:root {
  --bg: #ffffff;
  --fg: #111418;
  --muted: #6b7280;
  --line: #e7e9ee;
  --blue: #4d8ff5;
  --blue-dark: #2f6fd6;
  --blue-soft: #e8f1ff;
  --me: #d9f7cf;
  --them: #ffffff;
  --card: #ffffff;
  --shadow: 0 2px 0 #e3e6ec, 0 6px 18px rgba(17, 20, 24, .06);
  --sans: "Pretendard Variable", Pretendard, -apple-system, "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  --serif: "Noto Serif KR", "Nanum Myeongjo", serif, "Apple Color Emoji", "Segoe UI Emoji", "Noto Color Emoji";
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--fg); font-family: var(--sans); -webkit-font-smoothing: antialiased; overflow-x: hidden; }
a { color: inherit; }
button { font-family: inherit; cursor: pointer; }

/* header */
.top { position: sticky; top: 0; z-index: 50; height: 60px; display: flex; align-items: center; justify-content: space-between; padding: 0 20px; background: rgba(255,255,255,.92); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.logo { display: inline-flex; width: 34px; height: 34px; border-radius: 50%; background: #5aa0ff; align-items: center; justify-content: center; font-size: 20px; box-shadow: inset 0 0 0 2px #fff, 0 0 0 1px var(--line); text-decoration: none; }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 10px; border: 0; color: #fff; background: var(--blue); font-weight: 700; border-radius: 14px; box-shadow: 0 4px 0 var(--blue-dark); transition: transform .08s, box-shadow .08s; text-decoration: none; }
.btn:hover { filter: brightness(1.04); }
.btn:active { transform: translateY(3px); box-shadow: 0 1px 0 var(--blue-dark); }
.btn-sm { font-size: 14px; padding: 7px 14px; border-radius: 999px; box-shadow: 0 3px 0 var(--blue-dark); }
.btn-lg { font-size: 19px; padding: 14px 44px; min-width: 200px; }
.btn-ghost { background: #fff; color: var(--fg); border: 1px solid var(--line); box-shadow: 0 3px 0 var(--line); }

/* hero */
.hero { position: relative; text-align: center; padding: 120px 20px 60px; overflow: hidden; }
.float { position: absolute; font-size: 28px; opacity: .0; pointer-events: none; animation: drift 14s linear infinite; }
@keyframes drift { 0% { transform: translateY(40px) rotate(-8deg); opacity: 0; } 15% { opacity: .4; } 85% { opacity: .4; } 100% { transform: translateY(-220px) rotate(10deg); opacity: 0; } }
.stack { display: inline-flex; margin-bottom: 26px; }
.stack .av { width: 62px; height: 62px; margin-left: -12px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 30px; border: 4px solid #fff; box-shadow: 0 4px 12px rgba(0,0,0,.12); animation: pop .5s backwards; }
.stack .av:first-child { margin-left: 0; }
.stack .av.main { width: 72px; height: 72px; font-size: 38px; margin-top: -5px; z-index: 2; }
@keyframes pop { from { transform: scale(.4); opacity: 0; } }
.hero h1 { font-size: clamp(30px, 5.4vw, 46px); line-height: 1.3; letter-spacing: -.02em; margin: 0 auto 22px; max-width: 580px; font-weight: 800; word-break: keep-all; }
.hero p { color: var(--muted); font-size: 16px; line-height: 1.6; max-width: 460px; margin: 0 auto 36px; word-break: keep-all; }

/* marquee */
.marquee { padding: 20px 0 10px; display: grid; overflow: hidden; gap: 12px; mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent); -webkit-mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent); max-width: 720px; margin: 0 auto; }
.row { display: flex; gap: 10px; width: max-content; animation: slide 60s linear infinite; }
.row.rev { animation-direction: reverse; animation-duration: 70s; }
.row.slow { animation-duration: 80s; }
.marquee:hover .row { animation-play-state: paused; }
@keyframes slide { to { transform: translateX(-50%); } }
.chip { display: inline-flex; align-items: center; gap: 9px; padding: 7px 14px 7px 8px; border: 1px solid var(--line); border-radius: 14px; background: #fff; font-size: 14px; font-weight: 600; white-space: nowrap; box-shadow: 0 3px 0 #eceef2; transition: transform .15s; }
.chip:hover { transform: translateY(-3px) rotate(-1.5deg); }
.chip.on { border-color: var(--blue); box-shadow: 0 3px 0 var(--blue); }
.ico { width: 26px; height: 26px; border-radius: 8px; display: inline-flex; align-items: center; justify-content: center; font-size: 14px; flex: none; }
.ico.round { border-radius: 50%; }
.k { background: #fee500; color: #3c1e1e; font-size: 8px; font-weight: 900; }
.ig { background: linear-gradient(45deg, #fdc468, #df4996 55%, #8a3ab9); color: #fff; }
.wa { background: #25d366; color: #fff; }
.ln { background: #06c755; color: #fff; font-size: 8px; font-weight: 900; }
.im { background: #34c759; color: #fff; }
.ms { background: linear-gradient(45deg, #0a7cff, #a033ff); color: #fff; }
.tg { background: #2aabee; color: #fff; }

