/* ===========================================================================
 * AI 魔盒 — 视觉系统 (Ethereal Glass / Vision Pro 金属黑)
 * 核心：OLED 黑 + 径向多色渐变 + Vantablack 玻璃卡 + 双重嵌套边框
 * ========================================================================*/

/* ---------- 1. Reset & Tokens ---------- */
*,
*::before,
*::after { margin:0; padding:0; box-sizing:border-box; -webkit-tap-highlight-color:transparent; }

html { font-size: 16px; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; scroll-behavior: smooth; }

:root {
  /* —— 色板（OLED 黑 + 极细白发际线）—— */
  --bg-0:        #050505;
  --bg-1:        #0a0a0c;
  --bg-2:        #111114;
  --bg-glass:    rgba(255,255,255,0.04);
  --bg-glass-2:  rgba(255,255,255,0.07);

  --hairline:    rgba(255,255,255,0.08);
  --hairline-2:  rgba(255,255,255,0.14);
  --hairline-3:  rgba(255,255,255,0.22);

  /* —— 文字层级 —— */
  --fg:          #f5f5f7;
  --fg-soft:     rgba(245,245,247,0.72);
  --fg-mute:     rgba(245,245,247,0.46);
  --fg-faint:    rgba(245,245,247,0.28);

  /* —— Apple 系统色（Pro Display 暗色配） —— */
  --acc-blue:    #0a84ff;
  --acc-purple:  #bf5af2;
  --acc-pink:    #ff375f;
  --acc-green:   #30d158;
  --acc-orange:  #ff9f0a;
  --acc-cyan:    #64d2ff;

  /* —— 渐变体（按钮/光晕共用） —— */
  --grad-rainbow:   linear-gradient(135deg, #ff375f 0%, #bf5af2 35%, #0a84ff 70%, #64d2ff 100%);
  --grad-aurora:    linear-gradient(135deg, #bf5af2 0%, #0a84ff 50%, #30d158 100%);
  --grad-flame:     linear-gradient(135deg, #ff9f0a 0%, #ff375f 50%, #bf5af2 100%);
  --grad-mono:      linear-gradient(135deg, rgba(255,255,255,0.95), rgba(255,255,255,0.7));

  /* —— 形状 —— */
  --r-sm:  10px;
  --r-md:  16px;
  --r-lg:  22px;
  --r-xl:  28px;
  --r-2xl: 36px;
  --r-full: 9999px;

  /* —— 阴影/光晕 —— */
  --inset-hi:  inset 0 1px 0 rgba(255,255,255,0.08);
  --inset-hi-2: inset 0 1px 0 rgba(255,255,255,0.16);
  --shadow-card: 0 12px 60px -12px rgba(0,0,0,0.7), 0 0 0 1px rgba(255,255,255,0.06);
  --shadow-glow-blue:   0 8px 40px -6px rgba(10,132,255,0.55);
  --shadow-glow-purple: 0 8px 40px -6px rgba(191,90,242,0.45);

  /* —— 动效曲线 —— */
  --ease-spring:  cubic-bezier(0.32, 0.72, 0, 1);
  --ease-soft:    cubic-bezier(0.16, 1, 0.3, 1);
  --ease-snap:    cubic-bezier(0.5, 1.4, 0.3, 1);
  --dur-fast:     220ms;
  --dur-base:     500ms;
  --dur-slow:     900ms;

  /* —— 字体 —— */
  --font:         -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", system-ui, sans-serif;
  --font-mono:    "SF Mono", "JetBrains Mono", "Cascadia Code", Menlo, Consolas, monospace;
}

/* ---------- 2. Body / 底层背景画布 ---------- */
body {
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.55;
  color: var(--fg);
  background: var(--bg-0);
  min-height: 100dvh;
  overflow-x: hidden;
  position: relative;
  letter-spacing: -0.01em;
}

/* 多色径向光晕（固定背景层，不影响滚动性能） */
body::before {
  content: '';
  position: fixed; inset: -10vh -10vw;
  z-index: -2;
  background:
    radial-gradient(40vw 40vw at 12% 8%,   rgba(191,90,242,0.18), transparent 60%),
    radial-gradient(38vw 38vw at 92% 18%,  rgba(10,132,255,0.16),  transparent 62%),
    radial-gradient(50vw 50vw at 50% 110%, rgba(48,209,88,0.10),   transparent 65%),
    radial-gradient(28vw 28vw at 95% 90%,  rgba(255,55,95,0.10),   transparent 60%);
  filter: saturate(120%);
  pointer-events: none;
}

/* 极细噪点叠加（pointer-events:none + fixed，性能安全） */
body::after {
  content:'';
  position: fixed; inset: 0;
  z-index: 100;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='180' height='180'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0.55 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
  mix-blend-mode: overlay;
}

