/* ==========================================================================
   CinderTek - Components
   Generic, reusable UI primitives and the site-wide header.
   No page or section styling here.
   ========================================================================== */

/* --------------------------------------------------------------------------
   Button
   Orange appears on interaction or for the single most important action,
   never as the default fill for every button.
   -------------------------------------------------------------------------- */

.btn {
    --btn-bg: transparent;
    --btn-text: var(--color-text);
    --btn-border: transparent;

    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-3);
    min-height: var(--control-height);
    padding: 0 var(--space-6);
    font-family: var(--font-body);
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    line-height: var(--lh-none);
    letter-spacing: 0;
    white-space: nowrap;
    color: var(--btn-text);
    background-color: var(--btn-bg);
    border: var(--border-hairline) solid var(--btn-border);
    border-radius: var(--radius-full);
    transition:
        color var(--duration-fast) var(--ease-standard),
        background-color var(--duration-fast) var(--ease-standard),
        border-color var(--duration-fast) var(--ease-standard);
}

.btn--primary {
    --btn-bg: var(--color-accent);
    --btn-text: var(--color-on-accent);
    --btn-border: var(--color-accent);
}

.btn--accent {
    --btn-bg: var(--color-accent-strong);
    --btn-text: var(--color-on-accent);
    --btn-border: var(--color-accent-strong);
}

.btn--outline {
    --btn-border: var(--color-border-strong);
}

.btn--text {
    min-height: var(--tap-target);
    padding: 0;
    border: 0;
    border-radius: 0;
}

/* Interaction states. :active gives touch feedback; :hover only applies
   where hover exists, so a tapped button never stays "hovered". */
.btn--primary:active,
.btn--accent:active {
    --btn-bg: var(--color-accent-strong);
    --btn-text: var(--color-on-accent);
    --btn-border: var(--color-accent-strong);
}

.btn--outline:active {
    --btn-border: var(--color-text-body);
}

.btn--text:active {
    --btn-text: var(--color-link);
}

@media (hover: hover) {
    .btn--primary:hover,
    .btn--accent:hover {
        --btn-bg: var(--color-accent-strong);
        --btn-text: var(--color-on-accent);
        --btn-border: var(--color-accent-strong);
    }

    .btn--outline:hover {
        --btn-border: var(--color-text-body);
    }

    .btn--text:hover {
        --btn-text: var(--color-link);
    }
}

.btn--sm {
    min-height: 40px;
    padding: 0 var(--space-4);
    font-size: var(--fs-xs);
}

.btn--lg {
    min-height: 56px;
    padding: 0 var(--space-8);
    font-size: var(--fs-base);
}

.btn--block {
    display: flex;
    width: 100%;
}

.btn__icon {
    flex-shrink: 0;
    width: 1em;
    height: 1em;
    transition: transform var(--motion-shift);
}

.btn:hover .btn__icon {
    transform: translateX(var(--shift-sm));
}

.btn:disabled,
.btn[aria-disabled="true"] {
    opacity: 0.4;
    pointer-events: none;
}

/* --------------------------------------------------------------------------
   Link
   -------------------------------------------------------------------------- */

.link {
    color: var(--color-link);
    text-decoration: underline;
    text-decoration-color: var(--color-link-underline);
    text-decoration-thickness: var(--border-hairline);
    text-underline-offset: 0.25em;
    transition:
        color var(--duration-fast) var(--ease-standard),
        text-decoration-color var(--duration-fast) var(--ease-standard);
}

.link:hover {
    color: var(--color-text);
    text-decoration-color: currentColor;
}

/* Underline that draws in from the left; for navigation and quiet links. */
.link-draw {
    position: relative;
    display: inline-block;
}

.link-draw::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -0.2em;
    height: var(--border-hairline);
    background-color: currentColor;
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--duration-moderate) var(--ease-out);
}

.link-draw:hover::after,
.link-draw[aria-current="page"]::after {
    transform: scaleX(1);
    transform-origin: left;
}

/* --------------------------------------------------------------------------
   Eyebrow - section label with a square ember marker
   -------------------------------------------------------------------------- */

/* Section labels: small monospace, in the accent. */
.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: var(--space-3);
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    font-weight: var(--fw-regular);
    line-height: var(--lh-none);
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-accent);
}

.eyebrow::before {
    content: none;
}

/* --------------------------------------------------------------------------
   Index - technical numbering, e.g. "01 / 04"
   -------------------------------------------------------------------------- */

