:root {
    --bg-color: #0f172a;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --accent: #10b981;
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    background-color: var(--bg-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow-x: hidden;
    position: relative;
}

/* Dynamic animated background */
.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.15), transparent 25%),
                radial-gradient(circle at 85% 30%, rgba(16, 185, 129, 0.15), transparent 25%);
    z-index: -1;
    animation: pulse 10s infinite alternate linear;
}

@keyframes pulse {
    0% { transform: scale(1); opacity: 0.8; }
    100% { transform: scale(1.1); opacity: 1; }
}

.container {
    width: 100%;
    max-width: 1000px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

header {
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #60a5fa, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

@media (max-width: 768px) {
    main {
        grid-template-columns: 1fr;
    }
}

.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

.input-group {
    margin-bottom: 1.25rem;
    display: flex;
    flex-direction: column;
}

.input-group label {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.input-group input {
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    color: var(--text-main);
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    transition: all 0.3s ease;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

hr {
    border: 0;
    height: 1px;
    background: var(--glass-border);
    margin: 1.5rem 0;
}

.summary h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-main);
}

.result-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    font-size: 1rem;
    color: var(--text-muted);
}

.result-item span:last-child {
    color: var(--text-main);
    font-weight: 500;
}

.highlight-cost span {
    color: var(--text-main);
    font-weight: 600;
}

.result-total {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--glass-border);
}

.result-total span:first-child {
    font-size: 1.25rem;
    font-weight: 600;
}

.result-total span:last-child {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
}

button {
    width: 100%;
    margin-top: 2rem;
    padding: 1rem;
    border: none;
    border-radius: 8px;
    background: var(--primary);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.3s ease;
}

button:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

button:active {
    transform: translateY(0);
}