/* daiwen.ai — brand landing; visual language aligned with aidaiwen.com */
:root {
  --bg: #f7f7f4;
  --bg-elev: #ffffff;
  --bg-soft: #efefea;
  --line: rgba(15, 23, 42, 0.08);
  --line-strong: rgba(15, 23, 42, 0.14);
  --text: #0d0d0d;
  --muted: #5c5c5c;
  --dim: #8a8a8a;
  --accent: #10a37f;
  --accent-hover: #0d8f6e;
  --grad: linear-gradient(135deg, #10a37f 0%, #0d9488 45%, #6366f1 100%);
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.04), 0 12px 40px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 24px 64px rgba(15, 23, 42, 0.1);
  --radius: 20px;
  --radius-sm: 14px;
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  min-height: 100dvh;
  font-size: 16px;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }

.landing {
  position: relative;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.25rem 1rem 1.5rem;
  overflow: hidden;
}

.fx { position: absolute; inset: 0; pointer-events: none; z-index: 0; }
.fx-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(42px);
  opacity: 0.55;
}
.fx-a {
  width: min(480px, 90vw);
  height: min(480px, 90vw);
  top: -18%;
  left: 30%;
  background: radial-gradient(circle, rgba(16, 163, 127, 0.22), transparent 68%);
}
.fx-b {
  width: min(420px, 85vw);
  height: min(420px, 85vw);
  right: -12%;
  bottom: -22%;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.16), transparent 70%);
}
.fx-grid {
  position: absolute;
  inset: -10%;
  background-image:
    linear-gradient(rgba(15, 23, 42, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(15, 23, 42, 0.035) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 15%, transparent 72%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 15%, transparent 72%);
  opacity: 0.65;
}

.panel {
  position: relative;
  z-index: 1;
  width: min(100%, 420px);
  background: rgba(255, 255, 255, 0.86);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 1.35rem 1.25rem 1.15rem;
  text-align: center;
}
.panel.narrow { padding-top: 2rem; padding-bottom: 2rem; }

.brand-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.7rem;
  margin-bottom: 1.1rem;
}
.logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: contain;
  box-shadow: 0 4px 14px rgba(0, 180, 140, 0.22);
  flex-shrink: 0;
}
.brand-text { text-align: left; }
.brand-text strong {
  display: block;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  line-height: 1.2;
}
.brand-text span {
  display: block;
  font-size: 0.72rem;
  color: var(--dim);
  font-weight: 500;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin: 0 0 0.85rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.8);
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
}

h1 {
  font-size: clamp(1.55rem, 6.2vw, 1.95rem);
  line-height: 1.2;
  margin: 0 0 0.75rem;
  letter-spacing: -0.03em;
  font-weight: 700;
}
.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lead {
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.65;
  margin: 0 0 1.15rem;
}

.models {
  list-style: none;
  margin: 0 0 1.25rem;
  padding: 0;
  display: grid;
  gap: 0.55rem;
  text-align: left;
}
.models li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.72rem 0.85rem;
  border-radius: var(--radius-sm);
  background: var(--bg-soft);
  border: 1px solid var(--line);
}
.models strong {
  display: block;
  font-size: 0.95rem;
  line-height: 1.25;
}
.models em {
  display: block;
  font-style: normal;
  font-size: 0.78rem;
  color: var(--dim);
  margin-top: 0.1rem;
}
.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
  box-shadow: 0 0 0 3px rgba(16, 163, 127, 0.12);
}
.dot.gpt { background: #10a37f; }
.dot.gem { background: #4285f4; box-shadow: 0 0 0 3px rgba(66, 133, 244, 0.14); }
.dot.grok { background: #6366f1; box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.14); }
.dot.more { background: linear-gradient(135deg,#10a37f,#6366f1); box-shadow: 0 0 0 3px rgba(16,163,127,0.12); }

