body {
    margin: 0;
    padding: 0;
    min-height: 100vh;
    background: linear-gradient(135deg, #ffdde1 0%, #ee9ca7 100%);
    font-family: 'Segoe UI', 'Arial', sans-serif;
    position: relative;
    overflow: hidden;

    display: flex;                /* <-- Activa Flexbox */
    align-items: center;          /* <-- Centra verticalmente */
    justify-content: center;      /* <-- Centra horizontalmente */
}

form {
    background: rgba(255,255,255,0.90);
    padding: 32px 38px 30px 38px;
    border-radius: 20px;
    box-shadow: 0 2px 30px 7px #eea6b7bb;
    width: 350px;
    max-width: 90vw;
    margin: 0;                    /* <-- Importante: SIN margin-top */
    position: relative;
    z-index: 1;
}
form h2 {
    text-align: center;
    color: #d387ab;
    margin-bottom: 18px;
    font-family: 'Brush Script MT', cursive;
    font-size: 2em;
    letter-spacing: 3px;
    text-shadow: 0 1px 7px #eea47f44;
}
input[type="text"], input[type="password"] {
    width: 96%;
    padding: 10px;
    margin-bottom: 16px;
    border: 1px solid #dca1d7;
    border-radius: 8px;
    background: #ffeeed;
    font-size: 1em;
    transition: border 0.2s;
}
input[type="text"]:focus, input[type="password"]:focus {
    border: 1.5px solid #eea1b4;
    outline: none;
}
input[type="submit"] {
    background: linear-gradient(90deg, #eab6ca 50%, #f9dedf 100%);
    color: #a9517b;
    border: none;
    border-radius: 8px;
    padding: 12px 26px;
    font-size: 1.12em;
    font-family: 'Segoe UI', 'Arial', sans-serif;
    letter-spacing: 1px;
    cursor: pointer;
    box-shadow: 0 1px 11px 0px #efc4d6a8;
    transition: background 0.2s;
    margin-top: 5px;
}
input[type="submit"]:hover {
    background: linear-gradient(90deg, #f9dedf 0%, #eab6ca 100%);
    color: #ad5582;
}
p {
    text-align: center;
    color: #cf2655;
    font-weight: 500;
    margin-top: 8px;
}

/* Petalos animados */
.sakura-petal {
    position: fixed;
    top: -40px;
    width: 36px;
    height: 36px;
    pointer-events: none;
    z-index: 0;
    opacity: 0.85;
    animation: sakura-fall linear infinite;
}

@keyframes sakura-fall {
    0% { transform: translateY(0) rotate(0deg); opacity: 0.95; }
    90% { opacity: 0.9; }
    100% { transform: translateY(100vh) rotate(360deg); opacity: 0.3; }
}