/**
 * @file src/knopf.css
 * @description ALs-COMP-Knopf — primary button anatomy (six decisions):
 *   1 size 48/24 · 2 label 17px semibold · 3 label >= 4.5:1, edge >= 3:1
 *   4 depth: lit top edge, shadow falls down · 5 pill radius = height / 2, one icon 10px from label
 *   6 motion: feedback 100ms, done 300ms (hover rim, press, spinner, check).
 *   Layers share one grid cell, so the width never jumps between states.
 *   Works without JS as a plain styled button; knopf.js adds the states.
 */

/* ---------------------------------------------------------------------------
   Tokens — ALs-Petrol palette; override on .als-knopf or any ancestor
--------------------------------------------------------------------------- */
.als-knopf {
  --knopf-hoehe:        48px;
  --knopf-pad:          24px;
  --knopf-schrift:      17px;
  --knopf-luecke:       10px;       /* icon to label */
  --knopf-icon:         20px;

  --knopf-flaeche:      #26B896;    /* teal fill */
  --knopf-flaeche-hover:#2FCBA6;
  --knopf-text:         #0F1E2E;    /* dark label on teal: ~6.8:1 (white would be ~2.4:1) */
  --knopf-licht:        rgb(255 255 255 / .42);  /* lit top edge */
  --knopf-rand:         #7BE3C9;    /* rim lit on hover */
  --knopf-fehler:       #FF6B6B;
  --knopf-fokus:        #E6EEF5;
  --knopf-schatten:     0 1px 2px rgb(0 0 0 / .40), 0 4px 10px -4px rgb(0 0 0 / .55);
  --knopf-schatten-tief:0 1px 1px rgb(0 0 0 / .45);

  --knopf-rueckmeldung: 100ms;      /* hover / press feedback */
  --knopf-dauer:        300ms;      /* state change done */
  --knopf-ease:         cubic-bezier(.16, 1, .3, 1);
}

@media (prefers-reduced-motion: reduce) {
  .als-knopf { --knopf-rueckmeldung: 0ms; --knopf-dauer: 0ms; }
}

/* ---------------------------------------------------------------------------
   Base
--------------------------------------------------------------------------- */
.als-knopf {
  position: relative;
  display: inline-grid;
  place-items: center;
  /* Without knopf.js, icon + label are direct children: lay them out side by side.
     With knopf.js the state layers are pinned to cell 1/1 and never create columns. */
  grid-auto-flow: column;
  column-gap: var(--knopf-luecke);
  min-height: var(--knopf-hoehe);
  padding: 0 var(--knopf-pad);
  border: 1px solid transparent;
  border-radius: calc(var(--knopf-hoehe) / 2);
  background: var(--knopf-flaeche);
  color: var(--knopf-text);
  font-family: inherit;
  font-size: var(--knopf-schrift);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: 0;
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  box-shadow: inset 0 1px 0 var(--knopf-licht), var(--knopf-schatten);
  transition:
    background-color var(--knopf-rueckmeldung) var(--knopf-ease),
    border-color     var(--knopf-rueckmeldung) var(--knopf-ease),
    box-shadow       var(--knopf-rueckmeldung) var(--knopf-ease),
    transform        var(--knopf-rueckmeldung) var(--knopf-ease);
}

/* All layers occupy the same cell: the widest one sets the width once. */
.als-knopf > .als-knopf__inhalt,
.als-knopf > .als-knopf__laeuft,
.als-knopf > .als-knopf__erledigt { grid-area: 1 / 1; }

.als-knopf__inhalt,
.als-knopf__erledigt {
  display: inline-flex;
  align-items: center;
  gap: var(--knopf-luecke);
}

.als-knopf__icon {
  width: var(--knopf-icon);
  height: var(--knopf-icon);
  flex: none;
  fill: currentColor;            /* icon always in label colour */
}

/* ---------------------------------------------------------------------------
   Interaction
--------------------------------------------------------------------------- */
@media (hover: hover) and (pointer: fine) {
  .als-knopf:hover {
    background-color: var(--knopf-flaeche-hover);
    border-color: var(--knopf-rand);
  }
}

