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

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo i {
    font-size: 2.5rem;
    color: #4fc3f7;
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 300;
}

.calculator {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
}

.calculator-form {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 500px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #333;
    font-size: 0.95rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 15px;
    border: 2px solid #e1e5e9;
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: #f8f9fa;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #4fc3f7;
    background: white;
    box-shadow: 0 0 0 3px rgba(79, 195, 247, 0.1);
}

.calculate-btn {
    width: 100%;
    padding: 18px;
    background: linear-gradient(135deg, #4fc3f7 0%, #29b6f6 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 10px;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(79, 195, 247, 0.3);
}

.calculate-btn:active {
    transform: translateY(0);
}

.results {
    width: 100%;
    max-width: 600px;
    transition: all 0.5s ease;
}

.results.hidden {
    display: none;
}

.result-card {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    text-align: center;
    border: 1px solid rgba(255,255,255,0.2);
}

.result-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
}

.result-header i {
    font-size: 2rem;
    color: #4fc3f7;
}

.result-header h2 {
    font-size: 1.8rem;
    color: #333;
    font-weight: 600;
}

.water-amount {
    margin-bottom: 30px;
    padding: 30px;
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
    border-radius: 15px;
    border: 2px solid #4fc3f7;
}

.amount {
    font-size: 3.5rem;
    font-weight: 700;
    color: #1976d2;
    display: block;
}

.unit {
    font-size: 1.5rem;
    color: #1976d2;
    font-weight: 500;
}

.water-cups {
    margin-bottom: 30px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 12px;
}

.water-cups p {
    margin-bottom: 10px;
    color: #666;
    font-weight: 500;
}

.cups-info {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.cups {
    font-size: 2rem;
    font-weight: 700;
    color: #4fc3f7;
}

.cups-text {
    font-size: 1.1rem;
    color: #666;
    font-weight: 500;
}

.recommendations,
.tips {
    text-align: left;
    margin-bottom: 25px;
}

.recommendations h3,
.tips h3 {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    color: #333;
    font-size: 1.2rem;
    font-weight: 600;
}

.recommendations h3 i,
.tips h3 i {
    color: #4fc3f7;
}

.recommendations ul,
.tips ul {
    list-style: none;
    padding-left: 0;
}

.recommendations li,
.tips li {
    padding: 8px 0;
    border-bottom: 1px solid #f0f0f0;
    color: #555;
    position: relative;
    padding-left: 25px;
}

.recommendations li:before,
.tips li:before {
    content: "💧";
    position: absolute;
    left: 0;
    top: 8px;
}

.recommendations li:last-child,
.tips li:last-child {
    border-bottom: none;
}

.recalculate-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #ff9800 0%, #f57c00 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 20px;
}

.recalculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(255, 152, 0, 0.3);
}

.footer {
    text-align: center;
    margin-top: 40px;
    color: white;
    opacity: 0.8;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .calculator-form {
        padding: 30px 20px;
    }
    
    .result-card {
        padding: 30px 20px;
    }
    
    .amount {
        font-size: 2.5rem;
    }
    
    .unit {
        font-size: 1.2rem;
    }
    
    .cups {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .logo {
        flex-direction: column;
        gap: 10px;
    }
    
    .logo h1 {
        font-size: 1.8rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .calculator-form {
        padding: 25px 15px;
    }
    
    .result-card {
        padding: 25px 15px;
    }
    
    .amount {
        font-size: 2rem;
    }
    
    .result-header h2 {
        font-size: 1.5rem;
    }
}

/* Animation for results */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results:not(.hidden) {
    animation: fadeInUp 0.6s ease-out;
}

/* Loading animation */
.calculate-btn.loading {
    pointer-events: none;
    opacity: 0.7;
}

.calculate-btn.loading i {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}