body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f5f6f8;
    color: #1a1a2e;
    line-height: 1.5;
}

h1 {
    text-align: center;
    margin-top: 1.25rem;
    margin-bottom: 0.25rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: #1a1a2e;
}

#actions {
    display: grid;
    grid-template-columns: repeat(4, auto);
    justify-content: center;
    gap: 12px 16px;
    margin-top: 10px;
    padding: 0 10px;
}

#actions .btn-group:last-of-type {
    grid-column: 1 / -1;
    justify-self: center;
}

.btn-group {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.btn-desc {
    font-size: 0.7rem;
    color: #6b7280;
    margin-top: 4px;
}

#friend-code-form {
    max-width: 600px;
    margin: 20px auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    padding: 0 10px;
}

#friend-code-form input {
    padding: 10px;
    text-align: center;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    background-color: #ffffff;
    color: #1a1a2e;
    font-size: 0.95rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

#friend-code-form input:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

#friend-code-form input::placeholder {
    color: #9ca3af;
    opacity: 1;
}

.qr-display {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px 20px;
    justify-items: center;
    padding: 20px;
}

.qr-display>div {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: #ffffff;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.4s ease, transform 0.4s ease, box-shadow 0.2s ease;
}

.qr-display>div:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.qr-display>div.visible {
    opacity: 1;
    transform: translateY(0);
}

pre {
    background-color: #f0f1f3;
    color: #1a1a2e;
    padding: 10px;
    margin-bottom: 12px;
    word-wrap: break-word;
    width: 180px;
    text-align: center;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: 8px;
    border: 1px solid #e5e7eb;
}

.download-button,
#manual-refresh,
#export-codes,
#upload-codes,
#import-codes,
#clear-codes {
    margin-top: 8px;
    background-color: #1a1a2e;
    color: #ffffff;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.2s ease, transform 0.1s ease, box-shadow 0.2s ease;
}

.download-button:hover,
#manual-refresh:hover,
#export-codes:hover,
#upload-codes:hover {
    background-color: #2d2d4a;
}

.download-button:active,
#manual-refresh:active,
#export-codes:active,
#upload-codes:active {
    transform: scale(0.97);
}

#import-codes.btn-primary {
    background-color: #2563eb;
    font-weight: 600;
}

#import-codes.btn-primary:hover {
    background-color: #1d4ed8;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

#import-codes.btn-primary:active {
    transform: scale(0.97);
    background-color: #1e40af;
}

#clear-codes.btn-danger {
    background-color: transparent;
    color: #dc2626;
    border: 1px solid #dc2626;
}

#clear-codes.btn-danger:hover {
    background-color: #dc2626;
    color: #ffffff;
}

#clear-codes.btn-danger:active {
    transform: scale(0.97);
    background-color: #b91c1c;
}

#toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: #1a1a2e;
    color: #ffffff;
    padding: 10px 20px;
    border-radius: 8px;
    opacity: 0;
    transition: opacity 0.5s ease;
    z-index: 999;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    font-size: 0.9rem;
}

#toast.show {
    opacity: 1;
}

#scanner-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

#scanner-title {
    font-weight: bold;
    font-size: 1.1rem;
}

#scanner-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #1a1a2e;
    padding: 0 4px;
    transition: color 0.2s ease;
}

#scanner-close:hover {
    color: #dc2626;
}

#scanner-viewfinder {
    width: 100%;
    min-height: 250px;
    border-radius: 8px;
    overflow: hidden;
}

#scanner-status {
    text-align: center;
    margin-top: 10px;
    font-size: 0.9rem;
    color: #6b7280;
}

#scanner-upload-section {
    text-align: center;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid #ddd;
}

#scanner-upload-section p {
    margin: 0 0 8px;
    font-size: 0.85rem;
    color: #6b7280;
}

#scanner-upload-btn {
    background-color: #1a1a2e;
    color: #ffffff;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.2s ease;
}

#scanner-upload-btn:hover {
    background-color: #2d2d4a;
}

#empty-state {
    text-align: center;
    padding: 30px 20px;
    color: #6b7280;
}

#empty-state ul {
    list-style: none;
    padding: 0;
}

#empty-state li {
    margin: 8px 0;
}

#how-it-works {
    max-width: 600px;
    margin: 40px auto 20px;
    padding: 20px 24px;
    color: #6b7280;
    font-size: 0.9rem;
    background: #ffffff;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

#how-it-works h2 {
    font-size: 1.1rem;
    color: #1a1a2e;
    margin-top: 0;
    margin-bottom: 12px;
}

#how-it-works ol {
    padding-left: 20px;
    margin-bottom: 0;
}

#how-it-works li {
    margin-bottom: 6px;
}

@media (max-width: 768px) {

    #actions {
        grid-template-columns: repeat(2, auto);
    }

    #friend-code-form,
    .qr-display {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {

    #actions {
        grid-template-columns: repeat(2, 1fr);
    }

    #actions .btn-group {
        width: 100%;
    }

    #actions button {
        width: 100%;
    }

    #friend-code-form,
    .qr-display {
        grid-template-columns: 1fr;
    }

    pre {
        width: 90%;
    }
}

#scanner-dialog {
    border: none;
    border-radius: 16px;
    padding: 24px;
    width: 90%;
    max-width: 400px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
    background: #ffffff;
}

#scanner-dialog::backdrop {
    background: rgba(26, 26, 46, 0.7);
}

#scanner-nav {
    display: flex;
    align-items: center;
    gap: 12px;
}

#scanner-prev, #scanner-next {
    background: none;
    border: 1px solid #d1d5db;
    border-radius: 4px;
    padding: 2px 8px;
    cursor: pointer;
    font-size: 1rem;
    color: #1a1a2e;
    transition: background-color 0.2s;
}

#scanner-prev:hover, #scanner-next:hover {
    background-color: #e5e7eb;
}