/* ============================================
   INTERNETGEMEIN.DE - ONLINE-TASCHENRECHNER
   Professional Calculator Website Styles
   ============================================ */

/* === CSS Variables === */
:root {
    --primary-color: #DD0000;
    --primary-dark: #FFCC00;
    --primary-light: #dd6b00;
    --secondary-color: #1f2022;
    --accent-color: #FFCC00;
    --dark-color: #1c2833;
    --light-color: #ecf0f1;
    --white: #ffffff;
    --gray-100: #f8f9fa;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-600: #6c757d;
    --gray-800: #343a40;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.15);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.2);
    --transition: all 0.3s ease;
    --border-radius: 8px;
}

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

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: var(--gray-100);
    overflow-x: hidden;
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 1rem;
}

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: 1rem;
}

/* === Header Navigation === */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--white);
    font-size: 1.5rem;
    font-weight: 700;
    transition: var(--transition);
}

.logo:hover {
    transform: scale(1.05);
}

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

nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: var(--white);
    transform: translateX(-50%);
    transition: var(--transition);
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.nav-link:hover::after {
    width: 80%;
}

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

/* === Hero Section === */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 50%, var(--accent-color) 100%);
    color: var(--white);
    padding: 4rem 1.5rem;
    text-align: center;
    animation: fadeIn 0.8s ease-in;
}

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

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

/* === Main Container === */
main {
    max-width: 1200px;
    margin: 3rem auto;
    padding: 0 1.5rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* === Calculator Directory === */
.calculator-directory {
    margin-bottom: 4rem;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--primary-color);
    font-size: 2.5rem;
}

.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

/* === Calculator Card === */
.calculator-card {
    background: var(--white);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
    animation: slideUp 0.5s ease-out;
}

.calculator-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-color);
}

.calculator-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
    color: var(--primary-color);
}

.calculator-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.calculator-card p {
    color: var(--gray-600);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.btn-calculator {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

.btn-calculator:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

/* === Calculator Page Styles === */
.calculator-page {
    background: var(--white);
    border-radius: var(--border-radius);
    padding: 3rem;
    box-shadow: var(--shadow-md);
    margin-bottom: 3rem;
    animation: fadeIn 0.5s ease-in;
}

.calculator-header {
    text-align: center;
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 3px solid var(--accent-color);
}

.calculator-header h1 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.calculator-description {
    background: var(--gray-100);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
    border-left: 4px solid var(--accent-color);
}

/* === Form Styles === */
.calculator-form {
    display: grid;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 600;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-group input,
.form-group select {
    padding: 0.875rem;
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
    background-color: var(--white);
}

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

.form-group input[type="number"] {
    -moz-appearance: textfield;
}

.form-group input[type="number"]::-webkit-inner-spin-button,
.form-group input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* === Buttons === */
.btn {
    display: inline-block;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

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

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

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

.btn-group {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

/* === Results Display === */
.results {
    background: linear-gradient(135deg, #e8f5e9, #c8e6c9);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-top: 2rem;
    border-left: 5px solid var(--success-color);
    animation: slideIn 0.5s ease-out;
}

.results.hidden {
    display: none;
}

.results h3 {
    color: var(--success-color);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--white);
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    box-shadow: var(--shadow-sm);
}

.result-label {
    font-weight: 600;
    color: var(--gray-800);
}

.result-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

/* === Info Box === */
.info-box {
    background: #fff3cd;
    border-left: 4px solid var(--warning-color);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin: 2rem 0;
}

.info-box h4 {
    color: var(--warning-color);
    margin-bottom: 0.5rem;
}

/* === Footer === */
footer {
    background: var(--dark-color);
    color: var(--white);
    padding: 3rem 1.5rem 1.5rem;
    margin-top: 4rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--light-color);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--accent-color);
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--gray-300);
}

/* === Category Sections === */
.category-section {
    margin-bottom: 4rem;
}

.category-title {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--accent-color);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

/* === Animations === */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

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

/* === Scroll Animation Classes === */
.fade-in {
    opacity: 0;
    animation: fadeIn 0.8s ease-in forwards;
}

.slide-up {
    opacity: 0;
    animation: slideUp 0.6s ease-out forwards;
}

/* === Responsive Design === */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }

    nav {
        display: none;
        width: 100%;
        margin-top: 1rem;
    }

    nav.active {
        display: block;
    }

    nav ul {
        flex-direction: column;
        gap: 0;
    }

    .nav-link {
        display: block;
        width: 100%;
        padding: 1rem;
        border-radius: 0;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

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

    .calculator-page {
        padding: 1.5rem;
    }

    .btn-group {
        flex-direction: column;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }

    .header-container {
        padding: 0 1rem;
    }

    .hero {
        padding: 2rem 1rem;
    }

    .calculator-card {
        padding: 1.5rem;
    }

    .result-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}

/* === Print Styles === */
@media print {
    header, footer, .btn {
        display: none;
    }

    body {
        background: white;
    }

    .calculator-page {
        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 keyboard navigation */
a:focus,
button:focus,
input:focus,
select:focus {
    outline: 3px solid var(--accent-color);
    outline-offset: 2px;
}

/* === Loading Spinner === */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: var(--white);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* === Error Messages === */
.error-message {
    background: #fee;
    border-left: 4px solid var(--danger-color);
    color: var(--danger-color);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin: 1rem 0;
}

/* === Success Messages === */
.success-message {
    background: #efe;
    border-left: 4px solid var(--success-color);
    color: var(--success-color);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin: 1rem 0;
}

/* === Table Styles === */
.result-table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
    background: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.result-table th,
.result-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--gray-300);
}

.result-table th {
    background: var(--primary-color);
    color: var(--white);
    font-weight: 600;
}

.result-table tr:hover {
    background: var(--gray-100);
}