/* ==============================================
   styles.css — Stefan Sturm Personal Website
   Mobile-first · iOS Blue accent · Inter font
   ============================================== */

/* -------- Tokens -------- */
:root {
  --accent:          #007AFF;
  --accent-hover:    #0056CC;
  --accent-light:    #E5F0FF;
  --accent-mid:      #b3d3ff;

  --bg:              #ffffff;
  --bg-alt:          #f4f6fb;
  --surface:         #ffffff;
  --border:          #e4e8f0;

  --text:            #111827;
  --text-muted:      #6b7280;
  --text-light:      #9ca3af;

  --font:            'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --nav-h:           4rem;
  --max-w:           74rem;
  --pad:             1rem;

  --r-sm:  0.375rem;
  --r-md:  0.5rem;
  --r-lg:  0.75rem;
  --r-xl:  1rem;
  --r-2xl: 1.5rem;
  --r-full: 9999px;

  --sh-sm: 0 1px 3px rgba(0,0,0,.07), 0 1px 2px rgba(0,0,0,.04);
  --sh-md: 0 4px 8px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.04);
  --sh-lg: 0 10px 20px rgba(0,0,0,.09), 0 4px 8px rgba(0,0,0,.05);
  --sh-xl: 0 20px 40px rgba(0,0,0,.10), 0 8px 16px rgba(0,0,0,.06);

  --ease: cubic-bezier(.4,0,.2,1);
  --t-fast: 150ms var(--ease);
  --t-base: 250ms var(--ease);
  --t-slow: 450ms var(--ease);
}

/* -------- Dark mode tokens -------- */
[data-theme="dark"] {
  --bg:          #0f1117;
  --bg-alt:      #1a1d27;
  --surface:     #1e2130;
  --border:      #2e3348;

  --text:        #f0f2f8;
  --text-muted:  #9aa3b8;
  --text-light:  #6b7491;

  --accent-light: #0f2a4a;
  --accent-mid:   #1a4a8a;

  --sh-sm: 0 1px 3px rgba(0,0,0,.3), 0 1px 2px rgba(0,0,0,.2);
  --sh-md: 0 4px 8px rgba(0,0,0,.3), 0 2px 4px rgba(0,0,0,.2);
  --sh-lg: 0 10px 20px rgba(0,0,0,.35), 0 4px 8px rgba(0,0,0,.2);
  --sh-xl: 0 20px 40px rgba(0,0,0,.4), 0 8px 16px rgba(0,0,0,.25);
}

/* -------- Theme toggle button -------- */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--r-full);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: background var(--t-fast), color var(--t-fast), border-color var(--t-fast);
  flex-shrink: 0;
}
.theme-toggle:hover {
  background: var(--accent-light);
  color: var(--accent);
  border-color: var(--accent-mid);
}

/* -------- Reset -------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font: inherit; color: inherit; }

/* -------- Accessibility -------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  background: var(--accent);
  color: #fff;
  padding: .5rem 1rem;
  border-radius: var(--r-md);
  font-weight: 600;
  z-index: 9999;
  transition: top var(--t-fast);
}
.skip-link:focus { top: .5rem; outline: 2px solid #fff; }

*:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--r-sm);
}

/* -------- Utilities -------- */
.text-accent { color: var(--accent); }
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad);
}
@media (min-width: 640px)  { :root { --pad: 1.5rem; } }
@media (min-width: 1024px) { :root { --pad: 2rem; } }

