/* ============================================
   GLOBAL STYLES — Sejin Park Portfolio
   ============================================ */

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

:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #6b6b6b;
  --color-border: #d4d0c8;
  --font-primary: 'Cormorant', 'Georgia', serif;
  --max-width: 800px;
  --nav-height: 72px;
  --page-padding: 24px;
  --grid-gap: 10px;
  --ease-out: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --duration-fast: 0.2s;
  --duration-normal: 0.4s;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-weight: 300;
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
  min-height: 100vh;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
ul { list-style: none; }


/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: var(--color-bg);
}

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--page-padding);
  border-bottom: 1px solid var(--color-border);
}

.nav__logo {
  font-size: 1.25rem;
  font-weight: 700;
  font-style: italic;
  letter-spacing: -0.02em;
  transition: opacity var(--duration-fast) var(--ease-out);
}

.nav__logo:hover { opacity: 0.5; }

.nav__links {
  display: flex;
  gap: 28px;
}

.nav__link {
  font-size: 0.95rem;
  font-weight: 400;
  letter-spacing: 0.03em;
  color: var(--color-text-secondary);
  transition: color var(--duration-fast) var(--ease-out);
  position: relative;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--color-text);
  transition: width var(--duration-normal) var(--ease-out);
}

.nav__link:hover { color: var(--color-text); }
.nav__link:hover::after { width: 100%; }
.nav__link--active { color: var(--color-text); }
.nav__link--active::after { width: 100%; }


/* --- Footer --- */
.footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px var(--page-padding);
  border-top: 1px solid var(--color-border);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  letter-spacing: 0.04em;
}


/* --- Page Placeholder --- */
.page-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: calc(100vh - var(--nav-height) - 120px);
  margin-top: var(--nav-height);
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  letter-spacing: 0.05em;
}


/* --- Mobile --- */
@media (max-width: 600px) {
  :root {
    --page-padding: 16px;
    --nav-height: 60px;
    --grid-gap: 6px;
  }
  .nav__logo { font-size: 1.1rem; }
  .nav__links { gap: 16px; }
  .nav__link { font-size: 0.85rem; }
}