/* ===================================================================
   Apple-inspired design system
   Built against .claude/skills/apple-design/SKILL.md

   Principles applied here:
   - §12 Materials & depth: translucent chrome, scroll edge effects
   - §14 Reduced motion / transparency / contrast
   - §15 Typography: size-specific tracking, leading that tracks size
   - §1  Response: press feedback is instant, on pointer-down
   Motion that a gesture can touch lives in js/apple.js (springs).
   =================================================================== */

*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* -------------------------------------------------------------------
   Tokens — light is the base, dark redefines only what changes
   ------------------------------------------------------------------- */

:root {
    /* Surfaces: base sits behind, elevated is the card/sheet layer */
    --bg-base: #fbfbfd;
    --bg-alt: #f5f5f7;
    --bg-elevated: #ffffff;
    --bg-sunken: #f0f0f3;

    /* Text — a three-step ramp, never more */
    --text-primary: #1d1d1f;
    --text-secondary: #515154;
    --text-tertiary: #86868b;

    --accent: #0071e3;
    --accent-pressed: #0060c0;
    --accent-tint: rgba(0, 113, 227, 0.1);
    --on-accent: #ffffff;

    --separator: rgba(0, 0, 0, 0.09);
    --separator-strong: rgba(0, 0, 0, 0.16);

    /* Materials — §12. Weight encodes hierarchy. */
    --material-chrome: rgba(251, 251, 253, 0.72);
    --material-chrome-dense: rgba(251, 251, 253, 0.86);
    --material-sheet: rgba(255, 255, 255, 0.78);
    --material-edge: rgba(255, 255, 255, 0.7);
    --material-blur: 20px;
    --material-saturate: 180%;

    /* Bigger surfaces read as thicker: deeper blur, deeper shadow */
    --shadow-chip: 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.04), 0 8px 24px rgba(0, 0, 0, 0.06);
    --shadow-lifted: 0 2px 6px rgba(0, 0, 0, 0.06), 0 18px 48px rgba(0, 0, 0, 0.12);
    --shadow-sheet: 0 4px 12px rgba(0, 0, 0, 0.08), 0 32px 64px rgba(0, 0, 0, 0.18);

    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --radius-pill: 980px;

    /* The two easings used for non-gesture transitions.
       They are inverses of each other so reversible paths mirror (§7). */
    --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
    --ease-in: cubic-bezier(0.64, 0, 0.78, 0);
    --press: 90ms ease-out;      /* §1 — press feedback must feel immediate */
    --release: 320ms var(--ease-out);

    --measure: 68ch;
    --gutter: clamp(1.25rem, 4vw, 2.5rem);
}

[data-theme="dark"] {
    --bg-base: #000000;
    --bg-alt: #0a0a0c;
    --bg-elevated: #161618;
    --bg-sunken: #1c1c1f;

    --text-primary: #f5f5f7;
    --text-secondary: #b0b0b6;
    --text-tertiary: #86868b;

    --accent: #0a84ff;
    --accent-pressed: #409cff;
    --accent-tint: rgba(10, 132, 255, 0.16);
    --on-accent: #ffffff;

    --separator: rgba(255, 255, 255, 0.11);
    --separator-strong: rgba(255, 255, 255, 0.2);

    --material-chrome: rgba(22, 22, 24, 0.68);
    --material-chrome-dense: rgba(12, 12, 14, 0.85);
    --material-sheet: rgba(28, 28, 31, 0.8);
    --material-edge: rgba(255, 255, 255, 0.12);

    --shadow-chip: 0 1px 2px rgba(0, 0, 0, 0.5);
    --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.5), 0 8px 24px rgba(0, 0, 0, 0.45);
    --shadow-lifted: 0 2px 6px rgba(0, 0, 0, 0.55), 0 18px 48px rgba(0, 0, 0, 0.6);
    --shadow-sheet: 0 4px 12px rgba(0, 0, 0, 0.6), 0 32px 64px rgba(0, 0, 0, 0.7);
}

/* No-JS / first-paint dark, before the theme attribute is written */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        color-scheme: dark;
    }
}

