/* ==========================================================================
   Design tokens
   ========================================================================== */

:root {
  --color-bg: #f8f5ef;
  --color-surface: #fdfcf9;
  --color-text: #1d222d;
  --color-text-soft: #3a404c;
  --color-muted: #5b6270;
  --color-border: #e4dfd5;
  --color-border-strong: #d6d0c4;
  --color-accent: #b8602a;
  --color-accent-strong: #9a4d1f;
  --color-on-accent: #fdfcf9;
  --color-ink: #1d222d;
  --color-on-ink: #f0ece4;
  --color-ink-border: #3a404c;
  --color-error: #c2410c;
  --color-success: #2f7a4a;
  --color-rule: rgba(29, 34, 45, 0.06);
  --color-skeleton-a: #ece7de;
  --color-skeleton-b: #f5f1ea;

  --shadow-card: 0 1px 2px rgba(29, 34, 45, 0.04), 0 12px 32px -16px rgba(29, 34, 45, 0.16);
  --shadow-card-hover: 0 2px 4px rgba(29, 34, 45, 0.06), 0 24px 48px -20px rgba(29, 34, 45, 0.28);
  --shadow-float: 0 8px 24px -8px rgba(29, 34, 45, 0.5);
  --shadow-nav: 0 12px 32px -20px rgba(29, 34, 45, 0.3);

  --font-serif: 'Hahmlet', 'Noto Serif KR', 'Apple Myungjo', 'Batang', serif;
  --font-sans: 'IBM Plex Sans KR', 'Apple SD Gothic Neo', 'Malgun Gothic', sans-serif;
  --font-mono: 'IBM Plex Mono', 'SF Mono', Menlo, monospace;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-28: 7rem;

  --section-padding: clamp(var(--space-16), 5vw + 2rem, var(--space-28));
  --container-max: 1120px;
  --container-pad: clamp(1.25rem, 4vw, 2.5rem);

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-pill: 999px;

  --nav-height: 64px;
  --transition-base: 220ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 600ms cubic-bezier(0.2, 0.7, 0.2, 1);
}

[data-theme='dark'] {
  --color-bg: #15181f;
  --color-surface: #1d212b;
  --color-text: #f0ece4;
  --color-text-soft: #c9c5bd;
  --color-muted: #a3a8b3;
  --color-border: #2e3441;
  --color-border-strong: #3a404c;
  --color-accent: #e0925a;
  --color-accent-strong: #f0b184;
  --color-on-accent: #15181f;
  --color-ink: #f0ece4;
  --color-on-ink: #15181f;
  --color-ink-border: #cfc9be;
  --color-error: #f08a72;
  --color-success: #7fcf9a;
  --color-rule: rgba(240, 236, 228, 0.06);
  --color-skeleton-a: #262b37;
  --color-skeleton-b: #2f3542;

  --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.3), 0 16px 40px -20px rgba(0, 0, 0, 0.7);
  --shadow-card-hover: 0 2px 4px rgba(0, 0, 0, 0.4), 0 28px 56px -20px rgba(0, 0, 0, 0.85);
  --shadow-float: 0 8px 24px -8px rgba(224, 146, 90, 0.6);
  --shadow-nav: 0 12px 32px -16px rgba(0, 0, 0, 0.6);
}

/* ==========================================================================
   Base
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + var(--space-4));
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  background-color: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  transition: background-color var(--transition-base), color var(--transition-base);
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-base);
}

a:hover {
  color: var(--color-accent-strong);
}

h1,
h2,
h3 {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.2;
  margin: 0;
  word-break: keep-all;
  text-wrap: pretty;
}

p {
  margin: 0;
}

ul,
ol,
dl,
dd {
  margin: 0;
  padding: 0;
}

ul,
ol {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
}

.icon {
  width: 1.125em;
  height: 1.125em;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
}

