/* ============================================================
   EXAM-AI — landing page
   Hai chủ đề: TỐI và SÁNG. Mặc định chạy theo cài đặt máy của khách,
   có nút chuyển tay trên thanh điều hướng.

   LUẬT: mọi màu phụ thuộc chủ đề đều phải đi qua biến khai ở đây.
   Viết thẳng mã màu vào rule bên dưới là chỗ đó chết cứng một chủ đề,
   còn bản kia hỏng CÂM — không có lỗi nào báo ra.
   ============================================================ */

:root{
  /* ---------- nền, chữ, đường kẻ ---------- */
  --bg:        #070d18;
  --bg-2:      #0d1526;
  --bg-3:      #111c30;
  --surface:   rgba(255,255,255,.035);
  --surface-2: rgba(255,255,255,.055);
  --line:      rgba(255,255,255,.09);
  --line-2:    rgba(255,255,255,.14);
  --text:      #f1f5f9;
  --text-2:    #b6c2d4;
  --muted:     #8496ad;
  --accent:    #2563eb;
  --accent-2:  #60a5fa;
  --accent-3:  #1d4ed8;
  --ok:        #34d399;
  --warn:      #fbbf24;

  /* ---------- thanh điều hướng ---------- */
  --nav-bg:    rgba(7,13,24,.72);
  --nav-bg-2:  rgba(7,13,24,.9);
  --nav-bg-3:  rgba(7,13,24,.98);
  --seg-on-bg: rgba(37,99,235,.28);
  --seg-on-fg: #fff;

  /* ---------- quầng sáng trang trí ---------- */
  --orb-1:     rgba(37,99,235,.42);
  --orb-2:     rgba(99,102,241,.3);
  --orb-3:     rgba(37,99,235,.3);
  --glow-1:    rgba(37,99,235,.34);

  /* ---------- sắc xanh phụ trợ ---------- */
  --accent-soft:   rgba(37,99,235,.13);
  --accent-soft-2: rgba(37,99,235,.20);
  --accent-line:   rgba(96,165,250,.28);
  --accent-line-2: rgba(96,165,250,.45);
  --grad-a:    #60a5fa;
  --grad-b:    #dbeafe;
  --grad-c:    #3b82f6;
  --ic-a:      rgba(37,99,235,.22);
  --ic-b:      rgba(37,99,235,.08);
  --ic-hl-a:   rgba(96,165,250,.34);
  --ic-hl-b:   rgba(37,99,235,.14);
  --ic-hl-fg:  #dbeafe;

  /* ---------- khung cửa sổ giả (.win, .mom, khung ảnh chụp) ---------- */
  --panel-a:   #101c30;
  --panel-b:   #0b1322;
  --bar-1:     rgba(0,0,0,.24);
  --bar-2:     rgba(0,0,0,.3);
  --shot-bg:   #0e1728;
  --kbd-bg:    rgba(255,255,255,.07);
  --shadow-1:  rgba(0,0,0,.9);
  --ring:      rgba(37,99,235,.14);
  --hi:        rgba(255,255,255,.06);

  /* ---------- xanh lá, hồng ---------- */
  --ok-glow:   rgba(52,211,153,.8);
  --ok-soft:   rgba(52,211,153,.07);
  --ok-soft-2: rgba(52,211,153,.14);
  --ok-line:   rgba(52,211,153,.24);
  --ok-line-2: rgba(52,211,153,.4);
  --rec-fg:    #fda4af;
  --who-a-bg:  rgba(99,102,241,.2);
  --who-a-fg:  #a5b4fc;

  /* ---------- không phụ thuộc chủ đề ---------- */
  --radius:    16px;
  --radius-lg: 24px;
  --wrap:      1160px;
  --ease:      cubic-bezier(.22,.75,.28,1);
  --font:      'Plus Jakarta Sans', system-ui, -apple-system, 'Segoe UI', Roboto, Arial, sans-serif;
  --mono:      'JetBrains Mono', ui-monospace, 'Cascadia Mono', Consolas, monospace;

  color-scheme: dark;
}

/* ============================================================
   CHỦ ĐỀ SÁNG — khai HAI lần, cùng một bảng giá trị:
   1. trong @media: máy khách đặt nền sáng và khách chưa bấm chọn gì
   2. ở [data-theme="light"]: khách tự bấm nút chọn nền sáng
   Sửa màu thì phải sửa CẢ HAI, lệch nhau là hỏng câm.
   ============================================================ */
@media (prefers-color-scheme: light){
  :root:not([data-theme="dark"]){
    --bg:        #f5f8fd;
    --bg-2:      #eaf0f9;
    --bg-3:      #e3ebf7;
    --surface:   rgba(255,255,255,.82);
    --surface-2: #ffffff;
    --line:      rgba(15,23,42,.10);
    --line-2:    rgba(15,23,42,.17);
    --text:      #0f172a;
    --text-2:    #45546b;
    --muted:     #64748b;
    --accent:    #2563eb;
    --accent-2:  #1d4ed8;
    --accent-3:  #1e40af;
    --ok:        #059669;
    --warn:      #b45309;

