/* ===== DESIGN TOKENS ===== */
:root {
  --primary:       #1E3A5F;
  --primary-dark:  #152B47;
  --primary-light: #2D5A8E;
  --accent:        #F5A623;
  --accent-dark:   #E8961A;
  --success:       #27AE60;
  --error:         #E74C3C;
  --surface:       #F8F9FA;
  --border:        #E9ECEF;
  --text:          #1A1A2E;
  --text-muted:    #6C757D;
  --white:         #FFFFFF;
  --zalo:          #0068FF;
  --shadow-sm:     0 2px 8px rgba(0,0,0,0.06);
  --shadow-md:     0 4px 20px rgba(0,0,0,0.10);
  --shadow-lg:     0 8px 40px rgba(0,0,0,0.14);
  --r-sm:8px; --r-md:12px; --r-lg:16px; --r-xl:20px; --r-pill:9999px;
  --t:0.25s ease;
  --heading:'Be Vietnam Pro',sans-serif;
  --body:'Inter',sans-serif;
}

/* ===== RESET ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{font-family:var(--body);color:var(--text);background:var(--white);line-height:1.6;overflow-x:hidden;-webkit-font-smoothing:antialiased;}
img{max-width:100%;display:block;}
a{text-decoration:none;color:inherit;}
ul{list-style:none;}
button{cursor:pointer;border:none;background:none;font-family:inherit;}

.container{width:100%;max-width:1200px;margin:0 auto;padding:0 20px;}
@media(min-width:768px){.container{padding:0 32px;}}
@media(min-width:1024px){.container{padding:0 48px;}}

.section-title{font-family:var(--heading);font-weight:800;font-size:28px;color:var(--primary);text-align:center;margin-bottom:12px;}
.section-sub{font-size:16px;color:var(--text-muted);text-align:center;max-width:540px;margin:0 auto 48px;line-height:1.7;}
@media(min-width:768px){.section-title{font-size:36px;}}

/* ===== SCROLL PROGRESS ===== */
#scroll-progress{position:fixed;top:0;left:0;height:3px;background:var(--accent);z-index:9998;width:0%;transition:width 0.1s linear;}

/* ===== HEADER ===== */
#header{position:sticky;top:0;z-index:900;background:var(--white);border-bottom:1px solid transparent;transition:border-color var(--t),box-shadow var(--t);}
#header.scrolled{border-color:var(--border);box-shadow:var(--shadow-sm);}
.header-inner{padding:16px 0;}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:100%;}
.logo{display:flex;align-items:center;gap:10px;}
.logo-box{width:40px;height:40px;border-radius:10px;background:linear-gradient(135deg,var(--primary),var(--primary-light));display:flex;align-items:center;justify-content:center;font-size:20px;flex-shrink:0;}
.logo-name{font-family:var(--heading);font-weight:800;font-size:22px;}
.logo-name span:first-child{color:var(--primary);}
.logo-name span:last-child{color:var(--accent);}
.nav-links{display:none;}
@media(min-width:1024px){
  .nav-links{display:flex;align-items:center;gap:4px;}
  .nav-links a{font-size:15px;font-weight:500;padding:8px 14px;border-radius:6px;color:var(--text);transition:color var(--t),background var(--t);}
  .nav-links a:hover{color:var(--primary);background:var(--surface);}
}
.header-right{display:flex;align-items:center;gap:10px;}
.btn-cta{background:var(--accent);color:var(--primary);font-family:var(--heading);font-weight:700;font-size:14px;padding:10px 20px;border-radius:var(--r-pill);transition:background var(--t),transform var(--t),box-shadow var(--t);white-space:nowrap;}
.btn-cta:hover{background:var(--accent-dark);transform:translateY(-1px);box-shadow:0 4px 14px rgba(245,166,35,0.4);}
.hamburger{display:flex;flex-direction:column;gap:5px;width:38px;height:38px;align-items:center;justify-content:center;border-radius:8px;transition:background var(--t);}
.hamburger:hover{background:var(--surface);}
.hamburger span{display:block;width:22px;height:2px;background:var(--text);border-radius:2px;transition:transform 0.3s,opacity 0.3s;}
.hamburger.open span:nth-child(1){transform:translateY(7px) rotate(45deg);}
.hamburger.open span:nth-child(2){opacity:0;}
.hamburger.open span:nth-child(3){transform:translateY(-7px) rotate(-45deg);}
@media(min-width:1024px){.hamburger{display:none;}}
.mobile-nav{display:none;position:fixed;top:68px;left:0;right:0;background:var(--white);border-bottom:1px solid var(--border);box-shadow:var(--shadow-md);z-index:899;padding:16px 20px 24px;}
.mobile-nav.open{display:block;}
.mobile-nav a{display:block;font-size:16px;font-weight:500;padding:12px 16px;border-radius:var(--r-sm);color:var(--text);transition:background var(--t);}
.mobile-nav a:hover{background:var(--surface);}
.btn-cta-mobile{display:block;text-align:center;background:var(--accent);color:var(--primary);font-family:var(--heading);font-weight:700;font-size:15px;padding:14px;border-radius:var(--r-pill);margin-top:12px;}

