/* === CSS Variables === */
:root {
    /* Zelené odstíny - gradace od nejtmavší po nejsvětlejší */
    --green-900: #022309;
    --green-800: #043E12;
    --green-700: #065d1b;
    --green-600: #087d24;
    --green-500: #0a9d2d;
    --green-400: #2db856;
    --green-300: #5cd37f;
    --green-200: #a8e8ba;
    --green-100: #d4f4dd;
    --green-50: #f0faf3;

    /* Zlatá pro akcenty */
    --gold-600: #b88635;
    --gold-500: #D39E40;
    --gold-400: #ddb05f;
    --gold-300: #e7c280;
    --gold-200: #f0d4a0;

    /* Neutrální barvy */
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    /* Typografie */
    --font-primary: 'Tinos', Georgia, 'Times New Roman', Times, serif;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    --space-3xl: 6rem;

    /* Effects */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
}

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

* {
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    font-size: 1.0625rem;
    line-height: 1.7;
    color: var(--gray-700);
    background: var(--white);
    overflow-x: hidden;
}

img, picture, video, canvas, svg {
    display: block;
    max-width: 100%;
}

input, button, textarea, select {
    font: inherit;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
    color: var(--green-800);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
}

p {
    line-height: 1.7;
}

a {
    text-decoration: none;
    color: var(--gold-600);
    transition: var(--transition);
    border-bottom: 1px solid transparent;
}

a:hover {
    border-bottom-color: var(--gold-500);
}

/* === Header === */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, var(--green-900) 0%, var(--green-800) 100%);
    z-index: 1000;
    padding: var(--space-md) 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 40px;
    width: auto;
}

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

.nav-link {
    color: var(--white);
    font-size: 1.0625rem;
    font-weight: 500;
    position: relative;
    padding: var(--space-xs) 0;
    border-bottom: none;
}

.nav-link:not(.btn-primary):hover {
    color: var(--gold-400);
    border-bottom: 2px solid var(--gold-400);
}

.nav-link:not(.btn-primary)::after {
    display: none;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-xs);
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--green-800);
    border-radius: 2px;
    transition: var(--transition);
}

/* === Buttons === */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--gold-500) 0%, var(--gold-600) 100%);
    color: var(--white);
    padding: 0.875rem 2rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    font-size: 1rem;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--gold-600) 0%, #a77429 100%);
}

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

.btn-large {
    padding: 1.125rem 2.5rem;
    font-size: 1.125rem;
}

.btn-secondary {
    background: var(--green-800);
    color: var(--white);
}

.btn-secondary:hover {
    background: var(--green-900);
}

/* === Hero Section === */
.hero {
    margin-top: 80px;
    background: linear-gradient(135deg, var(--green-900) 0%, var(--green-800) 100%);
    color: var(--white);
    padding: calc(var(--space-3xl) * 1.5) 0;
    min-height: 70vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(4, 62, 18, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(4, 62, 18, 0.2) 0%, transparent 50%);
    pointer-events: none;
}

.hero::after {
    display: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    color: var(--white);
    margin-bottom: var(--space-lg);
    font-weight: 800;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.hero-subtitle {
    font-size: clamp(1.25rem, 2vw, 1.5rem);
    margin-bottom: var(--space-xl);
    opacity: 0.95;
    line-height: 1.6;
    font-weight: 400;
}

/* === Sections === */
section {
    padding: var(--space-3xl) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--space-md);
}

.section-subtitle {
    text-align: center;
    font-size: 1.25rem;
    color: var(--gray-600);
    margin-bottom: var(--space-2xl);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* === How It Works === */
.how-it-works {
    background: var(--green-50);
    position: relative;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-xl);
    max-width: 1100px;
    margin: 0 auto;
}

.step {
    background: var(--white);
    padding: var(--space-xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 2px solid transparent;
    position: relative;
}

.step:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--gold-300);
}

.step-number {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--green-800), var(--green-900));
    color: var(--white);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: var(--space-lg);
    box-shadow: 0 4px 12px rgba(4, 62, 18, 0.4);
}

.step-title {
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
    color: var(--green-800);
}

.step-description {
    color: var(--gray-600);
    font-size: 1.125rem;
    line-height: 1.7;
}

/* === Features === */
.features {
    background: var(--white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
    margin-top: var(--space-2xl);
}

.feature-card {
    background: var(--green-50);
    padding: var(--space-xl);
    border-radius: var(--radius-xl);
    border: 2px solid var(--green-100);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--green-800), var(--gold-500));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-card:hover {
    border-color: var(--gold-400);
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    background: var(--white);
}