/* -------------------------------------------------------------------
   Base
   ------------------------------------------------------------------- */

html {
    font-size: 100%;
    /* Scrolling is spring-driven in JS so it stays interruptible (§3) */
    scroll-behavior: auto;
    -webkit-text-size-adjust: 100%;
}

body {
    /* §15 — the system font already ships optical sizing and tracking tables */
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter",
        "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 1.0625rem;
    line-height: 1.6;
    letter-spacing: -0.003em;
    color: var(--text-primary);
    background-color: var(--bg-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
    /* Ease the dark↔light change — §14 warns against abrupt brightness jumps */
    transition: background-color 420ms var(--ease-out), color 420ms var(--ease-out);
}

img {
    max-width: 100%;
    display: block;
}

button {
    font: inherit;
    color: inherit;
    background: none;
    border: none;
    cursor: pointer;
    /* §1 — no 300ms tap delay on the input path */
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

a {
    color: var(--accent);
    text-decoration: none;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
    border-radius: 4px;
}

::selection {
    background: var(--accent-tint);
    color: var(--text-primary);
}

/* -------------------------------------------------------------------
   Type scale — §15
   Tracking is size-specific: large text tightens, small text opens up.
   Leading tracks size inversely: tight on display, loose on body.
   ------------------------------------------------------------------- */

h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: 600;
    text-wrap: balance;
}

h1 {
    font-size: clamp(2.5rem, 7vw, 4.5rem);
    line-height: 1.04;
    letter-spacing: -0.028em;
    font-weight: 700;
}

h2 {
    font-size: clamp(1.875rem, 4.2vw, 3rem);
    line-height: 1.08;
    letter-spacing: -0.022em;
    font-weight: 650;
}

h3 {
    font-size: clamp(1.25rem, 2.2vw, 1.5rem);
    line-height: 1.2;
    letter-spacing: -0.015em;
}

h4 {
    font-size: 1.1875rem;
    line-height: 1.3;
    letter-spacing: -0.01em;
}

/* Eyebrow label — small text wants *positive* tracking */
h5, .eyebrow {
    font-size: 0.8125rem;
    line-height: 1.4;
    letter-spacing: 0.055em;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--text-tertiary);
}

h6 {
    font-size: 0.8125rem;
    line-height: 1.45;
    letter-spacing: 0.012em;
    font-weight: 500;
    color: var(--text-tertiary);
    text-transform: none;
}

p {
    color: var(--text-secondary);
    line-height: 1.65;
    max-width: var(--measure);
}

p + p {
    margin-top: 1rem;
}

/* -------------------------------------------------------------------
   Layout
   All spacing in rem so it scales with the user's text size (§15)
   ------------------------------------------------------------------- */

.container {
    width: 100%;
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 var(--gutter);
}

.wrapper {
    max-width: 820px;
    margin: 0 auto;
}

.section {
    padding: clamp(4rem, 10vw, 7.5rem) 0;
    position: relative;
}

/* A quiet tint band, not a hard divider */
section.section:nth-of-type(even) {
    background-color: var(--bg-alt);
}

.section-intro {
    margin-bottom: clamp(2.5rem, 6vw, 4rem);
    max-width: 40ch;
}

.section-intro h5 {
    margin-bottom: 0.75rem;
}

.section-intro h2 {
    margin-bottom: 0.75rem;
}

.section-intro p {
    color: var(--text-tertiary);
    font-size: 1rem;
}

/* -------------------------------------------------------------------
   Header — a translucent floating layer, content scrolls under (§12)
   ------------------------------------------------------------------- */

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 900;
    background: var(--material-chrome);
    -webkit-backdrop-filter: blur(var(--material-blur)) saturate(var(--material-saturate));
    backdrop-filter: blur(var(--material-blur)) saturate(var(--material-saturate));
    transition: background-color 320ms var(--ease-out);
}

/* Scroll edge effect instead of a 1px rule — §12.
   It only appears where floating chrome actually overlaps content. */
header::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    height: 14px;
    pointer-events: none;
    background: linear-gradient(to bottom, var(--separator), transparent 65%);
    opacity: 0;
    transition: opacity 260ms var(--ease-out);
}

header.at-edge::after {
    opacity: 1;
}

header.at-edge {
    background: var(--material-chrome-dense);
}

.nav-container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0.85rem var(--gutter);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    position: relative;
}

.logo {
    font-size: 1.0625rem;
    font-weight: 600;
    letter-spacing: -0.015em;
}

.logo a {
    color: var(--text-primary);
    display: inline-block;
    /* §1 — feedback on the press itself */
    transition: transform var(--release), opacity var(--release);
}

