:root {
    --primary-color: #003366;
    --secondary-color: #005b9f;
    --bg-color: #f4f7f9;
    --text-color: #333333;
    --border-color: #cccccc;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
}

.app-header {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.header-container {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.security-badge {
    background-color: #28a745;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: bold;
}

.lang-btn {
    background-color: #ffffff;
    color: var(--primary-color);
    border: none;
    padding: 6px 14px;
    border-radius: 20px;
    font-weight: bold;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all 0.2s;
}

.lang-btn:hover {
    background-color: #e2e8f0;
}

.app-container {
    max-width: 800px;
    margin: 30px auto;
    background: white;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    overflow: hidden;
}

.tabs {
    display: flex;
    background-color: #e9ecef;
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    flex: 1;
    padding: 15px;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    color: #666;
    transition: all 0.2s;
}

.tab-btn.active {
    background-color: white;
    color: var(--primary-color);
    border-bottom: 3px solid var(--primary-color);
}

.tab-content {
    display: none;
    padding: 30px;
}

.tab-content.active {
    display: block;
}

.input-section label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    font-size: 1.1rem;
}

.input-box {
    display: flex;
    gap: 10px;
}

.input-box input[type="number"] {
    flex: 1;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1.2rem;
}

.output-group {
    margin-top: 25px;
}

.output-group h3 {
    margin-bottom: 8px;
    font-size: 1.1rem;
}

.result-box {
    display: flex;
    gap: 10px;
}

.result-box input {
    flex: 1;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1.1rem;
    background-color: #f8f9fa;
    color: #111;
    font-weight: 500;
}

.copy-btn, .primary-btn {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 0 20px;
    border-radius: 4px;
    cursor: pointer;
    font-weight: bold;
    font-size: 1rem;
    transition: background 0.2s;
}

.copy-btn:hover, .primary-btn:hover {
    background-color: var(--primary-color);
}

.privacy-note {
    margin-top: 30px;
    font-size: 0.85rem;
    color: #777;
    text-align: center;
}

.bank-list {
    margin-top: 20px;
    line-height: 1.6;
}