:root {
  --paper: #FAF8F5;
  --cream: #F5F0E8;
  --ink: #1A1A1A;
  --ink-90: rgba(26, 26, 26, 0.9);
  --ink-70: rgba(26, 26, 26, 0.7);
  --ink-55: rgba(26, 26, 26, 0.55);
  --ink-35: rgba(26, 26, 26, 0.35);
  --ink-08: rgba(26, 26, 26, 0.08);
  --accent: #E8825A;
  --accent-dark: #D06840;
  --accent-bg: #FFF5EF;
  --teal: #0F6E56;
  --font-display: 'Lora', Georgia, serif;
  --font-sans: 'DM Sans', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', monospace;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink-90);
  background: var(--paper);
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent-dark); text-decoration: none; transition: color 180ms var(--ease); }
a:hover { color: var(--accent); }

.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(32px, 5vw, 52px); line-height: 1.1; }
h2 { font-size: clamp(24px, 3.5vw, 36px); line-height: 1.2; margin-bottom: 18px; }
h3 { font-size: 18px; line-height: 1.3; margin-bottom: 8px; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
  display: inline-block;
  font-weight: 400;
}

/* ===== NAV ===== */
.nav {
  padding: 16px 0;
  border-bottom: 1px solid var(--ink-08);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(8px);
}
.nav-inner { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.logo {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  color: var(--ink);
  text-decoration: none;
}
.logo small {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.22em;
  color: var(--ink-55);
  text-transform: uppercase;
  display: block;
  margin-top: 2px;
  font-weight: 400;
}
.nav-cta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 10px 16px;
  border: 1px solid var(--ink);
  border-radius: 6px;
  color: var(--ink);
  background: var(--paper);
  transition: all 200ms var(--ease);
}
.nav-cta:hover { background: var(--ink); color: var(--paper); }

/* ===== HERO ===== */
.hero { padding: 80px 0 60px; }
.hero h1 { margin-bottom: 20px; max-width: 720px; }
.hero .lead {
  font-size: 18px;
  color: var(--ink-55);
  max-width: 620px;
  margin-bottom: 32px;
  line-height: 1.55;
}
.cta-row { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 30px; }
.btn {
  display: inline-block;
  padding: 14px 24px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: all 200ms var(--ease);
  text-decoration: none;
}
.btn-primary { background: var(--ink); color: #FFFFFF; }
.btn-primary:hover { background: var(--accent); color: #FFFFFF; }
.btn-secondary { background: transparent; border: 1px solid var(--ink); color: var(--ink); }
.btn-secondary:hover { background: var(--ink); color: var(--paper); }

.meta-row {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--ink-55);
  text-transform: uppercase;
  padding-top: 20px;
  border-top: 1px solid var(--ink-08);
  max-width: 620px;
}

/* ===== FILTER BAR ===== */
.filter-bar {
  padding: 20px 0;
  background: var(--cream);
  border-top: 1px solid var(--ink-08);
  border-bottom: 1px solid var(--ink-08);
  position: sticky;
  top: 61px;
  z-index: 30;
}
.filter-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 6px 0;
}
.filter-group + .filter-group { border-top: 1px dashed var(--ink-08); padding-top: 12px; margin-top: 4px; }
.filter-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-55);
  margin-right: 8px;
}
.filter-btn {
  font-family: var(--font-sans);
  font-size: 13px;
  padding: 7px 14px;
  border: 1px solid var(--ink-08);
  background: var(--paper);
  color: var(--ink-70);
  border-radius: 4px;
  cursor: pointer;
  transition: all 180ms var(--ease);
  font-weight: 400;
}
.filter-btn:hover { border-color: var(--ink); color: var(--ink); }
.filter-btn.active {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
  font-weight: 600;
}

/* ===== GRID ===== */
.main-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 24px;
  padding: 48px 24px;
}
.card {
  background: var(--paper);
  border: 1px solid var(--ink-08);
  border-radius: 10px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all 280ms var(--ease);
  position: relative;
}
.card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(232, 130, 90, 0.15);
}
.card-preview {
  aspect-ratio: 3/2;
  background: var(--cream);
  overflow: hidden;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.card-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 400ms var(--ease);
}
.card:hover .card-preview img { transform: scale(1.03); }
.card-preview .no-img {
  font-family: var(--font-display);
  color: var(--ink-55);
  font-style: italic;
  text-align: center;
  padding: 30px;
  font-size: 14px;
}
.card-badge {
  position: absolute;
  top: 10px;
  right: 10px;
  background: var(--accent);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 4px 8px;
  border-radius: 3px;
  font-weight: 600;
}
.card-badge.screenshot { background: var(--ink-55); }
.card-body { padding: 20px; flex: 1; display: flex; flex-direction: column; }
.card h3 { margin-bottom: 6px; line-height: 1.25; }
.card-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}
.card-tag {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 3px;
  background: var(--cream);
  color: var(--ink-55);
}
.card-tag.goi { background: var(--accent-bg); color: var(--accent-dark); }
.card-desc {
  font-size: 13px;
  color: var(--ink-55);
  line-height: 1.5;
  margin-bottom: 14px;
  flex: 1;
}
.card-actions {
  display: flex;
  gap: 8px;
  margin-top: auto;
}
.card-actions .btn {
  font-size: 12px;
  padding: 9px 14px;
  flex: 1;
  text-align: center;
}