/* ===== HERO ===== */
#hero{background:linear-gradient(135deg,#1E3A5F 0%,#2D5A8E 60%,#1a4570 100%);padding:56px 0 64px;position:relative;overflow:hidden;}
#hero::before{content:'';position:absolute;top:-100px;right:-100px;width:500px;height:500px;background:radial-gradient(circle,rgba(245,166,35,0.12) 0%,transparent 65%);pointer-events:none;}
@media(min-width:1024px){#hero{padding:96px 0 112px;}}
.hero-inner{display:flex;flex-direction:column;gap:48px;position:relative;z-index:1;}
@media(min-width:1024px){.hero-inner{flex-direction:row;align-items:center;gap:56px;}}
.hero-text{flex:1;}
.hero-badge{display:inline-flex;align-items:center;gap:8px;background:rgba(245,166,35,0.15);border:1px solid rgba(245,166,35,0.3);color:var(--accent);font-family:var(--heading);font-weight:600;font-size:13px;padding:6px 14px;border-radius:var(--r-pill);margin-bottom:20px;}
.badge-dot{width:7px;height:7px;background:var(--accent);border-radius:50%;animation:blink 1.5s infinite;}
@keyframes blink{0%,100%{opacity:1;}50%{opacity:0.3;}}
.hero-h1{font-family:var(--heading);font-weight:900;font-size:34px;color:var(--white);line-height:1.18;margin-bottom:18px;}
.hero-h1 .accent{color:var(--accent);}
@media(min-width:768px){.hero-h1{font-size:44px;}}
@media(min-width:1024px){.hero-h1{font-size:52px;}}
.hero-sub{font-size:17px;color:rgba(255,255,255,0.85);line-height:1.75;margin-bottom:36px;max-width:500px;}
@media(min-width:768px){.hero-sub{font-size:18px;}}
.hero-btns{display:flex;flex-wrap:wrap;gap:14px;margin-bottom:40px;}
.btn-hero-primary{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:var(--accent);color:var(--primary);font-family:var(--heading);font-weight:700;font-size:16px;padding:16px 32px;border-radius:var(--r-pill);box-shadow:0 4px 20px rgba(245,166,35,0.4);transition:all var(--t);min-width:160px;}
.btn-hero-primary:hover{background:var(--accent-dark);transform:translateY(-2px);box-shadow:0 8px 28px rgba(245,166,35,0.5);}
.btn-hero-outline{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:2px solid rgba(255,255,255,0.7);color:var(--white);font-family:var(--heading);font-weight:600;font-size:16px;padding:16px 32px;border-radius:var(--r-pill);transition:all var(--t);min-width:160px;}
.btn-hero-outline:hover{background:rgba(255,255,255,0.1);border-color:var(--white);transform:translateY(-1px);}
@media(max-width:640px){.btn-hero-primary,.btn-hero-outline{width:100%;}}
.hero-proof{display:flex;flex-wrap:wrap;gap:20px;}
.proof-item{display:flex;align-items:center;gap:8px;}
.proof-icon{font-size:20px;}
.proof-text{font-size:14px;color:rgba(255,255,255,0.8);font-weight:500;}
.proof-text strong{color:var(--white);font-weight:700;}
.hero-card-wrap{flex:0 0 400px;display:flex;justify-content:center;align-self:flex-start;width:100%;}
@media(max-width:1023px){.hero-card-wrap{flex:none;width:100%;max-width:480px;margin:0 auto;}}
.hero-card{background:rgba(255,255,255,0.1);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border:1px solid rgba(255,255,255,0.2);border-radius:var(--r-xl);padding:22px;width:100%;}

