/* ============================================================
   Dr. Aritra Bal — Personal Academic Website
   style.css
   ============================================================ */

/* ─── Design tokens ──────────────────────────────────────── */
:root {
  --cream:        #f5f3ef;
  --cream-dark:   #ece9e3;
  --sage:         #7a9e7e;
  --sage-light:   #a8c5ab;
  --sage-dark:    #5a7a5d;
  --sage-bg:      #edf2ee;
  --ink:          #1c1e1b;
  --ink-muted:    #4a4d48;
  --ink-faint:    #8a8d88;
  --white:        #ffffff;
  --accent:       #4d7a52;

  --font-serif:   'Cormorant Garamond', Georgia, serif;
  --font-sans:    'DM Sans', system-ui, sans-serif;

  --nav-h:        72px;
  --radius:       4px;
  --transition:   0.28s ease;
}

/* ─── Reset ─────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--cream);
  color: var(--ink);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { display: block; max-width: 100%; }

/* ─── Navbar ─────────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(1.5rem, 5vw, 4rem);
  background: rgba(245, 243, 239, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(122, 158, 126, 0.18);
  z-index: 100;
  gap: 1rem;
}

.navbar__brand {
  display: flex;
  flex-direction: column;
  gap: 1px;
  flex-shrink: 0;
}

.navbar__name {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--ink);
  line-height: 1.15;
}

.navbar__title {
  font-size: 0.68rem;
  font-weight: 300;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.navbar__links {
  display: flex;
  gap: 2.4rem;
  align-items: center;
}

.nav-link {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
  position: relative;
  transition: color var(--transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 0; bottom: -3px;
  width: 0; height: 1.5px;
  background: var(--accent);
  transition: width var(--transition);
}

.nav-link:hover,
.nav-link.active { color: var(--accent); }

.nav-link:hover::after,
.nav-link.active::after { width: 100%; }

/* Hamburger (mobile) */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
}
.hamburger span {
  display: block;
  width: 24px; height: 1.5px;
  background: var(--ink);
  transition: var(--transition);
}

/* Language switcher button */
.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: none;
  border: 1px solid rgba(122, 158, 126, 0.28);
  border-radius: 20px;
  padding: 0.28rem 0.65rem 0.28rem 0.45rem;
  cursor: pointer;
  color: var(--ink-muted);
  transition: border-color var(--transition), background var(--transition), color var(--transition);
  flex-shrink: 0;
}

.lang-btn:hover {
  border-color: var(--accent);
  background: rgba(77, 122, 82, 0.07);
  color: var(--accent);
}

.lang-flag {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  object-fit: cover;
  display: block;
}

.lang-code {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1;
}

/* Mobile nav drawer */
.mobile-nav {
  display: none;
  flex-direction: column;
  gap: 0;
  position: fixed;
  top: var(--nav-h); left: 0; right: 0;
  background: var(--cream);
  border-bottom: 1px solid var(--cream-dark);
  z-index: 99;
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.35s ease;
}
.mobile-nav.open { max-height: 260px; }
.mobile-nav .nav-link {
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--cream-dark);
  font-size: 0.88rem;
}

/* ─── Hero ───────────────────────────────────────────────── */
.hero {
  flex: 1;
  margin-top: var(--nav-h);
  min-height: calc(100vh - var(--nav-h) - 56px);
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  padding: clamp(3rem, 7vh, 5rem) clamp(1.5rem, 6vw, 5rem);
  gap: clamp(2rem, 4vw, 4rem);
  position: relative;
  overflow: hidden;

}

/* Background decorative SVG */
.hero__deco {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 0;
}

/* Text column */
.hero__text {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 1.6rem;
  max-width: 560px;
  animation: slideInLeft 0.75s ease both;
}

.hero__greeting {
  position: relative;
  height: 1.8rem;        /* fixed height prevents layout shift as words swap */
  display: block;
  margin-bottom: 0.2rem;
}

.greeting-word {
  position: absolute;
  left: 0;
  top: 0;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--sage-dark);
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.6s ease, transform 0.6s ease;
  pointer-events: none;
  white-space: nowrap;
}

.greeting-word.active {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

/* Per-language font assignments */
.greeting-word[lang="hi"] { font-family: 'Yatra One', serif;        font-size: 2.05rem; }
.greeting-word[lang="bn"] { font-family: 'Tiro Bangla', serif;      font-size: 2rem;    }
.greeting-word[lang="en"] { font-family: 'Cormorant Garamond', serif; font-style: italic; font-size: 2.15rem; font-weight: 400; letter-spacing: 0.035em; }
.greeting-word[lang="de"] { font-family: 'Cormorant Garamond', serif; font-style: italic; font-size: 2.15rem; font-weight: 400; letter-spacing: 0.035em; }