.icon-fill {
  fill: currentColor;
  stroke: none;
}

.skip-link {
  position: absolute;
  left: var(--space-4);
  top: -100px;
  padding: var(--space-2) var(--space-4);
  background: var(--color-ink);
  color: var(--color-on-ink);
  border-radius: var(--radius-sm);
  z-index: 200;
}

.skip-link:focus {
  top: var(--space-4);
}

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

/* ==========================================================================
   Layout primitives
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

.section {
  padding-block: var(--section-padding);
  border-top: 1px solid var(--color-border);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-3);
}

.section-title {
  font-size: clamp(1.875rem, 1.4rem + 1.8vw, 2.75rem);
  letter-spacing: -0.01em;
  margin-bottom: var(--space-8);
}

.section-heading-row {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.section-heading-row .section-title {
  margin-bottom: 0;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 3rem;
  padding: 0 var(--space-6);
  border-radius: var(--radius-sm);
  border: 1.5px solid transparent;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: transform var(--transition-base), box-shadow var(--transition-base),
    background-color var(--transition-base), color var(--transition-base), border-color var(--transition-base);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

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

.btn-primary:hover {
  background-color: var(--color-accent-strong);
  color: var(--color-on-accent);
  box-shadow: var(--shadow-card);
}

.btn-outline {
  border-color: var(--color-text);
  color: var(--color-text);
  background: transparent;
}

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

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

.btn-ink:hover {
  box-shadow: var(--shadow-card);
  color: var(--color-on-ink);
}

/* ==========================================================================
   Header / Navigation (Flexbox: logo left, menu right)
   ========================================================================== */

.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--nav-height);
  z-index: 100;
  background-color: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color var(--transition-base), box-shadow var(--transition-base),
    border-color var(--transition-base);
}

.site-header.is-scrolled {
  background-color: var(--color-surface);
  border-color: var(--color-border);
  box-shadow: var(--shadow-nav);
}

.navbar {
  height: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-2);
  color: var(--color-text);
}

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

.logo-name {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.25rem;
}

.logo-since {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  color: var(--color-muted);
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border-strong);
  background-color: var(--color-surface);
  cursor: pointer;
  transition: border-color var(--transition-base), transform var(--transition-base), color var(--transition-base);
}

.theme-toggle:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: rotate(15deg);
}

.theme-toggle .icon-sun {
  display: none;
}

[data-theme='dark'] .theme-toggle .icon-moon {
  display: none;
}

[data-theme='dark'] .theme-toggle .icon-sun {
  display: block;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0 11px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle-bar {
  width: 22px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.nav-toggle.is-active .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-active .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-active .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-menu {
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  display: flex;
  flex-direction: column;
  padding: var(--space-2) var(--container-pad) var(--space-6);
  background-color: var(--color-bg);
  border-bottom: 1.5px solid var(--color-text);
  transform: translateY(-8px);
  opacity: 0;
  visibility: hidden;
  transition: transform var(--transition-base), opacity var(--transition-base), visibility 0s linear var(--transition-base);
}

.nav-menu.is-open {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
  transition: transform var(--transition-base), opacity var(--transition-base), visibility 0s;
}

.nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 3.5rem;
  border-bottom: 1px solid var(--color-border);
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
}

.nav-menu li:last-child .nav-link {
  border-bottom: none;
}

.nav-link:hover {
  color: var(--color-accent);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--color-muted);
}

/* ==========================================================================
   Hero
   ========================================================================== */

.hero {
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding-block: calc(var(--nav-height) + var(--space-12)) var(--space-16);
  background-image: repeating-linear-gradient(to bottom, transparent 0 31px, var(--color-rule) 31px 32px);
}

.hero-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-10);
}

.hero-copy {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.hero-title {
  font-size: clamp(2.25rem, 1.1rem + 4vw, 4.25rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
}

.hero-title br {
  display: none;
}

.hero-role {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-muted);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 1.5em;
}

.hero-role-typed {
  color: var(--color-accent);
}

.hero-caret {
  display: inline-block;
  width: 2px;
  height: 1.1em;
  background-color: var(--color-accent);
  animation: blink 1s steps(2, start) infinite;
}