.als-knopf:active {
  transform: scale(.97);
  box-shadow: inset 0 1px 0 var(--knopf-licht), var(--knopf-schatten-tief);
}

.als-knopf:focus-visible {
  outline: 2px solid var(--knopf-fokus);
  outline-offset: 2px;
}
.als-knopf:focus:not(:focus-visible) { outline: none; }

/* Disabled: greyscale + not-allowed, never opacity (reads as "loading"). */
.als-knopf:disabled,
.als-knopf[aria-disabled="true"] {
  filter: grayscale(1);
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

/* ---------------------------------------------------------------------------
   State layers (driven by data-zustand from knopf.js)
--------------------------------------------------------------------------- */
.als-knopf__laeuft,
.als-knopf__erledigt {
  visibility: hidden;
  opacity: 0;
}
.als-knopf__inhalt,
.als-knopf__laeuft,
.als-knopf__erledigt {
  transition:
    opacity    var(--knopf-dauer) var(--knopf-ease),
    visibility var(--knopf-dauer) var(--knopf-ease);
}

.als-knopf[data-zustand="laeuft"] .als-knopf__inhalt,
.als-knopf[data-zustand="erledigt"] .als-knopf__inhalt {
  visibility: hidden;
  opacity: 0;
}
.als-knopf[data-zustand="laeuft"] .als-knopf__laeuft,
.als-knopf[data-zustand="erledigt"] .als-knopf__erledigt {
  visibility: visible;
  opacity: 1;
}
.als-knopf[data-zustand="laeuft"],
.als-knopf[data-zustand="erledigt"] { cursor: progress; }
.als-knopf[data-zustand="erledigt"] { cursor: default; }

/* Spinner: continuous motion is the one place for linear timing. */
.als-knopf__laeuft { display: inline-grid; place-items: center; }

/* A span is inline by default and would ignore width/height — the ring collapsed to a 4px arc (0.1.0). */
.als-knopf__spinner {
  display: block;
  box-sizing: border-box;
  width: var(--knopf-icon);
  height: var(--knopf-icon);
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: als-knopf-drehen 700ms linear infinite;
}

/* Check draws in from the left via clip-path — cheap, compositor-friendly. */
.als-knopf[data-zustand="erledigt"] .als-knopf__haken {
  animation: als-knopf-haken var(--knopf-dauer) var(--knopf-ease) both;
}

/* Error: red rim + a short shake, then back to the label. */
.als-knopf[data-zustand="fehler"] {
  border-color: var(--knopf-fehler);
  box-shadow: 0 0 0 2px var(--knopf-fehler), var(--knopf-schatten);
  animation: als-knopf-schuetteln var(--knopf-dauer) var(--knopf-ease);
}

@keyframes als-knopf-drehen   { to { transform: rotate(1turn); } }
@keyframes als-knopf-haken    { from { clip-path: inset(0 100% 0 0); } to { clip-path: inset(0 0 0 0); } }
@keyframes als-knopf-schuetteln {
  25% { transform: translateX(-4px); }
  50% { transform: translateX(4px); }
  75% { transform: translateX(-2px); }
}

@media (prefers-reduced-motion: reduce) {
  /* No movement: spinner becomes a static ring, check and shake appear instantly. */
  .als-knopf__spinner,
  .als-knopf[data-zustand="erledigt"] .als-knopf__haken,
  .als-knopf[data-zustand="fehler"] { animation: none; }
  .als-knopf:active { transform: none; }
}

/* Screen-reader-only live region (no inline style — CSP safe). */
.als-knopf__status {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ---------------------------------------------------------------------------
   Secondary: same anatomy, no fill — for the one other action next to a primary
--------------------------------------------------------------------------- */
.als-knopf--sekundaer {
  --knopf-text: #E6EEF5;
  background: transparent;
  border-color: #8FA6BC;          /* edge vs #0F1E2E: ~6.6:1 */
  box-shadow: none;
}
@media (hover: hover) and (pointer: fine) {
  .als-knopf--sekundaer:hover {
    background-color: rgb(230 238 245 / .06);
    border-color: #E6EEF5;
  }
}
.als-knopf--sekundaer:active { box-shadow: none; }