* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --radius: 16px;
    --radius-sm: 8px;
}

html, body { height: 100%; }

body.login-body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
    background-color: #0f172a;
    background-size: cover;
    background-position: top;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    -webkit-appearance: none;
    appearance: none;
}

/* 背景渐变遮罩，保证卡片可读 */
body.login-body::before {
    content: '';
    position: fixed;
    inset: 0;
    background: linear-gradient(180deg, rgba(15, 23, 42, 0.30) 0%, rgba(15, 23, 42, 0.55) 100%);
    z-index: 0;
    pointer-events: none;
}

.login-card {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 430px;
    padding: 40px 38px 30px;
    background: rgba(255, 255, 255, 0.92);
    border-radius: var(--radius);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

/* 四个系统图标横排 */
.login-icons {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 22px;
}
.login-icon {
    width: 58px;
    height: 58px;
    border-radius: 14px;
    overflow: hidden;
    background: #fff;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.12);
    border: 2px solid #eef2f7;
    display: flex;
    align-items: center;
    justify-content: center;
}
.login-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.login-title {
    text-align: center;
    font-size: 28px;
    font-weight: 800;
    color: #1e293b;
    letter-spacing: 0.5px;
    margin-bottom: 6px;
}
.login-title-sub {
    text-align: center;
    font-size: 14px;
    font-weight: 600;
    color: #475569;
    line-height: 1.5;
    margin-bottom: 28px;
}

.alert-error {
    background: #fef2f2;
    color: #dc2626;
    border: 1px solid #fecaca;
    border-radius: var(--radius-sm);
    padding: 10px 14px;
    margin-bottom: 16px;
    font-size: 14px;
    text-align: center;
}

.form-group { margin-bottom: 16px; }
.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: #334155;
    margin-bottom: 6px;
}
.form-control {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid #cbd5e1;
    border-radius: var(--radius-sm);
    font-size: 15px;
    color: #1e293b;
    background: #fff;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
    font-family: inherit;
}
.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.login-btn {
    width: 100%;
    padding: 13px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: background 0.2s;
    font-family: inherit;
    letter-spacing: 4px;
    margin-top: 4px;
}
.login-btn:hover { background: var(--primary-hover); }

.login-hint {
    text-align: center;
    margin-top: 20px;
    font-size: 13px;
    color: #64748b;
}