/* ===== Variables & reset ===== */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f4f7fb;
  --color-ink: #0b1f3a;
  --color-ink-soft: #44546a;
  --color-accent: #0284c7;
  --color-accent-strong: #0369a1;
  --color-accent-soft: #e0f2fe;
  --color-border: #dbe4ef;
  --color-success: #15803d;
  --color-error: #b91c1c;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius: 12px;
  --shadow: 0 4px 20px rgba(11, 31, 58, 0.07);
  --container: 1080px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  color: var(--color-ink);
  background: var(--color-bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--color-accent-strong); text-decoration: none; }
ul { list-style: none; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 1.5rem; }
.accent { color: var(--color-accent); }
.icon { width: 1.1em; height: 1.1em; flex-shrink: 0; }

/* ===== Header / nav ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: 68px;
}

.nav-logo {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-ink);
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-links a:not(.btn) {
  color: var(--color-ink-soft);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.15s;
}
.nav-links a:not(.btn):hover { color: var(--color-accent-strong); }

.nav-actions { display: flex; align-items: center; gap: 0.75rem; }

.lang-toggle {
  display: flex;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  overflow: hidden;
}
.lang-btn {
  border: none;
  background: transparent;
  padding: 0.3rem 0.7rem;
  font: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-ink-soft);
  cursor: pointer;
}
.lang-btn.active {
  background: var(--color-ink);
  color: #fff;
}

.nav-burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: transparent;
  cursor: pointer;
  padding: 0 10px;
}
.nav-burger span {
  height: 2px;
  background: var(--color-ink);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}
.nav-burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s, transform 0.1s;
}
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--color-accent);
  color: #fff;
}
.btn-primary:hover { background: var(--color-accent-strong); }

.btn-outline {
  border-color: var(--color-border);
  color: var(--color-ink);
  background: transparent;
}
.btn-outline:hover { border-color: var(--color-accent); color: var(--color-accent-strong); }

.btn-small { padding: 0.45rem 1rem; font-size: 0.85rem; }
.btn-full { width: 100%; }

/* ===== Hero ===== */
.hero {
  padding: 6.5rem 0 5.5rem;
  background:
    radial-gradient(circle at 85% 20%, var(--color-accent-soft) 0%, transparent 45%),
    linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
  border-bottom: 1px solid var(--color-border);
}

.hero-inner { max-width: 780px; }

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.hero-subtitle {
  display: block;
  font-size: clamp(1.15rem, 2.5vw, 1.5rem);
  font-weight: 600;
  color: var(--color-ink-soft);
  letter-spacing: -0.01em;
  margin-top: 0.75rem;
  line-height: 1.4;
}

.hero-lead {
  font-size: 1.1rem;
  color: var(--color-ink-soft);
  max-width: 620px;
  margin-bottom: 2rem;
}

.hero-cta { display: flex; flex-wrap: wrap; gap: 0.9rem; margin-bottom: 2.5rem; }

.hero-points { display: grid; gap: 0.5rem; }
.hero-points li {
  position: relative;
  padding-left: 1.6rem;
  color: var(--color-ink-soft);
  font-size: 0.98rem;
}
.hero-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.45em;
  width: 0.75em;
  height: 0.4em;
  border-left: 2.5px solid var(--color-accent);
  border-bottom: 2.5px solid var(--color-accent);
  transform: rotate(-45deg);
}

/* ===== Sections ===== */
.section { padding: 5.5rem 0; }
.section-alt { background: var(--color-bg-alt); border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); }

.section-title {
  font-size: clamp(1.7rem, 3.5vw, 2.2rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}
.section-number {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-accent);
  font-variant-numeric: tabular-nums;
}
.section-intro {
  color: var(--color-ink-soft);
  max-width: 640px;
  margin-bottom: 3rem;
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr;
  gap: 3rem;
  align-items: start;
  margin-top: 2rem;
}
.about-text p + p { margin-top: 1.1rem; }
.about-text { color: var(--color-ink-soft); font-size: 1.03rem; }

.about-facts {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.75rem;
}
.about-facts h3 { font-size: 1.05rem; margin-bottom: 1rem; }
.about-facts ul { display: grid; gap: 0.8rem; }
.about-facts li { font-size: 0.95rem; color: var(--color-ink-soft); }
.about-facts strong { color: var(--color-ink); display: block; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.04em; }

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.skill-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.9rem;
  box-shadow: var(--shadow);
}

.skill-icon {
  width: 46px;
  height: 46px;
  border-radius: 10px;
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
  display: grid;
  place-items: center;
  margin-bottom: 1.1rem;
}
.skill-icon svg { width: 24px; height: 24px; }