/* -------- Buttons -------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .75rem 1.5rem;
  border-radius: var(--r-full);
  font-weight: 600;
  font-size: .875rem;
  line-height: 1;
  min-height: 2.75rem; /* 44px touch target */
  white-space: nowrap;
  user-select: none;
  transition: background var(--t-base), color var(--t-base), border-color var(--t-base),
              box-shadow var(--t-base), transform var(--t-base);
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover, .btn-primary:focus-visible {
  background: var(--accent-hover);
  box-shadow: 0 4px 16px rgba(0,122,255,.35);
  transform: translateY(-1px);
}
.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 2px solid var(--accent);
}
.btn-outline:hover, .btn-outline:focus-visible {
  background: var(--accent);
  color: #fff;
  transform: translateY(-1px);
}
.btn-sm  { padding: .5rem 1rem; font-size: .75rem; min-height: 2.25rem; }
.btn-lg  { padding: .875rem 1.75rem; font-size: 1rem; min-height: 3rem; }

/* -------- Header -------- */
.header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--nav-h);
  z-index: 900;
  background: rgba(255,255,255,.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t-base), box-shadow var(--t-base), background var(--t-base);
}
[data-theme="dark"] .header { background: rgba(15,17,23,.88); }
.header.scrolled {
  border-bottom-color: var(--border);
  box-shadow: var(--sh-md);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-h);
  gap: 1rem;
}
.nav-logo {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  flex-shrink: 0;
}
.nav-logo-name  { font-weight: 700; font-size: 1rem; color: var(--text); }
.nav-logo-title { font-size: .75rem; color: var(--accent); font-weight: 500; }

.nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem; height: 2.75rem;
  border-radius: var(--r-md);
  color: var(--text);
  font-size: 1.125rem;
  transition: background var(--t-fast);
}
.nav-toggle:hover, .nav-toggle:focus-visible { background: var(--bg-alt); }

/* Mobile nav menu (drawer) */
.nav-menu {
  display: none;
  flex-direction: column;
  position: fixed;
  top: var(--nav-h);
  left: 0; right: 0;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: .75rem 1rem 1rem;
  gap: .25rem;
  box-shadow: var(--sh-lg);
  max-height: calc(100dvh - var(--nav-h));
  overflow-y: auto;
}
.nav-menu.open { display: flex; }

.nav-link {
  display: flex;
  align-items: center;
  padding: .75rem 1rem;
  border-radius: var(--r-md);
  font-weight: 500;
  font-size: .9375rem;
  color: var(--text);
  min-height: 2.75rem;
  transition: background var(--t-fast), color var(--t-fast);
}
.nav-link:hover, .nav-link.active {
  background: var(--accent-light);
  color: var(--accent);
}

/* Desktop nav */
@media (min-width: 1024px) {
  .nav-toggle { display: none; }
  .nav-menu {
    display: flex;
    flex-direction: row;
    align-items: center;
    position: static;
    background: none;
    border: none;
    padding: 0;
    gap: .25rem;
    box-shadow: none;
    max-height: none;
    overflow: visible;
  }
  .nav-link { font-size: .875rem; padding: .5rem .75rem; min-height: 2.25rem; }
}

/* -------- Sections -------- */
.section { padding: 4.5rem 0; }
.section-alt { background: var(--bg-alt); }
@media (min-width: 768px) { .section { padding: 6rem 0; } }

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 800;
  letter-spacing: -.025em;
  margin-bottom: 2.5rem;
  position: relative;
  padding-bottom: 1rem;
}
.section-title::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0;
  width: 3rem; height: 3px;
  background: var(--accent);
  border-radius: var(--r-full);
}

/* -------- Hero -------- */
.hero {
  position: relative;
  overflow: hidden;
  padding-top: calc(var(--nav-h) + 3.5rem);
  padding-bottom: 4rem;
  background: linear-gradient(160deg, #edf4ff 0%, #fff 50%, #f0f5ff 100%);
  min-height: 100svh;
  display: flex;
  align-items: center;
}
[data-theme="dark"] .hero { background: linear-gradient(160deg, #0d1829 0%, #0f1117 50%, #101524 100%); }
[data-theme="dark"] .shape-1 { background: radial-gradient(circle, rgba(0,122,255,.18), transparent 70%); }
[data-theme="dark"] .shape-2 { background: radial-gradient(circle, rgba(0,86,204,.15), transparent 70%); }
[data-theme="dark"] .shape-3 { background: radial-gradient(circle, rgba(88,86,214,.12), transparent 70%); }