    --nav-bg:    rgba(245,248,253,.78);
    --nav-bg-2:  rgba(245,248,253,.94);
    --nav-bg-3:  rgba(245,248,253,.98);
    --seg-on-bg: #2563eb;
    --seg-on-fg: #fff;

    --orb-1:     rgba(37,99,235,.16);
    --orb-2:     rgba(99,102,241,.13);
    --orb-3:     rgba(37,99,235,.12);
    --glow-1:    rgba(37,99,235,.14);

    --accent-soft:   rgba(37,99,235,.09);
    --accent-soft-2: rgba(37,99,235,.11);
    --accent-line:   rgba(37,99,235,.24);
    --accent-line-2: rgba(37,99,235,.45);
    --grad-a:    #2563eb;
    --grad-b:    #3b82f6;
    --grad-c:    #1e3a8a;
    --ic-a:      rgba(37,99,235,.14);
    --ic-b:      rgba(37,99,235,.05);
    --ic-hl-a:   rgba(37,99,235,.20);
    --ic-hl-b:   rgba(37,99,235,.08);
    --ic-hl-fg:  #1d4ed8;

    --panel-a:   #ffffff;
    --panel-b:   #f2f6fd;
    --bar-1:     rgba(15,23,42,.04);
    --bar-2:     rgba(15,23,42,.055);
    --shot-bg:   #eef3fb;
    --kbd-bg:    rgba(15,23,42,.05);
    --shadow-1:  rgba(15,23,42,.22);
    --ring:      rgba(37,99,235,.12);
    --hi:        rgba(255,255,255,.9);

    --ok-glow:   rgba(5,150,105,.45);
    --ok-soft:   rgba(5,150,105,.07);
    --ok-soft-2: rgba(5,150,105,.12);
    --ok-line:   rgba(5,150,105,.26);
    --ok-line-2: rgba(5,150,105,.42);
    --rec-fg:    #be123c;
    --who-a-bg:  rgba(99,102,241,.13);
    --who-a-fg:  #4338ca;

    color-scheme: light;
  }
}

:root[data-theme="light"]{
  --bg:        #f5f8fd;
  --bg-2:      #eaf0f9;
  --bg-3:      #e3ebf7;
  --surface:   rgba(255,255,255,.82);
  --surface-2: #ffffff;
  --line:      rgba(15,23,42,.10);
  --line-2:    rgba(15,23,42,.17);
  --text:      #0f172a;
  --text-2:    #45546b;
  --muted:     #64748b;
  --accent:    #2563eb;
  --accent-2:  #1d4ed8;
  --accent-3:  #1e40af;
  --ok:        #059669;
  --warn:      #b45309;

  --nav-bg:    rgba(245,248,253,.78);
  --nav-bg-2:  rgba(245,248,253,.94);
  --nav-bg-3:  rgba(245,248,253,.98);
  --seg-on-bg: #2563eb;
  --seg-on-fg: #fff;

  --orb-1:     rgba(37,99,235,.16);
  --orb-2:     rgba(99,102,241,.13);
  --orb-3:     rgba(37,99,235,.12);
  --glow-1:    rgba(37,99,235,.14);

  --accent-soft:   rgba(37,99,235,.09);
  --accent-soft-2: rgba(37,99,235,.11);
  --accent-line:   rgba(37,99,235,.24);
  --accent-line-2: rgba(37,99,235,.45);
  --grad-a:    #2563eb;
  --grad-b:    #3b82f6;
  --grad-c:    #1e3a8a;
  --ic-a:      rgba(37,99,235,.14);
  --ic-b:      rgba(37,99,235,.05);
  --ic-hl-a:   rgba(37,99,235,.20);
  --ic-hl-b:   rgba(37,99,235,.08);
  --ic-hl-fg:  #1d4ed8;

  --panel-a:   #ffffff;
  --panel-b:   #f2f6fd;
  --bar-1:     rgba(15,23,42,.04);
  --bar-2:     rgba(15,23,42,.055);
  --shot-bg:   #eef3fb;
  --kbd-bg:    rgba(15,23,42,.05);
  --shadow-1:  rgba(15,23,42,.22);
  --ring:      rgba(37,99,235,.12);
  --hi:        rgba(255,255,255,.9);

