:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --dark-bg: #0f172a;
    --darker-bg: #020617;
    --light-text: #f8fafc;
    --muted-text: #cbd5e1;
    --card-bg: #1e293b;
    --border-color: #334155;
}
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--darker-bg);
    color: var(--light-text);
    line-height: 1.6;
    overflow-x: hidden;
}
header {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}
.navbar { min-height: 70px; }
.navbar-brand { padding-top: 0; padding-bottom: 0; margin-right: 1rem; }
.navbar-logo { height: 45px; width: auto; }
@media (min-width: 992px) { .navbar-logo { height: 65px; } }
.nav-link {
    color: var(--light-text) !important;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}
.nav-link:hover { color: var(--accent-color) !important; }
.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 50%;
    background: var(--accent-color);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}
.nav-link:hover::after { width: 100%; }
.section { padding: 100px 0; }
.section-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--light-text);
}
.section-subtitle {
    font-size: 1.25rem;
    color: var(--muted-text);
    max-width: 800px;
    margin: 0 auto 3rem;
}
.hero {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--dark-bg) 0%, var(--darker-bg) 100%);
}
.modern-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2.5rem;
    height: 100%;
    transition: all 0.3s ease;
}
.modern-card h4 { color: var(--light-text); }
.modern-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
}
.modern-card .text-muted { color: var(--muted-text) !important; }
.feature-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    margin-bottom: 1.5rem;
}
.form-control {
    background: rgba(15,23,42,0.8);
    border: 1px solid var(--border-color);
    color: var(--light-text);
}
.form-control:focus {
    background: var(--dark-bg);
    border-color: var(--primary-color);
    color: var(--light-text);
    box-shadow: 0 0 0 0.25rem rgba(37,99,235,0.25);
}
.output-section {
    padding: 1.5rem;
    border-radius: 12px;
    margin-top: 1.5rem;
}
.cost-section {
    background-color: rgba(239,68,68,0.1);
    border: 1px solid var(--danger-color);
}
.gain-section {
    background-color: rgba(16,185,129,0.1);
    border: 1px solid var(--success-color);
}
.output-label {
    color: var(--muted-text);
    font-size: 0.9rem;
}
.output-value {
    font-size: 2.2rem;
    font-weight: 700;
}
.text-danger { color: var(--danger-color) !important; }
.text-success { color: var(--success-color) !important; }
.btn-group .btn { border-color: var(--border-color); }
.btn-primary-modern {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 12px 30px;
    border-radius: 12px;
    font-weight: 600;
    text-transform: none;
    transition: all 0.3s ease;
    border: none;
}
.btn-primary-modern:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37,99,235,0.4);
    color: white;
}
.language-switcher {
    background: rgba(248,250,252,0.1);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.5rem;
}
.language-flag {
    width: 24px;
    height: 18px;
    border-radius: 4px;
    object-fit: cover;
}
footer {
    background: var(--darker-bg);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
    text-align: center;
}
.offcanvas {
    background: var(--dark-bg);
    border-left: 1px solid var(--border-color);
}
.offcanvas .nav-link {
    font-size: 1.1rem;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}
.accordion-item {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    margin-bottom: 1rem;
    border-radius: 16px !important;
}
.accordion-header { border-radius: 16px !important; }
.accordion-button {
    background-color: transparent;
    color: var(--light-text);
    font-weight: 600;
    font-size: 1.1rem;
    border-radius: 16px !important;
}
.accordion-button:not(.collapsed) {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: none;
}
.accordion-button:focus {
    box-shadow: 0 0 0 0.25rem rgba(37,99,235,0.25);
    border-color: var(--primary-color);
}
.accordion-button::after {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23f8fafc'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
}
.accordion-button:not(.collapsed)::after {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23ffffff'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
}
.accordion-body {
    color: var(--muted-text);
    padding: 1.5rem;
    padding-top: 0.5rem;
}
.accordion { --bs-accordion-border-width: 0; }
/* Bubliny */
.mtg-bubbles {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}
.mtg-bubbles .floating-shape {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle at 30% 30%, rgba(37,99,235,0.18), rgba(37,99,235,0.04) 60%, transparent 70%);
    filter: blur(0.2px);
    animation: mtg-float 18s ease-in-out infinite;
    opacity: 0.85;
}
.mtg-bubbles .floating-shape:nth-child(1) { width: 140px; height: 140px; top: 18%; left: 8%; animation-duration: 22s; }
.mtg-bubbles .floating-shape:nth-child(2) { width: 220px; height: 220px; top: 55%; right: 6%; animation-duration: 28s; }
.mtg-bubbles .floating-shape:nth-child(3) { width: 100px; height: 100px; bottom: 12%; left: 22%; animation-duration: 20s; }
.mtg-bubbles .floating-shape:nth-child(4) { width: 180px; height: 180px; top: 75%; left: 55%; animation-duration: 26s; }
/* ============================================================
   KALKULAČKA – ŠPECIFICKÉ ŠTÝLY
   ============================================================ */

.calculator-section {
    background: var(--darker-bg);
    padding: 80px 0;
}

.calc-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem 2rem 2.5rem;
    height: 100%;
    transition: all 0.3s ease;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