/* Background decorative shapes */
.hero-bg-shapes { pointer-events: none; position: absolute; inset: 0; overflow: hidden; }
.shape {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: .45;
}
.shape-1 {
  width: 28rem; height: 28rem;
  background: radial-gradient(circle, #b3d3ff, transparent 70%);
  top: -8rem; right: -6rem;
}
.shape-2 {
  width: 20rem; height: 20rem;
  background: radial-gradient(circle, #c7d9ff, transparent 70%);
  bottom: -4rem; left: -4rem;
}
.shape-3 {
  width: 14rem; height: 14rem;
  background: radial-gradient(circle, #d0e8ff, transparent 70%);
  top: 40%; left: 50%;
}

.hero-grid {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
  align-items: center;
}
.hero-content {
  text-align: center;
  max-width: 38rem;
  margin: 0 auto;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  background: var(--accent-light);
  color: var(--accent);
  font-size: .8125rem;
  font-weight: 700;
  padding: .375rem 1rem;
  border-radius: var(--r-full);
  margin-bottom: 1.25rem;
  letter-spacing: .02em;
  text-transform: uppercase;
}
.hero-name {
  font-size: clamp(2.75rem, 10vw, 4.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -.04em;
  margin-bottom: .5rem;
}
.hero-tagline {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 1rem;
}
.hero-bio {
  font-size: .9375rem;
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 1.75rem;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  justify-content: center;
  margin-bottom: 1.5rem;
}
.hero-social {
  display: flex;
  gap: .75rem;
  justify-content: center;
  flex-wrap: wrap;
}
.hero-social-link {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  color: var(--text-muted);
  font-size: .875rem;
  font-weight: 500;
  padding: .5rem .875rem;
  border-radius: var(--r-full);
  border: 1px solid var(--border);
  background: var(--surface);
  min-height: 2.75rem;
  transition: all var(--t-base);
  box-shadow: var(--sh-sm);
}
.hero-social-link:hover, .hero-social-link:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 4px 12px rgba(0,122,255,.15);
  transform: translateY(-1px);
}

/* Hero aside */
.hero-aside {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.75rem;
  flex-shrink: 0;
}
.hero-avatar {
  position: relative;
  width: 10rem; height: 10rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent) 0%, #5856D6 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  box-shadow: 0 0 0 4px var(--surface), 0 0 0 8px var(--accent-light), var(--sh-xl);
}
.hero-avatar img {
  width: 100%; height: 100%;
  object-fit: cover;
  object-position: center top;
}
.avatar-initials {
  font-size: 2.5rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -.05em;
  display: none;
  align-items: center;
  justify-content: center;
  width: 100%; height: 100%;
  position: absolute;
  inset: 0;
}
.hero-stats {
  display: flex;
  gap: .75rem;
  flex-wrap: wrap;
  justify-content: center;
}
.hero-stat {
  text-align: center;
  background: var(--surface);
  border-radius: var(--r-xl);
  padding: .875rem 1.25rem;
  box-shadow: var(--sh-md);
  border: 1px solid var(--border);
  min-width: 5.5rem;
  transition: transform var(--t-base), box-shadow var(--t-base);
}
.hero-stat:hover { transform: translateY(-2px); box-shadow: var(--sh-lg); }
.hero-stat-val {
  display: block;
  font-size: 1.625rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  letter-spacing: -.03em;
  margin-bottom: .25rem;
}
.hero-stat-lbl {
  display: block;
  font-size: .6875rem;
  color: var(--text-muted);
  font-weight: 500;
  line-height: 1.3;
}

