* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
    padding: 40px;
    overflow: hidden;
    position: relative;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

h1 {
    color: #333;
    margin-bottom: 15px;
    text-align: center;
    font-weight: 600;
    font-size: 2.2rem;
    background: linear-gradient(90deg, #667eea, #764ba2);
    background-clip: text;
    -webkit-background-clip: text;
    color: transparent;
    position: relative;
    display: inline-block;
}

h1::after {
    content: '';
    position: absolute;
    width: 50px;
    height: 3px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 3px;
}

p {
    color: #666;
    margin-bottom: 30px;
    text-align: center;
    font-size: 1.1rem;
    line-height: 1.5;
}

.calculator {
    display: flex;
    flex-direction: column;
    gap: 30px;
    margin-bottom: 30px;
    background-color: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.5rem;
    font-weight: 600;
    position: relative;
    padding-bottom: 10px;
}

h2:after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 50px;
    height: 3px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 3px;
}

h3 {
    color: #444;
    margin-bottom: 15px;
    font-size: 1.2rem;
    font-weight: 500;
}

.date-input {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 25px;
}

.date-input label {
    min-width: 80px;
    font-weight: 500;
    color: #555;
    display: flex;
    align-items: center;
    gap: 5px;
}

.date-input input[type="date"] {
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 8px;
    flex: 1;
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
    background-color: #f9f9f9;
}

.date-input input[type="date"]:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
    outline: none;
}

button {
    padding: 12px 18px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    font-size: 1rem;
    box-shadow: 0 4px 6px rgba(102, 126, 234, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 10px rgba(102, 126, 234, 0.3);
}

button:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(102, 126, 234, 0.3);
}

#today-btn {
    background: transparent;
    color: #667eea;
    border: 1px solid #667eea;
    box-shadow: none;
    white-space: nowrap;
}

#today-btn:hover {
    background-color: rgba(102, 126, 234, 0.1);
}

.radio-group {
    display: flex;
    gap: 20px;
    margin-bottom: 25px;
    background-color: #f9f9f9;
    padding: 15px;
    border-radius: 8px;
}

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

.radio-group label {
    position: relative;
    padding-left: 30px;
    cursor: pointer;
    font-weight: 500;
    color: #555;
    user-select: none;
    display: flex;
    align-items: center;
    gap: 5px;
}

.radio-group label:before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    border: 2px solid #667eea;
    border-radius: 50%;
}

.radio-group input[type="radio"]:checked + label:after {
    content: '';
    position: absolute;
    left: 5px;
    top: 50%;
    transform: translateY(-50%);
    width: 10px;
    height: 10px;
    background: #667eea;
    border-radius: 50%;
}

.time-inputs {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-bottom: 30px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.input-group label {
    color: #555;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 5px;
}

.input-group input {
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s;
    background-color: #f9f9f9;
}

.input-group input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
    outline: none;
}

.input-group input::-webkit-inner-spin-button,
.input-group input::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

#calculate-btn {
    padding: 14px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    font-size: 1.1rem;
    margin-top: 15px;
    width: 100%;
    font-weight: 600;
    letter-spacing: 1px;
}

.results-section {
    background: #f9f9f9;
    padding: 25px;
    border-radius: 10px;
    border: 1px solid #eee;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.result p {
    text-align: left;
    font-size: 1.05rem;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.result p:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.result p span {
    font-weight: 600;
    color: #667eea;
    font-size: 1.1rem;
}

.additional-info {
    margin-top: 40px;
    padding-top: 25px;
    border-top: 1px solid #eee;
}

.additional-info h3 {
    margin-bottom: 20px;
    color: #333;
    text-align: center;
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.additional-info h3:after {
    content: '';
    position: absolute;
    width: 30px;
    height: 2px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 3px;
}

.additional-info ul {
    list-style-type: none;
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
}

.additional-info li {
    background: linear-gradient(90deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
    padding: 12px 18px;
    border-radius: 8px;
    color: #667eea;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    font-weight: 500;
    border: 1px solid rgba(102, 126, 234, 0.2);
    display: flex;
    align-items: center;
    gap: 8px;
}

.additional-info li:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 10px rgba(102, 126, 234, 0.2);
}

.additional-info li i {
    color: #764ba2;
}

.additional-info li a {
    text-decoration: none;
    color: inherit;
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    height: 100%;
}

.additional-info li:hover a {
    color: #764ba2;
}

footer {
    margin-top: 40px;
    text-align: center;
    border-top: 1px solid #eee;
    padding-top: 20px;
}

footer p {
    margin-bottom: 0;
    font-size: 0.9rem;
    color: #888;
}

i {
    color: #667eea;
}

@media (min-width: 768px) {
    .calculator {
        flex-direction: row;
    }
    
    .input-section {
        flex: 3;
        padding: 25px;
    }
    
    .results-section {
        flex: 2;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 30px 20px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    .calculator {
        gap: 25px;
    }
    
    .input-section {
        padding: 20px;
    }
}

@media (max-width: 600px) {
    .time-inputs {
        grid-template-columns: 1fr;
    }
    
    .additional-info ul {
        flex-direction: column;
    }
    
    .date-input {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .date-input label {
        margin-bottom: 5px;
    }
    
    .date-input input[type="date"] {
        width: 100%;
    }
}