	outline: none;
	border-bottom-color: var(--clr-primary);
	box-shadow: 0 1px 0 var(--clr-primary);
}

textarea {
	min-height: calc(6 * var(--zeile));
	resize: vertical;
}

select {
	padding-right: calc(36rem / 16);
	background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='m1 1 5 5 5-5' fill='none' stroke='%236e6e73' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
	background-repeat: no-repeat;
	background-position: right calc(14rem / 16) center;
}

input:focus,
textarea:focus,
select:focus {
	border-color: var(--clr-text);
	outline: 1px solid var(--clr-text);
	outline-offset: 0;
}

/*
 * <input type="email" required>
 * <p class="feld-fehler">Bitte eine gültige E-Mail-Adresse eingeben.</p>
 */
input:user-invalid,
textarea:user-invalid,
select:user-invalid {
	margin-bottom: calc(6rem / 16);
	border-color: var(--clr-error);
}

input:user-invalid:focus,
textarea:user-invalid:focus,
select:user-invalid:focus {
	outline-color: var(--clr-error);
}

.feld-fehler {
	display: none;
	margin: 0 0 var(--zeile);
	font-size: calc(13rem / 16);
	line-height: calc(20rem / 16);
	font-weight: 500;
	color: var(--clr-error);
}

:user-invalid + .feld-fehler {
	display: block;
}

/*
 * <p class="meldung meldung-erfolg" role="status">…</p>
 * <p class="meldung meldung-fehler" role="alert">…</p>
 * <p class="meldung meldung-hinweis">…</p>
 */
.meldung {
	display: flex;
	align-items: baseline;
	gap: 0.6em;
	margin: 0 0 var(--halbe-zeile);
	padding: calc(10rem / 16) calc(14rem / 16);
	border-radius: var(--radius);
}

.meldung-erfolg { background: var(--clr-primary-light); }
.meldung-fehler { background: var(--clr-error-light); }
.meldung-hinweis { background: var(--clr-gray-bg); }

.meldung::before {
	content: "";
	flex: none;
	width: 1rem;
	font-weight: 700;
	text-align: center;
}

.meldung-erfolg::before {
	content: "\2713";
	color: var(--clr-primary);
}

.meldung-fehler::before {
	content: "\00D7";
	font-size: 1.3em;
	line-height: 0;
	color: var(--clr-error);
}

.meldung-hinweis {
	color: var(--clr-text-muted);
}

::placeholder {
	color: var(--clr-text-muted);
	opacity: 1;
}

label,
legend {
	display: block;
	margin-bottom: calc(6rem / 16);
	font-weight: 600;
}

fieldset {
	margin: 0 0 var(--zeile);
	padding: 0;
	border: 0;
}

input[type="radio"] {
	width: 1.1em;
	height: 1.1em;
	margin: 0 0.5em 0 0;
	vertical-align: -0.15em;
	accent-color: var(--clr-primary);
}

/*
 * Segment: Einzelauswahl, grün; .segment-neutral in Textfarbe
 * <div class="segment"><label><input type="radio" name="a" checked>Eins</label><label><input type="radio" name="a">Zwei</label></div>
 * oder <div class="segment"><button aria-pressed="true">Eins</button>…</div>
 */

.segment {
	--segment: var(--clr-primary);
	--segment-auf: var(--clr-on-primary);
	display: inline-flex;
	max-width: 100%;
	color: var(--segment);
	border: 1px solid var(--segment);
	border-radius: var(--radius);
	overflow: hidden;
}

.segment-neutral {
	--segment: var(--clr-text);
	--segment-auf: var(--clr-background);
}

.segment > :is(label, button) {
	position: relative;
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: 0.4em;
	min-height: 32px;
	margin: 0;
	padding: 0 0.85rem;
	font: inherit;
	font-size: 0.875rem;
	font-weight: 500;
	line-height: 1.2;
	color: inherit;
	white-space: nowrap;
	background: none;
	border: 0;
	border-radius: 0;
	cursor: pointer;
	transition: color 0.15s ease, background-color 0.15s ease;
}

.segment > :is(label, button) + :is(label, button) {
	border-left: 1px solid var(--segment);
}

.segment input {
	position: absolute;
	inset: 0;
	width: 100%;
	height: 100%;
	margin: 0;
	opacity: 0;
	cursor: pointer;
}