/* 选中色 */
::selection { background: rgba(10,132,255,0.45); color: #fff; }

/* ---------- 3. Typography ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.22em;
  color: var(--fg-mute);
  padding: 6px 14px;
  border-radius: var(--r-full);
  background: var(--bg-glass);
  border: 1px solid var(--hairline);
  backdrop-filter: blur(8px);
}
.eyebrow .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--grad-rainbow); box-shadow: 0 0 12px currentColor; }

.h-display {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 0.98;
}
.h1 { font-size: clamp(40px, 7.5vw, 92px); }
.h2 { font-size: clamp(32px, 5.4vw, 60px); }
.h3 { font-size: clamp(22px, 3vw, 32px); font-weight: 600; letter-spacing: -0.02em; line-height: 1.15; }
.h4 { font-size: 18px; font-weight: 600; letter-spacing: -0.01em; }

.lead { font-size: clamp(16px, 1.6vw, 20px); color: var(--fg-soft); line-height: 1.55; max-width: 56ch; }
.muted { color: var(--fg-mute); }
.faint { color: var(--fg-faint); }

.text-grad {
  background: var(--grad-rainbow);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* ---------- 4. Container ---------- */
.shell { max-width: 1200px; margin: 0 auto; padding: 0 28px; }
@media (max-width: 768px) {
  .shell { padding: 0 18px; }
}

.section { padding: clamp(72px, 12vw, 160px) 0; position: relative; }

/* ---------- 5. Card / Double-Bezel ---------- */
.card {
  position: relative;
  background: var(--bg-glass);
  border-radius: var(--r-2xl);
  padding: 6px;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--hairline);
}
.card-inner {
  position: relative;
  background: linear-gradient(180deg, rgba(20,20,24,0.85) 0%, rgba(8,8,12,0.85) 100%);
  border: 1px solid var(--hairline);
  border-radius: calc(var(--r-2xl) - 6px);
  box-shadow: var(--inset-hi);
  padding: clamp(28px, 4vw, 44px);
  overflow: hidden;
}

/* 卡片内的微高光（顶部） */
.card-inner::before {
  content: '';
  position: absolute; top:0; left:10%; right:10%; height:1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.18), transparent);
  pointer-events: none;
}

/* ---------- 6. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 22px 14px 26px;
  border-radius: var(--r-full);
  font-family: var(--font);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  cursor: pointer;
  border: 1px solid var(--hairline);
  background: var(--bg-glass-2);
  color: var(--fg);
  text-decoration: none;
  transition: transform var(--dur-fast) var(--ease-spring),
              background var(--dur-fast) var(--ease-spring),
              border-color var(--dur-fast) var(--ease-spring);
  white-space: nowrap;
  position: relative;
  user-select: none;
}
.btn:hover { background: rgba(255,255,255,0.10); border-color: var(--hairline-2); }
.btn:active { transform: scale(0.97); }

/* Button-in-Button 箭头：内嵌圆形图标 */
.btn .btn-icon {
  width: 30px; height: 30px;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: var(--r-full);
  background: rgba(255,255,255,0.10);
  color: var(--fg);
  margin-right: -8px;
  transition: transform var(--dur-fast) var(--ease-spring),
              background var(--dur-fast) var(--ease-spring);
}
.btn:hover .btn-icon { transform: translate(2px, -1px) scale(1.06); background: rgba(255,255,255,0.18); }

/* Primary：彩虹渐变 */
.btn-primary {
  background: var(--grad-rainbow);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 8px 30px -6px rgba(191,90,242,0.5),
              inset 0 1px 0 rgba(255,255,255,0.25);
  font-weight: 700;
}
.btn-primary:hover { background: var(--grad-rainbow); transform: translateY(-1px); box-shadow: 0 10px 36px -6px rgba(191,90,242,0.65), inset 0 1px 0 rgba(255,255,255,0.32); }
.btn-primary .btn-icon { background: rgba(255,255,255,0.22); }
.btn-primary:hover .btn-icon { background: rgba(255,255,255,0.32); }

/* Ghost */
.btn-ghost { background: transparent; }
.btn-ghost:hover { background: var(--bg-glass); }

/* Block */
.btn-block { width: 100%; }

/* Size */
.btn-lg { padding: 17px 26px 17px 30px; font-size: 16px; }
.btn-lg .btn-icon { width: 36px; height: 36px; margin-right: -10px; }

/* ---------- 7. Inputs ---------- */
.field {
  position: relative;
  display: block;
}
.field-input {
  width: 100%;
  padding: 18px 20px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--hairline);
  border-radius: var(--r-md);
  color: var(--fg);
  font-family: var(--font);
  font-size: 16px;
  letter-spacing: 0.04em;
  outline: none;
  transition: border-color var(--dur-fast) var(--ease-spring),
              background var(--dur-fast) var(--ease-spring),
              box-shadow var(--dur-fast) var(--ease-spring);
}
.field-input::placeholder { color: var(--fg-faint); letter-spacing: 0.02em; }
.field-input:focus {
  border-color: var(--hairline-3);
  background: rgba(255,255,255,0.06);
  box-shadow: 0 0 0 4px rgba(10,132,255,0.18);
}
.field-input:read-only { color: var(--fg-soft); }

