:root {
  --navy: #071f30;
  --navy-deep: #04131e;
  --teal: #00b6bd;
  --teal-soft: #86f3ee;
  --gold: #ffbd3b;
  --coral: #ff6b58;
  --paper: #f5fbfb;
  --ink: #102a3c;
  --muted: #557083;
  --line: #cde3e4;
  --white: #fff;
  --shadow: 0 16px 40px rgba(4, 30, 45, .14);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: 16px; line-height: 1.6; }
a { color: inherit; }
img { display: block; max-width: 100%; }
.shell { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.site-header { background: rgba(4, 19, 30, .96); color: var(--white); position: sticky; top: 0; z-index: 10; border-bottom: 1px solid rgba(255,255,255,.11); backdrop-filter: blur(12px); }
.nav { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 22px; }
.brand { display: flex; align-items: center; gap: 11px; color: var(--white); font-weight: 800; text-decoration: none; letter-spacing: -.02em; }
.brand img { width: 42px; height: 42px; border-radius: 12px; }
.nav-links { display: flex; flex-wrap: wrap; gap: 19px; align-items: center; }
.nav-links a { color: #d5e7ea; font-size: .94rem; font-weight: 650; text-decoration: none; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--teal-soft); }
.hero { min-height: 610px; color: var(--white); background: linear-gradient(90deg, rgba(4,19,30,.9) 0%, rgba(4,19,30,.6) 44%, rgba(4,19,30,.05) 80%), url('khoai-store-developer-header-4096x2304.jpg') center / cover; display: grid; align-items: end; }
.hero-content { padding: 90px 0 84px; max-width: 660px; }
.eyebrow { color: var(--teal-soft); text-transform: uppercase; letter-spacing: .13em; font-weight: 800; font-size: .8rem; }
h1, h2, h3 { line-height: 1.12; letter-spacing: -.035em; margin: 0; }
h1 { font-size: clamp(3rem, 7vw, 5.6rem); }
h2 { font-size: clamp(2rem, 4vw, 3.1rem); }
h3 { font-size: 1.25rem; }
.hero p { font-size: clamp(1.1rem, 2vw, 1.28rem); margin: 22px 0 30px; max-width: 590px; color: #ecf9fa; }
.button { display: inline-flex; align-items: center; justify-content: center; border-radius: 999px; padding: 13px 20px; background: var(--gold); color: #1d2732; text-decoration: none; font-weight: 800; box-shadow: 0 8px 20px rgba(0,0,0,.2); }
.button:hover { transform: translateY(-2px); }
.button.secondary { background: transparent; color: var(--white); box-shadow: inset 0 0 0 1px rgba(255,255,255,.58); margin-left: 10px; }
.section { padding: 84px 0; }
.section-head { display: flex; gap: 24px; justify-content: space-between; align-items: end; margin-bottom: 34px; }
.section-head p { max-width: 480px; color: var(--muted); margin: 0; }
.app-card { overflow: hidden; display: grid; grid-template-columns: .93fr 1.07fr; background: var(--white); border: 1px solid var(--line); border-radius: 24px; box-shadow: var(--shadow); }
.app-art { min-height: 315px; background: linear-gradient(135deg, #005a72, #009ba5); display: grid; place-items: center; padding: 40px; }
.app-art img { width: min(250px, 70%); filter: drop-shadow(0 18px 16px rgba(0,0,0,.28)); border-radius: 25%; }
.app-info { padding: 46px; display: flex; flex-direction: column; align-items: flex-start; justify-content: center; }
.app-info p { color: var(--muted); max-width: 500px; }
.text-link { color: #006f80; font-weight: 800; text-decoration-thickness: 2px; text-underline-offset: 3px; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature { padding: 25px; background: #eaf7f7; border-radius: 18px; border: 1px solid #d4eeee; }
.feature p { margin-bottom: 0; color: var(--muted); }
.cta-band { background: var(--navy); color: var(--white); padding: 66px 0; }
.cta-band .shell { display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.cta-band p { color: #c0d6dd; max-width: 560px; margin-bottom: 0; }
.page-hero { color: var(--white); background: linear-gradient(135deg, #084b61, #063045); padding: 92px 0 72px; }
.game-hero { min-height: 500px; display: grid; align-items: end; background: url('mini-chess-puzzle-hero.png') center / cover no-repeat; }
.game-hero .shell { display: none; }
.page-hero p { max-width: 680px; color: #cfebed; font-size: 1.15rem; }
.content { width: min(800px, calc(100% - 40px)); margin: 0 auto; padding: 66px 0 82px; }
.content h2 { font-size: 1.7rem; margin: 42px 0 12px; }
.content h3 { margin: 26px 0 8px; }
.content p, .content li { color: #375366; }
.content li { margin: 7px 0; }
.notice { padding: 19px 21px; border-left: 4px solid var(--gold); border-radius: 8px; background: #fff7df; color: #5d491e; }
.app-page-card { display: grid; grid-template-columns: 200px 1fr; gap: 34px; padding: 36px; border: 1px solid var(--line); background: var(--white); border-radius: 22px; box-shadow: var(--shadow); }
.app-page-card img { border-radius: 22%; }
.site-footer { color: #bed5da; background: var(--navy-deep); padding: 42px 0 28px; }
.footer-row { display: flex; justify-content: space-between; align-items: start; gap: 32px; }
.footer-row p { color: #9ebac0; margin: 9px 0 0; max-width: 470px; }
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer-links a { color: #d9f1f2; font-size: .94rem; }
.copyright { color: #6f969f; font-size: .85rem; margin: 35px 0 0; }

@media (max-width: 700px) {
  .shell { width: min(100% - 30px, 1120px); }
  .nav { padding: 12px 0; align-items: start; }
  .nav-links { justify-content: flex-end; gap: 10px 15px; }
  .hero { min-height: 570px; background-position: 62% center; }
  .game-hero { min-height: 0; aspect-ratio: 2.048 / 1; background-size: contain; background-color: #060201; }
  .hero-content { padding: 70px 0 58px; }
  .button.secondary { margin: 12px 0 0; }
  .section { padding: 58px 0; }
  .section-head, .cta-band .shell, .footer-row { display: block; }
  .section-head p { margin-top: 15px; }
  .app-card, .app-page-card { grid-template-columns: 1fr; }
  .app-art { min-height: 235px; }
  .app-info, .app-page-card { padding: 29px; }
  .feature-grid { grid-template-columns: 1fr; }
  .cta-band .button { margin-top: 24px; }
  .footer-links { margin-top: 26px; }
}