/* ── Platform Card ─────────────────────────────────────────── */
.platform-card{display:flex;flex-direction:column;gap:12px;}
.platform-tag{display:inline-flex;align-items:center;gap:6px;background:rgba(245,166,35,0.15);border:1px solid rgba(245,166,35,0.3);color:var(--accent);font-family:var(--heading);font-weight:700;font-size:11px;padding:4px 12px;border-radius:var(--r-pill);letter-spacing:0.3px;text-transform:uppercase;width:fit-content;}
.platform-desc{font-size:13px;color:rgba(255,255,255,0.8);line-height:1.6;}
.platform-features{display:flex;flex-direction:column;gap:8px;padding:12px;background:rgba(255,255,255,0.06);border-radius:var(--r-md);border:1px solid rgba(255,255,255,0.1);}
.platform-feat{display:flex;align-items:center;gap:9px;font-size:13px;color:rgba(255,255,255,0.85);}
.feat-icon{font-size:15px;flex-shrink:0;}
.platform-btns{display:flex;flex-direction:column;gap:8px;}
.platform-btn-primary{display:flex;align-items:center;justify-content:center;gap:8px;padding:12px;background:var(--accent);color:var(--primary);font-family:var(--heading);font-weight:800;font-size:14px;border-radius:var(--r-pill);transition:all var(--t);box-shadow:0 4px 16px rgba(245,166,35,0.4);}
.platform-btn-primary:hover{background:var(--accent-dark);transform:translateY(-1px);}
.platform-btn-outline{display:flex;align-items:center;justify-content:center;gap:8px;padding:10px;border:1.5px solid rgba(255,255,255,0.35);color:var(--white);font-family:var(--heading);font-weight:700;font-size:13px;border-radius:var(--r-pill);transition:all var(--t);}
.platform-btn-outline:hover{background:rgba(255,255,255,0.1);border-color:var(--white);}
.platform-link{text-align:center;font-size:12px;color:rgba(255,255,255,0.5);transition:color var(--t);}
.platform-link:hover{color:var(--accent);}
.card-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:22px;}
.card-tutor{display:flex;align-items:center;gap:12px;}
.card-av{width:48px;height:48px;border-radius:50%;background:linear-gradient(135deg,#F5A623,#E8961A);display:flex;align-items:center;justify-content:center;font-size:22px;border:2px solid rgba(255,255,255,0.3);}
.card-av-name{font-family:var(--heading);font-weight:700;font-size:14px;color:var(--white);margin-bottom:2px;}
.card-av-sub{font-size:12px;color:rgba(255,255,255,0.65);}
.live-badge{display:inline-flex;align-items:center;gap:5px;background:rgba(39,174,96,0.2);border:1px solid rgba(39,174,96,0.4);color:#4ade80;font-size:11px;font-weight:700;padding:4px 10px;border-radius:var(--r-pill);}
.live-dot{width:6px;height:6px;background:#4ade80;border-radius:50%;animation:blink 1.5s infinite;}
.card-progress{margin-bottom:14px;}
.progress-meta{display:flex;justify-content:space-between;margin-bottom:7px;}
.progress-meta span{font-size:13px;color:rgba(255,255,255,0.8);font-weight:500;}
.progress-meta .pct{color:var(--accent);font-weight:700;}
.progress-track{height:6px;background:rgba(255,255,255,0.12);border-radius:3px;overflow:hidden;}
.progress-fill{height:100%;background:linear-gradient(90deg,var(--accent),#FFD166);border-radius:3px;animation:fillBar 1.8s ease forwards;}
@keyframes fillBar{from{width:0%}to{width:78%}}
.progress-fill-2{height:100%;background:linear-gradient(90deg,#F5A623,#FFD166);border-radius:3px;animation:fillBar2 1.8s ease 0.3s forwards;width:0%;}
@keyframes fillBar2{from{width:0%}to{width:62%}}
.card-footer{display:flex;justify-content:space-between;align-items:center;padding-top:16px;border-top:1px solid rgba(255,255,255,0.12);margin-top:14px;}
.online-pill{display:flex;align-items:center;gap:5px;background:rgba(39,174,96,0.15);border:1px solid rgba(39,174,96,0.3);color:#4ade80;font-size:12px;font-weight:600;padding:5px 12px;border-radius:var(--r-pill);}
.online-dot{width:6px;height:6px;background:#4ade80;border-radius:50%;animation:blink 1.5s infinite;}
.rating-pill{display:flex;align-items:center;gap:5px;background:rgba(245,166,35,0.15);border:1px solid rgba(245,166,35,0.3);padding:5px 12px;border-radius:var(--r-pill);}
.rating-pill .star{color:var(--accent);font-size:14px;}
.rating-pill .score{color:var(--white);font-size:13px;font-weight:700;}

