:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --card-border: #334155;
    --primary-color: #00e676;
    --primary-hover: #00c853;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --input-bg: #0f172a;
    --input-border: #475569;
    --error-color: #ff5252;
    --font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 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);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.calculator-card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 1.5rem;
    padding: 2rem;
    width: 100%;
    max-width: 440px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.5);
}

.brand-header {
    text-align: center;
    margin-bottom: 2rem;
}

.brand-title {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.brand-subtitle {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 1rem;
    position: relative;
}

.label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.input-container {
    display: flex;
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: 0.75rem;
    overflow: hidden;
    transition: border-color 0.2s ease;
}

.input-container:focus-within {
    border-color: var(--primary-color);
}

.amount-input {
    flex: 1;
    background: transparent;
    border: none;
    padding: 0.875rem 1rem;
    color: var(--text-primary);
    font-size: 1.25rem;
    font-weight: 600;
    outline: none;
    width: 100%;
}

.currency-select {
    background: transparent;
    border: none;
    border-left: 1px solid var(--input-border);
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    padding: 0 1rem;
    outline: none;
    cursor: pointer;
}

.currency-select option {
    background-color: var(--card-bg);
    color: var(--text-primary);
}

.swap-container {
    display: flex;
    justify-content: center;
    margin: 0.5rem 0;
}

.btn-swap {
    background-color: var(--card-bg);
    border: 1px solid var(--input-border);
    color: var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-swap:hover:not(:disabled) {
    border-color: var(--primary-color);
    transform: rotate(180deg);
}

.btn-swap:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    color: var(--text-secondary);
}

.rate-badge {
    background-color: rgba(0, 230, 118, 0.1);
    border: 1px solid rgba(0, 230, 118, 0.2);
    border-radius: 0.5rem;
    padding: 0.75rem;
    text-align: center;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.state-message {
    font-size: 0.875rem;
    text-align: center;
    padding: 0.5rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;

}

.state-message.error {
    background-color: rgba(255, 82, 82, 0.1);
    color: var(--error-color);
    border: 1px solid rgba(255, 82, 82, 0.2);
}

.state-message.warning {
    background-color: rgba(255, 193, 7, 0.1);
    color: #ffc107;
    border: 1px solid rgba(255, 193, 7, 0.2);
}

.footer-credits {
    margin-top: 2rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
}

@media (prefers-reduced-motion: reduce) {
    .btn-swap {
        transition: none;
    }
    .btn-swap:hover:not(:disabled) {
        transform: none;
    }
}