@media (min-width: 768px) {
  .hero-avatar { width: 13rem; height: 13rem; }
  .avatar-initials { font-size: 3.25rem; }
}
@media (min-width: 1024px) {
  .hero { min-height: auto; padding-bottom: 5rem; }
  .hero-grid { flex-direction: row-reverse; justify-content: space-between; align-items: center; gap: 4rem; }
  .hero-content { text-align: left; margin: 0; flex: 1; }
  .hero-actions { justify-content: flex-start; }
  .hero-social  { justify-content: flex-start; }
  .hero-avatar  { width: 16rem; height: 16rem; }
  .avatar-initials { font-size: 4rem; }
}

/* -------- About -------- */
.about-content { max-width: 50rem; }
.about-content p {
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}
.about-content p:last-child { margin-bottom: 0; }
.about-langs {
  display: flex;
  gap: .75rem;
  flex-wrap: wrap;
  margin-top: 1.75rem;
}
.lang-chip {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  padding: .875rem 1.5rem;
  box-shadow: var(--sh-sm);
  gap: .25rem;
}
.lang-name  { font-weight: 700; font-size: 1rem; }
.lang-level {
  font-size: .75rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-light);
  padding: .125rem .5rem;
  border-radius: var(--r-full);
}
.lang-note  { font-size: .75rem; color: var(--text-light); }

/* -------- Timeline (Experience) -------- */
.timeline {
  position: relative;
  padding-left: 1.25rem;
}
.timeline::before {
  content: '';
  position: absolute;
  left: .5rem; top: .6rem; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent) 0%, var(--border) 100%);
  border-radius: var(--r-full);
}
.timeline-item {
  position: relative;
  padding-left: 2rem;
  padding-bottom: 2.25rem;
}
.timeline-item:last-child { padding-bottom: 0; }

/* Dot */
.timeline-item::before {
  content: '';
  position: absolute;
  left: .125rem; top: .5rem;
  width: .875rem; height: .875rem;
  border-radius: 50%;
  background: var(--accent);
  border: 2.5px solid var(--bg);
  box-shadow: 0 0 0 2px var(--accent);
  transition: box-shadow var(--t-slow);
}
.timeline-item.current::before {
  animation: dot-pulse 2.2s ease-in-out infinite;
}
@keyframes dot-pulse {
  0%,100% { box-shadow: 0 0 0 2px var(--accent); }
  50%      { box-shadow: 0 0 0 7px rgba(0,122,255,.18); }
}

.timeline-period {
  font-size: .75rem;
  font-weight: 700;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: .06em;
  margin-bottom: .5rem;
}
.timeline-card {
  background: var(--surface);
  border-radius: var(--r-xl);
  padding: 1.5rem;
  box-shadow: var(--sh-md);
  border: 1px solid var(--border);
  transition: box-shadow var(--t-base), transform var(--t-base), border-color var(--t-base);
}
.timeline-card:hover {
  box-shadow: var(--sh-lg);
  transform: translateY(-2px);
  border-color: var(--accent-mid);
}
.timeline-role {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: .2rem;
}
.timeline-company {
  font-size: .9375rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: .15rem;
}
.timeline-meta {
  display: flex;
  gap: .75rem;
  flex-wrap: wrap;
  font-size: .8125rem;
  color: var(--text-light);
  margin-bottom: .75rem;
  align-items: center;
}
.timeline-meta i { font-size: .75rem; }
.timeline-app-link {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  font-size: .8125rem;
  color: var(--accent);
  font-weight: 500;
  background: var(--accent-light);
  padding: .3rem .75rem;
  border-radius: var(--r-full);
  margin-bottom: .75rem;
  transition: background var(--t-fast);
  min-height: 2rem;
  word-break: break-all;
}
.timeline-app-link:hover { background: var(--accent-mid); }
.timeline-desc {
  font-size: .875rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 1rem;
}
.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .375rem;
}
.tech-tag {
  font-size: .7rem;
  font-weight: 500;
  background: var(--bg-alt);
  color: var(--text-muted);
  padding: .25rem .6rem;
  border-radius: var(--r-full);
  border: 1px solid var(--border);
  white-space: nowrap;
  transition: background var(--t-fast), color var(--t-fast), border-color var(--t-fast);
}
.tech-tag:hover {
  background: var(--accent-light);
  color: var(--accent);
  border-color: var(--accent-mid);
}