@keyframes blink {
  to {
    visibility: hidden;
  }
}

.hero-subtitle {
  font-size: clamp(1rem, 0.9rem + 0.5vw, 1.25rem);
  color: var(--color-muted);
  max-width: 40rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  padding-top: var(--space-2);
}

.hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-3);
  padding-top: var(--space-5);
  border-top: 1.5px solid var(--color-text);
}

.fact {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.fact dt {
  order: 2;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  color: var(--color-muted);
}

.fact dd strong {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 1.2rem + 2vw, 2.75rem);
  font-weight: 700;
  line-height: 1;
}

.fact-unit {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 0.9rem;
  margin-left: 0.2em;
}

.fact-note {
  order: 3;
  display: none;
  font-size: 0.85rem;
  color: var(--color-muted);
}

/* ==========================================================================
   About
   ========================================================================== */

.about-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.about-photo {
  position: relative;
  margin: 0;
  width: 200px;
  aspect-ratio: 4 / 5;
}

.about-photo::before {
  content: '';
  position: absolute;
  inset: 12px -12px -12px 12px;
  background-color: var(--color-accent);
  opacity: 0.18;
}

.about-photo img {
  position: relative;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  filter: saturate(0.85);
}

.about-photo-caption {
  position: absolute;
  left: calc(100% + var(--space-6));
  bottom: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--color-muted);
  writing-mode: vertical-rl;
  transform: rotate(180deg);
}

.about-content {
  display: flex;
  flex-direction: column;
}

.about-text {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--color-text-soft);
}

.about-facts {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-top: var(--space-8);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border);
}

.about-facts dt {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--color-muted);
  margin-bottom: var(--space-1);
}

.about-facts dd {
  font-weight: 500;
}

/* ==========================================================================
   Experience timeline
   ========================================================================== */

.timeline {
  border-top: 1px solid var(--color-border);
}

.timeline-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-block: var(--space-5);
  border-bottom: 1px solid var(--color-border);
}

.timeline-period {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-muted);
}

.timeline-role {
  font-size: 1.2rem;
  font-weight: 600;
}

.timeline-title {
  font-weight: 400;
  color: var(--color-muted);
}

.timeline-body p {
  font-size: 0.95rem;
  color: var(--color-text-soft);
  margin-top: var(--space-1);
}

/* ==========================================================================
   Skills
   ========================================================================== */

.skills-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

.skill-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  padding: var(--space-6);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.skill-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.skill-card-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.skill-card h3 {
  font-size: 1.35rem;
  font-weight: 600;
}

.skill-card-since {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--color-accent);
}

.skill-card-featured {
  background-color: var(--color-ink);
  color: var(--color-on-ink);
  border-color: var(--color-ink);
}

.skill-card-featured .tag-list li {
  border-color: var(--color-ink-border);
}

.skill-card-note {
  font-size: 0.9rem;
  color: var(--color-muted);
  margin-top: auto;
}

.skill-card-featured .skill-card-note {
  color: color-mix(in oklch, var(--color-on-ink) 70%, transparent);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.tag-list li {
  padding: 0.35rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  font-size: 0.875rem;
}

/* ==========================================================================
   Projects (Grid: auto-fit + minmax)
   ========================================================================== */

.projects-source {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-muted);
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
  min-height: 2.5rem;
}

.filter-btn {
  padding: 0.45rem 1rem;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  background: transparent;
  font-size: 0.875rem;
  cursor: pointer;
  transition: background-color var(--transition-base), color var(--transition-base), border-color var(--transition-base);
}

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

.filter-btn.is-active {
  background-color: var(--color-ink);
  color: var(--color-on-ink);
  border-color: var(--color-ink);
  font-weight: 500;
}

.projects-status {
  min-height: 1.5rem;
  margin-bottom: var(--space-4);
}

.status-loading {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-muted);
  font-size: 0.95rem;
}