  --ok-glow:   rgba(5,150,105,.45);
  --ok-soft:   rgba(5,150,105,.07);
  --ok-soft-2: rgba(5,150,105,.12);
  --ok-line:   rgba(5,150,105,.26);
  --ok-line-2: rgba(5,150,105,.42);
  --rec-fg:    #be123c;
  --who-a-bg:  rgba(99,102,241,.13);
  --who-a-fg:  #4338ca;

  color-scheme: light;
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; scroll-padding-top:88px; -webkit-text-size-adjust:100%; }
body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:var(--font);
  font-size:17px;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,svg{ max-width:100%; }
a{ color:inherit; text-decoration:none; }
h1,h2,h3{ margin:0; line-height:1.15; letter-spacing:-.02em; font-weight:800; }
p{ margin:0; }
ul,ol{ margin:0; padding:0; list-style:none; }

.wrap{ width:100%; max-width:var(--wrap); margin-inline:auto; padding-inline:24px; }
.wrap.narrow{ max-width:840px; }

.skip{
  position:absolute; left:-9999px; top:0; z-index:200;
  background:var(--accent); color:#fff; padding:10px 18px; border-radius:0 0 10px 0;
}
.skip:focus{ left:0; }

/* ---------- buttons ---------- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  padding:14px 26px; border-radius:999px;
  font-weight:700; font-size:16px; letter-spacing:-.01em;
  border:1px solid transparent; cursor:pointer;
  transition:transform .18s var(--ease), box-shadow .25s var(--ease), background .2s, border-color .2s;
  white-space:nowrap;
}
.btn-sm{ padding:9px 18px; font-size:14.5px; }
.btn-primary{
  background:linear-gradient(135deg, var(--accent-3), var(--accent) 55%, #3b82f6);
  color:#fff;
  box-shadow:0 8px 26px -8px rgba(37,99,235,.75), inset 0 1px 0 rgba(255,255,255,.22);
}
.btn-primary:hover{ transform:translateY(-2px); box-shadow:0 14px 34px -8px rgba(37,99,235,.9), inset 0 1px 0 rgba(255,255,255,.28); }
.btn-ghost{ background:var(--surface); border-color:var(--line-2); color:var(--text); }
.btn-ghost:hover{ background:var(--surface-2); border-color:var(--accent-line-2); transform:translateY(-2px); }

/* ---------- nav ---------- */
.nav{
  position:sticky; top:0; z-index:100;
  background:var(--nav-bg);
  backdrop-filter:blur(16px); -webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid transparent;
  transition:border-color .3s, background .3s;
}
.nav.scrolled{ border-bottom-color:var(--line); background:var(--nav-bg-2); }
.nav-inner{ display:flex; align-items:center; gap:28px; height:70px; }

.brand{ display:inline-flex; align-items:center; gap:10px; font-weight:800; font-size:19px; letter-spacing:-.03em; }
.brand-mark{
  width:32px; height:32px; display:grid; place-items:center; border-radius:10px;
  background:linear-gradient(140deg, var(--accent-3), #3b82f6);
  color:#fff; box-shadow:0 4px 14px -4px rgba(37,99,235,.8);
}
.brand-mark svg{ width:17px; height:17px; }
.brand-accent{ color:var(--accent-2); }
.brand-text.small{ font-size:17px; font-weight:800; letter-spacing:-.03em; }

.nav-links{ display:flex; gap:26px; margin-left:auto; font-size:15px; font-weight:500; color:var(--text-2); }
.nav-links a{ position:relative; padding:6px 0; transition:color .2s; }
.nav-links a::after{
  content:''; position:absolute; left:0; right:100%; bottom:0; height:1.5px;
  background:var(--accent-2); transition:right .28s var(--ease);
}
.nav-links a:hover{ color:var(--text); }
.nav-links a:hover::after{ right:0; }

.nav-right{ display:flex; align-items:center; gap:12px; }
.lang{ display:flex; padding:3px; border:1px solid var(--line); border-radius:999px; background:var(--surface); }
.lang-btn{
  border:0; background:transparent; color:var(--muted); cursor:pointer;
  font:inherit; font-size:13px; font-weight:700; letter-spacing:.04em;
  padding:5px 11px; border-radius:999px; transition:background .2s, color .2s;
}
.lang-btn.is-on{ background:var(--seg-on-bg); color:var(--seg-on-fg); }
.lang-btn:hover:not(.is-on){ color:var(--text); }

.theme-btn{
  width:36px; height:36px; display:grid; place-items:center; padding:0;
  border:1px solid var(--line); background:var(--surface); border-radius:999px;
  color:var(--text-2); cursor:pointer;
  transition:color .2s, border-color .2s, background .2s;
}
.theme-btn:hover{ color:var(--text); border-color:var(--accent-line-2); background:var(--surface-2); }
.theme-btn svg{ width:17px; height:17px; fill:none; stroke:currentColor; stroke-width:1.9; stroke-linecap:round; stroke-linejoin:round; }
/* Hiện biểu tượng của chủ đề SẼ chuyển sang, không phải chủ đề đang dùng. */
.theme-btn .to-dark{ display:none; }
:root[data-theme="light"] .theme-btn .to-light{ display:none; }
:root[data-theme="light"] .theme-btn .to-dark{ display:block; }