.logo a:active {
    transform: scale(0.96);
    opacity: 0.6;
    transition: transform var(--press), opacity var(--press);
}

nav {
    position: relative;
}

nav ul {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    list-style: none;
}

nav a {
    display: inline-block;
    position: relative;
    padding: 0.4rem 0.85rem;
    border-radius: var(--radius-pill);
    font-size: 0.875rem;
    font-weight: 500;
    /* Vibrancy: text over a translucent surface needs contrast + a touch
       more weight and tracking than flat gray would give (§12) */
    letter-spacing: 0.004em;
    color: var(--text-secondary);
    transition: color 220ms var(--ease-out), transform var(--release);
    z-index: 1;
}

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

nav a:active {
    transform: scale(0.94);
    transition: transform var(--press);
}

nav a.active {
    color: var(--text-primary);
    font-weight: 600;
}

/* The selection pill is one shared element that springs between items,
   so the indicator moves continuously instead of cross-fading (§7). */
.nav-indicator {
    position: absolute;
    left: 0;
    top: 0;
    height: 0;
    width: 0;
    border-radius: var(--radius-pill);
    background: var(--bg-sunken);
    box-shadow: var(--shadow-chip);
    opacity: 0;
    pointer-events: none;
    z-index: 0;
    will-change: transform, width, height;
}

[data-theme="dark"] .nav-indicator {
    background: rgba(255, 255, 255, 0.1);
    box-shadow: none;
}

/* -------------------------------------------------------------------
   Menu toggle + mobile sheet
   ------------------------------------------------------------------- */

.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-pill);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 5px;
    background: var(--bg-sunken);
    transition: transform var(--release), background-color 220ms var(--ease-out);
}

.menu-toggle:active {
    transform: scale(0.9);
    transition: transform var(--press);
}

.menu-toggle span {
    display: block;
    width: 17px;
    height: 1.5px;
    border-radius: 2px;
    background: var(--text-primary);
    transition: transform 340ms var(--ease-out), opacity 200ms var(--ease-out);
}

.menu-toggle.active span:nth-child(1) {
    transform: translateY(6.5px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0.4);
}

.menu-toggle.active span:nth-child(3) {
    transform: translateY(-6.5px) rotate(-45deg);
}

/* A parallel, non-blocking panel: translucency + offset, a light scrim
   only (§12 — dim to focus, separate to keep flow). */
.nav-scrim {
    position: fixed;
    inset: 0;
    z-index: 890;
    background: rgba(0, 0, 0, 0.28);
    opacity: 0;
    pointer-events: none;
    -webkit-backdrop-filter: blur(2px);
    backdrop-filter: blur(2px);
}

.nav-scrim.engaged {
    pointer-events: auto;
}

/* -------------------------------------------------------------------
   Buttons — §1, response lives on the press
   ------------------------------------------------------------------- */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-pill);
    font-size: 0.9375rem;
    font-weight: 550;
    letter-spacing: 0.002em;
    line-height: 1.2;
    cursor: pointer;
    transition: transform var(--release), background-color 220ms var(--ease-out),
        border-color 220ms var(--ease-out), color 220ms var(--ease-out);
}

.btn:active {
    /* Instant, on pointer-down — waiting for the release feels dead */
    transform: scale(0.96);
    transition: transform var(--press);
}

.btn-primary {
    background: var(--accent);
    color: var(--on-accent);
}

.btn-primary:hover {
    background: var(--accent-pressed);
    color: var(--on-accent);
}

.btn-outline {
    background: transparent;
    color: var(--accent);
    box-shadow: inset 0 0 0 1px currentColor;
}

.btn-outline:hover {
    background: var(--accent-tint);
}

.cta-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

/* -------------------------------------------------------------------
   Hero
   ------------------------------------------------------------------- */

.hero {
    min-height: 100svh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 8rem var(--gutter) 5rem;
    max-width: 1120px;
    margin: 0 auto;
    position: relative;
}

.hero-content {
    max-width: 46rem;
}

.hero h5 {
    margin-bottom: 1rem;
}

.hero h1 {
    margin-bottom: 1.5rem;
    font-optical-sizing: auto;
}

.hero .lede {
    font-size: clamp(1.0625rem, 2vw, 1.3125rem);
    line-height: 1.5;
    letter-spacing: -0.008em;
    color: var(--text-secondary);
    max-width: 34ch;
    margin-bottom: 2rem;
}

.roles {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2.25rem;
}

.role-tag {
    padding: 0.4rem 0.9rem;
    border-radius: var(--radius-pill);
    background: var(--bg-sunken);
    color: var(--text-secondary);
    font-size: 0.8125rem;
    font-weight: 500;
    letter-spacing: 0.01em;
    box-shadow: var(--shadow-chip);
    transition: transform var(--release), color 220ms var(--ease-out);
}

