/* ==========================================================================
   1. RESET A ZÁKLADNÍ NASTAVENÍ (Box-sizing podle zadání)
   ========================================================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* Barevná paleta - Vesmírný temný režim s vysokým kontrastem */
    --bg-space: #0b0d17;
    --bg-card: #151926;
    --text-main: #f0f2f5;
    --text-muted: #b0b5c1;
    --accent-blue: #4f46e5;
    --accent-cyan: #06b6d4;
    --white: #ffffff;
    
    /* Typografie */
    --font-primary: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-space);
    color: var(--text-main);
    line-height: 1.6;
}

/* Pomocný kontejner pro zarovnání obsahu */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Přístupnost: Skrytí prvku pro běžné oči, ale čitelné pro čtečky obrazovky */
.sr-only-skip {
    position: absolute;
    left: -10000px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}
.sr-only-skip:focus {
    position: static;
    width: auto;
    height: auto;
    background: var(--accent-cyan);
    color: var(--bg-space);
    padding: 10px;
    display: block;
    text-align: center;
    font-weight: bold;
}

/* Klávesnicový focus pro lepší přístupnost (WCAG) */
a:focus, button:focus, input:focus {
    outline: 3px solid var(--accent-cyan);
    outline-offset: 2px;
}

/* ==========================================================================
   2. HLAVIČKA A NAVIGACE (Flexbox)
   ========================================================================== */
.main-header {
    background-color: rgba(21, 25, 38, 0.9);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-wrapper {
    display: flex;
    flex-direction: column; /* Mobile first: pod sebou */
    align-items: center;
    padding: 15px 20px;
}

.logo a {
    font-size: 1.4rem;
    font-weight: bold;
    color: var(--white);
    text-decoration: none;
}

.main-nav {
    margin-top: 15px;
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: 20px;
}

.main-nav a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 5px 10px;
}

.main-nav a:hover, .main-nav a.active {
    color: var(--accent-cyan);
}

/* ==========================================================================
   3. HERO SEKCE (Úvodní banner)
   ========================================================================== */
.hero-section {
    padding: 80px 0;
    text-align: center;
    background: radial-gradient(circle at center, #1e1b4b 0%, var(--bg-space) 70%);
}

.hero-content h1 {
    font-size: 2.5rem;
    color: var(--white);
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.1rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 30px auto;
}

/* Tlačítka */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    border: none;
}

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

.btn-primary:hover {
    background-color: #4338ca;
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: transparent;
    border: 2px solid var(--accent-cyan);
    color: var(--accent-cyan);
    width: 100%;
}

.btn-secondary:hover {
    background-color: var(--accent-cyan);
    color: var(--bg-space);
}

/* ==========================================================================
   4. ENCYKLOPEDIE PLANET (CSS Grid - Mobile First)
   ========================================================================== */
.planets-section {
    padding: 60px 0;
}

.planets-section h2, .calculator-section h2 {
    font-size: 2rem;
    text-align: center;
    color: var(--white);
    margin-bottom: 10px;
}

.section-subtitle {
    text-align: center;
    color: var(--text-muted);
    margin-bottom: 40px;
}

/* CSS Grid definice pro karty */
.planets-grid {
    display: grid;
    grid-template-columns: 1fr; /* Na mobilu 1 sloupec */
    gap: 30px;
}

.planet-card {
    background-color: var(--bg-card);
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.planet-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(6, 182, 212, 0.1);
}

.planet-card img {
    width: 100%;
    height: 250px;
    object-fit: cover; /* Aby se obrázek nedeformoval */
    background-color: #000; /* fallback než se načte obrázek */
}

.card-body {
    padding: 25px;
}

.card-body h3 {
    font-size: 1.5rem;
    color: var(--white);
    margin-bottom: 10px;
}

.card-body p {
    color: var(--text-muted);
    margin-bottom: 20px;
    font-size: 0.95rem;
}

/* ==========================================================================
   5. KALKULAČKA (Flexbox / Form styling)
   ========================================================================== */
.calculator-section {
    padding: 60px 0;
    background-color: rgba(21, 25, 38, 0.5);
}

.calculator-wrapper {
    max-width: 600px;
    margin: 0 auto;
}

.calc-form {
    margin-top: 30px;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 500;
    color: var(--text-main);
}