.hero__heading {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 3.1rem);
  font-weight: 500;
  line-height: 1.22;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.hero__heading em {
  font-style: italic;
  font-weight: 400;
  color: var(--accent);
}

.hero__sub {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 300;
  line-height: 1.75;
  color: var(--ink-muted);
  max-width: 440px;
  animation: fadeUp 0.9s 0.1s ease both;
}

/* CTA button */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  width: fit-content;
  padding: 0.78rem 1.6rem;
  background: var(--accent);
  color: var(--white);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: var(--radius);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  box-shadow: 0 4px 18px rgba(77, 122, 82, 0.22);
  animation: slideInLeft 0.75s 0.2s ease both;
}

.btn-primary:hover {
  background: var(--sage-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 26px rgba(77, 122, 82, 0.3);
}

.btn-primary svg {
  transition: transform var(--transition);
}
.btn-primary:hover svg { transform: translateX(4px); }

/* Portrait column */
.hero__portrait-wrap {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  animation: fadeUp 1s 0.55s ease both;
}

/* Ellipse container — controls shape */
.hero__portrait-bg {
  position: relative;
  width: clamp(340px, 36vw, 470px);
  height: clamp(340px, 52vw, 580px);
  border-radius: 50%;                    /* perfect ellipse via width/height ratio */
  overflow: hidden;
  background: #2d3d50;                   /* matches portrait background */
  box-shadow:
    0 30px 60px rgba(0, 0, 0, 0.15),
    0  8px 20px rgba(0, 0, 0, 0.10);
  flex-shrink: 0;
}

.hero__portrait {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  border-radius: 0;
  filter: none;
}

/* ─── Footer ─────────────────────────────────────────────── */
.footer {
  background: var(--cream-dark);
  border-top: 1px solid rgba(122, 158, 126, 0.2);
  padding: 0.9rem clamp(1.5rem, 5vw, 4rem);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  min-height: 56px;
}

.footer__links {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.footer__icon-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--ink-muted);
  padding: 0.3rem 0.5rem;
  border-radius: var(--radius);
  transition: color var(--transition), background var(--transition);
}

.footer__icon-link:hover {
  color: var(--accent);
  background: rgba(77, 122, 82, 0.08);
}

.footer__icon {
  width: 16px;
  height: 16px;
  opacity: 0.7;
  transition: opacity var(--transition);
  /* Tint SVGs to match ink color */
  filter: invert(20%) sepia(5%) saturate(400%) hue-rotate(80deg);
}

.footer__icon-link:hover .footer__icon {
  opacity: 1;
  filter: invert(35%) sepia(30%) saturate(500%) hue-rotate(85deg);
}

.footer__sep {
  display: inline-block;
  width: 1px;
  height: 14px;
  background: var(--ink-faint);
  opacity: 0.3;
}

.footer__copy {
  font-size: 0.72rem;
  color: var(--ink-faint);
  letter-spacing: 0.03em;
}

/* ─── Animations ─────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(22px); }
  to   { opacity: 1; transform: translateY(0);    }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-40px); }
  to   { opacity: 1; transform: translateX(0);     }
}
/* ─── Responsive ─────────────────────────────────────────── */
@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
    text-align: center;
    justify-items: center;
    padding-top: 2.5rem;
  }
  .hero__text { align-items: center; max-width: 100%; animation: slideInLeft 0.75s ease both;
  }
  .hero__sub  { max-width: 500px; animation: slideInLeft 0.75s 0.1s ease both;}
  .hero__portrait-wrap { order: -1; animation: fadeUp 0.9s 0.5s ease both; }
  .hero__portrait-bg {
    width:  clamp(280px, 38vw, 460px);
    height: clamp(280px, 38vw, 460px);
  }
    .hero__greeting {
  width: 100%;
  }

  .greeting-word {
    left: 50%;
    transform: translateX(-50%) translateY(6px);
  }

  .greeting-word.active {
    transform: translateX(-50%) translateY(0);
}
}

@media (max-width: 640px) {
  .navbar__links { display: none; }
  .hamburger     { display: flex; }
  .mobile-nav    { display: flex; }

  .navbar__title { display: none; }

  .hero {
    min-height: auto;
    padding: 1.5rem 1.2rem 2rem;
  }
  .hero__heading { font-size: 1.85rem; }
  .hero__portrait-wrap { width: 70%; }

  .footer {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
  .footer__copy { font-size: 0.68rem; }
}