.role-tag:hover {
    color: var(--text-primary);
}

.social-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 2.5rem;
}

.social-links a,
.footer-social a {
    width: 42px;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-pill);
    background: var(--bg-sunken);
    color: var(--text-secondary);
    font-size: 1rem;
    transition: transform var(--release), color 220ms var(--ease-out),
        background-color 220ms var(--ease-out);
}

.social-links a:hover,
.footer-social a:hover {
    color: var(--text-primary);
    background: var(--separator);
}

.social-links a:active,
.footer-social a:active,
.role-tag:active {
    transform: scale(0.9);
    transition: transform var(--press);
}

/* Scroll cue — a slow, small hint, kept under the 0.2Hz oscillation
   warning in §14 by being a single subtle travel, not a loop of jumps */
.scroll-cue {
    position: absolute;
    left: var(--gutter);
    bottom: 2.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-tertiary);
}

.scroll-cue i {
    font-size: 0.7rem;
}

/* -------------------------------------------------------------------
   About
   ------------------------------------------------------------------- */

.about-content {
    display: grid;
    grid-template-columns: minmax(0, 240px) minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 4rem);
    align-items: start;
}

.profile-image {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
}

.about-text p {
    font-size: 1.0625rem;
}

.about-text .cta-buttons {
    margin-top: 2rem;
}

/* -------------------------------------------------------------------
   Timeline — grouping by proximity, dates mapped beside their entry
   ------------------------------------------------------------------- */

.timeline {
    position: relative;
    padding-left: 1.75rem;
}

.timeline::before {
    content: "";
    position: absolute;
    left: 3px;
    top: 6px;
    bottom: 6px;
    width: 1px;
    background: var(--separator-strong);
}

.timeline-item {
    position: relative;
    padding-bottom: 2.25rem;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-item::before {
    content: "";
    position: absolute;
    left: -1.75rem;
    top: 7px;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--text-tertiary);
}

.timeline-item:first-child::before {
    background: var(--accent);
    box-shadow: 0 0 0 4px var(--accent-tint);
}

.timeline-header {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    justify-content: space-between;
    gap: 0.25rem 1rem;
    margin-bottom: 0.35rem;
}

.timeline-header h3 {
    font-size: 1.125rem;
    letter-spacing: -0.012em;
}

.timeline-header .date {
    font-size: 0.8125rem;
    letter-spacing: 0.012em;
    color: var(--text-tertiary);
    font-variant-numeric: tabular-nums;
}

.timeline-content h4 {
    font-size: 0.9375rem;
    font-weight: 550;
    color: var(--text-secondary);
    margin-bottom: 0.35rem;
}

.timeline-content p {
    font-size: 0.9375rem;
    color: var(--text-tertiary);
}

.subhead {
    font-size: 1.125rem;
    letter-spacing: -0.012em;
    margin-bottom: 1.75rem;
    color: var(--text-primary);
}

/* -------------------------------------------------------------------
   Cards — projects, blog, contact
   ------------------------------------------------------------------- */

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
    gap: 1.25rem;
}

.project-card {
    position: relative;
    display: flex;
    flex-direction: column;
    padding: 1.75rem;
    border-radius: var(--radius-lg);
    background: var(--bg-elevated);
    box-shadow: var(--shadow-card);
    /* Transform is spring-driven from JS on hover/press; the transition
       here only covers the non-gesture properties. */
    transition: box-shadow 320ms var(--ease-out), background-color 320ms var(--ease-out);
    will-change: transform;
}

[data-theme="dark"] .project-card {
    box-shadow: inset 0 0 0 1px var(--separator);
}

.project-card:hover {
    box-shadow: var(--shadow-lifted);
}

[data-theme="dark"] .project-card:hover {
    box-shadow: inset 0 0 0 1px var(--separator-strong), var(--shadow-lifted);
}

.project-card h4 {
    margin-bottom: 0.4rem;
}

/* A card title reads as a title whether or not it links out; the link
   affordance shows up on hover instead of splitting the grid into two
   visually different kinds of card (§16, familiarity/consistency). */
.project-card h4 a,
.project-card a h4 {
    color: var(--text-primary);
    transition: color 220ms var(--ease-out);
}

.project-card a:hover h4,
.project-card h4 a:hover {
    color: var(--accent);
}

.project-card h6 {
    margin-bottom: 0.9rem;
}

.project-card p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
}

.project-card .project-link {
    margin-top: auto;
    font-size: 0.8125rem;
    letter-spacing: 0.012em;
    color: var(--text-tertiary);
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}