/* ===== TRUST BAR ===== */
#trust{background:var(--white);border-top:4px solid var(--accent);border-bottom:1px solid var(--border);padding:36px 0;}
.trust-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:0;max-width:720px;margin:0 auto;}
@media(max-width:600px){.trust-grid{grid-template-columns:1fr;gap:20px;}}
.trust-item{text-align:center;position:relative;}
@media(min-width:768px){.trust-item:not(:last-child)::after{content:'';position:absolute;right:0;top:50%;transform:translateY(-50%);width:1px;height:52px;background:var(--border);}}
.trust-num{font-family:var(--heading);font-weight:900;font-size:38px;color:var(--primary);display:block;line-height:1;margin-bottom:6px;transition:color var(--t);}
@media(min-width:768px){.trust-num{font-size:44px;}}
.trust-item:hover .trust-num{color:var(--accent);}
.trust-label{font-size:14px;color:var(--text-muted);font-weight:500;}

/* ===== USP ===== */
#usp{background:var(--surface);padding:72px 0;}
.usp-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;}
@media(min-width:1024px){.usp-grid{grid-template-columns:repeat(4,1fr);gap:24px;}}
.usp-card{background:var(--white);border-radius:var(--r-md);padding:28px 22px;box-shadow:var(--shadow-sm);border-top:3px solid transparent;transition:transform var(--t),box-shadow var(--t),border-color var(--t);}
@media(min-width:768px){.usp-card{padding:32px 28px;}}
.usp-card:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg);border-top-color:var(--accent);}
.usp-icon{width:56px;height:56px;background:rgba(30,58,95,0.08);border-radius:14px;display:flex;align-items:center;justify-content:center;font-size:28px;margin-bottom:18px;}
.usp-card h3{font-family:var(--heading);font-weight:700;font-size:16px;color:var(--primary);margin-bottom:10px;line-height:1.3;}
@media(min-width:768px){.usp-card h3{font-size:17px;}}
.usp-card p{font-size:14px;color:var(--text-muted);line-height:1.7;}

/* ===== TUTOR ===== */
#tutor{background:var(--white);padding:72px 0;}
.tutor-inner{display:flex;flex-direction:column;gap:48px;align-items:center;}
@media(min-width:1024px){.tutor-inner{flex-direction:row;gap:72px;align-items:flex-start;}}
.tutor-img-wrap{flex-shrink:0;position:relative;}
.tutor-placeholder{width:260px;height:320px;background:linear-gradient(135deg,var(--primary) 0%,var(--primary-light) 100%);border-radius:var(--r-lg);border:4px solid var(--accent);box-shadow:8px 8px 0 rgba(245,166,35,0.18),var(--shadow-lg);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;}
@media(min-width:1024px){.tutor-placeholder{width:300px;height:380px;}}
.tutor-emoji{font-size:80px;}
@media(min-width:1024px){.tutor-emoji{font-size:100px;}}
.tutor-img-name{font-family:var(--heading);font-weight:700;font-size:15px;color:rgba(255,255,255,0.9);}
.tutor-badge-overlay{position:absolute;bottom:-14px;left:20px;background:var(--accent);color:var(--primary);font-family:var(--heading);font-weight:700;font-size:12px;padding:7px 16px;border-radius:var(--r-pill);box-shadow:0 4px 12px rgba(245,166,35,0.4);white-space:nowrap;}
.tutor-content{flex:1;}
.tutor-tag{display:inline-block;background:rgba(245,166,35,0.1);color:var(--accent-dark);font-family:var(--heading);font-weight:600;font-size:13px;padding:5px 14px;border-radius:var(--r-pill);margin-bottom:14px;letter-spacing:0.4px;}
.tutor-name{font-family:var(--heading);font-weight:900;font-size:30px;color:var(--primary);margin-bottom:6px;}
@media(min-width:768px){.tutor-name{font-size:36px;}}
.tutor-title{font-size:16px;color:var(--accent-dark);font-weight:600;margin-bottom:18px;}
.tutor-bio{font-size:15px;color:var(--text-muted);line-height:1.8;margin-bottom:20px;}
.tutor-quote{border-left:4px solid var(--accent);padding:14px 18px;background:rgba(245,166,35,0.05);border-radius:0 8px 8px 0;font-style:italic;font-size:15px;color:var(--text);line-height:1.75;margin-bottom:28px;}
.tutor-creds{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:32px;}
.cred{display:flex;align-items:center;gap:6px;background:var(--surface);padding:8px 14px;border-radius:var(--r-pill);font-size:13px;font-weight:500;}
.btn-outline{display:inline-flex;align-items:center;gap:8px;border:2px solid var(--primary);color:var(--primary);font-family:var(--heading);font-weight:700;font-size:15px;padding:12px 28px;border-radius:var(--r-pill);transition:all var(--t);}
.btn-outline:hover{background:var(--primary);color:var(--white);transform:translateY(-1px);}