.feature-icon {
    width: 72px;
    height: 72px;
    background: linear-gradient(135deg, var(--green-800), var(--green-900));
    color: var(--white);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-lg);
    box-shadow: 0 4px 12px rgba(4, 62, 18, 0.3);
}

.feature-title {
    font-size: 1.375rem;
    margin-bottom: var(--space-sm);
    color: var(--green-800);
}

.feature-description {
    color: var(--gray-600);
    font-size: 1.125rem;
    line-height: 1.7;
}

/* === Examples (Chat) === */
.examples {
    background: linear-gradient(180deg, var(--white) 0%, var(--green-50) 100%);
}

.chat-examples {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.chat-example {
    cursor: pointer;
}

.chat-bubble {
    padding: var(--space-lg) var(--space-xl);
    border-radius: var(--radius-2xl);
    margin-bottom: var(--space-md);
    transition: var(--transition);
    max-width: 90%;
    box-shadow: var(--shadow-md);
}

.question-bubble {
    background: var(--white);
    border: 2px solid var(--gold-400);
    margin-left: auto;
    position: relative;
    padding-right: calc(var(--space-xl) + 48px);
}

.question-bubble::before {
    content: '→';
    position: absolute;
    top: 50%;
    transform: translateY(-50%) rotate(0deg);
    right: var(--space-lg);
    width: 36px;
    height: 36px;
    background: var(--gold-500);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.chat-example.active .question-bubble::before {
    transform: translateY(-50%) rotate(-90deg);
}

.chat-example:hover .question-bubble {
    background: var(--gold-50);
    transform: translateX(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--gold-500);
}

.answer-bubble {
    background: linear-gradient(135deg, var(--green-800), var(--green-900));
    color: var(--white);
    margin-right: auto;
    box-shadow: var(--shadow-lg);
}

.answer-bubble strong {
    color: var(--green-100);
    font-weight: 600;
}

.answer-bubble ul {
    margin: var(--space-md) 0 var(--space-md) var(--space-lg);
}

.answer-bubble li {
    margin-bottom: var(--space-xs);
    line-height: 1.6;
}

.confidence {
    margin-top: var(--space-lg);
    padding-top: var(--space-md);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.confidence-label {
    whitespace: nowrap;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--green-100);
}

.confidence-bar {
    flex: 1;
    height: 10px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 999px;
    overflow: hidden;
}

.confidence-fill {
    height: 100%;
    background: var(--gold-500);
    border-radius: 999px;
    transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 0 10px rgba(211, 158, 64, 0.5);
}

.confidence-value {
    font-weight: 700;
    color: var(--gold-400);
    font-size: 1.125rem;
    min-width: 50px;
    text-align: right;
}

/* === Calculator === */
.calculator {
    background: var(--green-50);
}

.calculator-card {
    background: var(--white);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    margin-top: var(--space-xl);
    border: 1px solid var(--green-100);
}

.calculator-inputs {
    padding: var(--space-2xl);
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
    background: var(--green-50);
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.input-group label {
    font-weight: 600;
    color: var(--green-800);
    font-size: 1.0625rem;
}

.number-input {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.number-btn {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--gold-500) 0%, var(--gold-600) 100%);
    color: var(--white);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-sm);
}

.number-btn:hover {
    background: linear-gradient(135deg, var(--gold-600) 0%, #a77429 100%);
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

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

.input-group input[type="number"] {
    flex: 1;
    padding: 0.875rem var(--space-md);
    border: 2px solid var(--gold-400);
    border-radius: var(--radius-md);
    font-size: 1.125rem;
    font-weight: 600;
    transition: var(--transition);
    background: var(--white);
    text-align: center;
}

.input-group input[type="number"]:focus {
    outline: none;
    border-color: var(--gold-600);
    box-shadow: 0 0 0 3px rgba(211, 158, 64, 0.15);
}

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

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

.calculator-results {
    background: linear-gradient(135deg, var(--green-900), var(--green-800));
    color: var(--white);
    padding: var(--space-2xl);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.calculator-results h3 {
    color: var(--white);
    font-size: 1.75rem;
    margin-bottom: var(--space-md);
}

.result-item {
    padding: var(--space-lg);
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.result-item:hover {
    background: rgba(255, 255, 255, 0.12);
}

.result-primary {
    background: rgba(4, 62, 18, 0.3);
    border-color: var(--gold-500);
    border-width: 2px;
}

.result-secondary {
    padding: var(--space-md);
    background: rgba(255, 255, 255, 0.08);
}

