/* ========== 激活页 · 移动端优先 · 简洁不花哨 ========== */
:root {
  --brand: #2563eb;
  --brand-dark: #1d4ed8;
  --bg: #f7f9fc;
  --panel: #ffffff;
  --text: #0f172a;
  --text-sub: #64748b;
  --border: #e2e8f0;
  --error: #dc2626;
  --error-bg: #fee2e2;
  --success: #059669;
  --success-bg: #d1fae5;
  --radius: 10px;
  --shadow: 0 4px 24px rgba(15,23,42,0.06);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

.wrap {
  max-width: 420px;
  margin: 0 auto;
  padding: 24px 20px 40px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* ---- Brand ---- */
.brand {
  text-align: center;
  margin-bottom: 32px;
}
.logo {
  font-size: 22px;
  font-weight: 700;
  color: var(--brand);
  letter-spacing: 1px;
}
.sub {
  margin-top: 6px;
  color: var(--text-sub);
  font-size: 13px;
}

/* ---- Form ---- */
form {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 24px 20px;
  box-shadow: var(--shadow);
}

label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 8px;
}

input[type="text"] {
  width: 100%;
  height: 48px;
  padding: 0 14px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 16px; /* iOS 防止 focus 时缩放 */
  font-family: "SF Mono", Menlo, Consolas, "Courier New", monospace;
  letter-spacing: 1px;
  color: var(--text);
  background: #fff;
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
  text-transform: uppercase;
}
input[type="text"]:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
}
input[type="text"]::placeholder {
  color: #cbd5e1;
  letter-spacing: 1px;
  text-transform: none;
}

.hint {
  margin-top: 8px;
  color: var(--text-sub);
  font-size: 12px;
}

button[type="submit"] {
  width: 100%;
  height: 48px;
  margin-top: 20px;
  background: var(--brand);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
button[type="submit"]:hover:not(:disabled) {
  background: var(--brand-dark);
}
button[type="submit"]:active:not(:disabled) {
  transform: scale(0.98);
}
button[type="submit"]:disabled {
  background: #94a3b8;
  cursor: not-allowed;
}

.btn-spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255,255,255,0.4);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.msg {
  margin-top: 16px;
  padding: 10px 12px;
  border-radius: 6px;
  font-size: 13px;
  line-height: 1.4;
}
.msg.error {
  background: var(--error-bg);
  color: var(--error);
}
.msg.success {
  background: var(--success-bg);
  color: var(--success);
}

/* ---- Foot ---- */
.foot {
  margin-top: 24px;
  text-align: center;
  color: var(--text-sub);
  font-size: 12px;
  line-height: 1.6;
}
.foot-sub {
  margin-top: 4px;
  color: #94a3b8;
}

/* ---- 大屏适配 · 不做花哨的桌面版 ---- */
@media (min-width: 640px) {
  .wrap {
    padding: 60px 20px 40px;
  }
}