/* ===== SERVICES ===== */
#services{background:var(--surface);padding:72px 0;}
.services-grid{display:grid;grid-template-columns:1fr;gap:20px;}
@media(min-width:640px){.services-grid{grid-template-columns:1fr 1fr;}}
@media(min-width:1024px){.services-grid{grid-template-columns:repeat(4,1fr);}}
.svc-card{background:var(--white);border-radius:var(--r-md);padding:28px;box-shadow:var(--shadow-sm);border:1px solid var(--border);display:flex;flex-direction:column;transition:transform var(--t),box-shadow var(--t),border-color var(--t);position:relative;}
.svc-card:hover{transform:translateY(-5px);box-shadow:var(--shadow-lg);border-color:transparent;}
.svc-card.featured{border:2px solid var(--accent);background:linear-gradient(135deg,#FFFBF0,var(--white));}
.featured-badge{position:absolute;top:-12px;right:16px;background:var(--accent);color:var(--primary);font-family:var(--heading);font-weight:700;font-size:11px;padding:5px 14px;border-radius:var(--r-pill);box-shadow:0 3px 10px rgba(245,166,35,0.35);}
.svc-icon{font-size:36px;margin-bottom:16px;}
.svc-name{font-family:var(--heading);font-weight:700;font-size:18px;color:var(--primary);margin-bottom:6px;}
.svc-grade{font-size:13px;color:var(--text-muted);margin-bottom:14px;}
.svc-desc{font-size:14px;color:var(--text-muted);line-height:1.7;margin-bottom:20px;flex:1;}
.svc-price{font-family:var(--heading);font-weight:800;font-size:26px;color:var(--primary);margin-bottom:4px;}
.svc-unit{font-size:13px;color:var(--text-muted);margin-bottom:20px;}
.btn-svc{display:block;text-align:center;padding:12px;border-radius:var(--r-md);font-family:var(--heading);font-weight:700;font-size:14px;background:var(--primary);color:var(--white);transition:background var(--t),transform var(--t);}
.btn-svc:hover{background:var(--primary-dark);transform:translateY(-1px);}
.svc-card.featured .btn-svc{background:var(--accent);color:var(--primary);}
.svc-card.featured .btn-svc:hover{background:var(--accent-dark);}

/* ===== TESTIMONIALS ===== */
#testimonials{background:var(--white);padding:72px 0;}
.test-grid{display:grid;grid-template-columns:1fr;gap:20px;}
@media(min-width:768px){.test-grid{grid-template-columns:repeat(3,1fr);}}
.test-card{background:var(--white);border-radius:var(--r-md);padding:28px;box-shadow:var(--shadow-sm);border:1px solid var(--border);border-top:3px solid var(--accent);transition:transform var(--t),box-shadow var(--t);}
.test-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);}
.test-stars{color:var(--accent);font-size:18px;margin-bottom:14px;}
.test-text{font-size:15px;color:var(--text);line-height:1.75;margin-bottom:20px;font-style:italic;}
.test-text::before{content:'"';color:var(--accent);font-size:36px;line-height:0;vertical-align:-12px;margin-right:4px;}
.test-author{display:flex;align-items:center;gap:12px;}
.test-av{width:46px;height:46px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--primary-light));display:flex;align-items:center;justify-content:center;font-size:20px;border:2px solid var(--border);}
.test-name{font-family:var(--heading);font-weight:700;font-size:14px;color:var(--text);margin-bottom:2px;}
.test-info{font-size:13px;color:var(--text-muted);}

