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

:root {
    /* Colors */
    --primary-color: #e74c3c;
    --primary-dark: #c0392b;
    --secondary-color: #f39c12;
    --accent-color: #27ae60;
    --background-color: #f8f9fa;
    --surface-color: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --border-color: #e9ecef;
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.15);
    --shadow-heavy: 0 8px 30px rgba(0, 0, 0, 0.2);

    /* Typography */
    --font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 2.5rem; /* Reduced from 3rem */
    --spacing-3xl: 3rem; /* Reduced from 4rem */

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-color);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
.header {
    background: var(--surface-color);
    box-shadow: var(--shadow-light);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
}

.logo-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo {
    height: 50px;
    width: auto;
    border-radius: var(--radius-md);
}

.site-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--primary-color);
    margin: 0;
}

.nav {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: var(--transition-normal);
}

.nav-link:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: var(--spacing-2xl) 0; /* Reduced from var(--spacing-3xl) */
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-xl); /* Reduced from var(--spacing-2xl) */
    opacity: 0.9;
}

.hero-features {
    display: flex;
    justify-content: center;
    gap: var(--spacing-2xl);
    flex-wrap: wrap;
}

.feature {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 500;
}

.feature i {
    font-size: var(--font-size-xl);
    opacity: 0.8;
}

/* Main Content */
.main {
    padding: var(--spacing-3xl) 0;
}

.calculator-wrapper {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
    max-width: 800px;
    margin: 0 auto;
}

/* Cards */
.calculator-card,
.results-card {
    background: var(--surface-color);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-medium);
    overflow: hidden;
    transition: var(--transition-normal);
}

.calculator-card:hover,
.results-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-heavy);
}

.card-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: var(--spacing-xl);
    text-align: center;
}

.card-title {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.card-subtitle {
    opacity: 0.9;
    font-size: var(--font-size-base);
}

/* Form Styles */
.calculator-form {
    padding: var(--spacing-2xl);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.form-row.three-columns {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.form-label i {
    color: var(--primary-color);
    width: 16px;
}

.input-group {
    display: flex;
    align-items: center;
    background: var(--background-color);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition-normal);
}

.input-group:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(231, 76, 60, 0.1);
}

.form-input {
    flex: 1;
    border: none;
    padding: var(--spacing-md);
    font-size: var(--font-size-base);
    text-align: center;
    background: transparent;
    color: var(--text-primary);
    font-weight: 500;
}

.form-input:focus {
    outline: none;
}

.form-input::placeholder {
    color: var(--text-secondary);
}

.btn-counter {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: var(--spacing-md);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 44px;
}

.btn-counter:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

.btn-counter:active {
    transform: scale(0.95);
}

/* Calculate Button */
.button-container {
    display: flex;
    justify-content: center;
    margin-top: var(--spacing-lg);
}

.btn-calculate {
    width: 100%;
    max-width: 300px; /* Limit width for centering */
    background: linear-gradient(135deg, var(--accent-color) 0%, #229954 100%);
    color: white;
    border: none;
    padding: var(--spacing-lg) var(--spacing-xl);
    font-size: var(--font-size-lg);
    font-weight: 600;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.btn-calculate:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

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

/* Results */
.results-content {
    padding: var(--spacing-2xl);
}

.result-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    background: var(--background-color);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    transition: var(--transition-normal);
}

.result-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-light);
}

.result-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 500;
    color: var(--text-primary);
}

.result-label i {
    font-size: var(--font-size-lg);
    width: 24px;
    text-align: center;
}

.result-value {
    font-weight: 600;
    color: var(--primary-color);
    font-size: var(--font-size-lg);
}

/* Action Buttons */
.results-actions {
    padding: 0 var(--spacing-2xl) var(--spacing-2xl);
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.btn-primary,
.btn-secondary {
    flex: 1;
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-lg);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    min-width: 140px;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--background-color);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Tips Section */
.tips-section {
    background: var(--surface-color);
    padding: var(--spacing-3xl) 0;
}

.section-title {
    text-align: center;
    font-size: var(--font-size-3xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-2xl);
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
}

.tip-card {
    background: var(--background-color);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition-normal);
    border: 2px solid transparent;
}

.tip-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-medium);
}

.tip-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
}

.tip-icon i {
    font-size: var(--font-size-xl);
    color: white;
}

.tip-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.tip-text {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
}

.footer-text {
    color: #bdc3c7;
    line-height: 1.6;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: #bdc3c7;
    text-decoration: none;
    transition: var(--transition-normal);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid #34495e;
    color: #95a5a6;
}

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

.results-card {
    animation: fadeInUp 0.5s ease-out;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    .header .container {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .hero-title {
        font-size: var(--font-size-3xl);
    }

    .hero-features {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .form-row.three-columns {
        grid-template-columns: 1fr;
    }

    .results-actions {
        flex-direction: column;
    }

    .btn-primary,
    .btn-secondary {
        min-width: auto;
    }

    .tips-grid {
        grid-template-columns: 1fr;
    }

    .nav {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .hero {
        padding: var(--spacing-2xl) 0;
    }

    .main {
        padding: var(--spacing-2xl) 0;
    }

    .calculator-form,
    .results-content {
        padding: var(--spacing-lg);
    }

    .card-header {
        padding: var(--spacing-lg);
    }

    .card-title {
        font-size: var(--font-size-xl);
    }
}

/* Print Styles */
@media print {
    .header,
    .hero,
    .tips-section,
    .footer,
    .calculator-card,
    .results-actions {
        display: none !important;
    }

    .results-card {
        box-shadow: none;
        border: 1px solid #ddd;
    }

    .result-item {
        break-inside: avoid;
    }
}

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

/* Focus styles for keyboard navigation */
.btn-counter:focus,
.btn-calculate:focus,
.btn-primary:focus,
.btn-secondary:focus,
.nav-link:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.form-input:focus {
    outline: none;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #000;
        --text-primary: #000;
        --text-secondary: #333;
        --border-color: #000;
    }
}