/* ============================================================
   Nimbus · 私有云盘 — 共享主题
   设计语言：柔和光谱背景 + 半透明玻璃面板 + 紫蓝渐变主色
   ============================================================ */

:root {
  /* 文字 */
  --ink: #171A24;
  --ink-2: #454B60;
  --muted: #7C8296;
  --faint: #A3AABC;

  /* 品牌 */
  --brand: #5B7CFA;
  --brand-2: #9A6BF5;
  --brand-ink: #4353D6;
  --brand-soft: #EDF0FE;

  /* 语义色 */
  --mint: #2FB59B;
  --amber: #E0A03A;
  --rose: #E06A8B;
  --sky: #4FA8E8;

  /* 表面 */
  --bg: #F4F6FD;
  --glass: rgba(255, 255, 255, 0.58);
  --glass-2: rgba(255, 255, 255, 0.76);
  --glass-3: rgba(255, 255, 255, 0.92);
  --stroke: rgba(255, 255, 255, 0.86);
  --line: rgba(90, 105, 150, 0.16);
  --line-soft: rgba(90, 105, 150, 0.09);

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(40, 50, 100, 0.05);
  --shadow: 0 10px 30px -12px rgba(50, 60, 120, 0.22), 0 2px 6px rgba(50, 60, 120, 0.05);
  --shadow-lg: 0 30px 70px -32px rgba(45, 55, 120, 0.34), 0 8px 20px -14px rgba(45, 55, 120, 0.16);
  --shadow-brand: 0 10px 24px -10px rgba(91, 124, 250, 0.65);

  /* 圆角 */
  --r-xs: 8px;
  --r-sm: 10px;
  --r: 14px;
  --r-lg: 20px;
  --r-xl: 28px;

  --max: 1120px;
  --nav-h: 68px;

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --mono: "SFMono-Regular", ui-monospace, Menlo, Consolas, monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 16px);
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input {
  font: inherit;
  color: inherit;
}

img,
svg {
  display: block;
  max-width: 100%;
}

::selection {
  background: rgba(91, 124, 250, 0.22);
}

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
  border-radius: 6px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 背景：柔和光谱 ---------- */

.aurora {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  background:
    radial-gradient(58% 46% at 10% -4%, #DBE3FF 0%, rgba(219, 227, 255, 0) 62%),
    radial-gradient(48% 42% at 90% 2%, #EBD9FF 0%, rgba(235, 217, 255, 0) 64%),
    radial-gradient(52% 44% at 52% 104%, #D6F0F7 0%, rgba(214, 240, 247, 0) 66%),
    linear-gradient(180deg, #FAFBFF 0%, #F2F5FD 100%);
}

.aurora::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(90, 105, 150, 0.13) 1px, transparent 1px);
  background-size: 28px 28px;
  opacity: 0.45;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 68%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 68%);
}

/* ---------- 布局 ---------- */

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 玻璃面板 ---------- */

.glass {
  background: var(--glass);
  border: 1px solid var(--stroke);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  -webkit-backdrop-filter: blur(20px) saturate(150%);
  backdrop-filter: blur(20px) saturate(150%);
}

.glass-strong {
  background: var(--glass-3);
}

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 46px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  cursor: pointer;
  white-space: nowrap;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease,
    color 0.18s ease, border-color 0.18s ease;
}

.btn:active {
  transform: translateY(0) scale(0.99);
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-2) 100%);
  box-shadow: var(--shadow-brand);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 28px -10px rgba(91, 124, 250, 0.8);
}

.btn-ghost {
  color: var(--ink-2);
  background: var(--glass-2);
  border-color: var(--stroke);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.btn-ghost:hover {
  background: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.btn-sm {
  height: 38px;
  padding: 0 16px;
  font-size: 13px;
}

.btn-block {
  width: 100%;
}

.btn .arrow {
  width: 15px;
  height: 15px;
  transition: transform 0.2s ease;
}

.btn:hover .arrow {
  transform: translateX(3px);
}

/* ---------- 徽标 / 药丸标签 ---------- */

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-2) 100%);
  box-shadow: 0 6px 14px -6px rgba(91, 124, 250, 0.85);
}

.brand-mark svg {
  width: 18px;
  height: 18px;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 13px 6px 10px;
  border-radius: 999px;
  background: var(--glass-2);
  border: 1px solid var(--stroke);
  color: var(--brand-ink);
  font-size: 12.5px;
  font-weight: 500;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.pill .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 0 3px rgba(47, 181, 155, 0.18);
}

/* ---------- 分区标题 ---------- */

.sec {
  padding: 92px 0;
}

.sec-head {
  max-width: 620px;
  margin: 0 auto 44px;
  text-align: center;
}

.sec-eyebrow {
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--brand-ink);
}

.sec-title {
  margin: 12px 0 0;
  font-size: clamp(25px, 3.1vw, 34px);
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: -0.022em;
}

.sec-sub {
  margin: 12px 0 0;
  font-size: 15px;
  color: var(--muted);
}

/* ---------- 入场动画 ---------- */

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.75s cubic-bezier(0.2, 0.7, 0.2, 1),
    transform 0.75s cubic-bezier(0.2, 0.7, 0.2, 1);
  transition-delay: var(--d, 0ms);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 轻提示 ---------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: 32px;
  z-index: 90;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  border-radius: 999px;
  background: rgba(23, 26, 36, 0.92);
  color: #fff;
  font-size: 13px;
  box-shadow: 0 18px 40px -18px rgba(20, 25, 50, 0.7);
  transform: translate(-50%, 20px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.28s ease, transform 0.28s ease;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.toast.is-show {
  opacity: 1;
  transform: translate(-50%, 0);
}

.toast .toast-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #7FE3C8;
}

@media (max-width: 720px) {
  .sec {
    padding: 68px 0;
  }

  .wrap {
    padding: 0 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn,
  .btn:hover {
    transform: none;
  }
}