/* ==========================================================================
   基础样式：重置、排版、星空背景、滚动条、可访问性
   ========================================================================== */

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

[hidden] {
  display: none !important;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  min-height: 100%;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  color: var(--cream);
  background: var(--bg-0);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body[data-screen="setup"],
body[data-screen="result"] {
  overflow-y: auto;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.25;
  color: var(--cream);
}

p {
  margin: 0;
}

ol,
ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

button,
input {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: 0;
  background: none;
}

a {
  color: var(--gold-bright);
  text-decoration: none;
  border-bottom: 1px solid var(--gold-line);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

a:hover {
  color: #fff3d2;
  border-color: var(--gold);
}

::selection {
  background: rgba(201, 162, 74, 0.35);
  color: #fff;
}

:focus-visible {
  outline: 2px solid var(--gold-bright);
  outline-offset: 2px;
  border-radius: var(--radius-s);
}

/* 星空背景 ---------------------------------------------------------------- */

.backdrop {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(1100px 780px at 12% -8%, #14224a 0%, rgba(20, 34, 74, 0) 62%),
    radial-gradient(900px 700px at 92% 6%, #1a1a3d 0%, rgba(26, 26, 61, 0) 58%),
    linear-gradient(180deg, var(--bg-1) 0%, var(--bg-0) 100%);
}

.backdrop__stars {
  position: absolute;
  inset: 0;
  opacity: 0.9;
  background-image:
    radial-gradient(1.4px 1.4px at 18% 22%, rgba(255, 255, 255, 0.8), transparent 60%),
    radial-gradient(1.1px 1.1px at 72% 14%, rgba(255, 255, 255, 0.7), transparent 60%),
    radial-gradient(1.6px 1.6px at 44% 68%, rgba(255, 246, 220, 0.7), transparent 60%),
    radial-gradient(1px 1px at 88% 54%, rgba(255, 255, 255, 0.55), transparent 60%),
    radial-gradient(1.2px 1.2px at 26% 84%, rgba(255, 255, 255, 0.6), transparent 60%),
    radial-gradient(1px 1px at 62% 38%, rgba(228, 200, 124, 0.6), transparent 60%),
    radial-gradient(1.5px 1.5px at 8% 58%, rgba(255, 255, 255, 0.45), transparent 60%),
    radial-gradient(1px 1px at 52% 92%, rgba(255, 255, 255, 0.4), transparent 60%);
  background-size: 480px 480px, 620px 620px, 540px 540px, 700px 700px,
    520px 520px, 640px 640px, 760px 760px, 580px 580px;
  animation: twinkle 9s ease-in-out infinite alternate;
}

.backdrop__glow {
  position: absolute;
  left: 50%;
  top: -20%;
  width: min(1200px, 120vw);
  height: 70vh;
  transform: translateX(-50%);
  background: radial-gradient(closest-side, rgba(201, 162, 74, 0.12), transparent 70%);
  filter: blur(10px);
}

@keyframes twinkle {
  from { opacity: 0.55; }
  to { opacity: 0.95; }
}

/* 应用容器 ---------------------------------------------------------------- */

.app {
  min-height: 100vh;
}

/* 杂项工具类 -------------------------------------------------------------- */

.muted {
  color: var(--muted);
  font-size: 13px;
}

.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;
}

/* 滚动条 ------------------------------------------------------------------ */

* {
  scrollbar-width: thin;
  scrollbar-color: var(--line-strong) transparent;
}

*::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

*::-webkit-scrollbar-thumb {
  background: var(--line-strong);
  border-radius: 8px;
}

*::-webkit-scrollbar-track {
  background: transparent;
}

/* 错误提示层 -------------------------------------------------------------- */

.boot-error {
  position: fixed;
  left: 50%;
  bottom: 20px;
  z-index: 100;
  width: min(760px, calc(100vw - 32px));
  transform: translateX(-50%);
  padding: 14px 18px;
  border: 1px solid rgba(224, 90, 79, 0.6);
  border-radius: var(--radius-m);
  background: rgba(38, 12, 14, 0.94);
  box-shadow: var(--shadow-panel);
  color: #ffd8d2;
}

.boot-error__title {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-serif);
  letter-spacing: 0.04em;
}

.boot-error__detail {
  margin: 0;
  max-height: 30vh;
  overflow: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-word;
  color: #ffc9c1;
}

/* 动效降级 ---------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}