:root {
    --primary-color: #0D47A1; /* Deep Blue */
    --secondary-color: #E3F2FD; /* Lightest Blue */
    --accent-color: #2962FF; /* Vibrant Blue */
    --text-color: #212121; /* Dark Gray */
    --light-gray: #BDBDBD;
    --white: #ffffff;
    --shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
}

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(to bottom, var(--secondary-color), var(--white));
    color: var(--text-color);
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: flex-start; /* Align to top */
    min-height: 100vh;
    padding: 40px 20px;
    box-sizing: border-box;
}

.container {
    width: 100%;
    max-width: 500px;
    text-align: center;
}

header .logo {
    max-width: 180px;
    margin-bottom: 25px;
}

.donation-box {
    background: var(--white);
    padding: 35px;
    border-radius: 20px;
    box-shadow: var(--shadow);
    text-align: left;
}

h2 {
    font-size: 26px;
    font-weight: 700;
    color: var(--primary-color);
    text-align: center;
    margin-top: 0;
    margin-bottom: 10px;
}

p {
    font-size: 15px;
    line-height: 1.6;
    text-align: center;
    margin-bottom: 30px;
    color: #555;
}

hr {
    border: none;
    border-top: 1px solid #eeeeee;
    margin: 30px 0;
}

h3 {
    font-size: 17px;
    font-weight: 600;
    color: var(--primary-color);
    margin-top: 25px;
    margin-bottom: 20px;
}

.amount-selection {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 12px;
    margin-bottom: 20px;
}

.amount-btn {
    background: var(--white);
    border: 1px solid var(--light-gray);
    border-radius: 10px;
    padding: 14px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.amount-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(41, 98, 255, 0.1);
    border-color: var(--accent-color);
}

.amount-btn.selected {
    background: var(--accent-color);
    color: var(--white);
    border-color: var(--accent-color);
}

input[type="number"],
input[type="text"],
input[type="email"] {
    width: 100%;
    padding: 14px;
    border: 1px solid #CFD8DC; /* Bluish Gray */
    border-radius: 10px;
    font-family: 'Poppins', sans-serif;
    font-size: 15px;
    box-sizing: border-box;
    margin-bottom: 15px;
    transition: border-color 0.3s, box-shadow 0.3s;
}

input[type="number"]:focus,
input[type="text"]:focus,
input[type="email"]:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(41, 98, 255, 0.2);
}

input::placeholder {
    color: #90A4AE; /* Bluish Gray */
}

.payment-methods {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    margin-bottom: 30px;
}

.payment-methods span {
    padding: 8px 18px;
    border: 1px solid #CFD8DC;
    border-radius: 25px;
    font-size: 13px;
    font-weight: 600;
    color: #546E7A; /* Slate Gray */
    cursor: pointer;
    transition: all 0.3s ease;
}

.payment-methods span.selected {
    background-color: var(--accent-color);
    color: var(--white);
    border-color: var(--accent-color);
}

.donate-btn {
    background: var(--accent-color);
    color: var(--white);
    border: none;
    width: 100%;
    padding: 16px;
    font-size: 18px;
    font-weight: 700;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    box-shadow: 0 4px 12px rgba(41, 98, 255, 0.2);
}

.donate-btn:hover {
    background: #1E88E5; /* Slightly Lighter Blue */
    transform: translateY(-2px);
}

.download-btn {
    display: block;
    width: 100%;
    text-align: center;
    background: var(--primary-color);
    color: var(--white);
    padding: 12px;
    border-radius: 10px;
    text-decoration: none;
    margin-top: 15px;
    font-weight: 600;
    transition: background-color 0.3s;
}

.download-btn:hover {
    background: #0B3A82; /* Darker Blue */
}


#qris-payment h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--primary-color);
    margin-top: 25px;
    margin-bottom: 15px;
    text-align: center;
}

footer {
    margin-top: 40px;
    font-size: 13px;
    color: #78909C; /* Bluish Gray */
}

.hidden {
    display: none;
}

#thank-you-message h2 {
    color: var(--primary-color);
}

@media (max-width: 480px) {
    body {
        padding: 20px 15px;
    }
    .donation-box {
        padding: 25px;
    }
    .amount-selection {
        grid-template-columns: 1fr;
    }
}