/* gpt-main · OpenAI-inspired minimal aesthetic */
:root{--oi-bg:#fdfdfc;--oi-ink:#0d0d0d;--oi-sub:#6e6e80;--oi-line:#ececf1;--oi-green:#10a37f;--oi-green-d:#0b8a6b;--oi-soft:#f7f7f8}
*{box-sizing:border-box}html{scroll-behavior:smooth}body.oi{margin:0;background:var(--oi-bg);color:var(--oi-ink);font-family:Inter,"Söhne","PingFang SC","Microsoft YaHei",sans-serif}
a{color:inherit;text-decoration:none}
.oi-nav{position:sticky;top:0;z-index:40;background:rgba(253,253,252,.86);backdrop-filter:blur(12px);border-bottom:1px solid var(--oi-line)}
.oi-nav-in{width:min(1160px,calc(100% - 32px));margin:auto;height:60px;display:flex;align-items:center;justify-content:space-between}
.oi-logo{font-weight:800;font-size:19px;letter-spacing:-.4px}.oi-logo em{font-style:normal;background:linear-gradient(90deg,#10a37f,#0d9468);-webkit-background-clip:text;background-clip:text;color:transparent}
.oi-links{display:flex;gap:22px;font-size:14px;color:var(--oi-sub)}.oi-links a:hover{color:var(--oi-ink)}
.oi-btn{border-radius:999px;padding:9px 17px;font-weight:650;font-size:14px;transition:.2s;display:inline-flex;align-items:center;gap:7px;cursor:pointer}
.oi-btn.dark{background:var(--oi-ink);color:#fff}.oi-btn.green{background:var(--oi-green);color:#fff}.oi-btn.line{border:1px solid var(--oi-line);color:var(--oi-ink)}
.oi-btn:hover{opacity:.88;transform:translateY(-1px)}
.oi-hero{position:relative;padding:88px 0 72px;overflow:hidden;text-align:center}
.oi-orb{position:absolute;left:50%;top:-140px;transform:translateX(-50%);width:820px;height:520px;background:radial-gradient(closest-side,#10a37f2e,#10a37f14 55%,transparent);filter:blur(20px);pointer-events:none}
.oi-kicker{color:var(--oi-green);font-size:13px;font-weight:700;letter-spacing:.14em;text-transform:uppercase}
.oi-hero h1{font-size:clamp(38px,7vw,72px);line-height:1.06;letter-spacing:-.03em;margin:14px 0 16px;font-weight:680}
.oi-hero p{color:var(--oi-sub);font-size:clamp(15px,2.2vw,19px);max-width:620px;margin:0 auto;line-height:1.7}
.oi-actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-top:26px}
.oi-section{padding:64px 0}.oi-wrap{width:min(1160px,calc(100% - 32px));margin:auto}
.oi-h2{font-size:clamp(26px,4vw,42px);letter-spacing:-.02em;line-height:1.15;margin:8px 0 10px;font-weight:660}
.oi-sub{color:var(--oi-sub);line-height:1.75;max-width:640px}
.oi-grid{display:grid;gap:16px;margin-top:28px}
.g3{grid-template-columns:repeat(3,1fr)}.g4{grid-template-columns:repeat(4,1fr)}.g2{grid-template-columns:1.1fr .9fr}
.oi-card{border:1px solid var(--oi-line);border-radius:20px;padding:24px;background:#fff;transition:.25s}
.oi-card:hover{box-shadow:0 12px 40px #0d0d0d0d;transform:translateY(-2px)}
.oi-card h3{margin:8px 0 8px;font-size:18px;letter-spacing:-.01em}
.oi-card p{color:var(--oi-sub);font-size:14px;line-height:1.7;margin:0}
.oi-num{font-size:12px;font-weight:700;color:var(--oi-green);letter-spacing:.12em;text-transform:uppercase}
.oi-code{background:var(--oi-ink);color:#e8f7f1;border-radius:16px;padding:20px;font-family:ui-monospace,"SF Mono",Consolas,monospace;font-size:13px;line-height:1.9;overflow:auto;white-space:pre}
.oi-code .g{color:#19c37d}.oi-code .m{color:#8f9aa6}
.oi-price{border:1px solid var(--oi-line);border-radius:24px;padding:26px;background:#fff;display:flex;flex-direction:column;gap:10px;position:relative}
.oi-price.hot{border-color:var(--oi-green);box-shadow:0 18px 50px #10a37f1f}
.oi-price .amt{font-size:40px;font-weight:700;letter-spacing:-.03em}.oi-price .amt small{font-size:14px;color:var(--oi-sub);font-weight:500}
.oi-price ul{list-style:none;padding:0;margin:0;display:grid;gap:8px;color:var(--oi-sub);font-size:13.5px}
.oi-price li::before{content:"✓ ";color:var(--oi-green);font-weight:700}
.oi-tag{position:absolute;top:-12px;left:22px;background:var(--oi-green);color:#fff;font-size:12px;font-weight:700;padding:5px 12px;border-radius:999px}
.oi-foot{border-top:1px solid var(--oi-line);padding:26px 0;color:var(--oi-sub);font-size:12.5px}
.oi-foot-in{display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap}
.oi-menu{display:none;width:40px;height:40px;border:1px solid var(--oi-line);border-radius:10px;background:#fff;font-size:18px}
/* motion */
.rv{opacity:0;transform:translateY(22px);transition:opacity .7s cubic-bezier(.2,.6,.2,1),transform .7s cubic-bezier(.2,.6,.2,1)}
.rv.in{opacity:1;transform:none}
.oi-orb{animation:drift 14s ease-in-out infinite alternate}
@keyframes drift{from{transform:translateX(-52%) scale(1)}to{transform:translateX(-48%) scale(1.08)}}
.oi-hero h1{background:linear-gradient(180deg,#0d0d0d 55%,#3d3d4a);-webkit-background-clip:text;background-clip:text;color:transparent}
.oi-line-anim{position:absolute;left:0;right:0;top:0;height:1px;background:linear-gradient(90deg,transparent,#10a37f66,transparent);background-size:200% 100%;animation:sweep 6s linear infinite}
@keyframes sweep{from{background-position:200% 0}to{background-position:-200% 0}}
.oi-grid-bg{position:absolute;inset:0;background-image:linear-gradient(#0d0d0d08 1px,transparent 1px),linear-gradient(90deg,#0d0d0d08 1px,transparent 1px);background-size:52px 52px;mask-image:radial-gradient(ellipse at 50% 0,#000 20%,transparent 70%);pointer-events:none}
@media(max-width:920px){.g3,.g4{grid-template-columns:1fr 1fr}.g2{grid-template-columns:1fr}.oi-links{display:none;position:absolute;top:60px;left:0;right:0;background:#fff;border-bottom:1px solid var(--oi-line);flex-direction:column;padding:14px 20px;gap:14px}.oi-links.open{display:flex}.oi-menu{display:block}}
@media(max-width:600px){.g3,.g4{grid-template-columns:1fr}.oi-actions .oi-btn{flex:1;justify-content:center}}