.burger{ display:none; width:38px; height:34px; border:1px solid var(--line); background:var(--surface); border-radius:10px; cursor:pointer; padding:0; }
.burger span{ display:block; width:16px; height:1.7px; background:var(--text); margin:3.4px auto; border-radius:2px; transition:transform .25s var(--ease), opacity .2s; }
.burger[aria-expanded="true"] span:nth-child(1){ transform:translateY(5px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2){ opacity:0; }
.burger[aria-expanded="true"] span:nth-child(3){ transform:translateY(-5px) rotate(-45deg); }

/* ---------- decorative ---------- */
.orb{ position:absolute; border-radius:50%; filter:blur(90px); pointer-events:none; z-index:0; }
.orb-a{ width:620px; height:620px; top:-260px; left:-160px; background:radial-gradient(circle, var(--orb-1), transparent 68%); }
.orb-b{ width:520px; height:520px; top:120px; right:-200px; background:radial-gradient(circle, var(--orb-2), transparent 68%); }
.orb-c{ width:640px; height:640px; top:-180px; left:50%; transform:translateX(-50%); background:radial-gradient(circle, var(--orb-3), transparent 66%); }
.grid-bg{
  position:absolute; inset:0; z-index:0; opacity:.5;
  background-image:linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size:64px 64px;
  mask-image:radial-gradient(ellipse 90% 60% at 50% 0%, #000 30%, transparent 75%);
  -webkit-mask-image:radial-gradient(ellipse 90% 60% at 50% 0%, #000 30%, transparent 75%);
}

/* ---------- hero ---------- */
.hero{ position:relative; padding:84px 0 60px; overflow:hidden; }
.hero-grid{
  position:relative; z-index:2;
  display:grid; grid-template-columns:minmax(0,1.06fr) minmax(0,.94fr);
  gap:56px; align-items:center;
}
.eyebrow{
  display:inline-block; font-size:13px; font-weight:700; letter-spacing:.11em; text-transform:uppercase;
  color:var(--accent-2); background:var(--accent-soft); border:1px solid var(--accent-line);
  padding:6px 14px; border-radius:999px; margin-bottom:22px;
}
.hero h1{ font-size:clamp(38px, 5.2vw, 62px); letter-spacing:-.035em; }
.grad{
  background:linear-gradient(100deg, var(--grad-a), var(--grad-b) 45%, var(--grad-c));
  -webkit-background-clip:text; background-clip:text; color:transparent;
}
.lead{ color:var(--text-2); font-size:18.5px; margin-top:22px; max-width:56ch; }
.cta-row{ display:flex; flex-wrap:wrap; gap:14px; margin-top:34px; }
.hero-facts{ display:flex; flex-wrap:wrap; gap:10px 22px; margin-top:28px; font-size:14.5px; color:var(--muted); }
.hero-facts li{ display:flex; align-items:center; gap:8px; }
.hero-facts li::before{ content:''; width:6px; height:6px; border-radius:50%; background:var(--ok); box-shadow:0 0 10px var(--ok-glow); }

/* ---------- hero mockup ---------- */
.hero-demo{ position:relative; }
.demo-glow{ position:absolute; inset:-14% -8%; background:radial-gradient(ellipse at 50% 45%, var(--glow-1), transparent 68%); filter:blur(38px); }
.win{
  position:relative;
  background:linear-gradient(170deg, var(--panel-a), var(--panel-b));
  border:1px solid var(--line-2); border-radius:var(--radius-lg);
  box-shadow:0 40px 90px -30px var(--shadow-1), 0 0 0 1px var(--ring), inset 0 1px 0 var(--hi);
  overflow:hidden;
}
.win-bar{ display:flex; align-items:center; gap:7px; padding:13px 18px; border-bottom:1px solid var(--line); background:var(--bar-1); }
.dot{ width:10px; height:10px; border-radius:50%; }
.dot.r{ background:#ff5f57; } .dot.y{ background:#febc2e; } .dot.g{ background:#28c840; }
.win-title{ margin-left:10px; font-size:13px; color:var(--muted); }
.win-body{ padding:26px 22px 30px; min-height:186px; }
.doc-line{ font-size:16.5px; line-height:1.75; }
.doc-line.ghost{ color:var(--muted); margin-bottom:10px; }
.doc-line.typed{ color:var(--text); font-weight:500; }
.caret{ display:inline-block; width:2px; height:1.05em; background:var(--accent-2); vertical-align:-3px; margin-left:2px; animation:blink 1s steps(2) infinite; }
@keyframes blink{ 50%{ opacity:0; } }