@media (min-width: 768px) {
  .timeline { padding-left: 2.5rem; }
  .timeline::before { left: 1rem; }
  .timeline-item { padding-left: 3.25rem; }
  .timeline-item::before { left: .625rem; }
}

/* -------- Skills -------- */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}
@media (min-width: 640px)  { .skills-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .skills-grid { grid-template-columns: repeat(3, 1fr); } }

.skill-card {
  background: var(--surface);
  border-radius: var(--r-xl);
  padding: 1.5rem;
  box-shadow: var(--sh-md);
  border: 1px solid var(--border);
  transition: box-shadow var(--t-base), transform var(--t-base);
}
.skill-card:hover { box-shadow: var(--sh-lg); transform: translateY(-2px); }
.skill-card-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: .5rem;
  color: var(--text);
}
.skill-card-title i { color: var(--accent); font-size: .9375rem; }
.skill-chips {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}
.skill-chip {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--r-full);
  padding: .375rem .75rem;
  font-size: .8125rem;
  font-weight: 500;
  color: var(--text);
  transition: all var(--t-fast);
}
.skill-chip:hover {
  background: var(--accent-light);
  border-color: var(--accent-mid);
  color: var(--accent);
}
.skill-years {
  font-size: .6875rem;
  color: var(--text-light);
  background: var(--bg);
  padding: .1rem .45rem;
  border-radius: var(--r-full);
  border: 1px solid var(--border);
  white-space: nowrap;
}

/* -------- Projects -------- */
.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}
@media (min-width: 768px) { .projects-grid { grid-template-columns: repeat(2, 1fr); } }

.project-card {
  background: var(--surface);
  border-radius: var(--r-2xl);
  padding: 1.75rem;
  box-shadow: var(--sh-md);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: all var(--t-base);
}
.project-card:hover {
  box-shadow: var(--sh-xl);
  transform: translateY(-4px);
  border-color: var(--accent-mid);
}
.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: .75rem;
  flex-wrap: wrap;
}
.project-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
}
.project-badge {
  font-size: .6875rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-light);
  padding: .25rem .625rem;
  border-radius: var(--r-full);
  white-space: nowrap;
  text-transform: uppercase;
  letter-spacing: .04em;
}
.project-store-link {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  color: var(--accent);
  font-size: .875rem;
  font-weight: 600;
  min-height: 2.75rem;
  padding: .375rem 0;
  transition: color var(--t-fast);
}
.project-store-link:hover { text-decoration: underline; color: var(--accent-hover); }
.project-desc {
  font-size: .875rem;
  color: var(--text-muted);
  line-height: 1.75;
  flex: 1;
}

/* -------- Education -------- */
.education-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: .875rem;
}
@media (min-width: 640px)  { .education-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .education-grid { grid-template-columns: repeat(3, 1fr); } }

.edu-card {
  background: var(--surface);
  border-radius: var(--r-xl);
  padding: 1.25rem 1.5rem;
  box-shadow: var(--sh-sm);
  border: 1px solid var(--border);
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  transition: box-shadow var(--t-base), transform var(--t-base);
}
.edu-card:hover { box-shadow: var(--sh-md); transform: translateY(-1px); }
.edu-period {
  font-size: .75rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-light);
  padding: .3rem .6rem;
  border-radius: var(--r-md);
  white-space: nowrap;
  flex-shrink: 0;
  align-self: flex-start;
  line-height: 1.4;
  text-align: center;
}
.edu-degree {
  font-size: .9375rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: .2rem;
  line-height: 1.3;
}
.edu-inst {
  font-size: .8125rem;
  color: var(--text-muted);
  font-style: italic;
}