.project-card a.project-link {
    color: var(--accent);
    font-weight: 500;
}

.project-card a.project-link i {
    font-size: 0.7rem;
    transition: transform 280ms var(--ease-out);
}

.project-card a.project-link:hover i {
    transform: translate(2px, -2px);
}

/* Collapsed projects: hidden from layout *and* the a11y tree until shown */
.hidden-project {
    display: none;
}

.hidden-project.show {
    display: flex;
}

.grid-actions {
    display: flex;
    justify-content: center;
    margin-top: 2.5rem;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.25rem;
}

.contact-card {
    padding: 1.75rem;
    border-radius: var(--radius-lg);
    background: var(--bg-elevated);
    box-shadow: var(--shadow-card);
    will-change: transform;
}

[data-theme="dark"] .contact-card {
    box-shadow: inset 0 0 0 1px var(--separator);
}

.contact-card .icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    background: var(--accent-tint);
    color: var(--accent);
    font-size: 1rem;
    margin-bottom: 1rem;
}

.contact-card h5 {
    margin-bottom: 0.4rem;
}

.contact-card p {
    font-size: 0.9375rem;
    color: var(--text-primary);
}

.contact-card a {
    color: var(--text-primary);
}

.contact-card a:hover {
    color: var(--accent);
}

/* -------------------------------------------------------------------
   Footer
   ------------------------------------------------------------------- */

footer {
    padding: 3rem 0 3.5rem;
    background: var(--bg-base);
    border-top: 1px solid var(--separator);
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.copyright p {
    font-size: 0.8125rem;
    letter-spacing: 0.008em;
    color: var(--text-tertiary);
    margin: 0;
}

.footer-social {
    display: flex;
    gap: 0.5rem;
    list-style: none;
}

/* -------------------------------------------------------------------
   Floating controls — small chips, so a lighter material than the header
   ------------------------------------------------------------------- */

.floating-controls {
    position: fixed;
    right: clamp(1rem, 3vw, 2rem);
    bottom: clamp(1rem, 3vw, 2rem);
    z-index: 880;
    display: flex;
    flex-direction: column;
    gap: 0.625rem;
}

.theme-toggle,
#go-top a {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-pill);
    background: var(--material-sheet);
    -webkit-backdrop-filter: blur(16px) saturate(var(--material-saturate));
    backdrop-filter: blur(16px) saturate(var(--material-saturate));
    box-shadow: var(--shadow-card), inset 0 0 0 1px var(--material-edge);
    color: var(--text-primary);
    font-size: 0.9375rem;
    transition: transform var(--release), background-color 220ms var(--ease-out);
}

.theme-toggle:active,
#go-top a:active {
    transform: scale(0.9);
    transition: transform var(--press);
}

/* The icon crossfades in place; the button itself never spins */
.theme-icon {
    position: absolute;
    transition: opacity 260ms var(--ease-out), transform 380ms var(--ease-out);
}

.theme-toggle {
    position: relative;
}

.theme-toggle .sun-icon {
    opacity: 0;
    transform: scale(0.6) rotate(-40deg);
}

.theme-toggle .moon-icon {
    opacity: 1;
    transform: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    opacity: 1;
    transform: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    opacity: 0;
    transform: scale(0.6) rotate(40deg);
}

#go-top {
    opacity: 0;
    visibility: hidden;
    transform: scale(0.8);
    transition: opacity 260ms var(--ease-out), transform 320ms var(--ease-out),
        visibility 0s linear 260ms;
}

#go-top.visible {
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: opacity 260ms var(--ease-out), transform 320ms var(--ease-out),
        visibility 0s;
}

/* -------------------------------------------------------------------
   Reveal on scroll
   JS springs these in; the class is only added when JS is running, so
   without JS every element renders in its final state.
   ------------------------------------------------------------------- */

.js-reveal [data-reveal] {
    opacity: 0;
    will-change: transform, opacity;
}

/* -------------------------------------------------------------------
   Utilities kept from the previous stylesheet
   ------------------------------------------------------------------- */

.text-center { text-align: center; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }
.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }

/* -------------------------------------------------------------------
   Compact layout — the nav becomes a sheet anchored to its trigger
   ------------------------------------------------------------------- */

