/* ==========================================================================
   404 PAGE
   Full-bleed dark section. Uses the same --inverse-surface /
   --inverse-on-surface pairing as .du-privacy (_how-it-works.css) — the
   theme's existing convention for a dark, full-width section — rather
   than introducing a new dark-surface color pair. Buttons reuse
   .du-btn--inverse; the search field reuses .du-search-field with the
   --inverse modifier added in _components.css. Only the pieces with no
   existing equivalent (decorative watermark, technical error-code
   treatment, divider, secondary link) are new, scoped rules below.
   ========================================================================== */

.du-404 {
    position: relative;
    background-color: var(--inverse-surface);
    overflow: hidden;
    padding-top: var(--space-xl);
    padding-bottom: var(--space-xl);
    min-height: 70vh;
    display: flex;
    align-items: center;
}

.du-404__inner {
    position: relative;
    display: flex;
    justify-content: center;
}

/* ---- Decorative watermark ----
   Purely visual, sits behind the content, not part of the page's
   information hierarchy. */
.du-404__decorative {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    margin: 0;
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(7rem, 26vw, 15rem);
    line-height: 1;
    color: var(--inverse-on-surface);
    opacity: 0.06;
    z-index: 0;
    pointer-events: none;
    user-select: none;
}

.du-404__content {
    position: relative;
    z-index: 1;
    max-width: 640px;
    width: 100%;
    text-align: center;
}

/* ---- Error code ----
   "Technical/monospaced" per the design reference. --font-mono is the
   existing token for this (already used for financial data/scores via
   .du-text-number-display), borrowed here directly rather than reusing
   that class, since the intent (a wide-tracked status code) and size
   differ from a financial number display. */
.du-404__code {
    font-family: var(--font-mono);
    font-size: clamp(1.25rem, 3.2vw, 2rem);
    font-weight: 600;
    letter-spacing: 0.12em;
    color: var(--inverse-on-surface);
    opacity: 0.85;
    margin: 0 0 var(--space-md);
}

/* Same 32px / 2px / pill recipe already used under the eyebrow in the
   Reality Check Process and FAQ sections. */
.du-404__divider {
    display: block;
    width: 32px;
    height: 2px;
    background-color: var(--on-tertiary-container);
    border-radius: var(--radius-full);
    margin: 0 auto var(--space-lg);
}

.du-404__heading {
    font-style: italic;
    color: var(--on-primary);
    margin: 0 0 var(--space-md);
}

.du-404__description {
    color: var(--inverse-on-surface);
    opacity: 0.85;
    max-width: 48ch;
    margin: 0 auto var(--space-lg);
}

.du-404__search {
    max-width: 380px;
    margin: 0 auto var(--space-lg);
}

.du-404__actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
}

.du-404__secondary-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-sans);
    font-size: var(--label-caps-size);
    font-weight: 700;
    letter-spacing: var(--label-caps-tracking);
    text-transform: uppercase;
    color: var(--inverse-on-surface);
    text-decoration: none;
    padding: var(--space-xs);
    transition: color var(--transition-fast);
}

.du-404__secondary-link:hover,
.du-404__secondary-link:focus-visible {
    color: var(--on-primary);
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* ---- Tablet & up ---- */
@media (min-width: 768px) {
    .du-404__actions {
        flex-direction: row;
        justify-content: center;
        gap: var(--space-lg);
    }
}

/* ---- Reduced motion ----
   No animation is used on this page beyond the standard color/border
   transitions already defined on .du-btn / .du-search-field / links,
   which are simple property transitions, not motion effects — nothing
   further to disable here, but the query is included for parity with
   the rest of the theme's reduced-motion handling. */
@media (prefers-reduced-motion: reduce) {
    .du-404__secondary-link,
    .du-404__search .du-search-field__input,
    .du-404__actions .du-btn {
        transition: none;
    }
}