.index {
    font-family: var(--font-body);
    font-size: var(--fs-xs);
    font-weight: var(--fw-medium);
    line-height: var(--lh-none);
    letter-spacing: var(--ls-wide);
    font-variant-numeric: tabular-nums lining-nums;
    color: var(--color-text-muted);
}

.index strong {
    color: var(--color-text);
    font-weight: var(--fw-semibold);
}

/* --------------------------------------------------------------------------
   Tag
   -------------------------------------------------------------------------- */

.tag {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-1) var(--space-2);
    font-size: var(--fs-2xs);
    font-weight: var(--fw-medium);
    line-height: var(--lh-snug);
    letter-spacing: var(--ls-caps);
    text-transform: uppercase;
    color: var(--color-text-body);
    border: var(--border-default);
    border-radius: var(--radius-xs);
}

.tag--solid {
    color: var(--color-inverse-text);
    background-color: var(--color-inverse-bg);
    border-color: var(--color-inverse-bg);
}

/* --------------------------------------------------------------------------
   Rule
   -------------------------------------------------------------------------- */

.rule {
    width: 100%;
    height: 0;
    border: 0;
    border-top: var(--border-default);
}

.rule--strong {
    border-top: var(--border-strong);
}

.rule--accent {
    width: var(--space-12);
    border-top: var(--border-medium) solid var(--color-accent);
}

/* --------------------------------------------------------------------------
   Panel - flat bordered surface. No shadow, no rounding.
   -------------------------------------------------------------------------- */

.panel {
    padding: var(--panel-padding, var(--space-8));
    background-color: var(--color-surface);
    border: var(--border-default);
    border-radius: var(--radius-surface);
}

.panel--flush {
    background-color: transparent;
}

.panel--alt {
    background-color: var(--color-surface-alt);
    border-color: transparent;
}

/* --------------------------------------------------------------------------
   Frame - corner registration marks, for media or diagrams
   -------------------------------------------------------------------------- */

.frame {
    --frame-mark: 12px;
    --frame-color: var(--color-border-strong);

    position: relative;
}

.frame::before,
.frame::after {
    content: "";
    position: absolute;
    width: var(--frame-mark);
    height: var(--frame-mark);
    pointer-events: none;
}

.frame::before {
    top: 0;
    left: 0;
    border-top: var(--border-hairline) solid var(--frame-color);
    border-left: var(--border-hairline) solid var(--frame-color);
}

.frame::after {
    right: 0;
    bottom: 0;
    border-right: var(--border-hairline) solid var(--frame-color);
    border-bottom: var(--border-hairline) solid var(--frame-color);
}

/* --------------------------------------------------------------------------
   Form fields
   Error state uses copper plus text; never rely on color alone.
   -------------------------------------------------------------------------- */

.field {
    display: grid;
    align-content: start;
    gap: var(--space-2);
}

.field__label {
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    color: var(--color-text);
}

.field__hint,
.field__error {
    font-size: var(--fs-xs);
    line-height: var(--lh-normal);
}

.field__hint {
    color: var(--color-text-muted);
}

.field__error {
    color: var(--color-link);
    font-weight: var(--fw-medium);
}

.input,
.textarea,
.select select {
    width: 100%;
    min-height: var(--control-height);
    padding: var(--space-3) var(--space-4);
    font-size: var(--fs-base);
    line-height: var(--lh-normal);
    color: var(--color-text);
    background-color: var(--color-surface);
    border: var(--border-hairline) solid var(--color-border);
    border-radius: var(--radius-control);
    transition:
        border-color var(--duration-fast) var(--ease-standard),
        box-shadow var(--duration-fast) var(--ease-standard);
}

.input::placeholder,
.textarea::placeholder {
    color: var(--color-text-muted);
    opacity: 1;
}

.input:hover,
.textarea:hover,
.select select:hover {
    border-color: var(--color-border-strong);
}

.input:focus-visible,
.textarea:focus-visible,
.select select:focus-visible {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: inset 0 0 0 var(--border-hairline) var(--color-accent);
}

.input[aria-invalid="true"],
.textarea[aria-invalid="true"],
.select select[aria-invalid="true"] {
    border-color: var(--color-accent-strong);
}

.textarea {
    min-height: 160px;
    resize: vertical;
}

.select {
    position: relative;
}

.select select {
    appearance: none;
    padding-right: var(--space-12);
    cursor: pointer;
}