.result-secondary .result-label {
    color: rgba(255, 255, 255, 0.8);
}

.result-label {
    font-size: 0.9375rem;
    opacity: 0.95;
    margin-bottom: var(--space-xs);
    color: var(--white);
    font-weight: 500;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--white);
    line-height: 1;
}

.result-value-small {
    font-size: 1.5rem;
    color: rgba(255, 255, 255, 0.85);
}

.result-note {
    font-size: 0.8125rem;
    font-style: italic;
    margin-top: var(--space-sm);
    color: rgba(255, 255, 255, 0.7);
}

/* === Demo Form === */
.demo-section {
    background: linear-gradient(180deg, var(--green-50) 0%, var(--white) 100%);
}

.demo-content {
    max-width: 900px;
    margin: 0 auto;
}

.demo-form {
    background: var(--white);
    padding: var(--space-2xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--green-100);
}

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

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.form-group label {
    font-weight: 600;
    color: var(--green-800);
    font-size: 1.0625rem;
}

.form-group input,
.form-group textarea {
    padding: 0.875rem var(--space-md);
    border: 2px solid var(--gold-400);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--white);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--gold-600);
    box-shadow: 0 0 0 3px rgba(211, 158, 64, 0.15);
    background: var(--white);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.demo-form button[type="submit"] {
    width: 100%;
    margin-top: var(--space-md);
}

.form-note {
    text-align: center;
    margin-top: var(--space-md);
    font-size: 0.875rem;
    color: var(--gray-500);
}

.demo-success {
    background: var(--white);
    padding: var(--space-3xl) var(--space-2xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    text-align: center;
    border: 2px solid var(--gold-400);
}

.success-icon {
    width: 96px;
    height: 96px;
    background: linear-gradient(135deg, var(--green-800), var(--green-900));
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    margin: 0 auto var(--space-xl);
    box-shadow: 0 8px 24px rgba(4, 62, 18, 0.4);
}

.demo-success h3 {
    color: var(--green-800);
    font-size: 2rem;
    margin-bottom: var(--space-md);
}

.demo-success p {
    font-size: 1.125rem;
    color: var(--gray-600);
}

.demo-error {
    background: var(--white);
    padding: var(--space-3xl) var(--space-2xl);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    text-align: center;
    border: 2px solid #ef4444;
}

.error-icon {
    width: 96px;
    height: 96px;
    background: linear-gradient(135deg, #ef4444, #dc2626);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    margin: 0 auto var(--space-xl);
}

.demo-error h3 {
    color: #ef4444;
    font-size: 2rem;
    margin-bottom: var(--space-md);
}

.demo-error p {
    font-size: 1.125rem;
    color: var(--gray-600);
    margin-bottom: var(--space-sm);
}

/* === Footer === */
.footer {
    background: var(--green-900);
    color: var(--green-100);
    padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: var(--space-3xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand img {
    height: 48px;
    margin-bottom: var(--space-md);
}

.footer-tagline {
    margin-top: var(--space-md);
    opacity: 0.8;
    font-size: 0.9375rem;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
}

.footer-column h4 {
    color: var(--gold-400);
    margin-bottom: var(--space-md);
    font-size: 1rem;
    font-weight: 600;
}

.footer-column a {
    display: block;
    margin-bottom: var(--space-sm);
    opacity: 0.8;
    font-size: 0.9375rem;
    transition: var(--transition);
    color: var(--green-100);
    border-bottom: none;
}

.footer-column a:hover {
    opacity: 1;
    color: var(--gold-400);
    transform: translateX(4px);
    border-bottom: 1px solid var(--gold-400);
}

.footer-bottom {
    padding-top: var(--space-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    opacity: 0.6;
    font-size: 0.875rem;
}

/* === Responsive === */
@media (max-width: 968px) {
    .calculator-card {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }

    .footer-links {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --space-3xl: 4rem;
        --space-2xl: 3rem;
    }

    .nav {
        display: none;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .hero {
        padding: var(--space-2xl) 0;
    }

    section {
        padding: var(--space-2xl) 0;
    }

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

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

    .footer-links {
        grid-template-columns: 1fr;
    }

    .calculator-inputs,
    .calculator-results {
        padding: var(--space-lg);
    }

    .chat-bubble {
        max-width: 95%;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--space-md);
    }

    .demo-form {
        padding: var(--space-lg);
    }

    .question-bubble {
        padding-right: var(--space-xl);
    }

    .question-bubble::before {
        display: none;
    }
}