:root {
  color-scheme: light;

  /* 品牌色 */
  --brand:     #D44208;
  --brand-mid: #E8480A;
  --brand-bg:  #FEF2ED;

  /* 文字层级 */
  --ink:   #18181B;
  --ink-2: #52525B;
  --ink-3: #A1A1AA;

  /* 界面底色 */
  --bg:      #F4F4F6;
  --surface: #FFFFFF;
  --border:  #E4E4E7;
  --hover:   #F8F8FA;

  /* 状态色 */
  --green:    #16A34A;
  --green-bg: #F0FDF4;
  --red:      #DC2626;
  --yellow:   #D97706;

  /* 圆角 */
  --radius:    10px;
  --radius-sm: 7px;

  /* 阴影 */
  --shadow:    0 1px 3px rgba(0,0,0,0.06), 0 2px 8px rgba(0,0,0,0.04);
  --shadow-lg: 0 4px 20px rgba(0,0,0,0.10), 0 1px 4px rgba(0,0,0,0.06);

  /* 布局 */
  --sidebar-w: 232px;
  --topbar-h:  52px;
  --tabs-h:    56px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  min-height: 100dvh;
  color: var(--ink);
  background: var(--bg);
  font-family: -apple-system, "PingFang SC", "SF Pro Text", "Helvetica Neue",
               "Microsoft YaHei UI", "Microsoft YaHei", sans-serif;
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

button, input, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

h1, h2, h3, h4 { line-height: 1.25; font-weight: 600; letter-spacing: -0.01em; }
h2 { font-size: 20px; }
h3 { font-size: 16px; }
h4 { font-size: 13px; }

p { color: var(--ink-2); line-height: 1.65; }

input, textarea, select {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.12s, box-shadow 0.12s;
  color: var(--ink);
}

input, select {
  height: 42px;
  padding: 0 11px;
  font-size: 14px;
}

textarea {
  padding: 11px 12px;
  resize: vertical;
  min-height: 96px;
  font-size: 14px;
  line-height: 1.6;
}

input:focus, textarea:focus, select:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(212, 66, 8, 0.10);
}

input::placeholder, textarea::placeholder { color: var(--ink-3); }

.is-hidden { display: none !important; }
.muted { color: var(--ink-2); font-size: 13px; }
.small { font-size: 13px; }

.toast {
  position: fixed;
  top: 16px;
  left: 50%;
  z-index: 9999;
  min-width: 200px;
  max-width: min(420px, calc(100vw - 32px));
  padding: 11px 16px;
  color: #fff;
  background: #18181B;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  font-size: 14px;
  font-weight: 500;
  opacity: 0;
  transform: translate(-50%, -6px);
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
}
.toast.is-visible { opacity: 1; transform: translate(-50%, 0); }

.app-version {
  position: fixed;
  right: max(10px, env(safe-area-inset-right));
  bottom: max(8px, env(safe-area-inset-bottom));
  z-index: 1200;
  padding: 3px 7px;
  border-radius: 5px;
  background: rgba(24,24,27,0.55);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  color: rgba(255,255,255,0.75);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.03em;
  line-height: 1.4;
  pointer-events: none;
}