/* -------- Contact -------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: .875rem;
  max-width: 40rem;
}
@media (min-width: 560px) { .contact-layout { grid-template-columns: repeat(2, 1fr); } }

.contact-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: var(--surface);
  border-radius: var(--r-xl);
  padding: 1.125rem 1.25rem;
  box-shadow: var(--sh-sm);
  border: 1px solid var(--border);
  min-height: 4.5rem;
  transition: all var(--t-base);
}
.contact-card:hover {
  box-shadow: var(--sh-md);
  border-color: var(--accent-mid);
  transform: translateY(-1px);
}
.contact-icon {
  width: 2.75rem; height: 2.75rem;
  border-radius: var(--r-lg);
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  font-size: 1rem;
  flex-shrink: 0;
}
.contact-lbl {
  font-size: .6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-light);
  margin-bottom: .2rem;
}
.contact-val {
  font-size: .875rem;
  font-weight: 500;
  color: var(--text);
  word-break: break-all;
}
.contact-val a {
  color: var(--accent);
  transition: color var(--t-fast);
}
.contact-val a:hover { text-decoration: underline; color: var(--accent-hover); }

/* -------- Footer -------- */
.footer {
  padding: 2.5rem 0;
  background: var(--text);
  color: rgba(255,255,255,.55);
  text-align: center;
  font-size: .875rem;
}
.footer-sub { font-size: .8125rem; margin-top: .25rem; color: rgba(255,255,255,.35); }

/* -------- PDF overlay -------- */
.pdf-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.55);
  z-index: 9999;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}
.pdf-overlay.active { display: flex; }
.pdf-overlay-inner {
  background: var(--surface);
  border-radius: var(--r-2xl);
  padding: 2.5rem 3rem;
  text-align: center;
  box-shadow: var(--sh-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}
.pdf-overlay-inner p { font-weight: 600; color: var(--text); }
.pdf-spinner {
  width: 3rem; height: 3rem;
  border: 3px solid var(--accent-light);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* -------- Scroll reveal -------- */
.reveal {
  opacity: 0;
  transform: translateY(1.75rem);
  transition: opacity var(--t-slow), transform var(--t-slow);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* -------- Reduced motion -------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  html { scroll-behavior: auto; }
}

/* -------- AI & Tools Section -------- */
.ai-intro {
  font-size: 1.0625rem;
  color: var(--text-muted);
  line-height: 1.8;
  max-width: 50rem;
  margin-bottom: 2.5rem;
}

/* Journey */
.ai-journey {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-bottom: 2.75rem;
}
@media (min-width: 640px) { .ai-journey { grid-template-columns: repeat(2, 1fr); } }

.ai-journey-card {
  background: var(--surface);
  border-radius: var(--r-xl);
  padding: 1.5rem;
  box-shadow: var(--sh-md);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: .75rem;
  transition: box-shadow var(--t-base), transform var(--t-base);
}
.ai-journey-card:hover { box-shadow: var(--sh-lg); transform: translateY(-2px); }
.ai-journey-card.highlight {
  border-color: var(--accent-mid);
  background: linear-gradient(135deg, var(--accent-light) 0%, var(--surface) 100%);
}
.ai-journey-header {
  display: flex;
  align-items: center;
  gap: .75rem;
}
.ai-journey-icon {
  width: 2.5rem; height: 2.5rem;
  border-radius: var(--r-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .9375rem;
  flex-shrink: 0;
}
.ai-journey-icon.accent  { background: var(--accent-light); color: var(--accent); }
.ai-journey-icon.orange  { background: #fff3e0; color: #e65100; }
[data-theme="dark"] .ai-journey-icon.orange { background: #2d1a00; color: #ff8c42; }
.ai-journey-phase {
  font-size: .9375rem;
  font-weight: 700;
  color: var(--text);
}
.ai-journey-desc {
  font-size: .875rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* Learnings */
.ai-sub-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.ai-sub-title i { color: var(--accent); }

