:root {
    --azure: #22A0FE;
    --cobalt: #1452AB;
    --dark: #282828;
    --orange: #FF6B2B;
    --white: #FFFFFF;
    --light-bg: #F4F8FF;
    --gray: #888888;
    --light-gray: #DCDCDC;
  }
  * { margin: 0; padding: 0; box-sizing: border-box; }
  body { font-family: 'Nunito', sans-serif; color: var(--dark); overflow-x: hidden; }

  /* STICKY HEADER */
  .sticky-header {
    position: fixed; top: 0; width: 100%; z-index: 999;
    background: rgba(20,82,171,0.97); backdrop-filter: blur(8px);
    padding: 10px 20px; display: flex; align-items: center; justify-content: space-between;
    box-shadow: 0 2px 20px rgba(0,0,0,0.3);
  }
  .sticky-header .logo-wrap { display: flex; align-items: center; gap: 10px; }
  .sticky-header .logo-img { height: 50px; width: 96px; display: block; }
  .sticky-cta {
    background: var(--orange); color: white; border: none; padding: 10px 20px;
    border-radius: 50px; font-family: 'Nunito', sans-serif; font-weight: 800; font-size: 14px;
    cursor: pointer; text-decoration: none; display: inline-block;
    animation: pulse 2s infinite;
  }
  @keyframes pulse { 0%,100%{box-shadow:0 0 0 0 rgba(255,107,43,0.5)} 50%{box-shadow:0 0 0 10px rgba(255,107,43,0)} }

  /* HERO */
  .hero {
    margin-top: 60px;
    background: linear-gradient(135deg, #0A1628 0%, #1452AB 50%, #22A0FE 100%);
    min-height: 90vh; display: flex; align-items: center; position: relative; overflow: hidden;
    padding: 60px 20px;
  }
  .hero::before {
    content: ''; position: absolute; top: -50%; right: -20%; width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(34,160,254,0.3) 0%, transparent 70%);
    border-radius: 50%;
  }
  .hero::after {
    content: '🌡️'; position: absolute; font-size: 200px; top: 10%; right: 5%;
    opacity: 0.08; animation: float 4s ease-in-out infinite;
  }
  @keyframes float { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-20px)} }

  .hero-inner { max-width: 800px; margin: 0 auto; position: relative; z-index: 2; }
  .badge {
    display: inline-block; background: var(--orange); color: white; padding: 6px 16px;
    border-radius: 50px; font-size: 13px; font-weight: 800; letter-spacing: 1px;
    text-transform: uppercase; margin-bottom: 20px;
    animation: fadeInDown 0.6s ease;
  }
  @keyframes fadeInDown { from{opacity:0;transform:translateY(-20px)} to{opacity:1;transform:translateY(0)} }
  @keyframes fadeInUp { from{opacity:0;transform:translateY(30px)} to{opacity:1;transform:translateY(0)} }

  .hero h1 {
    font-family: 'Barlow Condensed', sans-serif; font-size: clamp(32px,6vw,64px);
    font-weight: 900; color: white; line-height: 1.1; margin-bottom: 20px;
    animation: fadeInUp 0.7s ease 0.2s both;
  }
  .hero h1 span { color: var(--azure); }
  .hero-sub {
    color: rgba(255,255,255,0.85); font-size: 18px; font-weight: 600; margin-bottom: 16px;
    animation: fadeInUp 0.7s ease 0.3s both;
  }
  .promo-badge {
    display: inline-block; background: #FFD60A; border: 2px solid #FFD60A;
    color: #1a1a1a; padding: 10px 24px; border-radius: 8px; font-weight: 900; font-size: 17px;
    margin-bottom: 32px; animation: fadeInUp 0.7s ease 0.4s both, glowPromo 2s ease-in-out infinite;
    box-shadow: 0 4px 20px rgba(255,214,10,0.5);
  }
  @keyframes glowPromo { 0%,100%{box-shadow:0 4px 20px rgba(255,214,10,0.5)} 50%{box-shadow:0 4px 30px rgba(255,214,10,0.9)} }
  .hero-cta {
    display: inline-flex; align-items: center; gap: 10px;
    background: #06C755; color: white; padding: 18px 36px; border-radius: 50px;
    font-size: 18px; font-weight: 800; text-decoration: none;
    box-shadow: 0 8px 30px rgba(6,199,85,0.5);
    animation: fadeInUp 0.7s ease 0.5s both, pulse-green 2s infinite 1.5s;
    transition: transform 0.2s;
  }
  .hero-cta:hover { transform: translateY(-3px); }
  @keyframes pulse-green { 0%,100%{box-shadow:0 8px 30px rgba(6,199,85,0.5)} 50%{box-shadow:0 8px 40px rgba(6,199,85,0.8)} }
  .hero-trust {
    margin-top: 30px; display: flex; flex-wrap: wrap; gap: 16px;
    animation: fadeInUp 0.7s ease 0.6s both;
  }
  .trust-chip {
    background: rgba(255,255,255,0.12); border: 1px solid rgba(255,255,255,0.25);
    color: white; padding: 8px 16px; border-radius: 50px; font-size: 14px; font-weight: 700;
  }

