/* [1-25] root vars + universal box-sizing reset */
:root {
  --yb-primary: #2174fd;
  --yb-primary-hover: #4098fc;
  --yb-primary-deep: #155bd7;
  --yb-violet: #5b54d3;
  --yb-bg: #fafcff;
  --yb-surface: #ffffff;
  --yb-border: #e6e9f0;
  --yb-border-soft: #eef2f9;
  --yb-text: #1c2536;
  --yb-text-soft: #66707f;
  --yb-text-muted: #98a2b3;

  /* 分层阴影体系：由弱到强，元素层级越高、越需要强调，阴影越重 */
  --yb-shadow-xs: 0 2px 8px rgba(23, 32, 51, 0.04);
  --yb-shadow-sm: 0 8px 20px rgba(33, 116, 253, 0.05);
  --yb-shadow: 0 18px 40px rgba(33, 116, 253, 0.07);
  --yb-shadow-lg: 0 30px 64px rgba(33, 116, 253, 0.11), 0 10px 26px rgba(23, 32, 51, 0.06);
  --yb-shadow-hover: 0 22px 46px rgba(33, 116, 253, 0.16), 0 8px 18px rgba(23, 32, 51, 0.08);

  /* 统一过渡节奏：交互反馈用更快的 ease-out，跨状态切换用更柔和的曲线 */
  --yb-ease: cubic-bezier(0.16, 1, 0.3, 1);
  --yb-duration-fast: 140ms;
  --yb-duration: 220ms;

  color: var(--yb-text);
  background: var(--yb-bg);
  font-family: Inter, "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* {
  box-sizing: border-box;
}

/* [27-37] html/body/#root reset + body overflow hidden */
html,
body,
#root {
  width: 100%;
  height: 100%;
  margin: 0;
}

body {
  overflow: hidden;
}

/* [159-188] sr-only + button/input/select font inherit + select arrow + button cursor */
.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;
}

button,
input,
select {
  font: inherit;
}

select {
  appearance: none;
  padding-right: 42px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='18' height='18' viewBox='0 0 24 24' fill='none' stroke='%23536176' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  background-size: 18px 18px;
}

button {
  cursor: pointer;
}
