:root {
    --bg-color: #111111;
    --card-bg: #222222;
    --text-color: #e0e0e0;
    --accent-color: #00EA5E;
    --accent-hover: #00c951;
    --border-radius: 8px;
    --input-bg: #1a1a1a;
    --input-border: #333333;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Inter', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.calculator-container {
    background-color: var(--card-bg);
    padding: 25px;
    border-radius: var(--border-radius);
    width: 100%;
    max-width: 450px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.7);
    border: 1px solid #333;
}

h1 {
    font-size: 22px;
    margin: 0;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.header-action {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.lang-switch {
    display: flex;
    background-color: var(--input-bg);
    border-radius: 4px;
    overflow: hidden;
    border: 1px solid var(--input-border);
}

.lang-btn {
    padding: 6px 12px;
    font-size: 12px;
    font-weight: 600;
    color: #888;
    background: transparent;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.lang-btn.active {
    background-color: var(--card-bg);
    color: var(--accent-color);
}

.form-group {
    margin-bottom: 15px;
    transition: all 0.3s ease;
}

label {
    display: block;
    margin-bottom: 6px;
    font-size: 13px;
    font-weight: 500;
    color: #b0b0b0;
}

input[type="number"],
select {
    width: 100%;
    height: 44px;
    padding: 10px 14px;
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    color: var(--text-color);
    border-radius: var(--border-radius);
    font-size: 15px;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
    outline: none;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: textfield;
}

input[type="number"]:focus,
select:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(0, 234, 94, 0.2);
}

/* Chrome, Safari, Edge, Opera - hide arrows */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.checkbox-group {
    height: 44px;
    margin-top: 15px;
    margin-bottom: 20px;
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: var(--border-radius);
    transition: background-color 0.2s, border-color 0.2s;
}

.checkbox-group.no-margin {
    margin-top: 0;
    margin-bottom: 0;
}

.checkbox-group:hover {
    background-color: #1e1e1e;
    border-color: #444;
}

.checkbox-label {
    display: flex;
    align-items: center;
    padding: 0 14px;
    height: 100%;
    cursor: pointer;
    margin: 0;
}

.checkbox-label input {
    display: none;
}

.custom-checkbox {
    width: 20px;
    height: 20px;
    border: 2px solid var(--input-border);
    border-radius: 4px;
    margin-right: 12px;
    flex-shrink: 0;
    position: relative;
    transition: border-color 0.2s, background-color 0.2s;
}

.checkbox-label input:checked+.custom-checkbox {
    background-color: var(--accent-color);
    border-color: var(--accent-color);
}

.checkbox-label input:checked+.custom-checkbox::after {
    content: '';
    position: absolute;
    left: 6px;
    top: 2px;
    width: 5px;
    height: 10px;
    border: solid var(--bg-color);
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.checkbox-text {
    font-size: 14px;
    user-select: none;
}

.result-container {
    padding-top: 15px;
    border-top: 1px solid var(--input-border);
    text-align: center;
}

.result-label {
    font-size: 14px;
    color: #b0b0b0;
    margin-bottom: 5px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.result-value {
    font-size: 38px;
    font-weight: 700;
    color: var(--accent-color);
    text-shadow: 0 0 15px rgba(0, 234, 94, 0.3);
    position: relative;
    display: flex;
    justify-content: center;
    align-items: baseline;
    gap: 8px;
}

.exact-price-display {
    font-size: 14px;
    font-weight: 400;
    color: #666;
    text-shadow: none;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#custom-price-group {
    animation: fadeIn 0.3s ease forwards;
}

/* Add inside style.css at EOF */
.tabs {
    display: flex;
    margin-bottom: 15px;
    background-color: var(--input-bg);
    border-radius: var(--border-radius);
    padding: 4px;
}

.tab-btn {
    flex: 1;
    padding: 10px;
    border: none;
    background: transparent;
    color: #888;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.2s;
}

.tab-btn.active {
    background-color: var(--card-bg);
    color: var(--accent-color);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.time-inputs {
    display: flex;
    align-items: center;
    gap: 10px;
}

.time-separator {
    font-weight: bold;
    font-size: 20px;
    color: #666;
}

.time-inputs input {
    text-align: center;
}

.quantity-group {
    border-top: 1px dashed #444;
    padding-top: 15px;
    margin-top: 5px;
}

/* Responsive Desktop Layout */
@media (min-width: 600px) {
    .calculator-container {
        max-width: 550px;
    }

    #pro-mode-container {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 0 20px;
    }

    #material-group,
    #custom-price-group {
        grid-column: 1 / -1;
    }
}

/* Visibility classes to prevent JS inline style override bugs */
.mode-hidden {
    display: none !important;
}