/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-dark: #05386B;
    --primary-medium: #379683;
    --primary-light: #5CDB95;
    --secondary-light: #8EE4AF;
    --background-light: #EDF5E1;
    --white: #ffffff;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --error: #e74c3c;
    --success: #27ae60;
    --warning: #f39c12;
    
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --border-radius: 8px;
    --box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--background-light);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-medium));
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
}

.header__title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

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

/* Main Content */
.main {
    flex: 1;
    padding: 3rem 0;
}

/* Calculator Section */
.calculator {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-bottom: 4rem;
}

.calculator__title {
    color: var(--primary-dark);
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

/* Form Styles */
.form {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.form__group {
    margin-bottom: 1.5rem;
}

.form__label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--primary-dark);
}

.required {
    color: var(--error);
}

.form__input,
.form__select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e1e8ed;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
    background-color: var(--white);
}

.form__input:focus,
.form__select:focus {
    outline: none;
    border-color: var(--primary-medium);
    box-shadow: 0 0 0 3px rgba(55, 150, 131, 0.1);
}

.form__input.error,
.form__select.error {
    border-color: var(--error);
}

.form__error {
    display: block;
    color: var(--error);
    font-size: 0.875rem;
    margin-top: 0.25rem;
    min-height: 1.2rem;
}

/* Button Styles */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

.btn--primary {
    background: linear-gradient(135deg, var(--primary-medium), var(--primary-light));
    color: var(--white);
    width: 100%;
    padding: 1rem;
    font-size: 1.1rem;
}

.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(55, 150, 131, 0.3);
}

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

/* Results Section */
.calculator__results {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.results__title {
    color: var(--primary-dark);
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.results__grid {
    display: grid;
    gap: 1rem;
    margin-bottom: 2rem;
}

/* Result Cards */
.result-card {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--background-light);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary-light);
}

.result-card--highlight {
    background: linear-gradient(135deg, var(--primary-light), var(--secondary-light));
    border-left-color: var(--primary-dark);
    color: var(--white);
}

.result-card__label {
    font-weight: 600;
    font-size: 0.9rem;
}

.result-card__value {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--primary-dark);
}

.result-card__value--large {
    font-size: 1.3rem;
}

.result-card__value--negative {
    color: var(--error);
}

.result-card--highlight .result-card__value {
    color: var(--white);
}

/* IR Table */
.ir-table {
    background: var(--background-light);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
}

.ir-table__title {
    color: var(--primary-dark);
    font-size: 1.2rem;
    margin-bottom: 1rem;
    text-align: center;
}

.ir-table__content {
    display: grid;
    gap: 0.5rem;
}

.ir-table__row {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem;
    background: var(--white);
    border-radius: 4px;
    font-size: 0.9rem;
}

/* FAQ Section */
.faq {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.faq__title {
    color: var(--primary-dark);
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
}

.faq__item {
    border-bottom: 1px solid #e1e8ed;
    margin-bottom: 1rem;
}

.faq__question {
    width: 100%;
    background: none;
    border: none;
    padding: 1rem 0;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-dark);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq__question:hover {
    color: var(--primary-medium);
}

.faq__icon {
    font-size: 1.5rem;
    transition: var(--transition);
}

.faq__question[aria-expanded="true"] .faq__icon {
    transform: rotate(45deg);
}

.faq__answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq__answer.active {
    max-height: 200px;
}

.faq__answer p {
    padding: 0 0 1rem 0;
    color: var(--text-light);
    line-height: 1.6;
}

/* Footer */
.footer {
    background: var(--primary-dark);
    color: var(--white);
    text-align: center;
    padding: 2rem 0;
    margin-top: auto;
}

.footer__text {
    font-size: 0.9rem;
}

.footer__link {
    color: var(--primary-light);
    text-decoration: none;
    transition: var(--transition);
}

.footer__link:hover {
    color: var(--secondary-light);
    text-decoration: underline;
}

/* Loading State */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.loading .btn--primary {
    background: var(--text-light);
    cursor: not-allowed;
}

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

.fade-in {
    animation: fadeIn 0.5s ease-out;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header__title {
        font-size: 2rem;
    }
    
    .header__subtitle {
        font-size: 1rem;
    }
    
    .calculator {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .main {
        padding: 2rem 0;
    }
    
    .form,
    .calculator__results,
    .faq {
        padding: 1.5rem;
    }
    
    .results__grid {
        gap: 0.75rem;
    }
    
    .result-card {
        padding: 0.75rem;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .result-card__value {
        font-size: 1rem;
    }
    
    .result-card__value--large {
        font-size: 1.2rem;
    }
    
    .faq__question {
        font-size: 1rem;
        padding: 0.75rem 0;
    }
    
    .ir-table__row {
        font-size: 0.8rem;
        padding: 0.4rem;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 1.5rem 0;
    }
    
    .header__title {
        font-size: 1.8rem;
    }
    
    .calculator__title,
    .results__title {
        font-size: 1.5rem;
    }
    
    .faq__title {
        font-size: 1.7rem;
    }
    
    .form__input,
    .form__select {
        padding: 0.6rem;
    }
    
    .btn--primary {
        padding: 0.8rem;
        font-size: 1rem;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --primary-dark: #000000;
        --primary-medium: #004d40;
        --text-dark: #000000;
        --text-light: #333333;
    }
    
    .form__input,
    .form__select {
        border-width: 3px;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .faq,
    .btn {
        display: none;
    }
    
    .calculator {
        grid-template-columns: 1fr;
    }
    
    .calculator__results {
        box-shadow: none;
        border: 1px solid #000;
    }
}