.cta { display: grid; gap: 0.65rem; }
.cta-sub {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.55rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  border-radius: 999px;
  padding: 0.85rem 1.2rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: 0.18s ease;
  font-size: 0.95rem;
  text-decoration: none;
  min-height: 48px;
  -webkit-tap-highlight-color: transparent;
}
.btn-primary {
  background: var(--accent);
  color: #fff !important;
  box-shadow: 0 8px 24px rgba(16, 163, 127, 0.28);
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff !important;
  transform: translateY(-1px);
}
.btn-ghost {
  background: var(--bg-elev);
  color: var(--text) !important;
  border-color: var(--line-strong);
  font-size: 0.88rem;
  min-height: 44px;
  padding: 0.65rem 0.75rem;
}
.btn-ghost:hover {
  border-color: rgba(16, 163, 127, 0.4);
  color: var(--text) !important;
}
.btn-taobao {
  background: linear-gradient(135deg, #ff6a00, #ff8a1a);
  color: #fff !important;
  box-shadow: 0 8px 22px rgba(255, 106, 0, 0.22);
  font-size: 0.88rem;
  min-height: 44px;
  padding: 0.65rem 0.75rem;
}
.btn-taobao:hover {
  filter: brightness(1.04);
  color: #fff !important;
}

.foot {
  margin-top: 1.15rem;
  padding-top: 0.85rem;
  border-top: 1px solid var(--line);
  font-size: 0.72rem;
  color: var(--dim);
  line-height: 1.5;
}
.foot a { color: var(--muted); font-weight: 500; }
.foot a:hover { color: var(--accent); }

@media (min-width: 480px) {
  .panel { padding: 1.6rem 1.5rem 1.25rem; }
  h1 { font-size: 2rem; }
}

@media (prefers-reduced-motion: reduce) {
  .btn { transition: none; }
  .btn-primary:hover { transform: none; }
}

/* —— Neon light sweep on headline —— */
.neon-title {
  --neon-s: 0;
  --nx0: 50%; --ny0: 50%; --na0: 0;
  --nx1: 50%; --ny1: 50%; --na1: 0;
  --nx2: 50%; --ny2: 50%; --na2: 0;
  --nx3: 50%; --ny3: 50%; --na3: 0;
  --nx4: 50%; --ny4: 50%; --na4: 0;
  --nx5: 50%; --ny5: 50%; --na5: 0;
  position: relative;
  display: block;
  isolation: isolate;
  touch-action: manipulation;
  cursor: crosshair;
  /* slight tech glow at rest */
  text-shadow: 0 0 24px rgba(16, 163, 127, 0.12);
}

.neon-title__base {
  position: relative;
  z-index: 1;
}

.neon-title__lit {
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  font: inherit;
  letter-spacing: inherit;
  line-height: inherit;
  font-weight: inherit;
  text-align: inherit;
  margin: 0;
  /* holographic neon fill */
  background:
    linear-gradient(
      115deg,
      #22d3ee 0%,
      #a78bfa 28%,
      #f472b6 52%,
      #38bdf8 78%,
      #34d399 100%
    );
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  /* trail of radial reveals — letters light up under the sweep */
  -webkit-mask-image:
    radial-gradient(circle 76px at var(--nx0) var(--ny0), rgba(0,0,0,var(--na0)) 0%, rgba(0,0,0,calc(var(--na0)*0.35)) 45%, transparent 72%),
    radial-gradient(circle 60px at var(--nx1) var(--ny1), rgba(0,0,0,var(--na1)) 0%, transparent 70%),
    radial-gradient(circle 48px at var(--nx2) var(--ny2), rgba(0,0,0,var(--na2)) 0%, transparent 68%),
    radial-gradient(circle 40px at var(--nx3) var(--ny3), rgba(0,0,0,var(--na3)) 0%, transparent 66%),
    radial-gradient(circle 34px at var(--nx4) var(--ny4), rgba(0,0,0,var(--na4)) 0%, transparent 64%),
    radial-gradient(circle 28px at var(--nx5) var(--ny5), rgba(0,0,0,var(--na5)) 0%, transparent 62%);
  mask-image:
    radial-gradient(circle 76px at var(--nx0) var(--ny0), rgba(0,0,0,var(--na0)) 0%, rgba(0,0,0,calc(var(--na0)*0.35)) 45%, transparent 72%),
    radial-gradient(circle 60px at var(--nx1) var(--ny1), rgba(0,0,0,var(--na1)) 0%, transparent 70%),
    radial-gradient(circle 48px at var(--nx2) var(--ny2), rgba(0,0,0,var(--na2)) 0%, transparent 68%),
    radial-gradient(circle 40px at var(--nx3) var(--ny3), rgba(0,0,0,var(--na3)) 0%, transparent 66%),
    radial-gradient(circle 34px at var(--nx4) var(--ny4), rgba(0,0,0,var(--na4)) 0%, transparent 64%),
    radial-gradient(circle 28px at var(--nx5) var(--ny5), rgba(0,0,0,var(--na5)) 0%, transparent 62%);
  -webkit-mask-composite: source-over;
  mask-composite: add;
  opacity: calc(0.15 + var(--neon-s) * 0.95);
  filter:
    drop-shadow(0 0 6px rgba(34, 211, 238, calc(var(--neon-s) * 0.85)))
    drop-shadow(0 0 14px rgba(244, 114, 182, calc(var(--neon-s) * 0.55)))
    drop-shadow(0 0 22px rgba(99, 102, 241, calc(var(--neon-s) * 0.35)));
  will-change: opacity, filter;
}