.win-foot{ display:flex; align-items:center; justify-content:space-between; gap:14px; padding:13px 18px; border-top:1px solid var(--line); background:var(--bar-2); flex-wrap:wrap; }
.kbd-set{ display:flex; gap:5px; }
kbd{
  font-family:var(--mono); font-size:11.5px; color:var(--text-2);
  background:var(--kbd-bg); border:1px solid var(--line-2);
  border-bottom-width:2px; border-radius:6px; padding:4px 8px;
}
.listening{ display:flex; align-items:center; gap:10px; font-size:13px; color:var(--accent-2); }
.wave{ display:flex; align-items:center; gap:3px; height:20px; }
.wave i{ width:3px; border-radius:2px; background:linear-gradient(var(--accent-2), var(--accent)); animation:eq 1.05s ease-in-out infinite; }
.wave i:nth-child(1){ animation-delay:0s;    height:7px;  }
.wave i:nth-child(2){ animation-delay:.11s;  height:14px; }
.wave i:nth-child(3){ animation-delay:.22s;  height:19px; }
.wave i:nth-child(4){ animation-delay:.33s;  height:11px; }
.wave i:nth-child(5){ animation-delay:.44s;  height:17px; }
.wave i:nth-child(6){ animation-delay:.55s;  height:9px;  }
.wave i:nth-child(7){ animation-delay:.66s;  height:13px; }
@keyframes eq{ 0%,100%{ transform:scaleY(.4); } 50%{ transform:scaleY(1.25); } }

/* ---------- app strip ---------- */
.apps{
  position:relative; z-index:2;
  display:flex; flex-wrap:wrap; align-items:center; gap:10px 22px;
  margin-top:64px; padding-top:30px; border-top:1px solid var(--line);
  font-size:15px; font-weight:600; color:var(--text-2);
}
.apps-label,.apps-more{ font-size:13px; font-weight:600; color:var(--muted); letter-spacing:.02em; }
.apps-more{ font-weight:500; font-style:italic; }

/* ---------- sections ---------- */
.sec{ position:relative; padding:96px 0; overflow:hidden; }
.sec.alt{ background:linear-gradient(180deg, var(--bg-2), var(--bg)); border-block:1px solid var(--line); }
.kicker{ font-size:13px; font-weight:700; letter-spacing:.13em; text-transform:uppercase; color:var(--accent-2); margin-bottom:14px; }
.sec-title{ font-size:clamp(28px, 3.6vw, 42px); max-width:20ch; }
.sec-title.big{ max-width:none; }
.sec-lead{ color:var(--text-2); font-size:18px; margin-top:20px; max-width:66ch; }

/* ---------- gap band ---------- */
.band{ position:relative; padding:70px 0; background:linear-gradient(180deg, var(--bg), var(--bg-3) 50%, var(--bg)); border-block:1px solid var(--line); }
.gap-grid{ display:grid; grid-template-columns:minmax(0,1.15fr) minmax(0,1fr); gap:52px; align-items:center; }
.gap-copy h2{ font-size:clamp(26px, 3.2vw, 36px); }
.gap-copy p{ color:var(--text-2); margin-top:18px; }
.stats{ display:grid; grid-template-columns:repeat(3,1fr); gap:14px; }
.stat{
  background:var(--surface); border:1px solid var(--line); border-radius:var(--radius);
  padding:22px 16px; text-align:center;
}
.stat b{ display:block; font-size:clamp(26px,3.4vw,36px); font-weight:800; letter-spacing:-.04em; color:var(--accent-2); }
.stat span{ display:block; margin-top:6px; font-size:13px; color:var(--muted); line-height:1.4; }
.stat.dim b{ color:var(--muted); }

/* ---------- steps ---------- */
.steps{ display:grid; grid-template-columns:repeat(3,1fr); gap:24px; margin-top:48px; counter-reset:s; }
.steps li{
  position:relative; padding:32px 26px 30px;
  background:var(--surface); border:1px solid var(--line); border-radius:var(--radius-lg);
  transition:border-color .25s, transform .25s var(--ease);
}
.steps li:hover{ border-color:var(--accent-line-2); transform:translateY(-3px); }
.step-no{
  display:grid; place-items:center; width:40px; height:40px; border-radius:12px;
  background:linear-gradient(140deg, var(--accent-3), #3b82f6); color:#fff;
  font-weight:800; font-size:17px; margin-bottom:18px;
  box-shadow:0 6px 18px -6px rgba(37,99,235,.8);
}
.steps h3{ font-size:20px; margin-bottom:10px; }
.steps p{ color:var(--text-2); font-size:16px; }