/* ===== FORM ===== */
.form-section {
  padding: 80px 0;
  background: var(--cream);
}
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 60px;
  max-width: 960px;
  margin: 0 auto;
  align-items: start;
}
.checklist { list-style: none; margin-top: 16px; }
.checklist li {
  padding: 10px 0 10px 24px;
  position: relative;
  color: var(--ink-90);
  border-bottom: 1px solid var(--ink-08);
  font-size: 14px;
}
.checklist li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-family: var(--font-mono);
}
.checklist li:last-child { border-bottom: none; }

form {
  background: var(--paper);
  border: 1px solid var(--ink-08);
  border-radius: 12px;
  padding: 32px;
}
form label {
  display: block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-55);
  margin-bottom: 6px;
  font-weight: 400;
}
form input, form select, form textarea {
  width: 100%;
  font-family: var(--font-sans);
  font-size: 14px;
  padding: 11px 13px;
  border: 1px solid var(--ink-08);
  border-radius: 5px;
  background: var(--paper);
  margin-bottom: 16px;
  color: var(--ink);
  font-weight: 400;
  transition: border-color 150ms var(--ease);
}
form input:focus, form select:focus, form textarea:focus {
  outline: none;
  border-color: var(--ink);
}
form textarea { resize: vertical; font-family: var(--font-sans); }
form input[readonly] { background: var(--cream); color: var(--ink-55); cursor: not-allowed; }
form .btn { width: 100%; padding: 15px; }
.form-msg {
  margin-top: 14px;
  font-size: 13px;
  text-align: center;
  color: var(--ink-55);
}
.form-msg.ok { color: var(--teal); font-weight: 600; }
.form-msg.err { color: var(--accent-dark); font-weight: 600; }

/* ===== FOOTER ===== */
footer {
  padding: 40px 0;
  background: var(--ink);
  color: rgba(250, 248, 245, 0.65);
  text-align: center;
  font-size: 13px;
}
footer p { margin-bottom: 6px; }
footer a { color: var(--accent); }

/* ===== RESPONSIVE ===== */
@media (max-width: 840px) {
  .form-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero { padding: 50px 0 30px; }
  .filter-bar { position: static; }
  form { padding: 24px; }
}
@media (max-width: 480px) {
  .nav-cta { font-size: 10px; padding: 8px 12px; }
  .logo { font-size: 17px; }
  .logo small { font-size: 9px; }
  .main-grid { gap: 16px; padding: 32px 16px; }
  .card-actions { flex-direction: column; }
}

/* ===== ANIMATION ===== */
.card.hidden { display: none; }
.card.show { animation: cardIn 380ms var(--ease) backwards; }
@keyframes cardIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: none; }
}

/* ===== ROTATING BORDER — các card có viền chạy cam ===== */
@property --angle {
  syntax: '<angle>';
  initial-value: 0deg;
  inherits: false;
}
.card {
  isolation: isolate;
  position: relative;
}
.card::before {
  content: "";
  position: absolute;
  inset: -2px;
  border-radius: 12px;
  padding: 2px;
  background: conic-gradient(from var(--angle), transparent 0deg, transparent 240deg, var(--accent) 310deg, var(--accent-dark) 340deg, transparent 360deg);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  opacity: 0;
  transition: opacity 300ms var(--ease);
  pointer-events: none;
  z-index: 1;
  animation: rotate-border 5s linear infinite;
}
.card:hover::before { opacity: 1; }
@keyframes rotate-border {
  to { --angle: 360deg; }
}

/* Form box + filter bar cũng rotating */
form {
  isolation: isolate;
  position: relative;
}
form::before {
  content: "";
  position: absolute;
  inset: -2px;
  border-radius: 12px;
  padding: 2px;
  background: conic-gradient(from var(--angle), transparent 0deg, transparent 280deg, var(--accent) 330deg, var(--accent-dark) 350deg, transparent 360deg);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  opacity: 0.7;
  pointer-events: none;
  z-index: 1;
  animation: rotate-border 7s linear infinite;
}

/* ===== FLOATING FAB — 2 ô nhỏ góc trái dưới ===== */
.fab-wrap {
  position: fixed;
  bottom: 20px;
  left: 16px;
  display: flex;
  gap: 10px;
  z-index: 80;
  opacity: 0;
  transform: translateY(16px);
  transition: all 380ms var(--ease);
  pointer-events: none;
}
.fab-wrap.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.fab {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px 9px 10px;
  background: var(--paper);
  border: 1px solid var(--ink-08);
  border-radius: 28px;
  text-decoration: none;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  color: var(--ink);
  transition: all 200ms var(--ease);
  box-shadow: 0 4px 14px rgba(26, 26, 26, 0.08);
  position: relative;
  isolation: isolate;
}
.fab:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(232, 130, 90, 0.2);
}
.fab-home::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: 28px;
  padding: 1.5px;
  background: conic-gradient(from var(--angle), transparent 0deg, transparent 280deg, var(--accent) 340deg, transparent 360deg);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  pointer-events: none;
  animation: rotate-border 5s linear infinite;
}
.fab-parent {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.fab-parent:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.fab-parent::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: 28px;
  padding: 1.5px;
  background: conic-gradient(from var(--angle), transparent 0deg, transparent 280deg, #5A9FD4 340deg, transparent 360deg);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  pointer-events: none;
  animation: rotate-border 6s linear infinite reverse;
}
.fab-dot {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  color: #fff;
  font-weight: 700;
  letter-spacing: 0;
}
.fab-parent .fab-dot {
  background: #5A9FD4;
  color: #fff;
}

@media (max-width: 520px) {
  .fab-wrap { bottom: 14px; left: 10px; gap: 6px; }
  .fab { padding: 8px 12px 8px 8px; font-size: 11px; }
  .fab-dot { width: 20px; height: 20px; font-size: 9px; }
  .fab-label-long { display: none; }
}