/* preview */
.preview { max-width: 360px; margin: 50px auto 0; min-height: 300px; padding: 0 16px; }
.hint { text-align: center; font-size: 14px; font-weight: 700; }
.hint .arrow { display: block; font-size: 18px; animation: bob 1.4s ease-in-out infinite; }
@keyframes bob { 50% { transform: translateY(-5px); } }
.mascot { width: 64px; height: 64px; border-radius: 50%; background: #5aa0ff; display: flex; align-items: center; justify-content: center; font-size: 34px; margin: 18px auto; box-shadow: 0 0 0 14px var(--blue-soft); }
.bars { display: flex; gap: 6px; margin-bottom: 4px; }
.bars i { flex: 1; height: 4px; border-radius: 4px; background: #e6e8ec; overflow: hidden; }
.bars i b { display: block; height: 100%; width: 0; background: #555; }
.beam { position: relative; height: 56px; display: flex; justify-content: center; align-items: center; }
.beam::before { content: ""; position: absolute; left: -10px; right: -10px; top: 50%; height: 2px; background: linear-gradient(90deg, transparent, var(--blue), transparent); box-shadow: 0 0 22px 8px rgba(77,143,245,.18); }
.beam .mascot { position: relative; margin: 0; width: 46px; height: 46px; font-size: 24px; box-shadow: 0 0 0 3px #fff, 0 4px 10px rgba(0,0,0,.15); }
.chat { display: flex; flex-direction: column; gap: 8px; padding: 6px 4px; max-height: 330px; overflow: hidden; mask-image: linear-gradient(#000 85%, transparent); -webkit-mask-image: linear-gradient(#000 85%, transparent); }
.bub { max-width: 78%; padding: 8px 11px 5px; border-radius: 14px; font-size: 13.5px; line-height: 1.45; box-shadow: 0 1px 2px rgba(0,0,0,.08); animation: rise .35s ease-out backwards; word-break: keep-all; }
.bub small { display: block; text-align: right; font-size: 10px; color: #9aa1ab; margin-top: 2px; }
.bub .who { display: block; font-size: 11px; font-weight: 700; color: var(--blue-dark); margin-bottom: 2px; }
.bub.me { align-self: flex-end; background: var(--me); }
.bub.them { align-self: flex-start; background: var(--them); border: 1px solid #eef0f3; }
.bub.note { align-self: stretch; max-width: none; background: var(--blue-soft); border: 1px solid #cfe0ff; font-size: 13px; }
.bub.note .who { color: var(--blue-dark); }
@keyframes rise { from { opacity: 0; transform: translateY(10px) scale(.97); } }

/* sections */
section.block { padding: 90px 20px 30px; }
.h2 { text-align: center; font-size: clamp(30px, 5vw, 42px); font-weight: 800; letter-spacing: -.02em; margin: 0 0 14px; }
.sub { text-align: center; color: var(--muted); margin: 0 0 40px; font-size: 16px; }

/* reviews */
.rail { display: flex; gap: 22px; overflow-x: auto; scroll-snap-type: x mandatory; scroll-padding-inline: 20px; padding: 10px 20px 26px; scrollbar-width: none; max-width: 1100px; margin: 0 auto; }
.rail::-webkit-scrollbar { display: none; }
.review { flex: 0 0 300px; scroll-snap-align: start; background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 22px; box-shadow: var(--shadow); display: flex; flex-direction: column; }
.review header { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 14px; padding-bottom: 14px; border-bottom: 1px solid var(--line); margin-bottom: 16px; }
.face { width: 34px; height: 34px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 18px; }
.review p { margin: 0 0 20px; font-size: 14.5px; line-height: 1.65; flex: 1; word-break: keep-all; }
.tags { display: flex; gap: 8px; flex-wrap: wrap; }
.pill { display: inline-flex; align-items: center; gap: 6px; padding: 4px 10px 4px 5px; border-radius: 999px; font-size: 12.5px; font-weight: 700; border: 1px solid var(--line); background: #fff; }
.pill .ico { width: 18px; height: 18px; border-radius: 6px; font-size: 10px; }
.pill .ico.k, .pill .ico.ln { font-size: 5px; }
.nav { display: flex; justify-content: center; gap: 14px; }
.nav button { width: 36px; height: 36px; border-radius: 50%; border: 1px solid var(--line); background: #fff; font-size: 16px; box-shadow: 0 2px 0 var(--line); }
.nav button:disabled { opacity: .35; cursor: default; }