/* ---------- feature cards ---------- */
.cards{ display:grid; grid-template-columns:repeat(auto-fill, minmax(290px,1fr)); gap:18px; margin-top:48px; }
.card{
  position:relative; padding:26px 24px 24px;
  background:var(--surface); border:1px solid var(--line); border-radius:var(--radius);
  transition:border-color .25s, background .25s, transform .25s var(--ease);
}
.card:hover{ border-color:var(--accent-line-2); background:var(--surface-2); transform:translateY(-3px); }
.card.hl{ background:linear-gradient(160deg, var(--accent-soft-2), var(--surface)); border-color:var(--accent-line); }
.ic{ font-size:26px; line-height:1; margin-bottom:14px; }
.card h3{ font-size:18px; margin-bottom:9px; letter-spacing:-.015em; }
.card p{ color:var(--text-2); font-size:15.5px; line-height:1.6; }

/* ---------- split / meeting ---------- */
.split{ display:grid; grid-template-columns:minmax(0,1fr) minmax(0,.92fr); gap:56px; align-items:center; }
.ticks{ margin-top:28px; display:grid; gap:14px; }
.ticks li{ position:relative; padding-left:34px; color:var(--text-2); font-size:16.5px; }
.ticks li::before{
  content:''; position:absolute; left:0; top:.42em; width:20px; height:20px; border-radius:6px;
  background:var(--ok-soft-2); border:1px solid var(--ok-line-2);
}
.ticks li::after{
  content:''; position:absolute; left:6.5px; top:.72em; width:7px; height:3.5px;
  border-left:2px solid var(--ok); border-bottom:2px solid var(--ok);
  transform:rotate(-45deg);
}

.mom{
  background:linear-gradient(170deg, var(--panel-a), var(--panel-b));
  border:1px solid var(--line-2); border-radius:var(--radius-lg);
  box-shadow:0 34px 80px -30px var(--shadow-1), inset 0 1px 0 var(--hi);
  overflow:hidden;
}
.mom-head{ display:flex; align-items:center; justify-content:space-between; padding:14px 18px; border-bottom:1px solid var(--line); background:var(--bar-1); }
.rec{ display:flex; align-items:center; gap:8px; font-size:13px; color:var(--rec-fg); }
.rec i{ width:8px; height:8px; border-radius:50%; background:#f43f5e; animation:pulse 1.4s ease-in-out infinite; }
@keyframes pulse{ 50%{ opacity:.25; transform:scale(.75); } }
.mom-time{ font-family:var(--mono); font-size:13px; color:var(--muted); }
.mom-body{ padding:20px 18px 22px; display:grid; gap:16px; }
.turn{ display:grid; gap:5px; }
.who{ justify-self:start; font-size:11px; font-weight:700; letter-spacing:.07em; text-transform:uppercase; padding:3px 9px; border-radius:999px; }
.who.a{ background:var(--who-a-bg); color:var(--who-a-fg); }
.who.b{ background:var(--accent-soft-2); color:var(--accent-2); }
.turn p{ font-size:15px; color:var(--text); }
.turn p.tr{ color:var(--muted); font-size:14px; font-style:italic; }
.mom-card{ margin-top:4px; padding:16px; border-radius:12px; background:var(--ok-soft); border:1px solid var(--ok-line); }
.mom-card b{ display:block; font-size:13px; letter-spacing:.05em; text-transform:uppercase; color:var(--ok); margin-bottom:10px; }
.mom-card ul{ display:grid; gap:7px; }
.mom-card li{ position:relative; padding-left:18px; font-size:14.5px; color:var(--text-2); }
.mom-card li::before{ content:''; position:absolute; left:2px; top:.62em; width:6px; height:6px; border-radius:50%; background:var(--ok); }

/* ---------- trio ---------- */
.trio{ display:grid; grid-template-columns:repeat(3,1fr); gap:18px; margin-top:44px; }
.tcard{ padding:28px 24px; background:var(--surface); border:1px solid var(--line); border-radius:var(--radius); }
.tcard h3{ font-size:18.5px; margin-bottom:10px; }
.tcard p{ color:var(--text-2); font-size:15.5px; }

/* ---------- who ---------- */
.who-grid{ display:grid; grid-template-columns:repeat(auto-fill, minmax(300px,1fr)); gap:18px; margin-top:44px; }
.who-card{ padding:26px 24px; background:var(--surface); border:1px solid var(--line); border-radius:var(--radius); transition:border-color .25s, transform .25s var(--ease); }
.who-card:hover{ border-color:var(--accent-line-2); transform:translateY(-3px); }
.who-ic{ font-size:26px; display:block; margin-bottom:12px; }
.who-card h3{ font-size:18px; margin-bottom:8px; }
.who-card p{ color:var(--text-2); font-size:15.5px; }

