:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --background: linear-gradient(45deg, #0f172a, #1e293b);
    --glass: rgba(255, 255, 255, 0.05);
    --text: #ffffff;
    --text-muted: #94a3b8;
    --error: #ef4444;
}

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

body {
    font-family: 'Inter', sans-serif;
    min-height: 100vh;
    background: var(--background);
    color: var(--text);
    padding: 2rem;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.37);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.header h1 {
    font-size: 2.8rem;
    margin: 1rem 0 0.5rem;
    background: linear-gradient(to right, var(--primary), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.05em;
}

.tagline {
    color: var(--text-muted);
    font-size: 1rem;
    font-weight: 500;
}

.input-card {
    background: var(--glass);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 2rem;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.1);
}

.input-group {
    display: grid;
    gap: 1.5rem;
    grid-template-columns: repeat(4, 1fr) auto;
    align-items: end;
}

.input-field {
    position: relative;
    min-width: 160px;
}

.input-field input {
    width: 100%;
    padding: 1.1rem 1rem;
    background: rgba(255, 255, 255, 0.07);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 10px;
    color: var(--text);
    font-size: 1rem;
    transition: all 0.3s ease;
}

.input-field input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.input-field label {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    pointer-events: none;
    transition: all 0.3s ease;
    background: rgba(15, 23, 42, 0.8);
    padding: 0 0.3rem;
}

.input-field input:focus ~ label,
.input-field input:not(:placeholder-shown) ~ label {
    top: 0;
    font-size: 0.85rem;
    color: var(--primary);
}

.input-field i {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1.2rem;
}

.input-note {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 1rem;
    text-align: center;
    opacity: 0.8;
}

.calculate-btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 0 2rem;
    border-radius: 10px;
    height: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: all 0.3s ease;
    font-weight: 500;
    white-space: nowrap;
}

.calculate-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

.results {
    margin-top: 2rem;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

.result-card {
    background: var(--glass);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(8px);
}

.result-card h3 {
    font-size: 0.95rem;
    color: var(--primary);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
}

.result-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin: 0.5rem 0;
    line-height: 1.5;
}

.result-card strong {
    color: var(--text);
    font-weight: 500;
}

.error-message {
    color: var(--error);
    padding: 1rem;
    border-radius: 8px;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-top: 1.5rem;
}

.footer {
    text-align: center;
    margin-top: 3rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
}

.footer a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer a:hover {
    color: var(--primary);
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 1200px) {
    .input-group {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .calculate-btn {
        grid-column: span 2;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1.5rem;
    }
    
    .input-group {
        grid-template-columns: 1fr;
    }
    
    .calculate-btn {
        grid-column: auto;
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    body {
        padding: 1rem;
    }
    
    .input-card {
        padding: 1.5rem;
    }
    
    .input-field input {
        padding: 1rem;
    }
}