/* ── Design tokens ────────────────────────────────────── */
:root {
  --bg:          #f5f6fa;
  --surface:     #ffffff;
  --border:      #e4e6ed;
  --border-focus:#4f7ef7;
  --text:        #111827;
  --text-muted:  #6b7280;
  --accent:      #4f7ef7;
  --accent-dark: #3b6ef0;
  --shadow-sm:   0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md:   0 4px 16px rgba(0,0,0,.08), 0 1px 4px rgba(0,0,0,.04);
  --radius:      12px;
}

/* ── Base ─────────────────────────────────────────────── */
html, body {
  min-height: 100vh;
  background: var(--bg) !important;
  color: var(--text) !important;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               Roboto, Helvetica, Arial, sans-serif !important;
  -webkit-font-smoothing: antialiased !important;
}

body::before, body::after { display: none !important; }

/* ── 备案链接 ─────────────────────────────────────────── */
.beian-link {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 11.5px;
  color: var(--text-muted) !important;
  text-decoration: none !important;
  letter-spacing: 0.3px;
  white-space: nowrap;
  z-index: 9999;
  transition: color .2s;
}
.beian-link:hover { color: var(--accent) !important; }

/* ── 登录卡片 ─────────────────────────────────────────── */
.MuiPaper-root,
.card,
[class*="MuiCard-root"] {
  background: var(--surface) !important;
  background-image: none !important;
  border: 1px solid var(--border) !important;
  border-radius: var(--radius) !important;
  box-shadow: var(--shadow-md) !important;
  backdrop-filter: none !important;
}

/* 隐藏头像框，居中标题 */
.MuiCardHeader-avatar { display: none !important; }
.MuiCardHeader-root {
  padding-bottom: 4px !important;
  justify-content: center !important;
}
.MuiCardHeader-content {
  flex: none !important;
  text-align: center !important;
  width: 100%;
}

/* ── 文字 ─────────────────────────────────────────────── */
.MuiTypography-h5 {
  font-size: 1.3rem !important;
  font-weight: 700 !important;
  color: var(--text) !important;
  letter-spacing: -.01em !important;
}
.MuiTypography-body2,
.MuiTypography-colorTextSecondary,
[class*="MuiFormHelperText-root"] {
  color: var(--text-muted) !important;
}

/* ── 输入框 ───────────────────────────────────────────── */
.MuiOutlinedInput-root {
  background: var(--surface) !important;
  border-radius: 8px !important;
}
.MuiOutlinedInput-notchedOutline {
  border-color: var(--border) !important;
  transition: border-color .15s !important;
}
.MuiOutlinedInput-root:hover .MuiOutlinedInput-notchedOutline {
  border-color: #b0bcf8 !important;
}
.MuiOutlinedInput-root.Mui-focused .MuiOutlinedInput-notchedOutline {
  border-color: var(--border-focus) !important;
  border-width: 2px !important;
}
.MuiOutlinedInput-root.Mui-focused {
  box-shadow: 0 0 0 3px rgba(79,126,247,.13) !important;
}
.MuiInputLabel-root            { color: var(--text-muted) !important; }
.MuiInputLabel-root.Mui-focused { color: var(--accent) !important; }
.MuiInputBase-input            { color: var(--text) !important; }

/* ── 主按钮 ───────────────────────────────────────────── */
.MuiButton-containedPrimary,
button[type="submit"] {
  background: var(--accent) !important;
  color: #fff !important;
  border-radius: 8px !important;
  font-weight: 600 !important;
  font-size: .9rem !important;
  text-transform: none !important;
  box-shadow: 0 2px 8px rgba(79,126,247,.28) !important;
  transition: background .15s, box-shadow .15s, transform .1s !important;
}
.MuiButton-containedPrimary:hover,
button[type="submit"]:hover {
  background: var(--accent-dark) !important;
  box-shadow: 0 4px 14px rgba(79,126,247,.38) !important;
  transform: translateY(-1px) !important;
}
.MuiButton-containedPrimary:active,
button[type="submit"]:active {
  transform: none !important;
  box-shadow: none !important;
}

/* ── 次级按钮 / 链接 ──────────────────────────────────── */
.MuiButton-text,
.MuiLink-root {
  color: var(--accent) !important;
  text-transform: none !important;
  text-decoration: none !important;
  font-weight: 500 !important;
}
.MuiButton-text:hover,
.MuiLink-root:hover {
  background: rgba(79,126,247,.07) !important;
  color: var(--accent-dark) !important;
}

/* ── 复选框 ───────────────────────────────────────────── */
.MuiCheckbox-root            { color: var(--border) !important; }
.MuiCheckbox-root.Mui-checked { color: var(--accent) !important; }

/* ── 通知条 ───────────────────────────────────────────── */
[class*="MuiAlert-root"] {
  border-radius: 8px !important;
  font-size: .875rem !important;
}
[class*="MuiAlert-standardError"]   { background: #fef2f2 !important; color: #b91c1c !important; }
[class*="MuiAlert-standardSuccess"] { background: #f0fdf4 !important; color: #15803d !important; }
[class*="MuiAlert-standardInfo"]    { background: #eff6ff !important; color: #1d4ed8 !important; }

/* ── 进度圈 ───────────────────────────────────────────── */
[class*="MuiCircularProgress-root"] { color: var(--accent) !important; }

/* ── 分割线 ───────────────────────────────────────────── */
[class*="MuiDivider-root"] { border-color: var(--border) !important; }

/* ── 图标 ─────────────────────────────────────────────── */
[class*="MuiIconButton-root"] svg        { color: var(--text-muted) !important; }
[class*="MuiIconButton-root"]:hover svg  { color: var(--accent) !important; }

/* ── 滚动条 ───────────────────────────────────────────── */
::-webkit-scrollbar       { width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #d1d5db; border-radius: 2px; }