.skill-card h3 { font-size: 1.15rem; margin-bottom: 0.5rem; }
.skill-card p { color: var(--color-ink-soft); font-size: 0.95rem; margin-bottom: 1.1rem; }

.skill-tags { display: flex; flex-wrap: wrap; gap: 0.45rem; }
.skill-tags li {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-ink-soft);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 0.25rem 0.7rem;
}

/* ===== Experience & projects ===== */
.subsection-title {
  font-size: 1.05rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-ink);
  margin: 2.5rem 0 1.5rem;
}
.section-title + .subsection-title { margin-top: 2rem; }

.xp-timeline {
  display: grid;
  gap: 1.25rem;
  margin-bottom: 1.5rem;
}
.xp-item {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 1.5rem;
  padding-left: 1.25rem;
  border-left: 3px solid var(--color-accent-soft);
}
.xp-period {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--color-accent-strong);
  font-variant-numeric: tabular-nums;
  padding-top: 0.15rem;
}
.xp-body h4 { font-size: 1.05rem; margin-bottom: 0.35rem; }
.xp-body p { color: var(--color-ink-soft); font-size: 0.95rem; }

.projects-list { display: grid; gap: 1.5rem; }

.project-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
}

.project-card header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.4rem;
}
.project-card h3 { font-size: 1.2rem; }
.project-card .skill-tags li { background: var(--color-accent-soft); border-color: transparent; color: var(--color-accent-strong); }

.project-card dl { display: grid; gap: 1rem; }
.project-card dt {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent-strong);
  margin-bottom: 0.15rem;
}
.project-card dd { color: var(--color-ink-soft); font-size: 0.97rem; }

/* ===== Roundfair app card ===== */
.app-card {
  background: linear-gradient(135deg, var(--color-accent-soft) 0%, var(--color-bg) 55%);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2.5rem;
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 2rem;
  align-items: start;
  box-shadow: var(--shadow);
}

.app-logo {
  width: 96px;
  height: 96px;
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.app-tagline {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent-strong);
  margin-bottom: 0.4rem;
}
.app-body h3 { font-size: 1.35rem; letter-spacing: -0.01em; margin-bottom: 0.9rem; }
.app-body p:not(.app-tagline):not(.app-soon) { color: var(--color-ink-soft); margin-bottom: 1rem; max-width: 640px; }

.app-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-top: 1.4rem;
}
.app-soon {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-ink-soft);
}

/* ===== Contact ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 3rem;
  align-items: start;
  margin-top: 2rem;
}

.contact-info h3 { font-size: 1.35rem; letter-spacing: -0.01em; margin-bottom: 0.9rem; }
.contact-info p { color: var(--color-ink-soft); margin-bottom: 1.75rem; }

.contact-links { display: flex; flex-direction: column; align-items: flex-start; gap: 0.9rem; }
.contact-email { font-weight: 600; font-size: 0.98rem; }

.contact-form {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
}

.form-field { margin-bottom: 1.25rem; }
.form-field label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.4rem;
}
.form-field input,
.form-field textarea {
  width: 100%;
  font: inherit;
  color: var(--color-ink);
  background: var(--color-bg-alt);
  border: 1.5px solid var(--color-border);
  border-radius: 8px;
  padding: 0.7rem 0.9rem;
  transition: border-color 0.15s, background 0.15s;
}
.form-field input:focus,
.form-field textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  background: var(--color-bg);
}
.form-field textarea { resize: vertical; }

.form-status { margin-top: 0.9rem; font-size: 0.92rem; font-weight: 500; min-height: 1.4em; }
.form-status.success { color: var(--color-success); }
.form-status.error { color: var(--color-error); }

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.9rem;
  color: var(--color-ink-soft);
}
.footer-links { display: flex; gap: 1.5rem; }
.footer-links a { color: var(--color-ink-soft); font-weight: 500; }
.footer-links a:hover { color: var(--color-accent-strong); }

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .about-grid,
  .contact-grid { grid-template-columns: 1fr; gap: 2rem; }
  .skills-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .nav-burger { display: flex; }

  .nav-links {
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 0.5rem 1.5rem 1.25rem;
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a:not(.btn) { display: block; padding: 0.8rem 0; font-size: 1.05rem; }
  .nav-linkedin { margin-top: 0.75rem; justify-content: center; }

  .hero { padding: 4.5rem 0 4rem; }
  .section { padding: 4rem 0; }
  .xp-item { grid-template-columns: 1fr; gap: 0.25rem; }
  .app-card { grid-template-columns: 1fr; padding: 1.75rem; }
  .app-logo { width: 72px; height: 72px; border-radius: 18px; }
  .hero-cta .btn { flex: 1 1 auto; }
  .project-card, .contact-form { padding: 1.5rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}