/* =============================================
   KI-Didaktik Portal - Professional Design System
   Expertenniveau für KI-Didaktik
   ============================================= */

:root {
    /* Primary Colors - Refined */
    --primary: #4f5da4;
    --primary-dark: #3d4a8a;
    --primary-light: #6b7ac0;
    --secondary: #5d4e7a;

    /* Neutral Colors */
    --ink: #1a1f36;
    --muted: #505a6b;
    --light: #8492a6;
    --border: #e1e5eb;
    --background: #f8f9fb;
    --paper: #ffffff;

    /* Decision Mode Colors - Muted, Professional */
    --prohibit: #c53030;
    --prohibit-bg: #fed7d7;
    --accompany: #c77c0a;
    --accompany-bg: #feebc8;
    --limit: #0d7377;
    --limit-bg: #c4f1f9;
    --allow: #276749;
    --allow-bg: #c6f6d5;

    /* Accent Colors */
    --accent-teal: #0d7377;
    --accent-warm: #c77c0a;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #4f5da4 0%, #5d4e7a 100%);
    --gradient-hero: linear-gradient(135deg, #f5f7fa 0%, #e8eaef 100%);
    --gradient-dark: linear-gradient(135deg, #1a1f36 0%, #2d3350 100%);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border Radius - Refined */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-full: 9999px;

    /* Shadows - Subtle */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 24px rgba(26, 31, 54, 0.1);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.12);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Source Serif Pro', 'Georgia', serif;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 400ms ease;
}

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-sans);
    color: var(--ink);
    background: var(--paper);
    line-height: 1.65;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

/* ---------- Typography ---------- */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.25;
    color: var(--ink);
    letter-spacing: -0.01em;
}

h1 {
    font-size: clamp(2rem, 4vw, 3rem);
}

h2 {
    font-size: clamp(1.5rem, 3vw, 2rem);
}

h3 {
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    font-family: var(--font-sans);
    font-weight: 600;
}

h4 {
    font-size: 1.1rem;
    font-family: var(--font-sans);
    font-weight: 600;
}

p {
    color: var(--muted);
    max-width: 65ch;
}

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

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

/* ---------- Layout ---------- */
.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section {
    padding: var(--space-3xl) 0;
}

.section-cta {
    background: var(--gradient-primary);
    color: white;
}

.section-label {
    color: var(--primary);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.8rem;
    letter-spacing: 0.1em;
    display: block;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.grid {
    display: grid;
    gap: var(--space-lg);
}

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

/* ---------- Navigation ---------- */
.nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border);
    padding: var(--space-md) 0;
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-xl);
}

.nav-logo {
    font-family: var(--font-sans);
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.nav-logo:hover {
    color: var(--primary-dark);
}

.nav-links {
    display: flex;
    gap: var(--space-xs);
    list-style: none;
}

.nav-links a {
    color: var(--muted);
    font-weight: 500;
    font-size: 0.95rem;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
    background: rgba(79, 93, 164, 0.08);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
    color: var(--ink);
}

@media (max-width: 800px) {
    .nav-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--paper);
        padding: var(--space-md);
        box-shadow: var(--shadow-lg);
        border-top: 1px solid var(--border);
    }

    .nav-links.open {
        display: flex;
    }
}

/* ---------- Hero Section (Expert) ---------- */
.hero-expert {
    background: var(--gradient-dark);
    color: white;
    padding: var(--space-3xl) 0;
    position: relative;
    overflow: hidden;
}

.hero-expert::before {
    content: '';
    position: absolute;
    top: -40%;
    right: -15%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(79, 93, 164, 0.25) 0%, transparent 70%);
    pointer-events: none;
}

.hero-expert-content {
    position: relative;
    z-index: 1;
}

.hero-expert h1 {
    color: white;
    margin-bottom: var(--space-lg);
}

.hero-expert .lead {
    color: rgba(255, 255, 255, 0.85);
    font-size: 1.15rem;
    max-width: 680px;
    line-height: 1.7;
}

.hero-stats {
    display: flex;
    gap: var(--space-2xl);
    margin-top: var(--space-2xl);
    flex-wrap: wrap;
}

.hero-stat {
    text-align: center;
}

.hero-stat-number {
    font-size: 2.25rem;
    font-weight: 700;
    font-family: var(--font-sans);
    color: white;
    display: block;
    line-height: 1;
}

.hero-stat-label {
    color: rgba(255, 255, 255, 0.65);
    font-size: 0.85rem;
    margin-top: 0.25rem;
}

/* ---------- Pills (Subtle) ---------- */
.pills {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.pill {
    display: inline-flex;
    align-items: center;
    padding: 0.35rem 0.85rem;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
}

/* ---------- Cards ---------- */
.card {
    background: var(--paper);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.card h3 {
    margin-bottom: var(--space-sm);
}

.card p {
    font-size: 0.95rem;
    margin-bottom: var(--space-md);
}

/* ---------- Feature List ---------- */
.feature-list {
    list-style: none;
    padding: 0;
    margin-bottom: 1.5rem;
}