.segment > :hover {
	background: var(--clr-gray-bg);
}

.segment > :is(label:has(input:checked), [aria-checked="true"], [aria-pressed="true"]) {
	color: var(--segment-auf);
	background: var(--segment);
}

.segment > :is(label:has(input:focus-visible), button:focus-visible) {
	outline: 2px solid var(--clr-primary);
	outline-offset: -4px;
}


/* Regler: <input type="range" class="regler"> */

.regler {
	width: 7.5rem;
	height: 1rem;
	margin: 0;
	color: inherit;
	background: none;
	cursor: pointer;
	-webkit-appearance: none;
	appearance: none;
}

.regler::-webkit-slider-runnable-track { height: 1px; background: currentColor; }
.regler::-moz-range-track { height: 1px; background: currentColor; }
.regler::-moz-range-progress { height: 1px; background: currentColor; }

.regler::-webkit-slider-thumb {
	width: 0.8rem;
	height: 0.8rem;
	margin-top: calc(-0.4rem + 0.5px);
	border: 0;
	border-radius: 50%;
	background: var(--clr-text);
	-webkit-appearance: none;
	appearance: none;
}

.regler::-moz-range-thumb {
	width: 0.8rem;
	height: 0.8rem;
	border: 0;
	border-radius: 50%;
	background: var(--clr-text);
}

.regler:hover::-webkit-slider-thumb { background: var(--clr-primary); }
.regler:hover::-moz-range-thumb { background: var(--clr-primary); }

.regler:focus-visible {
	outline: 2px solid var(--clr-primary);
	outline-offset: 4px;
}


/* Checkbox als Schalter */
input[type="checkbox"] {
	--knopf: calc(31rem / 16);
	flex: none;
	width: calc(51rem / 16);
	height: var(--knopf);
	margin: 0 0.6em 0 0;
	vertical-align: middle;
	cursor: pointer;
	border-radius: var(--knopf);
	background:
		radial-gradient(circle, #fff 0 calc(var(--knopf) / 2 - 2px), transparent calc(var(--knopf) / 2 - 1.5px))
		left center / var(--knopf) var(--knopf) no-repeat,
		var(--clr-switch-off);
	-webkit-appearance: none;
	appearance: none;
	transition: background-position 0.2s ease, background-color 0.2s ease;
}

input[type="checkbox"]:checked {
	background-color: var(--clr-primary);
	background-position: right center, 0 0;
}

input[type="checkbox"]:focus {
	outline: none;
}

input[type="checkbox"]:focus-visible {
	outline: 2px solid var(--clr-primary);
	outline-offset: 2px;
}

input[type="checkbox"]:disabled {
	opacity: 0.4;
	cursor: default;
}

@media (prefers-reduced-motion: reduce) {
	input[type="checkbox"] {
		transition: none;
	}
}

label > .label-body {
	display: inline-block;
	font-weight: 400;
}


/* 8. Listen
   ========================================================================== */

ul,
ol {
	--einzug: 1.25em;
	margin: 0 0 var(--zeile);
	padding-left: var(--einzug);
	list-style: none;
}

ul ul,
ul ol,
ol ol,
ol ul {
	margin: 0;
}

ul > li,
ol > li {
	position: relative;
}

ul > li::before {
	content: "";
	position: absolute;
	left: calc(-1 * var(--einzug));
	top: calc(var(--zeile) / 2 - 0.2em);
	width: 0.36em;
	height: 0.36em;
	background: currentColor;
}

ol {
	counter-reset: punkt;
}

ol > li {
	counter-increment: punkt;
}

ol > li::before {
	content: counter(punkt) ".";
	position: absolute;
	left: calc(-1 * var(--einzug));
	font-variant-numeric: tabular-nums;
}

dl {
	margin: 0 0 var(--zeile);
}

dt {
	font-weight: 600;
}

dd {
	margin: 0 0 var(--halbe-zeile);
}


/* 9. Code
   ========================================================================== */

code,
kbd,
pre {
	font-family: var(--schrift-mono);
	font-size: 0.88em;
}

code {
	padding: 0;
	background: none;
}

pre {
	margin: 0 0 var(--zeile);
	padding: 0 0 0 calc(16rem / 16);
	line-height: 1.55;
	overflow-x: auto;
	background: none;
	border-left: 1px solid var(--clr-text);
}

pre > code {
	padding: 0;
	font-size: inherit;
	background: none;
	white-space: pre;
}