.neon-title__lit .grad {
  background: none;
  -webkit-background-clip: unset;
  background-clip: unset;
  color: inherit;
}

/* soft bloom orbs following the trail (behind glyphs) */
.neon-title__bloom {
  position: absolute;
  inset: -18% -8%;
  z-index: 0;
  pointer-events: none;
  opacity: calc(var(--neon-s) * 0.9);
  background:
    radial-gradient(circle 90px at var(--nx0) var(--ny0), rgba(34, 211, 238, calc(var(--na0) * 0.38)), transparent 70%),
    radial-gradient(circle 70px at var(--nx1) var(--ny1), rgba(167, 139, 250, calc(var(--na1) * 0.28)), transparent 68%),
    radial-gradient(circle 56px at var(--nx2) var(--ny2), rgba(244, 114, 182, calc(var(--na2) * 0.22)), transparent 65%),
    radial-gradient(circle 44px at var(--nx3) var(--ny3), rgba(56, 189, 248, calc(var(--na3) * 0.16)), transparent 62%);
  mix-blend-mode: screen;
  filter: blur(10px);
  transition: opacity 0.12s linear;
}

@media (max-width: 480px) {
  .neon-title__lit {
    -webkit-mask-image:
      radial-gradient(circle 56px at var(--nx0) var(--ny0), rgba(0,0,0,var(--na0)) 0%, transparent 72%),
      radial-gradient(circle 44px at var(--nx1) var(--ny1), rgba(0,0,0,var(--na1)) 0%, transparent 70%),
      radial-gradient(circle 34px at var(--nx2) var(--ny2), rgba(0,0,0,var(--na2)) 0%, transparent 68%),
      radial-gradient(circle 28px at var(--nx3) var(--ny3), rgba(0,0,0,var(--na3)) 0%, transparent 66%);
    mask-image:
      radial-gradient(circle 56px at var(--nx0) var(--ny0), rgba(0,0,0,var(--na0)) 0%, transparent 72%),
      radial-gradient(circle 44px at var(--nx1) var(--ny1), rgba(0,0,0,var(--na1)) 0%, transparent 70%),
      radial-gradient(circle 34px at var(--nx2) var(--ny2), rgba(0,0,0,var(--na2)) 0%, transparent 68%),
      radial-gradient(circle 28px at var(--nx3) var(--ny3), rgba(0,0,0,var(--na3)) 0%, transparent 66%);
    filter:
      drop-shadow(0 0 4px rgba(34, 211, 238, calc(var(--neon-s) * 0.7)))
      drop-shadow(0 0 10px rgba(244, 114, 182, calc(var(--neon-s) * 0.4)));
  }
  .neon-title__bloom {
    filter: blur(8px);
    opacity: calc(var(--neon-s) * 0.65);
  }
  .neon-title { cursor: default; }
}

/* gentle discoverability shimmer when idle on desktop */
.neon-title--hint .neon-title__base {
  animation: neon-hint 4.8s ease-in-out infinite;
}
@keyframes neon-hint {
  0%, 100% { filter: brightness(1); }
  50% { filter: brightness(1.04); }
}
.neon-title--hint:hover .neon-title__base,
.neon-title:hover .neon-title__base {
  animation: none;
}

.neon-title--static .neon-title__lit,
.neon-title--static .neon-title__bloom {
  display: none;
}

@media (prefers-reduced-motion: reduce) {
  .neon-title--hint .neon-title__base { animation: none; }
  .neon-title__lit,
  .neon-title__bloom { display: none; }
}