/* ===== Mobile-first Form Style ===== */
.input,
.btn-login {
    width: 100%;
    box-sizing: border-box;
    font-family: 'Segoe UI', Arial;
}

/* ===== TextBox Style ===== */
.input {
    height: 52px;
    padding: 0 16px;
    margin-bottom: 14px;
    border-radius: 12px;
    border: 1px solid #D1D5DB;
    background: #FFFFFF;
    font-size: 16px;
    color: #111827;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

    .input::placeholder {
        color: #9CA3AF;
    }

    /* Focus 状态（很重要，像 App） */
    .input:focus {
        border-color: #2F80ED;
        box-shadow: 0 0 0 3px rgba(47,128,237,0.15);
    }

/* ===== Error Message ===== */
.error {
    display: block;
    margin: 6px 0 12px;
    color: #DC2626;
    font-size: 14px;
}

/* ===== Login Button Style ===== */
.btn-login {
    height: 54px;
    border: none;
    border-radius: 14px;
    background: linear-gradient(90deg, #2F80ED, #56CCF2);
    color: #FFFFFF;
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 0.3px;
    cursor: pointer;
    box-shadow: 0 10px 24px rgba(47,128,237,0.35);
    transition: transform 0.15s, box-shadow 0.15s, opacity 0.15s;
}

    /* 点击 & Hover */
    .btn-login:hover {
        opacity: 0.95;
    }

    .btn-login:active {
        transform: translateY(1px);
        box-shadow: 0 6px 14px rgba(47,128,237,0.35);
    }

.logo-box {
    text-align: center;
    margin-bottom: 40px;
}

    .logo-box img {
        display: block;
        margin: 0 auto 12px;
        width: 64px;
        height: auto;
    }

    .logo-box h1 {
        margin: 0;
        font-size: 28px;
        color: #1F2937;
    }

    .logo-box p {
        margin-top: 6px;
        font-size: 14px;
        color: #6B7280;
    }
html, body {
    margin: 0;
    padding: 0;
    min-height: 100vh;
    font-family: 'Segoe UI', Arial;
    background-color: #F3F6FB; /* ← 就用这个 */
}