* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --tg-theme-bg-color: #ffffff;
    --tg-theme-text-color: #000000;
    --tg-theme-hint-color: #999999;
    --tg-theme-secondary-bg-color: #f4f4f5;
    --primary-color: #ff8c00;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, sans-serif;
    background-color: var(--tg-theme-bg-color);
    color: var(--tg-theme-text-color);
    overflow-x: hidden;
    user-select: none;
}

.screen {
    display: none;
    min-height: 100vh;
    padding: 16px;
}

.screen.active {
    display: block;
}

.header {
    text-align: center;
    margin-bottom: 24px;
    padding-top: 20px;
    position: relative;
}

.header h1, .header h2 {
    font-size: 24px;
    font-weight: 600;
}

.back-btn {
    position: absolute;
    left: 0;
    top: 20px;
    background: none;
    border: none;
    color: var(--primary-color);
    font-size: 16px;
    cursor: pointer;
    padding: 8px;
}

.cards-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 32px;
}

.card {
    background: var(--tg-theme-secondary-bg-color);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.card:active {
    transform: scale(0.98);
    opacity: 0.9;
}

.card-icon {
    font-size: 32px;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--tg-theme-bg-color);
    border-radius: 12px;
}

.card-title {
    font-size: 16px;
    font-weight: 500;
    flex: 1;
}

.footer {
    text-align: center;
    padding: 20px 0;
    color: var(--tg-theme-hint-color);
    font-size: 14px;
}

.form-container {
    max-width: 500px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--tg-theme-text-color);
}

.form-group input[type="number"] {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    background: var(--tg-theme-bg-color);
    color: var(--tg-theme-text-color);
}

.form-group input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    margin: 0;
}

.checkbox-group input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.calc-btn {
    width: 100%;
    padding: 14px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    margin-bottom: 20px;
    transition: opacity 0.2s;
}

.calc-btn:active {
    opacity: 0.8;
}

.result {
    background: var(--tg-theme-secondary-bg-color);
    border-radius: 12px;
    padding: 20px;
    margin-top: 20px;
    min-height: 100px;
}

.result h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--primary-color);
}

.result p {
    margin-bottom: 8px;
    font-size: 16px;
    line-height: 1.5;
}

.result strong {
    font-weight: 600;
}

.result small {
    color: var(--tg-theme-hint-color);
    font-size: 14px;
}

.result .warning {
    color: #ff6b00;
    font-weight: 500;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid #ddd;
}

#loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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