/* ---------- faq ---------- */
.faq{ margin-top:40px; display:grid; gap:12px; }
.faq details{ background:var(--surface); border:1px solid var(--line); border-radius:var(--radius); overflow:hidden; transition:border-color .25s; }
.faq details[open]{ border-color:var(--accent-line-2); background:var(--surface-2); }
.faq summary{
  cursor:pointer; list-style:none; padding:20px 52px 20px 24px; position:relative;
  font-weight:700; font-size:17px; letter-spacing:-.01em;
}
.faq summary::-webkit-details-marker{ display:none; }
.faq summary::after{
  content:''; position:absolute; right:24px; top:50%; width:9px; height:9px;
  border-right:2px solid var(--accent-2); border-bottom:2px solid var(--accent-2);
  transform:translateY(-70%) rotate(45deg); transition:transform .25s var(--ease);
}
.faq details[open] summary::after{ transform:translateY(-25%) rotate(-135deg); }
.faq p{ padding:0 24px 22px; color:var(--text-2); font-size:16px; }

/* ---------- contact ---------- */
.contact{ text-align:center; padding-bottom:110px; }
.contact .kicker,.contact .sec-title,.contact .sec-lead{ position:relative; z-index:2; }
.contact .sec-lead{ margin-inline:auto; }
.contact-cards{ position:relative; z-index:2; display:grid; grid-template-columns:repeat(3,1fr); gap:16px; margin-top:44px; }
.ccard{
  display:grid; justify-items:center; gap:6px; padding:26px 18px;
  background:var(--surface); border:1px solid var(--line); border-radius:var(--radius);
  transition:border-color .25s, background .25s, transform .25s var(--ease);
}
.ccard:hover{ border-color:var(--accent-line-2); background:var(--surface-2); transform:translateY(-3px); }
.cic{
  width:44px; height:44px; display:grid; place-items:center; border-radius:12px; margin-bottom:6px;
  background:var(--accent-soft-2); border:1px solid var(--accent-line);
  font-size:20px; font-weight:800; color:var(--accent-2);
}
.clabel{ font-size:12.5px; letter-spacing:.09em; text-transform:uppercase; color:var(--muted); font-weight:700; }
.cval{ font-size:16px; font-weight:600; color:var(--text); word-break:break-word; }
.ccard.is-off{ opacity:.45; pointer-events:none; }

.person{
  position:relative; z-index:2;
  display:inline-flex; align-items:center; gap:14px; margin-top:40px;
  padding:14px 24px 14px 14px; border-radius:999px;
  background:var(--surface); border:1px solid var(--line); text-align:left;
}
.avatar{
  width:46px; height:46px; border-radius:50%; display:grid; place-items:center;
  background:linear-gradient(140deg, var(--accent-3), #3b82f6); color:#fff;
  font-weight:800; letter-spacing:.04em; font-size:15px;
}
.person-txt{ display:grid; }
.person-txt b{ font-size:16px; }
.alias{ color:var(--muted); font-weight:600; }
.person-txt span{ font-size:14px; color:var(--muted); }

/* ---------- footer ---------- */
.foot{ border-top:1px solid var(--line); background:var(--bg-2); padding:28px 0; }
.foot-inner{ display:flex; align-items:center; justify-content:space-between; gap:16px; flex-wrap:wrap; }
.foot-note{ font-size:14px; color:var(--muted); }
.foot-link{ font-size:14px; color:var(--text-2); border-bottom:1px solid var(--line-2); padding-bottom:2px; }
.foot-link:hover{ color:var(--accent-2); border-color:var(--accent-2); }

/* ---------- reveal ---------- */
.reveal{ opacity:0; transform:translateY(18px); transition:opacity .6s var(--ease), transform .6s var(--ease); }
.reveal.in{ opacity:1; transform:none; }