/* 10. Tabellen und Akkordeon
   ========================================================================== */

table {
	width: 100%;
	margin: 0 0 var(--zeile);
	border-collapse: collapse;
	font-variant-numeric: tabular-nums;
}

th,
td {
	padding: calc(8rem / 16) calc(12rem / 16);
	text-align: left;
	border-bottom: 1px solid var(--clr-gray-border);
}

th:first-child,
td:first-child {
	padding-left: calc(8rem / 16);
}

th:last-child,
td:last-child {
	padding-right: calc(8rem / 16);
}

tbody tr:nth-child(even) {
	background: var(--clr-stripe);
}

th {
	font-weight: 600;
}

/* Zahlenspalte: <td class="zahl"> */
:is(th, td).zahl {
	text-align: right;
}

/* Linien trennen Zeilen, unter der letzten steht keine */
tbody tr:last-child > :is(td, th) {
	border-bottom: 0;
}

/* Breite Tabelle scrollt in sich, erste Spalte bleibt stehen:
   <div class="tabelle-scroll"><table>…</table></div> */
.tabelle-scroll {
	max-width: 100%;
	overflow-x: auto;
	overscroll-behavior-x: contain;
	-webkit-overflow-scrolling: touch;
	margin: 0 0 var(--zeile);
}

.tabelle-scroll table {
	margin: 0;
}

.tabelle-scroll :is(th, td) {
	white-space: nowrap;
}

.tabelle-scroll :is(th, td):first-child {
	position: sticky;
	left: 0;
	z-index: 1;
	background: var(--abschnitt, var(--clr-background));
}

.tabelle-scroll tbody tr:nth-child(even) > :first-child {
	background: color-mix(in srgb, var(--clr-text) 2.5%, var(--abschnitt, var(--clr-background)));
}

/* <details><summary>Frage</summary><p>Antwort</p></details> */
details {
	max-width: 36em;
	border-bottom: 1px solid var(--clr-gray-border);
}

details:not(details + details) {
	border-top: 1px solid var(--clr-gray-border);
}

summary {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: var(--spalten-abstand);
	min-height: 52px;
	cursor: pointer;
	list-style: none;
}

summary::-webkit-details-marker {
	display: none;
}

summary::after {
	content: "";
	flex: none;
	width: 14px;
	height: 8px;
	background: var(--clr-text-muted);
	-webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 8'%3E%3Cpath d='m1 1 6 6 6-6' fill='none' stroke='%23000' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat center / contain;
	mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 8'%3E%3Cpath d='m1 1 6 6 6-6' fill='none' stroke='%23000' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat center / contain;
	transition: transform 0.25s ease;
}

details[open] > summary::after {
	transform: rotate(180deg);
}

details > :not(summary) {
	margin-top: 0;
}

details[open] > :not(summary) {
	animation: aufklappen 0.25s ease;
}

details > :last-child:not(summary) {
	margin-bottom: var(--halbe-zeile);
}

@keyframes aufklappen {
	from { opacity: 0; transform: translateY(-4px); }
	to   { opacity: 1; transform: none; }
}

@media (prefers-reduced-motion: reduce) {
	summary::after { transition: none; }
	details[open] > :not(summary) { animation: none; }
}


/* 11. Bilder und Abschnitte
   ========================================================================== */

img,
svg,
video {
	max-width: 100%;
	height: auto;
}

figure {
	margin: 0 0 var(--zeile);
}

figure img {
	display: block;
	width: 100%;
	border-radius: var(--radius);
}

section {
	padding: calc(4 * var(--zeile)) 0;
}

@media (max-width: 734px) {
	section {
		padding: calc(2.5 * var(--zeile)) 0;
	}
}


/* 12. Seitenkopf, Seitenfuß, Hell/Dunkel, Nach oben, Toast
   ========================================================================== */

.seitenkopf {
	padding: var(--zeile) 0;
}

.seitenkopf .container {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: var(--spalten-abstand);
}

.seitenkopf-name {
	font-weight: 600;
	color: var(--clr-text);
	text-decoration: none;
}

.seitenkopf-name:hover {
	color: var(--clr-text);
	text-decoration: none;
}

.seitenfuss {
	padding: var(--zeile) 0;
	font-size: calc(13rem / 16);
	line-height: calc(20rem / 16);
	color: var(--clr-text-muted);
	border-top: 1px solid var(--clr-gray-border);
}

