/* 登录 / 注册页 */
:root {
  color-scheme: light;
  --font-sans: "IBM Plex Sans", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-display: "Space Grotesk", "Noto Sans SC", "PingFang SC", sans-serif;
  --ink-1: #141414;
  --ink-2: #3d3d3d;
  --ink-3: #6b6f76;
  --paper-1: #f7f3ee;
  --paper-2: #efe9e2;
  --paper-3: #e6dfd6;
  --accent-1: #e04e39;
  --accent-2: #f28f3b;
  --accent-3: rgba(224, 78, 57, 0.18);
  --border: rgba(20, 20, 20, 0.1);
  --shadow-lg: 0 28px 60px rgba(18, 18, 18, 0.16);
}

body.dark-theme {
  color-scheme: dark;
  --ink-1: #f7f4f0;
  --ink-2: #d2cbc4;
  --ink-3: #a9a39c;
  --paper-1: #0f1317;
  --paper-2: #141a20;
  --paper-3: #1a2128;
  --accent-1: #ff6b4a;
  --accent-2: #f7a348;
  --accent-3: rgba(255, 107, 74, 0.2);
  --border: rgba(247, 244, 240, 0.12);
  --shadow-lg: 0 28px 60px rgba(0, 0, 0, 0.45);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-sans);
  color: var(--ink-1);
  background:
    radial-gradient(circle at 12% 8%, rgba(224, 78, 57, 0.14), transparent 40%),
    radial-gradient(circle at 88% 12%, rgba(31, 138, 122, 0.18), transparent 45%),
    linear-gradient(180deg, var(--paper-1) 0%, var(--paper-2) 100%);
  -webkit-font-smoothing: antialiased;
}

.auth-shell {
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.auth-card {
  width: min(400px, 100%);
  padding: 28px 26px 22px;
  border-radius: 24px;
  border: 1px solid var(--border);
  background: var(--paper-1);
  box-shadow: var(--shadow-lg);
}

.auth-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 22px;
}

.auth-logo {
  width: 44px;
  height: 44px;
  border-radius: 12px;
}

.auth-brand h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 20px;
  letter-spacing: -0.02em;
}

.auth-brand p {
  margin: 2px 0 0;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
}

.auth-tabs {
  display: flex;
  gap: 6px;
  padding: 4px;
  margin-bottom: 18px;
  border-radius: 999px;
  background: var(--paper-2);
}

.auth-tab {
  flex: 1;
  height: 34px;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--ink-2);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.auth-tab.active {
  background: var(--paper-1);
  color: var(--accent-1);
  box-shadow: 0 3px 10px rgba(18, 18, 18, 0.08);
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.auth-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 12px;
  font-weight: 700;
  color: var(--ink-2);
}

.auth-field input {
  height: 42px;
  padding: 0 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--paper-2);
  color: var(--ink-1);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.auth-field input:focus {
  border-color: var(--accent-1);
  box-shadow: 0 0 0 3px var(--accent-3);
}

.auth-field[hidden] {
  display: none;
}

.auth-error {
  margin: 0;
  padding: 8px 10px;
  border-radius: 8px;
  font-size: 12px;
  color: #b91c1c;
  background: rgba(185, 28, 28, 0.1);
}

.auth-error[hidden] {
  display: none;
}

.auth-submit {
  height: 44px;
  margin-top: 4px;
  border: none;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.auth-submit:hover {
  transform: translateY(-1px);
}

.auth-submit:active {
  transform: scale(0.98);
}

.auth-submit:disabled {
  opacity: 0.6;
  cursor: default;
  transform: none;
}

.auth-tip {
  margin: 16px 0 0;
  font-size: 12px;
  color: var(--ink-2);
  text-align: center;
  line-height: 1.6;
}

.auth-foot {
  margin: 8px 0 0;
  font-size: 11px;
  color: var(--ink-3);
  text-align: center;
}