/* stats */
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; max-width: 760px; margin: 0 auto; }
.stat { text-align: center; padding: 26px 10px; border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); }
.stat b { display: block; font-size: clamp(28px, 5vw, 42px); font-weight: 800; letter-spacing: -.02em; }
.stat span { color: var(--muted); font-size: 14px; }

.apps { display: flex; justify-content: center; flex-wrap: wrap; gap: 14px; max-width: 600px; margin: 0 auto; }
.apps .app { display: flex; flex-direction: column; align-items: center; gap: 8px; font-size: 12.5px; font-weight: 600; color: var(--muted); width: 74px; }
.apps .ico { width: 54px; height: 54px; border-radius: 15px; font-size: 26px; box-shadow: 0 3px 0 rgba(0,0,0,.08); }
.apps .ico.k, .apps .ico.ln { font-size: 14px; }

.wall { columns: 3 240px; column-gap: 16px; max-width: 900px; margin: 0 auto; }
.react { break-inside: avoid; margin-bottom: 16px; border: 1px solid var(--line); border-radius: 16px; padding: 16px; box-shadow: var(--shadow); font-size: 14px; line-height: 1.55; }
.react .meta { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 13px; margin-bottom: 8px; }
.react .meta em { font-style: normal; font-weight: 500; color: var(--muted); }
.dm { text-align: center; font-size: 14px; color: var(--muted); margin-top: 26px; }
.dm a { color: var(--fg); font-weight: 700; }

.final { text-align: center; padding: 120px 20px 140px; }
.final h2 { font-size: clamp(30px, 5vw, 44px); margin: 0 0 30px; font-weight: 800; letter-spacing: -.02em; }
footer { border-top: 1px solid var(--line); padding: 30px 20px; text-align: center; color: var(--muted); font-size: 13px; }
footer a { margin: 0 8px; text-decoration: none; }

/* modal */
.modal { position: fixed; inset: 0; z-index: 100; display: none; align-items: center; justify-content: center; background: rgba(17,20,24,.45); padding: 16px; }
.modal.open { display: flex; }
.sheet { background: #fff; border-radius: 22px; width: 100%; max-width: 440px; padding: 26px; position: relative; animation: rise .25s; }
.sheet h3 { margin: 0 0 6px; font-size: 21px; }
.sheet .x { position: absolute; top: 14px; right: 14px; border: 0; background: #f2f3f5; width: 32px; height: 32px; border-radius: 50%; font-size: 15px; }
.steps { margin: 14px 0 18px; padding-left: 18px; color: var(--muted); font-size: 14px; line-height: 1.7; }
.drop { border: 2px dashed #c9d6ee; border-radius: 16px; padding: 30px 16px; text-align: center; background: #f7faff; font-size: 14px; color: var(--muted); transition: background .15s; }
.drop.over { background: var(--blue-soft); border-color: var(--blue); }
.drop strong { display: block; color: var(--fg); font-size: 16px; margin-bottom: 4px; }
.err { color: #d33; font-size: 13px; margin-top: 10px; min-height: 18px; }
.sample { display: block; margin: 12px auto 0; background: none; border: 0; color: var(--blue-dark); font-weight: 700; font-size: 14px; text-decoration: underline; }
.spin { display: inline-block; width: 22px; height: 22px; border: 3px solid var(--blue-soft); border-top-color: var(--blue); border-radius: 50%; animation: r .8s linear infinite; vertical-align: middle; margin-right: 8px; }
@keyframes r { to { transform: rotate(360deg); } }

@media (max-width: 640px) {
  .hero { padding-top: 70px; }
  .float { font-size: 20px; }
  .float:nth-child(n+7) { display: none; }
  .stack .av { width: 48px; height: 48px; font-size: 24px; margin-left: -10px; }
  .stack .av.main { width: 56px; height: 56px; font-size: 30px; }
  .stats { grid-template-columns: 1fr; }
  .review { flex-basis: 82vw; }
}
@media (prefers-reduced-motion: reduce) { .row, .float { animation: none; } }