* { margin: 0; padding: 0; box-sizing: border-box; font-family: "Microsoft YaHei", "PingFang SC", sans-serif; }
body { min-height: 100vh; background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%); }

.page { min-height: 100vh; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 20px; }
.hidden { display: none !important; }

/* 登录 */
.login-box { background: #fff; border-radius: 12px; padding: 40px 36px; width: 100%; max-width: 380px; box-shadow: 0 12px 40px rgba(0,0,0,.3); }
.login-logo { font-size: 24px; font-weight: bold; color: #1e3c72; text-align: center; }
.login-sub { font-size: 12px; color: #999; text-align: center; margin: 6px 0 28px; letter-spacing: 1px; }
.login-box label { display: block; font-size: 13px; color: #666; margin: 14px 0 6px; }
.login-box input { width: 100%; height: 42px; border: 1px solid #ddd; border-radius: 6px; padding: 0 12px; font-size: 14px; outline: none; transition: border .2s; }
.login-box input:focus { border-color: #2a5298; }
.error-msg { color: #e74c3c; font-size: 13px; min-height: 20px; margin-top: 10px; }
.btn-primary { width: 100%; height: 44px; margin-top: 10px; background: #2a5298; color: #fff; border: none; border-radius: 6px; font-size: 16px; cursor: pointer; letter-spacing: 6px; }
.btn-primary:hover { background: #1e3c72; }
.btn-primary:disabled { opacity: .6; cursor: not-allowed; }

/* 版本选择 */
.select-title { color: #fff; font-size: 26px; font-weight: bold; margin-bottom: 36px; letter-spacing: 2px; }
.select-cards { display: flex; gap: 28px; flex-wrap: wrap; justify-content: center; }
.select-card { background: #fff; border-radius: 14px; width: 240px; padding: 36px 24px; text-align: center; cursor: pointer; box-shadow: 0 8px 30px rgba(0,0,0,.25); transition: transform .2s, box-shadow .2s; }
.select-card:hover { transform: translateY(-6px); box-shadow: 0 14px 40px rgba(0,0,0,.35); }
.card-icon { font-size: 52px; }
.card-name { font-size: 20px; font-weight: bold; color: #1e3c72; margin: 14px 0 8px; }
.card-desc { font-size: 13px; color: #888; line-height: 1.6; }
.btn-back { display: block; margin: 16px auto 0; background: none; border: none; color: #2a5298; font-size: 13px; cursor: pointer; }
.btn-back:hover { text-decoration: underline; }
.btn-link { margin-top: 34px; background: none; border: none; color: rgba(255,255,255,.75); font-size: 14px; cursor: pointer; text-decoration: underline; }
.btn-link:hover { color: #fff; }