:root {
    --bg-color: #0d0d0d;
    --card-bg: #1a1a1a;
    --card-hover: #222222;
    --text-primary: #f2f2f2;
    --text-secondary: #a0a0a0;
    --accent-gold: #d4af37;
    --accent-gold-hover: #e5c156;
    --accent-gold-dim: rgba(212, 175, 55, 0.1);
    --border-color: #333;
    --danger: #ff4d4d;
    --shadow-soft: 0 8px 30px rgba(0, 0, 0, 0.5);
    --shadow-hover: 0 12px 40px rgba(212, 175, 55, 0.15);
    --radius-lg: 16px;
    --radius-md: 8px;
    --radius-sm: 4px;
    --transition-speed: 0.3s;
    --font-family: 'Outfit', sans-serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-family);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.app-container {
    width: 100%;
    max-width: 480px;
    /* Mobile-first limit */
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Header */
.app-header {
    text-align: center;
    margin-bottom: 10px;
}

.app-header h1 {
    font-weight: 600;
    font-size: 2rem;
    background: linear-gradient(45deg, var(--text-primary), var(--accent-gold));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 4px;
}

.app-header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 300;
}

/* Card Styles */
.card {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-soft);
    border: 1px solid var(--border-color);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
    border-color: var(--accent-gold-dim);
}

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

.card-header h2 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--accent-gold);
}

/* Button & Icon Styles */
.icon-btn {
    background: var(--accent-gold-dim);
    border: 1px solid var(--accent-gold);
    color: var(--accent-gold);
    padding: 6px 12px;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    transition: all var(--transition-speed);
}

.icon-btn:hover {
    background: var(--accent-gold);
    color: var(--bg-color);
}

/* Weight Table Grid */
.weight-table-header {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr 32px;
    gap: 8px;
    margin-bottom: 12px;
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding-right: 12px;
    /* Scrollbar offset if needed */
}

.weight-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr 32px;
    gap: 8px;
    margin-bottom: 12px;
    animation: fadeIn 0.3s ease-out;
}

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

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

.weight-input {
    width: 100%;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 8px 4px;
    text-align: center;
    border-radius: var(--radius-md);
    font-family: var(--font-family);
    transition: border-color var(--transition-speed);
}

.weight-input:focus {
    outline: none;
    border-color: var(--accent-gold);
}

/* No spinners on number input */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type=number] {
    appearance: textfield;
    -moz-appearance: textfield;
}

.remove-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.2s;
}

.remove-btn:hover {
    color: var(--danger);
}

/* Total Display */
.total-weight-display {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.total-weight-display .label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.total-weight-display .result-value {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.decimal-weight {
    font-size: 0.9rem;
    color: var(--accent-gold);
    font-family: monospace;
    opacity: 0.9;
}

/* Price Section */
.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.price-input-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.price-input-header label {
    margin-bottom: 0;
}

.unit-toggle {
    display: flex;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 2px;
}

.unit-toggle input[type="radio"] {
    display: none;
}

.unit-toggle label {
    padding: 4px 12px;
    font-size: 0.8rem;
    cursor: pointer;
    border-radius: 2px;
    transition: all 0.2s;
    color: var(--text-secondary);
}

.unit-toggle input[type="radio"]:checked+label {
    background: var(--accent-gold);
    color: var(--bg-color);
    font-weight: 600;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper .currency-symbol {
    position: absolute;
    left: 12px;
    color: var(--accent-gold);
    font-weight: 600;
}

.input-wrapper input {
    width: 100%;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    padding: 12px 12px 12px 32px;
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: var(--font-family);
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--accent-gold);
}


/* Karat Selector */
.karat-selector label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.karat-options {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}

.karat-btn {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 8px 4px;
    /* Tight on mobile */
    font-size: 0.8rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s;
}

.karat-btn:hover {
    border-color: var(--accent-gold);
}

.karat-btn.active {
    background: var(--accent-gold);
    color: var(--bg-color);
    border-color: var(--accent-gold);
    font-weight: 600;
}

.custom-karat-wrapper {
    margin-top: 12px;
    animation: fadeIn 0.3s;
}

.custom-karat-wrapper.hidden {
    display: none;
}

.custom-karat-wrapper input {
    width: 100%;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    padding: 10px;
    border-radius: var(--radius-md);
    color: var(--text-primary);
}

/* Result Card */
.result-card {
    background: linear-gradient(135deg, #1a1a1a 0%, #252525 100%);
    border: 1px solid var(--accent-gold-dim);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.result-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(212, 175, 55, 0.05) 0%, transparent 70%);
    pointer-events: none;
}

.result-label {
    display: block;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent-gold);
    margin-bottom: 8px;
}

.final-price-wrapper {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

.breakdown-text {
    font-size: 0.8rem;
    color: var(--text-secondary);
    opacity: 0.7;
}

/* Ad Placeholder */
.ad-placeholder {
    margin-top: 24px;
    height: 60px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px dashed var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 0.75rem;
    border-radius: var(--radius-md);
}

/* Footer */
footer {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.8rem;
    opacity: 0.5;
}

/* Responsive Tweaks */
@media (max-width: 360px) {
    .karat-options {
        grid-template-columns: repeat(3, 1fr);
    }
}