* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
    background: #f1f5f9;
    color: #1e293b;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ---------- 通用 ---------- */
.btn {
    display: inline-block;
    padding: 10px 24px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
    transition: all .2s;
}
.btn-primary { background: #3b82f6; color: #fff; }
.btn-primary:hover { background: #2563eb; }
.btn-block { width: 100%; }
.btn-danger { background: #ef4444; color: #fff; }
.btn-warning { background: #f59e0b; color: #fff; }
.btn-success { background: #16a34a; color: #fff; }
.btn-info { background: #06b6d4; color: #fff; }
.btn-small {
    padding: 4px 12px;
    border: none;
    border-radius: 4px;
    font-size: 12px;
    cursor: pointer;
    margin: 2px;
}

.alert {
    padding: 10px 14px;
    border-radius: 8px;
    margin-bottom: 16px;
    font-size: 13px;
}
.alert-error { background: #fef2f2; color: #dc2626; border-left: 4px solid #dc2626; }
.alert-success { background: #f0fdf4; color: #16a34a; border-left: 4px solid #16a34a; }

.form-group { margin-bottom: 16px; }
.form-group label {
    display: block;
    font-weight: 600;
    color: #334155;
    margin-bottom: 5px;
    font-size: 13px;
}
.form-group input[type="text"],
.form-group input[type="password"],
.form-group input[type="number"] {
    width: 100%;
    padding: 11px 14px;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: 14px;
    background: #f8fafc;
    outline: none;
    transition: border-color .2s;
}
.form-group input:focus { border-color: #3b82f6; background: #fff; }

.site-footer {
    text-align: center;
    color: #94a3b8;
    font-size: 13px;
    padding: 24px;
    margin-top: auto;
}

/* ---------- 登录页 ---------- */
.login-wrap {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
}
.login-card {
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0,0,0,.5);
    padding: 40px;
    width: 100%;
    max-width: 400px;
}
.login-logo { text-align: center; font-size: 48px; margin-bottom: 16px; }
.login-card h1 {
    text-align: center;
    color: #0f172a;
    font-size: 22px;
    margin-bottom: 4px;
}
.login-sub {
    text-align: center;
    color: #94a3b8;
    font-size: 13px;
    margin-bottom: 28px;
}
.login-info {
    text-align: center;
    color: #94a3b8;
    font-size: 12px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid #f1f5f9;
}
.login-back {
    display: block;
    text-align: center;
    color: #3b82f6;
    text-decoration: none;
    margin-top: 12px;
    font-size: 13px;
}

/* ---------- 首页 ---------- */
.home-wrap {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px;
    width: 100%;
}
.home-card {
    background: #fff;
    border-radius: 16px;
    padding: 40px;
    margin-bottom: 24px;
    box-shadow: 0 4px 20px rgba(0,0,0,.06);
}
.hero { text-align: center; }
.hero-logo { font-size: 64px; margin-bottom: 16px; }
.hero h1 { font-size: 30px; color: #1e293b; margin-bottom: 10px; }
.hero-sub { color: #64748b; font-size: 16px; }

.home-card h2 {
    font-size: 20px;
    color: #1e293b;
    margin-bottom: 24px;
    text-align: center;
}
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}
.feature-item {
    padding: 20px;
    background: #f8fafc;
    border-radius: 12px;
    border-left: 4px solid #667eea;
}
.fi-icon { font-size: 32px; margin-bottom: 8px; }
.fi-name { font-weight: 600; color: #1e293b; margin-bottom: 6px; font-size: 15px; }
.fi-desc { color: #64748b; font-size: 13px; line-height: 1.5; }

.tip-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 18px;
}
.tip-item {
    padding: 16px;
    background: #f8fafc;
    border-radius: 10px;
    border-left: 3px solid #667eea;
}
.tip-title { font-size: 13px; font-weight: 600; color: #334155; margin-bottom: 6px; }
.tip-desc { font-size: 12px; color: #64748b; line-height: 1.7; }