:root {
  --bg: #f5f5f5;
  --fg: #333;
  --primary: #000;
  --accent: #444;
  --radius: 12px;
  --maxw: 980px;
  --space: clamp(0.75rem, 2vw, 1.25rem);
  --transition: 0.25s ease-in-out;
  font-size: 16px;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  line-height: 1.6;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--primary);
  color: #fff;
  padding: 0 var(--space);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.125rem;
}

.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: var(--space);
}

.main-nav a {
  color: #fff;
  text-decoration: none;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  transition: background var(--transition);
}

.main-nav a:hover,
.main-nav a:focus {
  background: var(--accent);
}

.menu-toggle {
  display: none;
}

.hamburger {
  display: none;
  cursor: pointer;
  width: 28px;
  height: 22px;
  position: relative;
}

.hamburger span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 3px;
  background: #fff;
  transition: transform var(--transition), opacity var(--transition);
}

.hamburger span:nth-child(1) {
  top: 0;
}

.hamburger span:nth-child(2) {
  top: 9px;
}

.hamburger span:nth-child(3) {
  top: 18px;
}

.menu-toggle:checked+.hamburger span:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}

.menu-toggle:checked+.hamburger span:nth-child(2) {
  opacity: 0;
}

.menu-toggle:checked+.hamburger span:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

.menu-toggle:checked~.main-nav {
  max-height: 260px;
  opacity: 1;
}

.section {
  background: #fff;
  padding: var(--space);
  margin-top: var(--space);
  border-radius: var(--radius);
  box-shadow: 0 2px 6px rgba(0, 0, 0, .06);
}

.section h2 {
  margin-top: 0;
  text-align: center;
  font-size: clamp(1.25rem, 3vw, 1.75rem);
}

.container {
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 0 var(--space) var(--space);
}

.welcome {
  text-align: center;
  background: var(--primary);
  color: #fff;
  padding: clamp(2rem, 6vw, 4rem) var(--space);
  margin-top: 0;
}

.welcome h1 {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  line-height: 1.3;
}

.nickname {
  font-size: .8em;
  opacity: .8;
}

.profile {
  margin: var(--space) auto 0;
  text-align: center;
}

.profile img {
  max-width: 240px;
  width: 100%;
  height: auto;
  border-radius: 50%;
  box-shadow: 0 4px 16px rgba(0, 0, 0, .12);
}

.hobby-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.hobby-card {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  cursor: pointer;
}

.hobby-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  transition: transform .4s ease;
  display: block;
}

.hobby-card:hover img {
  transform: scale(1.15);
}

.hobby-card figcaption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: .4rem .6rem;
  background: rgba(0, 0, 0, .55);
  color: #fff;
  font-size: .9rem;
  text-align: center;
}

.birthday-wrapper {
  position: relative;
  min-height: 320px;
}

.birthday-view,
.birthday-form {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  transition: opacity .6s ease;
}

.birthday-view img {
  max-width: 240px;
  border-radius: var(--radius);
  box-shadow: 0 4px 16px rgba(0, 0, 0, .12);
  margin-top: 50px;
}

.birthday-form {
  opacity: 0;
  pointer-events: none;
}

@keyframes showForm {
  to {
    opacity: 1;
    pointer-events: auto;
  }
}

@keyframes hideView {
  to {
    opacity: 0;
    pointer-events: none;
  }
}

.birthday-wrapper .birthday-form {
  animation: showForm 0.6s 5s forwards;
}

.birthday-wrapper .birthday-view {
  animation: hideView 0.6s 5s forwards;
}

.birthday-form textarea {
  width: 100%;
  max-width: 480px;
}

.contact-form {
  display: grid;
  gap: var(--space);
  max-width: 560px;
  margin: 0 auto;
}

.form-control {
  display: flex;
  flex-direction: column;
  gap: .35rem;
}

.form-control input,
.form-control textarea {
  padding: .75rem;
  border: 1px solid #ccc;
  border-radius: var(--radius);
  font: inherit;
}

.form-actions {
  display: flex;
  gap: .75rem;
  justify-content: center;
}

.btn {
  padding: .65rem 1.25rem;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  background: var(--accent);
  color: #fff;
  font-weight: 500;
  transition: opacity var(--transition);
  text-decoration: none;
  display: inline-block;
}

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

.btn:hover {
  opacity: .85;
}

.social {
  display: flex;
  gap: 12px;
  justify-content: center;
  align-items: center;
}

.social img {
  width: 28px;
  height: 28px;
  filter: invert(0);
}

.slider {
  position: relative;
  overflow: hidden;
}

.slider input {
  display: none;
}

.slides {
  display: flex;
  width: 100%;
  transition: transform .6s ease;
}

.slide {
  flex: 0 0 50%;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  aspect-ratio: 16/9;
  overflow: hidden;
}

.slide img {
  width: 100%;
  height: 100%;
  object-fit: contain
}

.caption {
  position: absolute;
  top: 12px;
  left: 12px;
  background: rgba(0, 0, 0, .6);
  color: #fff;
  padding: .35rem .6rem;
  border-radius: 6px;
  font-size: .85rem;
}

.controls {
  display: flex;
  justify-content: center;
  gap: .5rem;
  margin-top: .75rem;
}

.controls label {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #bbb;
  cursor: pointer;
  transition: background .3s;
}

#s1:checked~.slides {
  transform: translateX(0);
}

#s2:checked~.slides {
  transform: translateX(-100%);
}

#s1:checked~.controls label[for="s1"],

.controls label:nth-child(n+3) {
  display: none;
}

.cv h3 {
  margin-bottom: .35rem;
}

.skills {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  padding: 0;
  list-style: none;
}

.skills li {
  background: var(--bg);
  padding: .35rem .65rem;
  border-radius: var(--radius);
  font-size: .9rem;
}

.site-footer {
  text-align: center;
  padding: 1.25rem var(--space);
  background: #fff;
  margin-top: var(--space);
  font-size: .9rem;
}

@media (max-width:768px) {
  .hamburger {
    display: block;
  }

  .main-nav {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--primary);
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    transition: max-height var(--transition), opacity var(--transition);
  }

  .main-nav ul {
    flex-direction: column;
    padding: var(--space);
  }

  .main-nav a {
    display: block;
  }

  .slide img {
    max-height: 220px;
    height: auto;
    object-fit: contain;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111;
    --fg: #e5e5e5;
    --primary: #1f1f1f;
    --accent: #333;
  }

  .section {
    background: #1b1b1b;
    box-shadow: 0 2px 8px rgba(0, 0, 0, .4);
  }

  .hobby-card figcaption {
    background: rgba(0, 0, 0, .7);
  }

  .hobby-card li {
    background: #222;
  }

  .site-footer {
    background: #1b1b1b;
  }

  .form-control input,
  .form-control textarea {
    background: #222;
    border-color: #444;
    color: var(--fg);
  }

  .controls label {
    background: #555;
  }
}