/* ===== REGISTER FORM ===== */
#register{background:linear-gradient(135deg,var(--primary) 0%,var(--primary-light) 100%);padding:72px 0;position:relative;overflow:hidden;}
#register::before{content:'';position:absolute;top:-80px;right:-80px;width:400px;height:400px;background:radial-gradient(circle,rgba(245,166,35,0.12) 0%,transparent 65%);pointer-events:none;}
.register-inner{display:flex;flex-direction:column;gap:48px;position:relative;z-index:1;}
@media(min-width:1024px){.register-inner{flex-direction:row;align-items:flex-start;gap:64px;}}
.register-left{flex:1;}
.register-tag{display:inline-block;background:rgba(245,166,35,0.2);border:1px solid rgba(245,166,35,0.4);color:var(--accent);font-family:var(--heading);font-weight:700;font-size:12px;padding:5px 14px;border-radius:var(--r-pill);margin-bottom:20px;letter-spacing:0.5px;text-transform:uppercase;}
.register-h2{font-family:var(--heading);font-weight:900;font-size:32px;color:var(--white);line-height:1.2;margin-bottom:16px;}
@media(min-width:768px){.register-h2{font-size:40px;}}
.register-sub{font-size:16px;color:rgba(255,255,255,0.85);line-height:1.75;margin-bottom:32px;}
.benefit-list{display:flex;flex-direction:column;gap:14px;margin-bottom:36px;}
.benefit{display:flex;align-items:flex-start;gap:12px;}
.benefit-check{width:22px;height:22px;background:var(--success);border-radius:50%;display:flex;align-items:center;justify-content:center;color:white;font-size:12px;flex-shrink:0;margin-top:1px;}
.benefit-text{font-size:15px;color:rgba(255,255,255,0.9);line-height:1.6;}
.benefit-text strong{color:var(--white);}
.social-proof-row{display:flex;align-items:center;gap:12px;}
.sp-avatars{display:flex;}
.sp-av{width:36px;height:36px;border-radius:50%;border:2px solid rgba(255,255,255,0.8);background:linear-gradient(135deg,var(--primary-light),#3A6EA8);display:flex;align-items:center;justify-content:center;font-size:16px;margin-left:-10px;}
.sp-av:first-child{margin-left:0;}
.sp-text{font-size:14px;color:rgba(255,255,255,0.85);font-weight:500;}
.sp-text strong{color:var(--white);}
.form-card{background:var(--white);border-radius:var(--r-xl);padding:36px 28px;box-shadow:0 24px 64px rgba(0,0,0,0.22);flex:0 0 440px;}
@media(min-width:768px){.form-card{padding:40px 36px;}}
.form-title{font-family:var(--heading);font-weight:800;font-size:22px;color:var(--primary);margin-bottom:6px;}
.form-sub{font-size:14px;color:var(--text-muted);margin-bottom:6px;}
.form-divider{width:40px;height:3px;background:var(--accent);border-radius:2px;margin-bottom:28px;}
.form-group{margin-bottom:18px;position:relative;}
.form-label{display:block;font-size:14px;font-weight:600;color:var(--text);margin-bottom:6px;}
.form-label .req{color:var(--error);}
.form-input{width:100%;height:48px;border:1.5px solid var(--border);border-radius:var(--r-sm);padding:0 14px 0 44px;font-size:15px;color:var(--text);background:var(--white);transition:border-color var(--t),box-shadow var(--t);outline:none;}
.form-input::placeholder{color:#adb5bd;}
.form-input:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(30,58,95,0.1);}
.form-input.error{border-color:var(--error);box-shadow:0 0 0 3px rgba(231,76,60,0.1);}
.form-icon{position:absolute;left:14px;top:50%;transform:translateY(8px);font-size:16px;pointer-events:none;}
.form-select{width:100%;height:48px;border:1.5px solid var(--border);border-radius:var(--r-sm);padding:0 14px 0 44px;font-size:15px;color:var(--text);background:var(--white);appearance:none;cursor:pointer;outline:none;transition:border-color var(--t),box-shadow var(--t);}
.form-select:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(30,58,95,0.1);}
.form-select-icon{position:absolute;right:14px;top:50%;transform:translateY(8px);pointer-events:none;color:var(--text-muted);}
.radio-group{display:flex;gap:12px;}
.radio-label{flex:1;}
.radio-label input{display:none;}
.radio-btn{display:block;text-align:center;padding:12px;border:1.5px solid var(--border);border-radius:var(--r-sm);font-size:14px;font-weight:500;cursor:pointer;transition:all var(--t);}
.radio-label input:checked + .radio-btn{border-color:var(--primary);background:rgba(30,58,95,0.07);color:var(--primary);font-weight:700;}
.radio-btn:hover{border-color:var(--primary-light);}
.error-msg{font-size:12px;color:var(--error);margin-top:5px;display:none;}
.error-msg.show{display:block;}
.btn-submit{width:100%;height:54px;border-radius:var(--r-md);background:linear-gradient(135deg,var(--accent),var(--accent-dark));color:var(--primary);font-family:var(--heading);font-weight:800;font-size:16px;cursor:pointer;border:none;transition:all var(--t);box-shadow:0 4px 16px rgba(245,166,35,0.4);margin-top:8px;display:flex;align-items:center;justify-content:center;gap:8px;}
.btn-submit:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(245,166,35,0.5);}
.form-note{font-size:12px;color:var(--text-muted);text-align:center;margin-top:12px;}
.form-success{display:none;text-align:center;padding:20px 0;}
.form-success.show{display:block;}
.success-icon{font-size:56px;margin-bottom:16px;}
.success-title{font-family:var(--heading);font-weight:800;font-size:22px;color:var(--primary);margin-bottom:10px;}
.success-sub{font-size:15px;color:var(--text-muted);line-height:1.7;}

