/* -- OTP Input -------------------------------------------------- */
/* One real <input> under a row of slots. The input keeps every native */
/* behaviour (paste, one-time-code autofill, selection, form value);   */
/* the slots are a mirror of its value.                                */

@layer components {
  .otp-input {
    --otp-input-slot-size: 2.75rem;

    position: relative;
    display: inline-flex;
    width: max-content;

    /* The field covers the slots so clicks, drags and taps land on the real
       control. Its own text is invisible — the slots do the drawing — but it
       stays a normal input to the browser and to assistive technology. */
    & > input {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
      margin: 0;
      padding: 0;
      border: 0;
      background: transparent;
      color: transparent;
      caret-color: transparent;
      font-size: 1rem; /* >=16px keeps iOS from zooming on focus */
      text-align: center;
      outline: none;
      cursor: text;

      /* the selection highlight would show through the transparent text */
      &::selection {
        background: transparent;
      }

      &:disabled {
        cursor: not-allowed;
      }
    }
  }

  .otp-input-slots {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    pointer-events: none; /* the field beneath owns every pointer event */
  }

  .otp-input-slot {
    /* --otp-input-slot-size is the outer size, border included */
    box-sizing: border-box;
    display: grid;
    place-items: center;
    width: var(--otp-input-slot-size);
    height: var(--otp-input-slot-size);
    border: 1px solid var(--input);
    border-radius: var(--radius-md);
    background: var(--background);
    color: var(--foreground);
    font-family: var(--font-mono);
    font-size: 1.125rem;
    font-variant-numeric: tabular-nums;
    transition: border-color 150ms, box-shadow 150ms;

    &[data-filled] {
      border-color: var(--ring);
    }

    /* the slot the caret sits in — the field's own caret is hidden */
    &[data-active],
    &[data-caret] {
      border-color: var(--ring);
      box-shadow: 0 0 0 3px color-mix(in oklch, var(--ring) 25%, transparent);
    }

    &[data-caret]::after {
      content: "";
      width: 1px;
      height: 1.125rem;
      background: var(--foreground);
      animation: otp-input-caret 1s steps(2, start) infinite;
    }
  }

  /* Gap between groups, e.g. 3-3 for a six digit code. */
  .otp-input-separator {
    width: 0.75rem;
    height: 1px;
    background: var(--border);
    flex-shrink: 0;
  }

  /* -- Invalid ------------------------------------------------ */
  .otp-input[data-invalid] .otp-input-slot {
    border-color: var(--destructive);

    &[data-active],
    &[data-caret] {
      box-shadow: 0 0 0 3px color-mix(in oklch, var(--destructive) 25%, transparent);
    }
  }

  /* -- Disabled ----------------------------------------------- */
  /* Deliberately not a blanket opacity fade: the digits must stay readable,
     so only the surface dims while the border and text keep their contrast. */
  .otp-input:has(> input:disabled) .otp-input-slot {
    background: var(--muted);
    color: var(--muted-foreground);
    border-color: var(--border);
  }

  @keyframes otp-input-caret {
    0% { opacity: 1; }
    100% { opacity: 0; }
  }
}

@media (prefers-reduced-motion: reduce) {
  @layer components {
    .otp-input,
    .otp-input *,
    .otp-input::before,
    .otp-input::after,
    .otp-input *::before,
    .otp-input *::after,
    .otp-input-slot,
    .otp-input-slot::before,
    .otp-input-slot::after {
      transition: none;
      animation: none;
    }
  }
}

@media (prefers-contrast: more) {
  @layer components {
    .otp-input-slot {
      border-width: 2px;
      border-color: var(--foreground);
    }

    .otp-input[data-invalid] .otp-input-slot {
      border-color: var(--destructive);
    }
  }
}

@media (forced-colors: active) {
  @layer components {
    .otp-input-slot {
      border-color: ButtonText;
      color: ButtonText;

      &[data-active],
      &[data-caret] {
        border-color: Highlight;
      }
    }

    .otp-input[data-invalid] .otp-input-slot {
      border-color: LinkText;
    }

    .otp-input:has(> input:disabled) .otp-input-slot {
      border-color: GrayText;
      color: GrayText;
    }
  }
}