.icon-knopf,
.theme-schalter {
	display: inline-flex;
	width: var(--feld-hoehe);
	min-width: var(--feld-hoehe);
	margin: 0;
	padding: 0;
	color: var(--clr-text);
	background: none;
	border: 0;
}

.icon-knopf:hover,
.theme-schalter:hover {
	color: var(--clr-text);
	background: none;
	opacity: 0.6;
}

.theme-schalter svg {
	width: 22px;
	height: 22px;
}

.icon-knopf {
	align-items: center;
	justify-content: center;
	height: var(--feld-hoehe);
	cursor: pointer;
}

.icon-knopf .icon {
	width: 20px;
	height: 20px;
}

/* Variante Kontrast: <button class="theme-schalter theme-schalter-kontrast"> mit Quadrat-Symbol */
.theme-schalter-kontrast svg {
	width: 16px;
	height: 16px;
}

.theme-schalter .symbol-sonne,
:root[data-theme="dark"] .theme-schalter .symbol-mond {
	display: none;
}

:root[data-theme="dark"] .theme-schalter .symbol-sonne {
	display: block;
}

@media (prefers-color-scheme: dark) {
	:root:not([data-theme="light"]) .theme-schalter .symbol-mond { display: none; }
	:root:not([data-theme="light"]) .theme-schalter .symbol-sonne { display: block; }
}

.nach-oben {
	position: fixed;
	right: 24px;
	bottom: 43px;
	z-index: 100;
	display: flex;
	align-items: center;
	justify-content: center;
	width: var(--feld-hoehe);
	height: var(--feld-hoehe);
	color: var(--clr-text);
	opacity: 0;
	pointer-events: none;
	transition: opacity 0.2s ease;
}

.nach-oben.sichtbar {
	opacity: 1;
	pointer-events: auto;
}

.nach-oben:hover {
	color: var(--clr-text);
	opacity: 0.6;
}

.nach-oben svg {
	width: 26px;
	height: 26px;
}

@media (max-width: 734px) {
	.nach-oben {
		right: 12px;
		bottom: 12px;
	}

	.nach-oben.am-ende {
		opacity: 0;
		pointer-events: none;
	}
}

/*
 * Glas-Panel: das Panel selbst ist aus Glas, der Hintergrund wird nur abgedunkelt
 * <div class="sheet"><div class="backdrop"></div><section class="panel">…</section></div>
 * <dialog class="panel">…</dialog>
 * Fenster, mobil als Blatt von unten: <dialog class="panel blatt">…</dialog>
 */
.backdrop {
	position: absolute;
	inset: 0;
}

.backdrop,
dialog.panel::backdrop {
	background: rgba(0, 0, 0, 0.28);
}

.panel {
	background: var(--clr-surface);
	border: 1px solid var(--clr-gray-border);
	border-radius: var(--radius);
}

@supports ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
	.panel {
		background: color-mix(in srgb, var(--clr-surface) 55%, transparent);
		-webkit-backdrop-filter: blur(28px) saturate(1.6);
		backdrop-filter: blur(28px) saturate(1.6);
	}
}

dialog.blatt {
	width: min(30rem, calc(100% - 32px));
	max-height: calc(100dvh - 48px);
	padding: 24px;
	color: var(--clr-text);
	overflow-y: auto;
	overscroll-behavior: contain;
}

@media (max-width: 560px) {
	dialog.blatt {
		width: 100%;
		max-width: none;
		margin: auto 0 0;
		padding: 20px 16px calc(20px + env(safe-area-inset-bottom));
		border-width: 1px 0 0;
		border-radius: 0;
		max-height: calc(100dvh - 32px);
	}
}

@media (prefers-reduced-motion: no-preference) {
	dialog.blatt[open] { animation: panel-auf .28s cubic-bezier(.2, .9, .25, 1); }
	dialog.panel[open]::backdrop { animation: blende-auf .2s ease-out; }
}

@media (prefers-reduced-motion: no-preference) and (max-width: 560px) {
	dialog.blatt[open] { animation: blatt-auf .34s cubic-bezier(.2, .9, .25, 1); }
}