/* ===== FOOTER ===== */
#footer{background:#0F1923;padding:60px 0 0;}
.footer-grid{display:grid;grid-template-columns:1fr;gap:40px;margin-bottom:48px;}
@media(min-width:768px){.footer-grid{grid-template-columns:2fr 1fr 1fr 1fr;gap:48px;}}
.footer-logo-name{font-family:var(--heading);font-weight:800;font-size:22px;margin-bottom:14px;}
.footer-logo-name span:first-child{color:var(--white);}
.footer-logo-name span:last-child{color:var(--accent);}
.footer-desc{font-size:14px;color:rgba(255,255,255,0.55);line-height:1.75;margin-bottom:24px;max-width:280px;}
.footer-socials{display:flex;gap:10px;margin-bottom:24px;}
.social-btn{width:38px;height:38px;border-radius:50%;background:rgba(255,255,255,0.08);border:1px solid rgba(255,255,255,0.1);display:flex;align-items:center;justify-content:center;font-size:16px;cursor:pointer;transition:background var(--t),border-color var(--t),transform var(--t);}
.social-btn:hover{background:var(--accent);border-color:var(--accent);transform:scale(1.1);}
.footer-contact{display:flex;flex-direction:column;gap:10px;}
.footer-contact-item{display:flex;align-items:center;gap:8px;font-size:14px;color:rgba(255,255,255,0.7);transition:color var(--t);}
.footer-contact-item:hover{color:var(--white);}
.footer-col-title{font-family:var(--heading);font-weight:700;font-size:13px;color:var(--accent);text-transform:uppercase;letter-spacing:1px;margin-bottom:20px;position:relative;padding-bottom:14px;}
.footer-col-title::after{content:'';position:absolute;bottom:0;left:0;width:24px;height:2px;background:var(--accent);border-radius:2px;}
.footer-links{display:flex;flex-direction:column;gap:10px;}
.footer-links a{font-size:14px;color:rgba(255,255,255,0.6);transition:color var(--t),padding-left var(--t);}
.footer-links a:hover{color:var(--white);padding-left:4px;}
.footer-bottom{border-top:1px solid rgba(255,255,255,0.08);padding:20px 0;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;}
.footer-copy{font-size:13px;color:rgba(255,255,255,0.4);}
.footer-copy span{color:var(--accent);}

/* ===== FLOATING BUTTONS ===== */
.floating-wrap{position:fixed;bottom:28px;right:28px;z-index:9999;display:flex;flex-direction:column;gap:12px;align-items:center;animation:slideUp 0.6s ease 1.5s both;}
@keyframes slideUp{from{transform:translateY(80px);opacity:0;}to{transform:translateY(0);opacity:1;}}
.zalo-btn{width:60px;height:60px;border-radius:50%;background:var(--zalo);color:white;font-size:26px;display:flex;align-items:center;justify-content:center;box-shadow:0 4px 20px rgba(0,104,255,0.45);position:relative;cursor:pointer;transition:transform var(--t),box-shadow var(--t);}
.zalo-btn:hover{transform:scale(1.1);box-shadow:0 8px 30px rgba(0,104,255,0.55);}
.zalo-btn::before,.zalo-btn::after{content:'';position:absolute;border-radius:50%;width:100%;height:100%;background:rgba(0,104,255,0.25);animation:pulse-ring 2s ease-out infinite;}
.zalo-btn::after{animation-delay:1s;background:rgba(0,104,255,0.15);}
@keyframes pulse-ring{0%{transform:scale(1);opacity:0.8;}100%{transform:scale(1.9);opacity:0;}}
.zalo-notif{position:absolute;top:-3px;right:-3px;width:20px;height:20px;background:var(--error);border-radius:50%;border:2px solid white;display:flex;align-items:center;justify-content:center;font-size:11px;font-weight:700;color:white;animation:bounce 1.5s ease infinite;}
@keyframes bounce{0%,100%{transform:scale(1);}50%{transform:scale(1.2);}}
.phone-btn{width:48px;height:48px;border-radius:50%;background:var(--success);color:white;font-size:20px;display:flex;align-items:center;justify-content:center;box-shadow:0 4px 16px rgba(39,174,96,0.4);transition:transform var(--t),box-shadow var(--t);position:relative;cursor:pointer;}
.phone-btn:hover{transform:scale(1.1);box-shadow:0 8px 24px rgba(39,174,96,0.5);}

