/* ═══════════════════════════════════════════════════════
   digital.edu — Global Design System
   Aesthetic: Clean · Youthful · Premium · Intelligent
   Inspired by Google DeepMind + Apple HIG
═══════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Google+Sans:wght@400;500;700&family=Google+Sans+Display:wght@400;700&family=Google+Sans+Mono&display=swap');

:root {
  /* Core palette */
  --bg:         #e9e9e9;
  --surface:    #f2f2f2;
  --surface-2:  #ffffff;
  --border:     rgba(0,0,0,0.08);
  --border-mid: rgba(0,0,0,0.14);

  /* Text */
  --ink:        #111111;
  --ink-mid:    #444444;
  --ink-light:  #888888;

  /* Accent — multi-color particle palette */
  --blue:       #8ab4f8;
  --blue-deep:  #4285f4;
  --purple:     #c58af9;
  --amber:      #f29900;
  --coral:      #f28b82;
  --green:      #81c995;
  --cyan:       #78d9ec;

  /* Nav */
  --nav-h: 64px;

  /* Fonts */
  --font-display: 'Google Sans Display', 'Google Sans', system-ui, sans-serif;
  --font-body:    'Google Sans', system-ui, sans-serif;
  --font-mono:    'Google Sans Mono', monospace;

  /* Radius */
  --r-sm:  8px;
  --r-md:  12px;
  --r-lg:  20px;
  --r-xl:  32px;
  --r-full: 999px;

  /* Shadows */
  --shadow-sm: 0 1px 4px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.10);
  --shadow-lg: 0 12px 48px rgba(0,0,0,0.14);

  /* Transitions */
  --t: 0.22s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--ink);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: var(--font-body); cursor: pointer; border: none; }

/* ─────────── NAVIGATION ─────────── */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 300;
  height: var(--nav-h);
  display: flex; align-items: center;
  padding: 0 40px;
  gap: 0;
  background: rgba(233,233,233,0.85);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t), background var(--t);
}
.nav.scrolled {
  background: rgba(233,233,233,0.97);
  border-bottom-color: var(--border);
}
.nav-logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin-right: 40px;
  flex-shrink: 0;
}
.nav-logo .dot { color: var(--blue); }

/* Search bar */
.nav-search {
  flex: 1;
  max-width: 480px;
  position: relative;
  margin-right: 32px;
}
.nav-search input {
  width: 100%;
  padding: 9px 16px 9px 38px;
  background: rgba(0,0,0,0.05);
  border: 1px solid var(--border);
  border-radius: var(--r-full);
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--ink);
  outline: none;
  transition: border-color var(--t), background var(--t);
}
.nav-search input::placeholder { color: var(--ink-light); }
.nav-search input:focus {
  border-color: var(--blue-deep);
  background: var(--surface-2);
}
.nav-search-icon {
  position: absolute; left: 12px; top: 50%;
  transform: translateY(-50%);
  font-size: 14px; color: var(--ink-light);
  pointer-events: none;
}

/* Nav links */
.nav-links {
  display: flex; align-items: center; gap: 4px;
  list-style: none; margin-right: auto;
}
.nav-links a {
  padding: 7px 12px;
  border-radius: var(--r-sm);
  font-size: 13px; font-weight: 500;
  color: var(--ink-mid);
  transition: background var(--t), color var(--t);
  white-space: nowrap;
}
.nav-links a:hover { background: rgba(0,0,0,0.06); color: var(--ink); }
.nav-links a.active { color: var(--blue-deep); background: rgba(66,133,244,0.08); }

/* Nav right */
.nav-right { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }

/* Language selector */
.lang-select {
  display: flex; align-items: center; gap: 6px;
  padding: 7px 14px;
  border: 1px solid var(--border-mid);
  border-radius: var(--r-full);
  background: transparent;
  font-size: 13px; font-weight: 500;
  color: var(--ink-mid);
  transition: all var(--t);
}
.lang-select:hover { border-color: var(--blue-deep); color: var(--ink); }

.btn-nav {
  padding: 8px 22px;
  border-radius: var(--r-full);
  font-size: 14px; font-weight: 500;
  transition: all var(--t);
}
.btn-nav.ghost {
  border: 1px solid var(--border-mid);
  background: transparent; color: var(--ink-mid);
}
.btn-nav.ghost:hover { border-color: var(--ink); color: var(--ink); }
.btn-nav.fill {
  background: var(--ink); color: #fff;
}
.btn-nav.fill:hover { opacity: 0.85; }

