/* ========================================
   INTERNETGEMEIN.DE - Online-Taschenrechner
   Professional Calculator Website
   ======================================== */

/* ============ CSS Variables ============ */
:root {
    /* Professional Color Palette */
    --primary-color: #DD0000;
    --primary-dark: #FFCC00;
    --primary-light: #dd6b00;
    --secondary-color: #eed704;
    --accent-color: #FFCC00;
    --warning-color: #f39c12;
    --dark-color: #1a252f;
    --light-bg: #ecf0f1;
    --white: #ffffff;
    --text-dark: #000000;
    --text-light: #000000;
    --border-color: #bdc3c7;
    --shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 5px 25px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-primary: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-mono: 'Courier New', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

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

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

/* ============ Typography ============ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-light);
}

a {
    text-decoration: none;
    color: var(--secondary-color);
    transition: color var(--transition-fast);
}

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

/* ============ Header & Navigation ============ */
.site-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--dark-color) 100%);
    color: var(--white);
    padding: var(--spacing-sm) 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    animation: slideDown 0.5s ease;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--white);
    font-size: 1.5rem;
    font-weight: 700;
    transition: transform var(--transition-fast);
}

.site-logo:hover {
    transform: scale(1.05);
    color: var(--white);
}

.logo-icon {
    font-size: 2rem;
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-link {
    color: var(--white);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    font-weight: 500;
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--white);
    transform: translateY(-2px);
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--white);
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-xs);
}

/* ============ Hero Section ============ */
.hero-section {
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--primary-color) 100%);
    color: var(--white);
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
    animation: fadeIn 0.8s ease;
}

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

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    color: var(--white);
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.8s ease 0.2s both;
}

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

.hero-description {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

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

/* ============ Calculator Grid ============ */
.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
}

.calculator-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow);
    transition: all var(--transition-normal);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    animation: fadeInUp 0.6s ease both;
}

.calculator-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
    transition: left var(--transition-normal);
}

.calculator-card:hover::before {
    left: 0;
}

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

.calculator-card:nth-child(1) { animation-delay: 0.1s; }
.calculator-card:nth-child(2) { animation-delay: 0.2s; }
.calculator-card:nth-child(3) { animation-delay: 0.3s; }
.calculator-card:nth-child(4) { animation-delay: 0.4s; }
.calculator-card:nth-child(5) { animation-delay: 0.5s; }
.calculator-card:nth-child(6) { animation-delay: 0.6s; }

.card-icon {
    font-size: 3rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-sm);
    display: block;
    transition: transform var(--transition-fast);
}

.calculator-card:hover .card-icon {
    transform: scale(1.1) rotate(5deg);
}

.calculator-card h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.calculator-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.card-link {
    display: inline-block;
    margin-top: var(--spacing-sm);
    color: var(--secondary-color);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.card-link:hover {
    color: var(--accent-color);
    transform: translateX(5px);
}

/* ============ Calculator Page Styles ============ */
.calculator-header {
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--primary-color) 100%);
    color: var(--white);
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.calculator-header h1 {
    color: var(--white);
    margin-bottom: var(--spacing-sm);
}

.calculator-header p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.1rem;
}

.calculator-main {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow);
    margin-bottom: var(--spacing-lg);
}

.calculator-explanation {
    background: var(--light-bg);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.calculator-explanation h2 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.calculator-explanation ul,
.calculator-explanation ol {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
}

.calculator-explanation li {
    margin-bottom: var(--spacing-xs);
    color: var(--text-light);
}

/* ============ Form Elements ============ */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--text-dark);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-sm);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: var(--font-primary);
    transition: all var(--transition-fast);
    background-color: var(--white);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.form-group input[type="number"] {
    font-family: var(--font-mono);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

/* ============ Buttons ============ */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: center;
    font-family: var(--font-primary);
}

.btn-primary {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    color: var(--white);
    box-shadow: 0 4px 15px rgba(52, 152, 219, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.4);
}

.btn-secondary {
    background-color: var(--border-color);
    color: var(--text-dark);
}

.btn-secondary:hover {
    background-color: var(--text-light);
    color: var(--white);
}