.select::after {
    content: "";
    position: absolute;
    top: 50%;
    right: var(--space-4);
    width: 7px;
    height: 7px;
    border-right: var(--border-hairline) solid var(--color-text);
    border-bottom: var(--border-hairline) solid var(--color-text);
    transform: translateY(-70%) rotate(45deg);
    pointer-events: none;
}

.checkbox,
.radio {
    display: inline-flex;
    align-items: flex-start;
    gap: var(--space-3);
    font-size: var(--fs-sm);
    cursor: pointer;
}

.checkbox input,
.radio input {
    flex-shrink: 0;
    width: 18px;
    height: 18px;
    margin-top: 0.15em;
    accent-color: var(--color-accent-strong);
}

/* --------------------------------------------------------------------------
   Site header
   Mobile overlay rules live in responsive.css. navigation.js sets
   data-theme="dark" while a dark section is under the header.
   -------------------------------------------------------------------------- */

.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    z-index: var(--z-header);
    color: var(--color-text);
    background-color: transparent;
    border-bottom: var(--border-hairline) solid transparent;
    transition:
        background-color var(--duration-moderate) var(--ease-standard),
        border-color var(--duration-moderate) var(--ease-standard),
        color var(--duration-moderate) var(--ease-standard);
}

/* A near-opaque bar instead of a backdrop blur: a full-width blur over
   moving content is recomputed every scroll frame. */
.site-header.is-scrolled {
    background-color: rgba(var(--rgb-well), 0.9);
    border-bottom-color: var(--color-border);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-8);
    height: var(--header-height);
}

/* Hidden until navigation.js has set up the entrance animation. */
.js .site-header:not(.is-ready) [data-nav-intro] {
    opacity: 0;
}

/* Logo */

.site-logo {
    display: inline-flex;
    align-items: center;
    min-height: var(--tap-target);
}

.site-logo img,
.site-logo__svg {
    display: block;
    width: auto;
    height: 40px;
    overflow: visible;
}

.site-logo__cinder { fill: var(--mark-word); transition: fill var(--motion-tone); }
.site-logo__tek { fill: var(--mark-ember); }

/* Hover: the mark opens into an exploded view, then closes again. */
.site-logo__mark .mark-piece {
    transform-box: fill-box;
    /* The hover uses the individual translate property so it never fights
       the GSAP assembly, which animates transform. */
    transition: translate var(--duration-slow) var(--ease-out), fill var(--motion-tone);
}

@media (hover: hover) {
    .site-logo:hover .mark-piece { translate: var(--dx, 0) var(--dy, 0); }
    .site-logo:hover .mark-piece--ember { animation: ember-flicker 1.1s var(--ease-precise) infinite; }
}

/* --------------------------------------------------------------------------
   Logo mark tones - shared by every inline rendering of the mark
   -------------------------------------------------------------------------- */

.mark-piece { stroke: none; }
.mark-piece--dark { fill: var(--mark-dark); }
.mark-piece--slate { fill: var(--mark-slate); }
.mark-piece--copper { fill: var(--mark-copper); }
.mark-piece--ember { fill: var(--mark-ember); }

@keyframes ember-flicker {
    0%, 100% { opacity: 1; }
    35% { opacity: 0.72; }
    55% { opacity: 0.95; }
    70% { opacity: 0.8; }
}

/* Scroll progress - a hairline of ember under the header */
.site-progress {
    position: absolute;
    left: 0;
    right: 0;
    bottom: -1px;
    height: 2px;
    background: var(--color-accent);
    transform: scaleX(0);
    transform-origin: left center;
    pointer-events: none;
}

/* Desktop navigation */

.site-nav {
    display: flex;
    align-items: center;
    gap: var(--space-10);
    margin-left: auto;
}

.site-nav__list {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.site-nav__link {
    display: inline-flex;
    align-items: center;
    min-height: var(--tap-target);
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    letter-spacing: var(--ls-wide);
    color: var(--color-text-body);
    transition: color var(--duration-fast) var(--ease-standard);
}

.site-nav__link:hover,
.site-nav__link[aria-current="page"] {
    color: var(--color-text);
}

.site-nav__label {
    position: relative;
}

.site-nav__label::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -0.35em;
    height: var(--border-hairline);
    background-color: currentColor;
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--duration-moderate) var(--ease-out);
}

.site-nav__link:hover .site-nav__label::after,
.site-nav__link[aria-current="page"] .site-nav__label::after {
    transform: scaleX(1);
    transform-origin: left;
}

