body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: #f0f2f5;
}

/* HEADER */
.header {
    background: #1877f2;
    color: #fff;
    padding: 14px;
    text-align: center;
    font-weight: bold;
    font-size: 18px;
}

/* CONTAINER */
.container {
    max-width: 400px;
    margin: 40px auto;
    padding: 20px;
}

/* CARD */
.card {
    background: #fff;
    border-radius: 14px;
    padding: 25px;
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    text-align: center;
}

/* ICON */
.icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 15px;
    border-radius: 50%;
    background: #e7f3ff;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon img {
    width: 30px;
}

/* TEXT */
h1 {
    font-size: 20px;
    margin-bottom: 5px;
}

.sub {
    font-size: 14px;
    color: #666;
    margin-bottom: 20px;
}

.notice {
    font-size: 14px;
    color: #333;
    background: #f7f8fa;
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 20px;
}

/* BUTTON */
.btn {
    width: 100%;
    padding: 14px;
    border-radius: 10px;
    border: none;
    font-size: 15px;
    font-weight: bold;
    cursor: pointer;
    margin-bottom: 10px;
}

.btn.primary {
    background: #1877f2;
    color: white;
}

.btn.primary:hover {
    background: #166fe5;
}

.btn.secondary {
    background: #e4e6eb;
}

/* LOADING */
.loading {
    display: none;
    margin-top: 15px;
    font-size: 14px;
    color: #555;
}

.spinner {
    border: 3px solid #eee;
    border-top: 3px solid #1877f2;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    margin: 10px auto;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    100% { transform: rotate(360deg); }
}

/* FOOTER */
.footer {
    text-align: center;
    font-size: 12px;
    color: #888;
    margin-top: 20px;
}