  /* SYMPTOMS */
  .symptoms { background: white; padding: 70px 20px; }
  .section-title {
    font-family: 'Barlow Condensed', sans-serif; font-size: clamp(28px,4vw,42px);
    font-weight: 900; text-align: center; margin-bottom: 12px; color: var(--dark);
  }
  .section-title span { color: var(--azure); }
  .section-sub { text-align: center; color: var(--gray); font-size: 16px; margin-bottom: 48px; }
  .symptoms-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px; max-width: 900px; margin: 0 auto;
  }
  .symptom-card {
    background: var(--light-bg); border-radius: 16px; padding: 28px 24px;
    border-left: 4px solid var(--azure); transition: all 0.3s; cursor: default;
    position: relative; overflow: hidden;
  }
  .symptom-card::after {
    content: ''; position: absolute; bottom: 0; right: 0; width: 80px; height: 80px;
    background: radial-gradient(circle, rgba(34,160,254,0.1) 0%, transparent 70%);
  }
  .symptom-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(34,160,254,0.2); border-left-color: var(--orange); }
  .symptom-icon { font-size: 36px; margin-bottom: 12px; }
  .symptom-card h3 { font-size: 18px; font-weight: 800; margin-bottom: 8px; color: var(--dark); }
  .symptom-card p { font-size: 14px; color: var(--gray); line-height: 1.6; }

  /* PRICING */
  .pricing { background: var(--dark); padding: 70px 20px; }
  .pricing .section-title { color: white; }
  .pricing .section-sub { color: rgba(255,255,255,0.6); }
  .price-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px; max-width: 860px; margin: 0 auto 32px;
  }
  .price-card {
    background: rgba(255,255,255,0.07); border: 1px solid rgba(255,255,255,0.12);
    border-radius: 16px; padding: 28px 24px; text-align: center; transition: all 0.3s;
  }
  .price-card:hover { background: rgba(34,160,254,0.15); border-color: var(--azure); transform: translateY(-4px); }
  .price-card.featured { background: linear-gradient(135deg, #22A0FE22, #1452AB33); border-color: var(--azure); }
  .price-card .icon { font-size: 40px; margin-bottom: 12px; }
  .price-card h3 { color: white; font-size: 16px; font-weight: 700; margin-bottom: 12px; }
  .price-amount { font-family: 'Barlow Condensed', sans-serif; font-size: 36px; font-weight: 900; color: var(--azure); }
  .price-note { font-size: 12px; color: rgba(255,255,255,0.5); margin-top: 6px; }
  .pricing-disclaimer {
    text-align: center; color: rgba(255,255,255,0.6); font-size: 14px; font-style: italic;
    max-width: 500px; margin: 0 auto 32px;
  }
  .pricing-cta {
    text-align: center;
  }
  .btn-zalo {
    display: inline-flex; align-items: center; gap: 10px;
    background: #06C755; color: white; padding: 16px 36px; border-radius: 50px;
    font-size: 17px; font-weight: 800; text-decoration: none;
    box-shadow: 0 6px 24px rgba(6,199,85,0.4); transition: all 0.2s;
  }
  .btn-zalo:hover { transform: translateY(-3px); box-shadow: 0 10px 30px rgba(6,199,85,0.6); }

  /* PROCESS */
  .process { background: var(--light-bg); padding: 70px 20px; }
  .steps { display: flex; flex-wrap: wrap; justify-content: center; gap: 0; max-width: 900px; margin: 0 auto; }
  .step {
    flex: 1; min-width: 180px; max-width: 250px; text-align: center; padding: 24px 20px;
    position: relative;
  }
  .step:not(:last-child)::after {
    content: '→'; position: absolute; right: -10px; top: 40px;
    font-size: 24px; color: var(--azure); font-weight: 900;
  }
  .step-num {
    width: 64px; height: 64px; border-radius: 50%;
    background: linear-gradient(135deg, var(--azure), var(--cobalt));
    color: white; font-family: 'Barlow Condensed', sans-serif; font-size: 28px; font-weight: 900;
    display: flex; align-items: center; justify-content: center; margin: 0 auto 16px;
    box-shadow: 0 6px 20px rgba(34,160,254,0.4);
  }
  .step h3 { font-size: 16px; font-weight: 800; margin-bottom: 8px; color: var(--cobalt); }
  .step p { font-size: 13px; color: var(--gray); line-height: 1.5; }

  /* TRUST */
  .trust { background: white; padding: 70px 20px; }
  .trust-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 24px; max-width: 900px; margin: 0 auto 48px;
  }
  .trust-item { text-align: center; padding: 28px 20px; border-radius: 16px; background: var(--light-bg); }
  .trust-item .t-icon { font-size: 48px; margin-bottom: 12px; }
  .trust-item h3 { font-family: 'Barlow Condensed', sans-serif; font-size: 22px; font-weight: 900; color: var(--cobalt); margin-bottom: 6px; }
  .trust-item p { font-size: 14px; color: var(--gray); }
  .final-cta {
    text-align: center; background: linear-gradient(135deg, var(--cobalt), #22A0FE);
    border-radius: 24px; padding: 48px 32px; max-width: 700px; margin: 0 auto;
    box-shadow: 0 20px 60px rgba(20,82,171,0.3);
  }
  .final-cta h2 { font-family: 'Barlow Condensed', sans-serif; font-size: 32px; font-weight: 900; color: white; margin-bottom: 12px; }
  .final-cta p { color: rgba(255,255,255,0.85); margin-bottom: 28px; font-size: 16px; }

  /* STICKY ZALO */
  .sticky-zalo {
    position: fixed; bottom: 24px; right: 24px; z-index: 998;
    background: #06C755; color: white; padding: 14px 24px; border-radius: 50px;
    font-weight: 800; font-size: 15px; text-decoration: none;
    box-shadow: 0 8px 30px rgba(6,199,85,0.5);
    display: flex; align-items: center; gap: 8px;
    animation: bounce 3s ease-in-out infinite;
  }
  @keyframes bounce { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-8px)} }

  footer { background: var(--dark); color: rgba(255,255,255,0.5); text-align: center; padding: 24px; font-size: 13px; }

  @media(max-width:600px) {
    .step:not(:last-child)::after { display: none; }
    .hero::after { display: none; }
  }