/* ---------- responsive ---------- */
@media (max-width:1000px){
  .hero-grid{ grid-template-columns:1fr; gap:44px; }
  .hero-demo{ max-width:560px; }
  .gap-grid,.split{ grid-template-columns:1fr; gap:36px; }
  .steps,.trio{ grid-template-columns:1fr; }
  .contact-cards{ grid-template-columns:1fr; }
  .sec-title{ max-width:none; }
}
@media (max-width:1060px){
  .nav-links{
    position:fixed; inset:70px 0 auto; z-index:99;
    flex-direction:column; gap:0; margin:0;
    background:var(--nav-bg-3); backdrop-filter:blur(18px);
    border-bottom:1px solid var(--line);
    padding:8px 24px 20px;
    transform:translateY(-12px); opacity:0; pointer-events:none;
    transition:opacity .22s var(--ease), transform .22s var(--ease);
  }
  .nav-links.open{ opacity:1; transform:none; pointer-events:auto; }
  .nav-links a{ padding:14px 0; border-bottom:1px solid var(--line); font-size:16px; }
  .nav-links a::after{ display:none; }
  .burger{ display:block; }
  .nav-cta{ display:none; }
}
@media (max-width:620px){
  body{ font-size:16px; }
  .hero{ padding-top:56px; }
  .sec{ padding:70px 0; }
  .stats{ grid-template-columns:1fr; }
  .stat{ display:flex; align-items:baseline; justify-content:space-between; text-align:left; padding:16px 18px; }
  .stat span{ margin-top:0; }
  .apps{ margin-top:48px; }
  .person{ display:flex; border-radius:var(--radius); }
  .foot-inner{ justify-content:center; text-align:center; }
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{ animation-duration:.001ms !important; animation-iteration-count:1 !important; transition-duration:.001ms !important; }
  html{ scroll-behavior:auto; }
  .reveal{ opacity:1; transform:none; }
}

/* ============================================================
   Icon sprite — thay cho emoji (emoji cờ 🇻🇳 trên Windows ra "VN")
   ============================================================ */
.ic, .who-ic{
  width:46px; height:46px; display:grid; place-items:center;
  border-radius:13px; margin-bottom:16px;
  background:linear-gradient(150deg, var(--ic-a), var(--ic-b));
  border:1px solid var(--accent-line);
  color:var(--accent-2);
}
.ic svg, .who-ic svg, .cic svg{
  width:22px; height:22px;
  fill:none; stroke:currentColor; stroke-width:1.75;
  stroke-linecap:round; stroke-linejoin:round;
}
.card.hl .ic{ background:linear-gradient(150deg, var(--ic-hl-a), var(--ic-hl-b)); border-color:var(--accent-line-2); color:var(--ic-hl-fg); }
.card:hover .ic, .who-card:hover .who-ic{ border-color:var(--accent-line-2); }
.cic svg{ width:21px; height:21px; }

/* contact: email dài không được ngắt giữa từ */
.contact .wrap{ max-width:980px; }
.cval{ font-size:15px; overflow-wrap:anywhere; word-break:normal; hyphens:none; }
#v-email{ font-size:14.5px; letter-spacing:-.01em; }

/* ============================================================
   Khối ảnh chụp ứng dụng
   ============================================================ */
.shots .sec-lead{ margin-bottom:34px; }

.shot-tabs{ display:flex; flex-wrap:wrap; gap:9px; margin-bottom:26px; }
.shot-tab{
  font:inherit; font-size:14.5px; font-weight:600; cursor:pointer;
  color:var(--text-2); background:var(--surface);
  border:1px solid var(--line); border-radius:999px; padding:9px 18px;
  transition:color .2s, background .2s, border-color .2s, transform .18s var(--ease);
}
.shot-tab:hover{ color:var(--text); border-color:var(--accent-line-2); transform:translateY(-1px); }
.shot-tab.is-on{
  color:#fff; border-color:transparent;
  background:linear-gradient(135deg, var(--accent-3), var(--accent) 60%, #3b82f6);
  box-shadow:0 6px 20px -8px rgba(37,99,235,.85);
}

.shot{ margin:0; position:relative; }
.shot::before{
  content:''; position:absolute; inset:-6% -4% 12%;
  background:radial-gradient(ellipse at 50% 40%, var(--glow-1), transparent 70%);
  filter:blur(50px); pointer-events:none;
}
.shot-frame{
  position:relative; overflow:hidden;
  border:1px solid var(--line-2); border-radius:var(--radius-lg);
  background:var(--shot-bg);
  box-shadow:0 44px 100px -34px var(--shadow-1), 0 0 0 1px var(--ring), inset 0 1px 0 var(--hi);
}
.shot-bar{
  display:flex; align-items:center; gap:7px;
  padding:12px 18px; border-bottom:1px solid var(--line); background:var(--bar-2);
}
.shot-bar-title{ margin-left:10px; font-size:12.5px; color:var(--muted); }
.shot-frame img{
  display:block; width:100%; height:auto;
  transition:opacity .25s var(--ease);
}
.shot-frame.is-swapping img{ opacity:.25; }

.shot figcaption{
  position:relative;
  margin-top:22px; max-width:74ch;
  color:var(--text-2); font-size:16.5px; line-height:1.6;
  padding-left:16px; border-left:2px solid var(--accent-line-2);
}
.shot-note{
  margin-top:26px; font-size:14px; color:var(--muted); font-style:italic;
}

@media (max-width:620px){
  .shot-tabs{ gap:7px; }
  .shot-tab{ font-size:13.5px; padding:8px 14px; }
  .shot-bar{ padding:10px 14px; }
  .shot figcaption{ font-size:15.5px; }
}