@keyframes panel-auf { from { opacity: 0; transform: translateY(8px) scale(.985); } }
@keyframes blatt-auf { from { transform: translateY(100%); } }
@keyframes blende-auf { from { opacity: 0; } }

/* <div class="toast" role="status">Kopiert</div>, sichtbar mit .sichtbar; .toast-oben für oben */
.toast {
	position: fixed;
	left: 50%;
	bottom: 24px;
	z-index: 200;
	max-width: calc(100% - 2 * var(--rand));
	padding: calc(10rem / 16) calc(16rem / 16);
	font-size: calc(15rem / 16);
	line-height: calc(20rem / 16);
	font-weight: 500;
	color: var(--clr-background);
	background: var(--clr-text);
	border-radius: var(--radius);
	opacity: 0;
	pointer-events: none;
	transform: translate(-50%, 8px);
	transition: opacity 0.2s ease, transform 0.2s ease;
}

.toast.sichtbar {
	opacity: 1;
	pointer-events: auto;
	transform: translate(-50%, 0);
}

.toast-oben {
	top: calc(16px + env(safe-area-inset-top));
	bottom: auto;
	transform: translate(-50%, -8px);
}

.toast-oben.sichtbar {
	transform: translate(-50%, 0);
}

.toast-erfolg {
	color: var(--clr-on-primary);
	background: var(--clr-primary);
}

.toast-fehler {
	color: #ffffff;
	background: var(--clr-error);
}

@media (prefers-reduced-motion: reduce) {
	.toast { transition: none; }
}

@media (prefers-reduced-motion: no-preference) {
	html {
		scroll-behavior: smooth;
	}
}


/* 13. Symbole und Icons
   ========================================================================== */

/*
 * Symbole: Form klappt beim Drüberfahren zu Inhalt auf und schiebt die folgenden weg
 * <span class="symbole">
 *   <span class="symbol-aktion"><span class="symbol" aria-hidden="true"></span><span class="symbol-inhalt"><a href="#">Teilen</a></span></span>
 *   <span class="symbol-aktion symbol-kreis">…</span>
 *   <span class="symbol-aktion symbol-dreieck">…</span>
 * </span>
 */

.symbole {
	display: inline-flex;
	align-items: center;
	gap: 8px;
}

.symbol-aktion {
	display: inline-flex;
	align-items: center;
}

.symbol {
	flex: 0 0 14px;
	width: 14px;
	height: 14px;
	background: currentColor;
	transition: flex-basis 0.2s ease, width 0.2s ease, opacity 0.2s ease;
}

.symbol-kreis > .symbol { border-radius: 50%; }
.symbol-dreieck > .symbol { clip-path: polygon(50% 0, 100% 100%, 0 100%); }

.symbol-inhalt {
	display: inline-flex;
	align-items: center;
	flex-shrink: 0;
	gap: 6px;
	max-width: 0;
	overflow: hidden;
	white-space: nowrap;
	opacity: 0;
	transition: max-width 0.25s ease, opacity 0.2s ease;
}

.symbol-aktion:is(:hover, :focus-within) > .symbol {
	flex-basis: 0;
	width: 0;
	opacity: 0;
}

.symbol-aktion:is(:hover, :focus-within) > .symbol-inhalt {
	max-width: 220px;
	opacity: 1;
	color: var(--clr-primary);
}

.symbol-inhalt a {
	display: inline-flex;
	align-items: center;
	gap: 4px;
	color: inherit;
	text-decoration: none;
}

.symbol-inhalt a:focus-visible {
	outline-offset: -2px;
}


/* Icons: Linien-SVG in Textgröße, <svg class="icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6"> */

.icon {
	width: 1em;
	height: 1em;
	vertical-align: -0.125em;
}

@media (prefers-reduced-motion: reduce) {
	.symbol,
	.symbol-inhalt { transition: none; }
}

/* 14. Hilfsklassen
   ========================================================================== */

.u-full-width     { width: 100%; max-width: none; }
.u-max-full-width { max-width: 100%; }
.u-pull-right     { float: right; }
.u-pull-left      { float: left; }
.u-cf::after      { content: ""; display: table; clear: both; }
.u-muted          { color: var(--clr-text-muted); }

.u-visually-hidden {
	position: absolute;
	width: 1px;
	height: 1px;
	overflow: hidden;
	clip: rect(0 0 0 0);
	white-space: nowrap;
}