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

.btn-success:hover {
    background-color: #229954;
}

.btn-block {
    width: 100%;
    display: block;
}

.button-group {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

/* ============ Results Display ============ */
.result-box {
    background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
    border-left: 4px solid var(--success-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-lg);
    animation: slideIn 0.5s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.result-box h3 {
    color: var(--success-color);
    margin-bottom: var(--spacing-sm);
}

.result-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: var(--font-mono);
}

.result-details {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 2px solid rgba(39, 174, 96, 0.2);
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xs) 0;
}

.result-item span:first-child {
    font-weight: 600;
    color: var(--text-dark);
}

.result-item span:last-child {
    color: var(--text-light);
    font-family: var(--font-mono);
}

.error-box {
    background: linear-gradient(135deg, #ffebee 0%, #ffcdd2 100%);
    border-left: 4px solid var(--accent-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-lg);
    color: var(--accent-color);
}

/* ============ Tables ============ */
.table-responsive {
    overflow-x: auto;
    margin: var(--spacing-lg) 0;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow);
}

thead {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    color: var(--white);
}

th, td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
}

th {
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.9rem;
}

tbody tr {
    border-bottom: 1px solid var(--border-color);
    transition: background-color var(--transition-fast);
}

tbody tr:hover {
    background-color: var(--light-bg);
}

tbody tr:last-child {
    border-bottom: none;
}

/* ============ Footer ============ */
.site-footer {
    background: linear-gradient(135deg, var(--dark-color) 0%, var(--primary-color) 100%);
    color: var(--white);
    padding: var(--spacing-xl) var(--spacing-md) var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-section h3 {
    color: var(--white);
    margin-bottom: var(--spacing-md);
}

.footer-section p,
.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
}

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

.footer-nav li {
    margin-bottom: var(--spacing-xs);
}

.footer-nav a {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: all var(--transition-fast);
}

.footer-nav a:hover {
    color: var(--white);
    transform: translateX(5px);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

/* ============ Utility Classes ============ */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

.hidden { display: none; }

/* ============ Responsive Design ============ */
@media (max-width: 768px) {
    html { font-size: 14px; }
    
    .hero-title { font-size: 2rem; }
    .hero-description { font-size: 1rem; }
    
    .menu-toggle { display: block; }
    
    .main-nav ul {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--primary-color);
        padding: var(--spacing-md);
        box-shadow: var(--shadow);
    }
    
    .main-nav ul.active {
        display: flex;
    }
    
    .calculator-grid {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .button-group .btn {
        width: 100%;
    }
    
    .calculator-main {
        padding: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .header-container {
        padding: 0 var(--spacing-sm);
    }
    
    .site-logo {
        font-size: 1.2rem;
    }
    
    .logo-icon {
        font-size: 1.5rem;
    }
    
    .result-value {
        font-size: 1.5rem;
    }
}

/* ============ Animations ============ */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.loading {
    animation: pulse 1.5s infinite;
}

/* ============ Print Styles ============ */
@media print {
    .site-header,
    .site-footer,
    .button-group,
    .menu-toggle {
        display: none;
    }
    
    body {
        background: white;
    }
    
    .calculator-main {
        box-shadow: none;
    }
}

/* ============ Accessibility ============ */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Focus styles for accessibility */
*:focus-visible {
    outline: 3px solid var(--secondary-color);
    outline-offset: 2px;
}

/* ============ Calculator-Specific Styles ============ */
.calculator-input-section {
    background: var(--light-bg);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.calculation-steps {
    background: var(--white);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.calculation-steps h3 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.calculation-steps ol {
    margin-left: var(--spacing-lg);
}

.calculation-steps li {
    margin-bottom: var(--spacing-sm);
    color: var(--text-light);
}

.info-badge {
    display: inline-block;
    background: var(--secondary-color);
    color: var(--white);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    margin-left: var(--spacing-xs);
}

.warning-badge {
    display: inline-block;
    background: var(--warning-color);
    color: var(--white);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
}

/* Contact Form Specific */
.contact-info {
    background: var(--light-bg);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-lg);
}

.contact-info-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.contact-info-item i {
    font-size: 1.5rem;
    color: var(--secondary-color);
}