/* ===== GROUP CLASSES ===== */
.group-section{padding:64px 0;background:var(--surface);scroll-margin-top:80px;}
.group-filter{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:28px;}
.group-filter-btn{padding:8px 18px;border-radius:var(--r-pill);border:1.5px solid var(--border);background:var(--white);font-size:13px;font-weight:600;color:var(--text-muted);cursor:pointer;transition:all var(--t);}
.group-filter-btn.active,.group-filter-btn:hover{background:var(--primary);color:var(--white);border-color:var(--primary);}
.group-grid{display:grid;grid-template-columns:1fr;gap:20px;}
@media(min-width:640px){.group-grid{grid-template-columns:repeat(2,1fr);}}
@media(min-width:1024px){.group-grid{grid-template-columns:repeat(3,1fr);}}
.group-card{background:var(--white);border-radius:var(--r-lg);padding:24px;border:2px solid var(--border);display:flex;flex-direction:column;gap:12px;transition:all var(--t);}
.group-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-md);border-color:var(--primary-light);}
.group-card-top{display:flex;justify-content:space-between;align-items:flex-start;gap:8px;}
.group-subject{font-family:var(--heading);font-weight:700;font-size:16px;color:var(--primary);}
.group-badge{font-size:11px;font-weight:700;padding:4px 10px;border-radius:var(--r-pill);}
.group-badge.open{background:#e8f8f0;color:var(--success);}
.group-badge.full{background:#fce8e8;color:var(--error);}
.group-meta{display:flex;flex-direction:column;gap:6px;}
.group-meta-row{font-size:13px;color:var(--text-muted);display:flex;align-items:center;gap:6px;}
.group-slots{display:flex;align-items:center;gap:8px;}
.group-slots-bar{flex:1;height:6px;background:var(--border);border-radius:3px;overflow:hidden;}
.group-slots-fill{height:100%;background:var(--success);border-radius:3px;transition:width 0.4s;}
.group-slots-fill.near-full{background:var(--accent);}
.group-slots-fill.full{background:var(--error);}
.group-price{font-family:var(--heading);font-weight:800;font-size:22px;color:var(--primary);}
.group-price span{font-size:13px;font-weight:500;color:var(--text-muted);}
.group-join-btn{display:block;text-align:center;padding:12px;border-radius:var(--r-md);font-family:var(--heading);font-weight:700;font-size:14px;background:var(--primary);color:var(--white);border:none;cursor:pointer;transition:all var(--t);margin-top:auto;}
.group-join-btn:hover{background:var(--primary-dark);transform:translateY(-1px);}
.group-join-btn:disabled{background:var(--border);color:var(--text-muted);cursor:not-allowed;transform:none;}
.group-empty{text-align:center;padding:48px 24px;color:var(--text-muted);grid-column:1/-1;}
.group-create-wrap{text-align:center;margin-top:32px;padding:24px;background:var(--white);border-radius:var(--r-lg);border:2px dashed var(--border);}
.group-create-wrap p{color:var(--text-muted);font-size:14px;margin-bottom:12px;}
.btn-group-create{display:inline-flex;align-items:center;gap:8px;padding:12px 28px;border-radius:var(--r-pill);background:var(--accent);color:var(--primary);font-family:var(--heading);font-weight:700;font-size:15px;border:none;cursor:pointer;transition:all var(--t);}
.btn-group-create:hover{background:var(--accent-dark);transform:translateY(-1px);}
/* Homepage compact group */
.group-mini-section{padding:56px 0;}
.group-mini-grid{display:grid;grid-template-columns:1fr;gap:16px;margin-bottom:20px;}
@media(min-width:768px){.group-mini-grid{grid-template-columns:repeat(3,1fr);}}
.group-mini-card{background:var(--white);border-radius:var(--r-md);padding:20px;border:1.5px solid var(--border);display:flex;flex-direction:column;gap:8px;transition:all var(--t);}
.group-mini-card:hover{border-color:var(--primary-light);box-shadow:var(--shadow-sm);}
.group-mini-subject{font-family:var(--heading);font-weight:700;font-size:15px;color:var(--primary);}
.group-mini-info{font-size:13px;color:var(--text-muted);}
.group-mini-footer{display:flex;justify-content:space-between;align-items:center;margin-top:4px;}
.group-mini-slots{font-size:12px;font-weight:600;color:var(--success);}
.group-mini-price{font-family:var(--heading);font-weight:700;font-size:15px;color:var(--primary);}