/* ─────────── BUTTONS ─────────── */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px; border-radius: var(--r-full);
  font-size: 15px; font-weight: 500;
  transition: all var(--t);
}
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { opacity: 0.84; transform: scale(0.99); }
.btn-secondary {
  background: transparent; color: var(--ink);
  border: 1.5px solid rgba(0,0,0,0.20);
}
.btn-secondary:hover { border-color: var(--ink); background: rgba(0,0,0,0.04); }
.btn-blue { background: var(--blue-deep); color: #fff; }
.btn-blue:hover { opacity: 0.88; }
.btn-sm { padding: 8px 18px; font-size: 13px; }

/* ─────────── CARDS ─────────── */
.card {
  background: var(--surface-2);
  border-radius: var(--r-md);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: box-shadow var(--t), transform var(--t);
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }

/* ─────────── SECTION LAYOUT ─────────── */
.section { padding: 100px 0; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 40px; }
.section-label {
  font-size: 11px; font-weight: 600;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--ink-light); margin-bottom: 14px;
}
.section-title {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(32px, 4.5vw, 52px);
  letter-spacing: -0.03em; line-height: 1.1;
  color: var(--ink);
}
.section-sub {
  font-size: 17px; color: var(--ink-mid);
  line-height: 1.7; max-width: 560px;
}

/* ─────────── TICKER / MARQUEE ─────────── */
.ticker-wrap {
  overflow: hidden;
  padding: 18px 0;
  background: var(--surface-2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  position: relative;
}
.ticker-wrap::before,
.ticker-wrap::after {
  content: '';
  position: absolute; top: 0; bottom: 0; width: 80px;
  z-index: 2; pointer-events: none;
}
.ticker-wrap::before { left: 0; background: linear-gradient(to right, var(--surface-2), transparent); }
.ticker-wrap::after  { right: 0; background: linear-gradient(to left, var(--surface-2), transparent); }

.ticker-track {
  display: flex; align-items: center; gap: 0;
  width: max-content;
  animation: tickerScroll 55s linear infinite;
}
.ticker-track:hover { animation-play-state: paused; }
@keyframes tickerScroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}
.ticker-item {
  display: flex; align-items: center; gap: 10px;
  padding: 0 28px;
  border-right: 1px solid var(--border);
  white-space: nowrap;
}
.ticker-item:last-child { border-right: none; }
.ticker-uni {
  font-size: 13px; font-weight: 500;
  color: var(--ink-mid);
}
.ticker-flag { font-size: 18px; }

/* ─────────── PROGRESS BAR ─────────── */
.progress-bar {
  height: 5px; background: rgba(0,0,0,0.08);
  border-radius: var(--r-full); overflow: hidden;
}
.progress-fill {
  height: 100%; border-radius: var(--r-full);
  background: linear-gradient(90deg, var(--blue-deep), var(--purple));
  transition: width 0.8s ease;
}

/* ─────────── BADGE ─────────── */
.badge {
  display: inline-flex; align-items: center;
  padding: 4px 10px; border-radius: var(--r-full);
  font-size: 11px; font-weight: 600;
  letter-spacing: 0.04em;
}
.badge-blue { background: rgba(66,133,244,0.12); color: var(--blue-deep); }
.badge-green { background: rgba(129,201,149,0.2); color: #2d7d46; }
.badge-amber { background: rgba(242,153,0,0.15); color: #b56b00; }
.badge-purple { background: rgba(197,138,249,0.15); color: #7c3aed; }

/* ─────────── AVATAR ─────────── */
.avatar {
  border-radius: 50%; object-fit: cover;
  background: linear-gradient(135deg, var(--blue), var(--purple));
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; color: #fff;
  font-size: 14px; flex-shrink: 0;
}

/* ─────────── FOOTER ─────────── */
.footer {
  background: var(--ink); color: rgba(255,255,255,0.5);
  padding: 60px 0 32px;
}
.footer-logo {
  font-family: var(--font-display); font-weight: 700;
  font-size: 24px; letter-spacing: -0.025em;
  color: #fff; margin-bottom: 8px;
}
.footer-logo .dot { color: var(--blue); }
.footer-tagline { font-size: 14px; margin-bottom: 40px; }
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 40px; margin-bottom: 48px;
}
.footer-col-title {
  font-size: 11px; font-weight: 600;
  letter-spacing: 0.15em; text-transform: uppercase;
  color: rgba(255,255,255,0.35); margin-bottom: 16px;
}
.footer-col a {
  display: block; font-size: 13px; padding: 4px 0;
  color: rgba(255,255,255,0.5);
  transition: color var(--t);
}
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: 28px;
  display: flex; justify-content: space-between;
  align-items: center; font-size: 12px;
}

/* ─────────── RESPONSIVE ─────────── */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-search { max-width: 200px; }
  .container { padding: 0 20px; }
  .section { padding: 70px 0; }
}
@media (max-width: 480px) {
  .nav-search { display: none; }
  .footer-grid { grid-template-columns: 1fr; }
}