.spinner {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-pill);
  border: 3px solid var(--color-border);
  border-top-color: var(--color-accent);
  animation: spin 900ms linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.status-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-10) var(--space-6);
  border-radius: var(--radius-md);
  text-align: center;
}

.status-panel .icon {
  width: 2.25rem;
  height: 2.25rem;
  stroke-width: 1.6;
}

.status-panel h3 {
  font-size: 1.25rem;
  font-weight: 600;
}

.status-panel p {
  font-size: 0.9rem;
  color: var(--color-muted);
}

.status-error {
  border: 1.5px dashed var(--color-error);
}

.status-error .icon {
  color: var(--color-error);
}

.status-empty {
  border: 1px solid var(--color-border);
  background-color: color-mix(in oklch, var(--color-surface) 50%, var(--color-bg));
}

.status-empty .icon {
  color: var(--color-muted);
}

.retry-btn {
  margin-top: var(--space-2);
  min-height: 2.75rem;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr));
  gap: var(--space-5);
}

.project-card,
.skeleton-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-6);
  min-height: 220px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
}

.project-card {
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-border-strong);
}

.project-card-meta,
.project-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--color-muted);
}

.project-card-meta {
  font-family: var(--font-mono);
}

.project-card-stars {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-sans);
}

.project-card-title {
  font-size: 1.3rem;
  font-weight: 600;
  overflow-wrap: anywhere;
}

.project-card-desc {
  font-size: 0.9rem;
  color: var(--color-text-soft);
  flex-grow: 1;
}

.project-card-desc.is-empty {
  color: var(--color-muted);
  font-style: italic;
}

.project-card-lang {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.lang-dot {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-pill);
  background-color: var(--lang-color, var(--color-muted));
}

.project-card-link {
  font-weight: 600;
  font-size: 0.875rem;
}

.skeleton {
  border-radius: 3px;
  background: linear-gradient(90deg, var(--color-skeleton-a) 0%, var(--color-skeleton-b) 50%, var(--color-skeleton-a) 100%);
  background-size: 800px 100%;
  animation: shimmer 1.4s linear infinite;
}

@keyframes shimmer {
  0% {
    background-position: -400px 0;
  }

  100% {
    background-position: 400px 0;
  }
}

.projects-count {
  margin-top: var(--space-6);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-muted);
  text-align: center;
}

/* ==========================================================================
   Contact
   ========================================================================== */

.contact-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.contact-text {
  font-size: 1.05rem;
  color: var(--color-text-soft);
  max-width: 34rem;
}

.contact-channels {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-top: var(--space-6);
}

.contact-channels li {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.contact-channels .icon {
  color: var(--color-accent);
}

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

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

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
  padding: var(--space-6);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-field label {
  font-size: 0.875rem;
  font-weight: 600;
}

.form-field input,
.form-field textarea {
  width: 100%;
  font: inherit;
  font-size: 0.95rem;
  padding: 0.75rem 0.875rem;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background-color: var(--color-bg);
  color: var(--color-text);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.form-field input::placeholder,
.form-field textarea::placeholder {
  color: color-mix(in oklch, var(--color-muted) 60%, transparent);
}

.form-field input:focus,
.form-field textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px color-mix(in oklch, var(--color-accent) 22%, transparent);
}

.form-field.is-invalid input,
.form-field.is-invalid textarea {
  border-width: 1.5px;
  border-color: var(--color-error);
}

.error-message {
  min-height: 1.2em;
  font-size: 0.8rem;
  color: var(--color-error);
}

.form-footer {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.form-hint {
  font-size: 0.8rem;
  color: var(--color-muted);
}

.form-success {
  min-height: 1.2em;
  font-weight: 600;
  color: var(--color-success);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  border-top: 1.5px solid var(--color-text);
  padding-block: var(--space-8);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.footer-meta {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  font-size: 0.875rem;
}

.footer-built {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-muted);
}

.footer-links {
  display: flex;
  gap: var(--space-5);
}

.footer-links a {
  display: inline-flex;
  color: var(--color-text);
}

.footer-links .icon {
  width: 1.375rem;
  height: 1.375rem;
}

.footer-links a:hover {
  color: var(--color-accent);
}

/* ==========================================================================
   Scroll-to-top
   ========================================================================== */

