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

body {
    font-family: 'JetBrains Mono', monospace;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: #2d2d44;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    overflow: hidden;
    border: 1px solid #404060;
}

h1 {
    text-align: center;
    padding: 30px;
    background: linear-gradient(135deg, #6c5ce7 0%, #a29bfe 100%);
    color: white;
    margin-bottom: 0;
    font-size: 2.5em;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.tab-container {
    display: flex;
    background: #3c3c56;
    border-bottom: 1px solid #505070;
}

.tab-btn {
    flex: 1;
    padding: 15px 20px;
    border: none;
    background: #3c3c56;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s ease;
    color: #b8bcc8;
    font-family: 'JetBrains Mono', monospace;
}

.tab-btn:hover {
    background: #4a4a68;
    color: #e8eaed;
}

.tab-btn.active {
    background: #2d2d44;
    color: #6c5ce7;
    border-bottom: 3px solid #6c5ce7;
}

.tab-content {
    display: none;
    padding: 30px;
}

.tab-content.active {
    display: block;
}

h2 {
    color: #e8eaed;
    margin-bottom: 30px;
    text-align: center;
    font-size: 2em;
}

h3 {
    color: #c9ccd1;
    margin-bottom: 20px;
    font-size: 1.3em;
    border-bottom: 2px solid #6c5ce7;
    padding-bottom: 10px;
}

.calculator-section {
    margin-bottom: 40px;
    padding: 25px;
    background: #3c3c56;
    border-radius: 10px;
    border: 1px solid #505070;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

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

.input-group label {
    min-width: 130px;
    font-weight: 600;
    color: #b8bcc8;
}

.date-input,
.time-input,
.datetime-input,
.number-input,
select {
    padding: 10px 15px;
    border: 2px solid #505070;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    min-width: 200px;
    background: #2d2d44;
    color: #e8eaed;
}

.date-input:focus,
.time-input:focus,
.datetime-input:focus,
.number-input:focus,
select:focus {
    outline: none;
    border-color: #6c5ce7;
    box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.2);
}

.calculate-btn {
    background: linear-gradient(135deg, #6c5ce7 0%, #a29bfe 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s ease;
    margin: 20px 0;
    box-shadow: 0 4px 15px rgba(108, 92, 231, 0.4);
    font-family: 'JetBrains Mono', monospace;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(108, 92, 231, 0.5);
}

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

.result {
    margin-top: 20px;
    padding: 20px;
    background: #2d2d44;
    border-radius: 10px;
    border: 1px solid #505070;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    font-weight: 500;
    color: #b8bcc8;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

.result.has-content {
    background: linear-gradient(135deg, #4c4c6a 0%, #3c3c56 100%);
    border-color: #6c5ce7;
    color: #e8eaed;
}

.multiple-results {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: flex-start;
}

.result-item {
    background: rgba(108, 92, 231, 0.2);
    padding: 8px 15px;
    border-radius: 20px;
    border: 1px solid rgba(108, 92, 231, 0.3);
    font-weight: 600;
}

.error {
    color: #ff6b8a;
    background: #4a2d36;
    border-color: #6b4249;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        margin: 10px;
        border-radius: 10px;
    }
    
    h1 {
        font-size: 2em;
        padding: 20px;
    }
    
    .tab-content {
        padding: 20px;
    }
    
    .calculator-section {
        padding: 20px;
    }
    
    .input-group {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
    
    .input-group label {
        min-width: auto;
    }
    
    .date-input,
    .time-input,
    .datetime-input,
    .number-input,
    select {
        width: 100%;
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .tab-btn {
        padding: 12px 15px;
        font-size: 14px;
    }
    
    h1 {
        font-size: 1.8em;
    }
    
    h2 {
        font-size: 1.5em;
    }
}