.ai-learnings {
  display: grid;
  grid-template-columns: 1fr;
  gap: .625rem;
  margin-bottom: 2.75rem;
}
@media (min-width: 768px) { .ai-learnings { grid-template-columns: repeat(2, 1fr); } }

.ai-learning-item {
  display: flex;
  align-items: flex-start;
  gap: .75rem;
  background: var(--surface);
  border-radius: var(--r-lg);
  padding: 1rem 1.25rem;
  box-shadow: var(--sh-sm);
  border: 1px solid var(--border);
  font-size: .875rem;
  color: var(--text-muted);
  line-height: 1.65;
  transition: box-shadow var(--t-base), border-color var(--t-base);
}
.ai-learning-item:hover { box-shadow: var(--sh-md); border-color: var(--accent-mid); }
.ai-learning-bullet {
  width: 1.5rem; height: 1.5rem;
  border-radius: 50%;
  background: var(--accent-light);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .625rem;
  font-weight: 800;
  flex-shrink: 0;
  margin-top: .05rem;
}

/* Model Matrix */
.ai-models-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-bottom: 2.75rem;
}
@media (min-width: 640px)  { .ai-models-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .ai-models-grid { grid-template-columns: repeat(3, 1fr); } }

.ai-model-card {
  background: var(--surface);
  border-radius: var(--r-xl);
  padding: 1.25rem 1.5rem;
  box-shadow: var(--sh-sm);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: .75rem;
  transition: box-shadow var(--t-base), transform var(--t-base);
}
.ai-model-card:hover { box-shadow: var(--sh-md); transform: translateY(-2px); }
.ai-model-header {
  display: flex;
  align-items: center;
  gap: .625rem;
}
.ai-model-icon {
  width: 2.25rem; height: 2.25rem;
  border-radius: var(--r-md);
  background: var(--accent-light);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .875rem;
  flex-shrink: 0;
}
.ai-model-category {
  font-size: .9rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}
.ai-model-desc {
  font-size: .8125rem;
  color: var(--text-muted);
  line-height: 1.6;
}
.ai-model-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .375rem;
}
.ai-model-tag {
  font-size: .7rem;
  font-weight: 600;
  background: var(--accent-light);
  color: var(--accent);
  padding: .25rem .625rem;
  border-radius: var(--r-full);
  border: 1px solid var(--accent-mid);
}

/* Tool Stack */
.ai-tools-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: .75rem;
  margin-bottom: 2rem;
}
@media (min-width: 480px)  { .ai-tools-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .ai-tools-grid { grid-template-columns: repeat(3, 1fr); } }

.ai-tool-card {
  display: flex;
  align-items: center;
  gap: .875rem;
  background: var(--surface);
  border-radius: var(--r-lg);
  padding: .875rem 1.1rem;
  box-shadow: var(--sh-sm);
  border: 1px solid var(--border);
  min-height: 3.5rem;
  transition: all var(--t-base);
}
.ai-tool-card:hover {
  box-shadow: var(--sh-md);
  border-color: var(--accent-mid);
  transform: translateX(3px);
}
.ai-tool-icon {
  width: 2.25rem; height: 2.25rem;
  border-radius: var(--r-md);
  background: var(--accent-light);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .875rem;
  flex-shrink: 0;
}
.ai-tool-name {
  font-size: .9rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: .1rem;
}
.ai-tool-desc {
  font-size: .75rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* Blog link */
.ai-blog-link {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  color: var(--accent);
  font-size: .875rem;
  font-weight: 600;
  padding: .625rem 1.25rem;
  border-radius: var(--r-full);
  border: 1.5px solid var(--accent);
  min-height: 2.75rem;
  transition: all var(--t-base);
  margin-top: .5rem;
}
.ai-blog-link:hover {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 12px rgba(0,122,255,.25);
}