.calc-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 12px 40px rgba(37, 99, 235, 0.15);
}

.calc-card-header {
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 1rem;
    margin-bottom: 1.5rem;
}

.calc-card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--light-text);
    margin: 0;
}

.calc-card-body {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.calc-field {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.calc-label {
    font-weight: 600;
    color: var(--light-text);
    font-size: 0.95rem;
}

.calc-value-badge {
    background: var(--primary-color);
    color: #fff;
    padding: 0.15rem 0.9rem;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.9rem;
    min-width: 60px;
    text-align: center;
}

/* --- SLIDER --- */
.calc-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--border-color);
    outline: none;
    transition: background 0.2s;
}

.calc-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    cursor: pointer;
    box-shadow: 0 0 15px rgba(37, 99, 235, 0.4);
    border: 2px solid var(--dark-bg);
    transition: 0.2s;
}

.calc-slider::-webkit-slider-thumb:hover {
    transform: scale(1.15);
    box-shadow: 0 0 25px rgba(37, 99, 235, 0.6);
}

.calc-slider::-moz-range-thumb {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    cursor: pointer;
    border: 2px solid var(--dark-bg);
}

.calc-slider-labels {
    font-size: 0.75rem;
    color: var(--muted-text);
    margin-top: 0.2rem;
}

/* --- INPUT GROUP --- */
.calc-input-group {
    display: flex;
    align-items: center;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: border-color 0.2s;
}

.calc-input-group:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

.calc-input-prefix {
    padding: 0 0 0 1rem;
    font-weight: 600;
    color: var(--muted-text);
    background: transparent;
}

.calc-input {
    flex: 1;
    background: transparent;
    border: none;
    padding: 0.75rem 1rem;
    color: var(--light-text);
    font-size: 1rem;
    outline: none;
    min-width: 0;
}

.calc-input:read-only {
    color: var(--muted-text);
    cursor: default;
}

/* --- RADIO BUTTON GROUP --- */
.calc-btn-group {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.calc-btn-radio {
    flex: 1;
    text-align: center;
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s;
    color: var(--light-text);
    background: rgba(255, 255, 255, 0.03);
    min-width: 60px;
}

.calc-btn-radio:hover {
    border-color: var(--primary-color);
    background: rgba(37, 99, 235, 0.1);
}

.btn-check:checked + .calc-btn-radio {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-color: transparent;
    color: #fff;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

/* --- OUTPUT GROUP --- */
.calc-output-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 0.5rem;
}

.calc-output-item {
    background: rgba(15, 23, 42, 0.5);
    border-radius: 16px;
    padding: 1.25rem 1.5rem;
    border: 1px solid var(--border-color);
}

.calc-output-item.cost {
    border-left: 4px solid var(--danger-color);
}

.calc-output-item.gain {
    border-left: 4px solid var(--success-color);
}

.calc-output-label {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--muted-text);
    display: block;
    margin-bottom: 0.5rem;
}

.calc-output-values {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.calc-output-number {
    font-size: 2rem;
    font-weight: 800;
    display: block;
    line-height: 1.2;
}

.calc-output-number.gain {
    color: var(--success-color);
}

.calc-output-number.danger {
    color: var(--danger-color);
}

.calc-output-sub {
    font-size: 0.8rem;
    color: var(--muted-text);
    display: block;
}

.calc-divider {
    border-color: var(--border-color);
    margin: 1rem 0;
}

/* --- FLAT FEE INFO (dynamic) --- */
#flatFeeInfo .alert {
    border-radius: 16px;
    padding: 1.25rem 1.5rem;
    background: rgba(16, 185, 129, 0.08);
    border: 1px solid var(--success-color);
    color: var(--light-text);
}

#flatFeeInfo .alert strong {
    color: var(--success-color);
}

/* --- RESPONZIVITA --- */
@media (max-width: 768px) {
    .calculator-section {
        padding: 50px 0;
    }

    .calc-card {
        padding: 1.5rem;
    }

    .calc-output-values {
        flex-direction: column;
        gap: 0.5rem;
    }

    .calc-output-number {
        font-size: 1.6rem;
    }

    .calc-btn-radio {
        font-size: 0.85rem;
        padding: 0.4rem 0.8rem;
        min-width: 50px;
    }

    .calc-value-badge {
        font-size: 0.8rem;
        min-width: 50px;
    }
}

@media (max-width: 576px) {
    .calc-card-title {
        font-size: 1.25rem;
    }

    .calc-output-item {
        padding: 1rem;
    }

    .calc-input {
        font-size: 0.9rem;
        padding: 0.6rem 0.8rem;
    }
}

@keyframes mtg-float {
    0% { transform: translateY(0) translateX(0) scale(1); }
    50% { transform: translateY(-40px) translateX(20px) scale(1.08); }
    100% { transform: translateY(0) translateX(0) scale(1); }
}
@media (max-width: 576px) {
    body { overflow-x: hidden; }
    .container, .navbar, .section { width: 100%; padding-left: 0; padding-right: 0; }
    .navbar-brand { margin-right: 0; }
    .output-section { max-width: 100%; overflow: hidden; }
    .output-value { font-size: 1.6rem; word-break: break-all; }
}