@media (max-width: 860px) {
    .menu-toggle {
        display: flex;
    }

    nav {
        position: fixed;
        top: calc(env(safe-area-inset-top, 0px) + 4.25rem);
        left: 0.75rem;
        right: 0.75rem;
        z-index: 895;
        visibility: hidden;
    }

    nav.open,
    nav.animating {
        visibility: visible;
    }

    nav ul {
        flex-direction: column;
        align-items: stretch;
        gap: 0.125rem;
        padding: 0.5rem;
        border-radius: var(--radius-xl);
        background: var(--material-sheet);
        -webkit-backdrop-filter: blur(30px) saturate(var(--material-saturate));
        backdrop-filter: blur(30px) saturate(var(--material-saturate));
        box-shadow: var(--shadow-sheet), inset 0 0 0 1px var(--material-edge);
        /* §7 — the sheet originates from the button that opened it */
        transform-origin: top right;
        will-change: transform, opacity;
    }

    nav a {
        display: block;
        padding: 0.8rem 1rem;
        border-radius: var(--radius-md);
        font-size: 1rem;
        font-weight: 500;
        letter-spacing: -0.005em;
    }

    nav a.active {
        background: var(--accent-tint);
        color: var(--accent);
    }

    /* Grab affordance: the sheet dismisses back up the way it came in.
       A pseudo-element, so the desktop nav row stays a clean list. */
    nav ul::before {
        content: "";
        display: block;
        width: 36px;
        height: 4px;
        border-radius: 2px;
        background: var(--separator-strong);
        margin: 0.5rem auto 0.25rem;
    }

    .nav-indicator {
        display: none;
    }

    .hero {
        padding-top: 7rem;
        min-height: auto;
    }

    .scroll-cue {
        display: none;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .profile-image {
        max-width: 200px;
    }

    .footer-content {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 480px) {
    .cta-buttons .btn {
        flex: 1 1 auto;
    }

    .timeline-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* Touch devices: hover lift is meaningless, and a sticky :hover state
   left behind after a tap reads as a bug */
@media (hover: none) {
    .project-card:hover {
        box-shadow: var(--shadow-card);
    }
}

/* -------------------------------------------------------------------
   §14 — Accessibility preferences
   Reduced motion is not "no feedback"; it is gentler, non-vestibular
   feedback. Opacity and color changes stay, travel and overshoot go.
   ------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 180ms !important;
    }

    .js-reveal [data-reveal] {
        opacity: 1;
        transform: none !important;
    }

    .btn:active,
    nav a:active,
    .menu-toggle:active,
    .theme-toggle:active,
    .social-links a:active,
    .footer-social a:active,
    .role-tag:active,
    #go-top a:active {
        /* Keep a press signal, drop the movement */
        transform: none;
        opacity: 0.6;
    }
}

/* Frostier, not clearer: raise opacity and drop the blur */
@media (prefers-reduced-transparency: reduce) {
    header,
    header.at-edge {
        background: var(--bg-base);
        -webkit-backdrop-filter: none;
        backdrop-filter: none;
        border-bottom: 1px solid var(--separator);
    }

    nav ul,
    .theme-toggle,
    #go-top a {
        background: var(--bg-elevated);
        -webkit-backdrop-filter: none;
        backdrop-filter: none;
    }

    .nav-scrim {
        -webkit-backdrop-filter: none;
        backdrop-filter: none;
    }
}

/* Near-solid backgrounds with a defined, contrasting border */
@media (prefers-contrast: more) {
    :root {
        --text-secondary: #33333a;
        --text-tertiary: #4a4a52;
        --separator: rgba(0, 0, 0, 0.3);
        --separator-strong: rgba(0, 0, 0, 0.45);
    }

    [data-theme="dark"] {
        --text-secondary: #e4e4e8;
        --text-tertiary: #c9c9cf;
        --separator: rgba(255, 255, 255, 0.35);
        --separator-strong: rgba(255, 255, 255, 0.5);
    }

    .project-card,
    .contact-card,
    nav ul,
    .theme-toggle,
    #go-top a {
        box-shadow: inset 0 0 0 1px var(--separator-strong);
        -webkit-backdrop-filter: none;
        backdrop-filter: none;
        background: var(--bg-elevated);
    }

    header,
    header.at-edge {
        background: var(--bg-base);
        -webkit-backdrop-filter: none;
        backdrop-filter: none;
        border-bottom: 1px solid var(--separator-strong);
    }
}

@media print {
    header,
    .floating-controls,
    .scroll-cue,
    .grid-actions {
        display: none;
    }

    .js-reveal [data-reveal] {
        opacity: 1 !important;
        transform: none !important;
    }
}