:root {
  --pink: #d94f7c;
  --pink-dark: #a9345d;
  --pink-soft: #fff0f5;
  --pink-panel: #f9dce7;
  --ink: #25131a;
  --muted: #84606c;
  --white: #fff;
  --line: rgba(169, 52, 93, .16);
  --shadow: 0 18px 45px rgba(133, 49, 78, .12);
}

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

body {
  font-family: Arial, Helvetica, sans-serif;
  color: var(--ink);
  font-size: 14px;
  background:
    radial-gradient(circle at 18% 12%, rgba(255,255,255,.95) 0 9%, transparent 10%),
    linear-gradient(90deg, rgba(255,255,255,.35) 1px, transparent 1px),
    linear-gradient(0deg, rgba(255,255,255,.35) 1px, transparent 1px),
    #fde8ef;
  background-size: auto, 92px 92px, 92px 92px, auto;
  min-height: 100vh;
}

/* Navigation */
.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: rgba(255, 255, 255, .85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 100;
}

.navbar .logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--pink-dark);
  font-weight: 900;
  font-size: 18px;
}

.navbar .logo img {
  width: 40px;
  height: 40px;
  border-radius: 8px;
}

.nav-links {
  display: flex;
  gap: 6px;
  list-style: none;
  flex-wrap: wrap;
}

.nav-links a {
  text-decoration: none;
  color: var(--pink-dark);
  font-weight: 700;
  font-size: 13px;
  padding: 8px 14px;
  border-radius: 10px;
  transition: background .2s, color .2s;
}

.nav-links a:hover,
.nav-links a.active {
  background: var(--pink);
  color: white;
}

.nav-toggle {
  display: none;
  background: none;
  border: 2px solid var(--pink);
  color: var(--pink);
  font-size: 20px;
  padding: 6px 10px;
  border-radius: 8px;
  cursor: pointer;
}

/* Hero Section */
.hero {
  max-width: 1180px;
  margin: 24px auto 20px;
  padding: 32px 28px;
  border-radius: 22px;
  background: rgba(255, 255, 255, .62);
  box-shadow: var(--shadow);
  border: 1px solid rgba(255,255,255,.9);
  position: relative;
  overflow: hidden;
  text-align: center;
}

.hero:before, .hero:after {
  content: "";
  position: absolute;
  border-radius: 999px;
  filter: blur(1px);
  opacity: .65;
}

.hero:before {
  width: 96px; height: 96px;
  right: 80px; top: 28px;
  background: linear-gradient(135deg, #ff6aa0, #fff);
}

.hero:after {
  width: 140px; height: 140px;
  left: -40px; bottom: -50px;
  background: linear-gradient(135deg, #fff, #ff8bb7);
}

.hero h1 {
  margin: 0 auto;
  max-width: 780px;
  font-size: clamp(24px, 3vw, 38px);
  line-height: 1.2;
  color: var(--pink-dark);
  position: relative;
  z-index: 1;
}

.hero p {
  margin: 12px 0 0;
  font-size: 16px;
  color: var(--muted);
  position: relative;
  z-index: 1;
}

/* Content Container */
.container {
  max-width: 1180px;
  margin: 0 auto 40px;
  padding: 0 20px;
}

/* Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.card {
  background: rgba(255,255,255,.72);
  border: 1px solid rgba(255,255,255,.85);
  border-radius: 20px;
  box-shadow: var(--shadow);
  padding: 28px 24px;
  transition: transform .2s, box-shadow .2s;
  text-decoration: none;
  color: var(--ink);
  display: block;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 24px 60px rgba(133, 49, 78, .18);
}

.card-icon {
  font-size: 40px;
  margin-bottom: 14px;
}

.card h2 {
  font-size: 20px;
  color: var(--pink-dark);
  margin-bottom: 8px;
}

.card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

/* Interactive App (for reference pages) */
.app {
  max-width: 1180px;
  margin: 0 auto 38px;
  background: rgba(255,255,255,.72);
  border: 1px solid rgba(255,255,255,.85);
  border-radius: 24px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 16px;
  background: #fff5f8;
  border-bottom: 1px solid var(--line);
}

.select {
  appearance: none;
  border: 1px solid var(--line);
  background: white;
  border-radius: 12px;
  padding: 9px 13px;
  font-weight: 700;
  color: var(--pink-dark);
  min-width: 160px;
  font-size: 13px;
}

.doc-line {
  padding: 15px 18px;
  background: var(--pink-soft);
  font-size: 15px;
  font-weight: 700;
}

.doc-line span {
  color: var(--pink-dark);
}

.tab-strip {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  padding: 0 16px;
  background: #fff;
  border-bottom: 1px solid var(--line);
}

.tab-btn {
  flex: 0 0 auto;
  border: 0;
  background: #efc4d3;
  color: #7b3550;
  padding: 10px 16px;
  font-weight: 800;
  cursor: pointer;
  border-radius: 12px 12px 0 0;
  font-size: 13px;
}

.tab-btn.active {
  background: var(--pink);
  color: white;
}

.task-row {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  padding: 10px 16px 0;
  background: var(--pink-panel);
}

.task-btn {
  flex: 0 0 auto;
  min-width: 88px;
  border: 0;
  background: #b45776;
  color: white;
  padding: 9px 14px;
  font-weight: 800;
  cursor: pointer;
  font-size: 13px;
}

.task-btn.active {
  background: white;
  color: var(--pink-dark);
  text-decoration: underline;
}

.card-content {
  min-height: 210px;
  padding: 19px 20px;
  background: var(--pink-panel);
}

.tool {
  margin: 0 0 12px;
  font-size: 17px;
  font-weight: 900;
  color: #230b13;
}

.english {
  margin: 0 0 16px;
  font-size: 14px;
  line-height: 1.45;
  font-weight: 700;
  color: #111;
}

.divider {
  border: 0;
  border-top: 1px dashed rgba(169, 52, 93, .55);
  margin: 12px 0;
}

.vietnamese {
  margin: 0;
  font-size: 14px;
  line-height: 1.45;
  font-weight: 700;
  color: #111;
}

/* Footer */
.footer {
  text-align: center;
  padding: 24px;
  color: var(--muted);
  font-size: 13px;
  border-top: 1px solid var(--line);
  background: rgba(255,255,255,.5);
}

/* Responsive */
@media (max-width: 760px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(255,255,255,.95);
    padding: 16px;
    border-bottom: 1px solid var(--line);
  }
  .nav-toggle { display: block; }
  .hero { margin: 14px 10px; padding: 20px; }
  .container { padding: 0 10px; }
  .cards-grid { grid-template-columns: 1fr; }
  .app { margin: 0 10px 24px; }
  .doc-line, .english { font-size: 14px; }
}