.site-nav__index,
.site-nav__meta {
    display: none;
}

.site-nav__cta {
    transition:
        color var(--duration-fast) var(--ease-standard),
        background-color var(--duration-fast) var(--ease-standard),
        border-color var(--duration-fast) var(--ease-standard);
}

/* Theme switch: dark (default) and light. */

.site-header__theme {
    position: relative;
    display: inline-grid;
    place-items: center;
    flex: none;
    width: 40px;
    height: 40px;
    margin-left: calc(var(--space-8) * -0.5);
    border: 1px solid var(--color-border-strong);
    border-radius: 50%;
    color: var(--color-text);
    background: transparent;
    cursor: pointer;
    transition: border-color var(--duration-fast) var(--ease-standard), background-color var(--duration-fast) var(--ease-standard), color var(--duration-fast) var(--ease-standard);
}

.site-header__theme:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.site-header__theme svg {
    grid-area: 1 / 1;
    width: 18px;
    height: 18px;
    transition: opacity var(--duration-moderate) var(--ease-standard), transform var(--duration-moderate) var(--ease-out);
}

/* Shows what you switch to: the sun in the dark theme, the moon in the light one. */
.site-header__theme .icon-moon { opacity: 0; transform: rotate(-60deg) scale(0.6); }
:root[data-theme="light"] .site-header__theme .icon-sun { opacity: 0; transform: rotate(60deg) scale(0.6); }
:root[data-theme="light"] .site-header__theme .icon-moon { opacity: 1; transform: none; }

/* Menu button (visible below lg) */

.site-header__toggle {
    display: none;
    align-items: center;
    gap: var(--space-3);
    min-height: var(--tap-target);
    padding-inline: var(--space-1);
    color: inherit;
}

.site-header__toggle-label {
    font-size: var(--fs-xs);
    font-weight: var(--fw-semibold);
    line-height: var(--lh-none);
    letter-spacing: var(--ls-caps);
    text-transform: uppercase;
}

.site-header__toggle-icon {
    display: grid;
    gap: 6px;
    width: 22px;
}

.site-header__toggle-icon span {
    display: block;
    height: var(--border-hairline);
    background-color: currentColor;
    transition: transform var(--duration-moderate) var(--ease-out);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-icon span:first-child {
    transform: translateY(3.5px) rotate(45deg);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-icon span:last-child {
    transform: translateY(-3.5px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   Site footer
   Dark on every page; on the homepage it continues the closing CTA.
   The logo reuses the header's .site-logo styles.
   -------------------------------------------------------------------------- */

.site-footer {
    padding-block: var(--space-20) var(--space-6);
    border-top: var(--border-default);
}

.site-footer__main {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-12) var(--space-16);
}

.site-footer__tagline {
    margin-top: var(--space-4);
    font-size: var(--fs-xs);
    font-weight: var(--fw-semibold);
    line-height: var(--lh-normal);
    letter-spacing: var(--ls-caps);
    text-transform: uppercase;
    color: var(--color-text-muted);
}

.site-footer__list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2) var(--space-10);
}

.site-footer__link {
    font-family: var(--font-display);
    font-size: var(--fs-md);
    font-weight: var(--fw-semibold);
    line-height: var(--lh-none);
    letter-spacing: var(--ls-tight);
    color: var(--color-text);
    padding-block: var(--space-3);
}

.site-footer__link::after {
    bottom: var(--space-1);
}

.site-footer__link[aria-current="page"]::after {
    background-color: var(--color-accent);
}

.site-footer__bottom {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-2) var(--space-8);
    margin-top: var(--space-20);
    padding-top: var(--space-4);
    border-top: var(--border-default);
    font-size: var(--fs-xs);
    letter-spacing: var(--ls-wide);
    color: var(--color-text-muted);
}

.site-footer__legal {
    margin-right: auto;
}

.site-footer__social {
    display: flex;
    gap: var(--space-8);
}

.site-footer__meta-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    min-height: var(--tap-target);
    font-weight: var(--fw-medium);
    color: var(--color-text-muted);
    transition: color var(--duration-fast) var(--ease-standard);
}

.site-footer__meta-link:hover {
    color: var(--color-text);
}

.site-footer__top-link svg {
    width: 12px;
    height: 12px;
    transition: transform var(--motion-shift);
}

.site-footer__top-link:hover svg {
    transform: translateY(calc(var(--shift-sm) * -1));
}