/* ---------- 8. 信任徽章 / 标签胶囊 ---------- */
.pill {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 14px;
  border-radius: var(--r-full);
  background: var(--bg-glass);
  border: 1px solid var(--hairline);
  font-size: 13px;
  color: var(--fg-soft);
}
.pill svg { width: 14px; height: 14px; flex-shrink: 0; }

/* ---------- 9. Toast ---------- */
.toast {
  display: none;
  margin-top: 12px;
  padding: 12px 16px;
  border-radius: var(--r-md);
  font-size: 13px;
  border: 1px solid var(--hairline);
  background: var(--bg-glass);
  text-align: left;
}
.toast.show { display: block; animation: toast-in var(--dur-base) var(--ease-spring) both; }
.toast.ok  { background: rgba(48,209,88,0.10);  border-color: rgba(48,209,88,0.30);  color: #6ddf85; }
.toast.err { background: rgba(255,55,95,0.10);  border-color: rgba(255,55,95,0.30);  color: #ff8094; }
.toast.info { background: rgba(10,132,255,0.10); border-color: rgba(10,132,255,0.30); color: #6ab2ff; }
@keyframes toast-in { from { opacity:0; transform: translateY(6px); } to { opacity:1; transform: translateY(0); } }

/* ---------- 10. Reveal on scroll ---------- */
.reveal {
  opacity: 0;
  transform: translateY(36px);
  filter: blur(8px);
  transition: opacity 900ms var(--ease-soft),
              transform 900ms var(--ease-soft),
              filter 900ms var(--ease-soft);
  will-change: opacity, transform;
}
.reveal.in { opacity: 1; transform: none; filter: none; }
.reveal[data-delay="1"] { transition-delay: 80ms; }
.reveal[data-delay="2"] { transition-delay: 160ms; }
.reveal[data-delay="3"] { transition-delay: 240ms; }
.reveal[data-delay="4"] { transition-delay: 320ms; }
.reveal[data-delay="5"] { transition-delay: 400ms; }

/* ---------- 11. Floating Glass Nav ---------- */
.nav {
  position: fixed;
  top: 18px; left: 50%;
  transform: translateX(-50%);
  z-index: 60;
  display: flex; align-items: center; gap: 4px;
  padding: 6px 6px 6px 18px;
  border-radius: var(--r-full);
  background: rgba(10,10,12,0.6);
  border: 1px solid var(--hairline);
  backdrop-filter: blur(28px) saturate(160%);
  -webkit-backdrop-filter: blur(28px) saturate(160%);
  box-shadow: var(--shadow-card);
}
.nav-brand { font-weight: 700; font-size: 14px; letter-spacing: -0.01em; padding-right: 10px; }
.nav-brand .badge {
  display: inline-block; width: 8px; height: 8px; border-radius: 50%;
  background: var(--grad-rainbow); margin-right: 8px; vertical-align: middle;
  box-shadow: 0 0 10px rgba(191,90,242,0.6);
}
.nav-link {
  font-size: 13px; padding: 8px 14px; border-radius: var(--r-full);
  color: var(--fg-soft); text-decoration: none;
  transition: color var(--dur-fast) var(--ease-spring), background var(--dur-fast) var(--ease-spring);
}
.nav-link:hover { color: var(--fg); background: rgba(255,255,255,0.06); }
.nav-cta { padding: 8px 16px 8px 18px; font-size: 13px; }

@media (max-width: 640px) {
  .nav-link { display: none; }
  .nav { padding: 6px 6px 6px 14px; }
}

/* ---------- 12. Footer ---------- */
.foot {
  padding: 60px 0 80px;
  border-top: 1px solid var(--hairline);
  margin-top: 80px;
}
.foot-row { display: flex; justify-content: space-between; align-items: center; gap: 20px; flex-wrap: wrap; }
.foot small { color: var(--fg-mute); font-size: 12px; }

/* ---------- 13. Utility ---------- */
.center  { text-align: center; }
.flex    { display: flex; }
.col     { display: flex; flex-direction: column; }
.items-c { align-items: center; }
.justify-c { justify-content: center; }
.justify-b { justify-content: space-between; }
.gap-2  { gap: 8px; }
.gap-3  { gap: 12px; }
.gap-4  { gap: 16px; }
.gap-6  { gap: 24px; }
.gap-8  { gap: 32px; }
.mt-2   { margin-top: 8px; }
.mt-4   { margin-top: 16px; }
.mt-6   { margin-top: 24px; }
.mt-8   { margin-top: 32px; }
.mt-12  { margin-top: 48px; }
.w-full { width: 100%; }
.hidden { display: none !important; }

/* 小屏 helper */
@media (max-width: 640px) {
  .sm\:col   { flex-direction: column; }
  .sm\:full  { width: 100%; }
  .sm\:hide  { display: none; }
}