/* ═══════════════════════════════════════════
   digital.edu — Main Stylesheet
   Design: Google DeepMind aesthetic
   Light gray bg, multi-color particles,
   Google Sans typography
═══════════════════════════════════════════ */

/* ── RESET & ROOT ── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-hero:    #e8e8e8;
  --bg-about:   #efefef;
  --bg-contact: #efefef;
  --bg-footer:  #e0e0e0;

  --text-dark:  #1a1a1a;
  --text-mid:   #444444;
  --text-light: #777777;

  --accent-blue:   #8ab4f8;
  --accent-purple: #c58af9;
  --accent-coral:  #f28b82;

  --font-display: 'Google Sans Display', 'Google Sans', system-ui, sans-serif;
  --font-body:    'Google Sans', system-ui, sans-serif;

  --nav-height: 68px;
  --transition: 0.25s ease;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background: var(--bg-hero);
  color: var(--text-dark);
  font-family: var(--font-body);
  font-weight: 400;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}


/* ═══════════════════════════════════════════
   NAVIGATION
═══════════════════════════════════════════ */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px;
  background: rgba(232, 232, 232, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  transition: background var(--transition);
}

#navbar.scrolled {
  background: rgba(232, 232, 232, 0.97);
}

.nav-logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: -0.025em;
  color: var(--text-dark);
  user-select: none;
}

.nav-logo span {
  color: var(--accent-blue);
}

.nav-cta {
  background: var(--text-dark);
  color: #ffffff;
  border: none;
  padding: 10px 24px;
  border-radius: 24px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  letter-spacing: 0.01em;
  transition: opacity var(--transition), transform var(--transition);
}

.nav-cta:hover {
  opacity: 0.82;
  transform: scale(0.98);
}


/* ═══════════════════════════════════════════
   HERO SECTION
═══════════════════════════════════════════ */
#hero {
  position: relative;
  width: 100vw;
  height: 100vh;
  min-height: 600px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--bg-hero);
}

#particles-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* ── Hero text ── */
.hero-content {
  position: relative;
  z-index: 10;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 22px;
  max-width: 820px;
  padding: 0 24px;
  animation: heroFadeIn 1.1s ease both;
}

@keyframes heroFadeIn {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero-eyebrow {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-light);
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(60px, 10.5vw, 116px);
  line-height: 1.0;
  letter-spacing: -0.045em;
  color: var(--text-dark);
}

.hero-title .dot {
  color: var(--accent-blue);
}

.hero-sub {
  font-size: clamp(15px, 1.8vw, 18px);
  color: var(--text-mid);
  line-height: 1.65;
  max-width: 500px;
  font-weight: 400;
}

.hero-cta-row {
  display: flex;
  gap: 12px;
  margin-top: 6px;
  flex-wrap: wrap;
  justify-content: center;
}

.btn-primary {
  background: var(--text-dark);
  color: #ffffff;
  border: none;
  padding: 14px 32px;
  border-radius: 28px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  letter-spacing: 0.01em;
  transition: opacity var(--transition), transform var(--transition);
}

.btn-primary:hover {
  opacity: 0.82;
  transform: scale(0.98);
}

.btn-ghost {
  background: transparent;
  color: var(--text-dark);
  border: 1.5px solid rgba(26, 26, 26, 0.22);
  padding: 13px 28px;
  border-radius: 28px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}

.btn-ghost:hover {
  border-color: rgba(26, 26, 26, 0.5);
  background: rgba(26, 26, 26, 0.04);
}

/* ── Scroll hint ── */
.scroll-hint {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  opacity: 0.42;
  animation: hintFadeIn 1.5s ease 1.2s both;
}

@keyframes hintFadeIn {
  from { opacity: 0; transform: translateX(-50%) translateY(12px); }
  to   { opacity: 0.42; transform: translateX(-50%) translateY(0); }
}

.scroll-hint span {
  font-size: 10px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--text-mid);
}

.scroll-arrow {
  width: 14px;
  height: 14px;
  border-right: 1.5px solid var(--text-mid);
  border-bottom: 1.5px solid var(--text-mid);
  transform: rotate(45deg);
  animation: arrowBounce 1.9s ease-in-out infinite;
}

@keyframes arrowBounce {
  0%, 100% { transform: rotate(45deg) translateY(0); }
  50%       { transform: rotate(45deg) translateY(5px); }
}


/* ═══════════════════════════════════════════
   ABOUT SECTION
═══════════════════════════════════════════ */
#about {
  position: relative;
  background: var(--bg-about);
  padding: 140px 24px 110px;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow: hidden;
}

#about-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.28;
  pointer-events: none;
  z-index: 0;
}

.about-inner {
  position: relative;
  z-index: 2;
  max-width: 700px;
  width: 100%;
  text-align: center;
}

.section-tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-light);
  margin-bottom: 44px;
  padding: 6px 18px;
  border: 1px solid rgba(0, 0, 0, 0.12);
  border-radius: 20px;
}

.about-heading {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(42px, 6vw, 72px);
  letter-spacing: -0.035em;
  line-height: 1.07;
  color: var(--text-dark);
  margin-bottom: 52px;
}

.about-heading em {
  font-style: normal;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple), var(--accent-coral));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.about-body {
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.about-body p {
  font-size: clamp(15px, 1.75vw, 17px);
  line-height: 1.88;
  color: #555555;
  font-weight: 400;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.75s ease, transform 0.75s ease;
}

.about-body p.visible {
  opacity: 1;
  transform: translateY(0);
}

.about-body p strong {
  color: var(--text-dark);
  font-weight: 500;
}

.about-body p.tagline {
  font-size: 17px;
  font-style: italic;
  color: #888888;
  margin-top: 8px;
}

.section-divider {
  width: 100%;
  height: 1px;
  background: linear-gradient(to right, transparent, rgba(0, 0, 0, 0.1), transparent);
  margin-top: 76px;
}


/* ═══════════════════════════════════════════
   CONTACT SECTION
═══════════════════════════════════════════ */
#contact {
  background: var(--bg-contact);
  padding: 90px 24px 110px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.contact-label {
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-light);
}

.contact-email {
  font-family: var(--font-body);
  font-size: clamp(18px, 2.4vw, 26px);
  font-weight: 500;
  color: var(--text-dark);
  text-decoration: none;
  padding: 16px 42px;
  border-radius: 50px;
  border: 1.5px solid rgba(0, 0, 0, 0.15);
  letter-spacing: 0.01em;
  transition: background var(--transition), color var(--transition), border-color var(--transition), transform var(--transition);
}

.contact-email:hover {
  background: var(--text-dark);
  color: #ffffff;
  border-color: var(--text-dark);
  transform: scale(0.99);
}


/* ═══════════════════════════════════════════
   FOOTER
═══════════════════════════════════════════ */
#footer {
  background: var(--bg-footer);
  padding: 22px 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-light);
  border-top: 1px solid rgba(0, 0, 0, 0.07);
}


/* ═══════════════════════════════════════════
   RESPONSIVE
═══════════════════════════════════════════ */
@media (max-width: 768px) {
  #navbar {
    padding: 0 24px;
  }

  .hero-title {
    font-size: clamp(52px, 14vw, 80px);
  }

  .hero-sub br { display: none; }

  #about {
    padding: 100px 20px 80px;
  }

  #footer {
    padding: 20px 24px;
    flex-direction: column;
    gap: 6px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero-cta-row {
    flex-direction: column;
    width: 100%;
    max-width: 280px;
  }
  .btn-primary, .btn-ghost {
    width: 100%;
    text-align: center;
  }
}