.scroll-top-btn {
  position: fixed;
  right: var(--space-5);
  bottom: var(--space-5);
  width: 48px;
  height: 48px;
  border-radius: var(--radius-pill);
  border: none;
  background-color: var(--color-ink);
  color: var(--color-on-ink);
  box-shadow: var(--shadow-float);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity var(--transition-base), transform var(--transition-base), background-color var(--transition-base);
  z-index: 90;
}

.scroll-top-btn.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.scroll-top-btn:hover {
  background-color: var(--color-accent);
  color: var(--color-on-accent);
}

/* ==========================================================================
   Scroll reveal (IntersectionObserver adds .is-visible)
   ========================================================================== */

[data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Breakpoints — mobile first: 768px (tablet), 1024px (desktop)
   ========================================================================== */

@media (min-width: 768px) {
  :root {
    --nav-height: 72px;
  }

  .nav-toggle {
    display: none;
  }

  .nav-controls {
    order: 3;
  }

  .nav-menu {
    position: static;
    flex-direction: row;
    align-items: center;
    gap: var(--space-8);
    padding: 0;
    margin-left: auto;
    margin-right: var(--space-6);
    background: transparent;
    border: none;
    transform: none;
    opacity: 1;
    visibility: visible;
    transition: none;
  }

  .nav-link {
    min-height: 0;
    border: none;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 500;
  }

  .nav-index {
    display: none;
  }

  .hero {
    background-image: repeating-linear-gradient(to bottom, transparent 0 39px, var(--color-rule) 39px 40px);
  }

  .hero-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-6);
  }

  .fact-note {
    display: block;
  }

  .about-inner {
    flex-direction: row;
    align-items: flex-start;
    gap: var(--space-12);
  }

  .about-photo {
    width: 260px;
    flex-shrink: 0;
  }

  .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-6);
  }

  .timeline-item {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: var(--space-8);
    padding-block: var(--space-6);
  }

  .timeline-period {
    padding-top: 0.25rem;
  }

  .skills-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .skill-card-featured,
  .skill-card-wide {
    grid-column: span 2;
  }

  .section-heading-row {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-end;
  }

  .contact-inner {
    display: grid;
    grid-template-columns: 5fr 7fr;
    gap: var(--space-10);
    align-items: start;
  }

  .contact-form {
    padding: var(--space-8);
  }

  .form-footer {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .footer-links {
    padding-right: 4.5rem;
  }
}

@media (min-width: 1024px) {
  .hero-inner {
    display: grid;
    grid-template-columns: 8fr 4fr;
    gap: var(--space-10);
    align-items: end;
  }

  .hero-facts {
    grid-template-columns: 1fr;
    gap: 0;
    padding-top: 0;
    border-top: none;
    border-left: 1.5px solid var(--color-text);
    padding-left: var(--space-8);
  }

  .fact {
    padding-block: var(--space-5);
    border-bottom: 1px solid var(--color-border);
  }

  .fact:last-child {
    border-bottom: none;
    padding-bottom: 0;
  }

  .fact:first-child {
    padding-top: 0;
  }

  .fact dt {
    order: 0;
  }

  .about-photo {
    width: 320px;
  }

  .skills-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .skill-card-featured {
    grid-column: span 2;
  }

  .skill-card-wide {
    grid-column: span 4;
    flex-direction: row;
    align-items: center;
    gap: var(--space-8);
  }

  .skill-card-wide .skill-card-header {
    min-width: 180px;
  }

  .scroll-top-btn {
    right: var(--space-10);
    bottom: var(--space-10);
  }
}

@media (min-width: 1280px) {
  .hero-title br {
    display: inline;
  }
}

/* ==========================================================================
   Reduced motion
   ========================================================================== */

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

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

  [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .hero-caret {
    animation: none;
  }
}