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

/* ── Themes ── */
:root {
  --bg:           #f0f0f0;
  --text:         #111;
  --text-muted:   #888;
  --surface:      #fff;
  --border:       #ddd;
  --border-hover: #bbb;
  --surface-hover:#f8f8f8;
  --badge-color:  #444;
}

[data-theme="dark"] {
  --bg:           #0f0f0f;
  --text:         #f0f0f0;
  --text-muted:   #777;
  --surface:      #1a1a1a;
  --border:       #2e2e2e;
  --border-hover: #555;
  --surface-hover:#222;
  --badge-color:  #aaa;
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s, color 0.3s;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  padding: 24px;
  text-align: center;
}

/* ── Badge ── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--badge-color);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 16px;
  transition: background 0.3s, border-color 0.3s, color 0.3s;
}

/* ── Theme toggle ── */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 24px;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 50%;
  cursor: pointer;
  transition: background 0.3s, border-color 0.3s, transform 0.15s;
  z-index: 10;
}

.theme-toggle:hover {
  border-color: var(--border-hover);
  transform: scale(1.08);
}

.theme-toggle svg {
  color: var(--badge-color);
  transition: color 0.3s;
}

.icon-sun  { display: none; }
.icon-moon { display: block; }
[data-theme="dark"] .icon-sun  { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

/* ── Name ── */
h1 {
  font-size: clamp(1.5rem, 9vw, 7rem);
  font-weight: 300;
  color: var(--text);
  letter-spacing: -0.03em;
  line-height: 1;
  text-transform: uppercase;
  cursor: default;
  transition: color 0.3s;
  white-space: nowrap;
}

h1 .letter {
  display: inline-block;
  animation: letterIn 0.6s cubic-bezier(0.34, 1.56, 0.64, 1) both;
}

h1 .space {
  display: inline-block;
  width: 0.25em;
}

h1:hover .letter {
  animation: wave 0.5s ease both;
}

@keyframes letterIn {
  from { opacity: 0; transform: translateY(50px) scale(0.8); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes wave {
  0%, 100% { transform: translateY(0); }
  40%       { transform: translateY(-14px); }
  60%       { transform: translateY(-6px); }
}

/* ── Tagline ── */
.tagline {
  font-size: 1.125rem;
  color: var(--text-muted);
  font-weight: 400;
  max-width: 420px;
  transition: color 0.3s;
}

/* ── Nav buttons ── */
nav {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 8px;
}

nav a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px 24px;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, transform 0.1s, color 0.3s;
}

nav a:hover {
  background: var(--surface-hover);
  border-color: var(--border-hover);
  transform: translateY(-1px);
}

/* ── Mobile ── */
@media (max-width: 480px) {
  .badge {
    font-size: 0.75rem;
    padding: 5px 12px;
    gap: 6px;
  }

  .theme-toggle {
    top: 16px;
    right: 16px;
    width: 34px;
    height: 34px;
  }

  header {
    top: 16px;
  }

  nav a {
    font-size: 0.875rem;
    padding: 10px 18px;
  }

  .tagline {
    font-size: 1rem;
    padding: 0 8px;
  }
}