.feature-list li {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
    color: var(--ink);
}

.check-icon {
    width: 20px;
    height: 20px;
    min-width: 20px;
    background: var(--allow);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 2px;
}

.check-icon::after {
    content: '';
    width: 10px;
    height: 10px;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3'%3E%3Cpath d='M5 12l5 5L19 7'/%3E%3C/svg%3E") center/contain no-repeat;
}

/* ---------- Featured Section ---------- */
.featured-model {
    background: var(--background);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
    align-items: center;
}

@media (max-width: 768px) {
    .featured-model {
        grid-template-columns: 1fr;
        padding: var(--space-xl);
    }
}

.featured-model-visual {
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 360px;
}

/* ---------- Blog Cards ---------- */
.blog-card {
    display: flex;
    flex-direction: column;
    background: var(--paper);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.blog-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.blog-card-image {
    height: 140px;
    width: 100%;
    object-fit: cover;
    display: block;
}

.blog-card-image--research {
    background: linear-gradient(135deg, #4f5da4 0%, #3d4a8a 100%);
}

.blog-card-image--practice {
    background: linear-gradient(135deg, #0d7377 0%, #065f62 100%);
}

.blog-card-image--opinion {
    background: linear-gradient(135deg, #5d4e7a 0%, #4a3d62 100%);
}

.blog-card-content {
    padding: var(--space-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.blog-card-meta {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-sm);
    font-size: 0.8rem;
    color: var(--light);
}

.blog-card-tag {
    background: rgba(79, 93, 164, 0.1);
    color: var(--primary);
    padding: 0.15rem 0.6rem;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.75rem;
}

.blog-card h3 {
    font-size: 1.1rem;
    margin-bottom: var(--space-sm);
    line-height: 1.4;
}

.blog-card p {
    font-size: 0.9rem;
    flex: 1;
}

.blog-card-link {
    color: var(--primary);
    font-weight: 600;
    font-size: 0.9rem;
    margin-top: var(--space-md);
}

/* ---------- Research Cards ---------- */
.research-card {
    background: var(--paper);
    border-left: 3px solid var(--primary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    padding: var(--space-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.research-card:hover {
    box-shadow: var(--shadow-md);
}

.research-card-source {
    color: var(--primary);
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-bottom: var(--space-sm);
}

.research-card h4 {
    font-size: 1.05rem;
    margin-bottom: var(--space-sm);
    line-height: 1.4;
}

.research-card p {
    font-size: 0.9rem;
    margin-bottom: var(--space-md);
}

.research-card-link {
    font-size: 0.85rem;
    font-weight: 600;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.65rem 1.25rem;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

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

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

.btn-secondary {
    background: var(--paper);
    color: var(--primary);
    border-color: var(--primary);
}

.btn-secondary:hover {
    background: rgba(79, 93, 164, 0.08);
}

.btn-outline {
    background: transparent;
    color: var(--muted);
    border-color: var(--border);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

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

.btn-white:hover {
    background: rgba(255, 255, 255, 0.92);
    color: var(--primary);
}

/* ---------- Newsletter ---------- */
.newsletter-card {
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
    padding: 2.5rem;
}

.newsletter-form {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    flex-wrap: wrap;
}

.newsletter-form input {
    padding: 0.7rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    min-width: 260px;
    font-size: 0.95rem;
    font-family: inherit;
    transition: border-color var(--transition-fast);
}

.newsletter-form input:focus {
    outline: none;
    border-color: var(--primary);
}

/* ---------- Footer ---------- */
.footer {
    background: var(--ink);
    color: rgba(255, 255, 255, 0.7);
    padding: var(--space-3xl) 0 var(--space-2xl);
}

.footer-logo {
    color: white;
    display: inline-flex;
}

.footer-logo:hover {
    color: rgba(255, 255, 255, 0.9);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.footer h4 {
    color: white;
    font-size: 0.95rem;
    font-family: var(--font-sans);
    margin-bottom: var(--space-md);
}

.footer a {
    color: rgba(255, 255, 255, 0.6);
    display: block;
    padding: 0.3rem 0;
    font-size: 0.9rem;
}

.footer a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--space-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-md);
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.5);
}

/* ---------- Animations ---------- */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(16px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

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

.animate-fade-in-up {
    animation: fadeInUp 0.5s ease-out both;
}

.delay-100 {
    animation-delay: 100ms;
}

.delay-200 {
    animation-delay: 200ms;
}

.delay-300 {
    animation-delay: 300ms;
}

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

.mt-sm {
    margin-top: var(--space-sm);
}

.mt-md {
    margin-top: var(--space-md);
}

.mt-lg {
    margin-top: var(--space-lg);
}

.mt-xl {
    margin-top: var(--space-xl);
}

.mb-sm {
    margin-bottom: var(--space-sm);
}

.mb-md {
    margin-bottom: var(--space-md);
}

.mb-lg {
    margin-bottom: var(--space-lg);
}

.mb-xl {
    margin-bottom: var(--space-xl);
}

/* ---------- Import Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Source+Serif+Pro:wght@600&display=swap');