.form-group input {
    padding: 12px;
    border-radius: 8px;
    border: 2px solid rgba(255, 255, 255, 0.1);
    background-color: var(--bg-space);
    color: var(--white);
    font-size: 1rem;
}

.calc-result {
    margin-top: 30px;
    padding: 20px;
    border-radius: 8px;
    background-color: var(--bg-card);
    border-left: 4px solid var(--accent-cyan);
    min-height: 50px;
}

/* ==========================================================================
   6. PATIČKA
   ========================================================================== */
.main-footer {
    padding: 40px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer-wrapper p + p {
    margin-top: 5px;
}

/* ==========================================================================
   7. RESPONSIVE DESIGN (Média dotazy pro Tablet a Desktop)
   ========================================================================== */

/* Tablet a širší (nad 600px) */
@media (min-width: 600px) {
    .header-wrapper {
        flex-direction: row; /* Navigace a logo vedle sebe */
        justify-content: space-between;
    }
    
    .main-nav {
        margin-top: 0;
    }
    
    .planets-grid {
        grid-template-columns: repeat(2, 1fr); /* 2 karty vedle sebe */
    }
    
    .hero-content h1 {
        font-size: 3.5rem;
    }
}

/* Velký desktop (nad 900px) */
@media (min-width: 900px) {
    .planets-grid {
        grid-template-columns: repeat(3, 1fr); /* 3 karty vedle sebe */
    }
}

/* ==========================================
   MODÁLNÍ DIALOG – Detail planety
   Přidat na konec souboru css/style.css
   ========================================== */

/* Základní dialog element */
#planet-modal {
    border: none;
    border-radius: 20px;
    padding: 0;
    background: #0f1117;
    color: #e8eaf0;
    max-width: 680px;
    width: calc(100% - 2rem);
    max-height: 90vh;
    overflow: hidden;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.7), 0 0 0 1px rgba(255, 255, 255, 0.06);

    /* Animace otevření */
    opacity: 0;
    transform: translateY(24px) scale(0.97);
    transition: opacity 0.28s ease, transform 0.28s ease;
}

#planet-modal.modal-open {
    opacity: 1;
    transform: translateY(0) scale(1);
}

/* Backdrop */
#planet-modal::backdrop {
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
}

.modal-inner {
    display: flex;
    flex-direction: column;
    max-height: 90vh;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(255,255,255,0.1) transparent;
}

/* HLAVIČKA modálu */
.modal-header {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 2rem;
    background: var(--planet-color-light, rgba(193, 68, 14, 0.12));
    border-bottom: 1px solid rgba(255, 255, 255, 0.07);
    position: relative;
}

/* Vizuální koule planety */
.modal-planet-visual {
    position: relative;
    flex-shrink: 0;
}

.modal-planet-orb {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    box-shadow:
        inset -12px -12px 24px rgba(0,0,0,0.5),
        0 0 30px rgba(193, 68, 14, 0.35),
        0 0 60px rgba(193, 68, 14, 0.1);
    animation: planetFloat 4s ease-in-out infinite;
}

.modal-planet-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) rotateX(75deg);
    width: 120px;
    height: 120px;
    border-radius: 50%;
    border: 2px solid rgba(193, 68, 14, 0.3);
    pointer-events: none;
}

@keyframes planetFloat {
    0%, 100% { transform: translateY(0px); }
    50%       { transform: translateY(-6px); }
}

/* Text v hlavičce */
.modal-header-text {
    flex: 1;
    min-width: 0;
}

.modal-subtitle {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--planet-color, #c1440e);
    margin: 0 0 0.25rem;
}

.modal-header-text h2 {
    font-size: 2rem;
    font-weight: 700;
    margin: 0 0 0.75rem;
    color: #ffffff;
    line-height: 1.1;
}

.modal-description {
    font-size: 0.9rem;
    line-height: 1.6;
    color: #9aa0b0;
    margin: 0;
}

/* Tlačítko zavřít */
.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: #9aa0b0;
    font-size: 0.85rem;
    transition: background 0.2s, color 0.2s;
    flex-shrink: 0;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.12);
    color: #ffffff;
}

/* TĚLO modálu */
.modal-body {
    padding: 1.75rem 2rem 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

.modal-section-title {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #5a6075;
    margin: 0 0 1rem;
}

/* Mřížka statistik */
.modal-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 0.5rem;
}

.modal-stat {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 10px;
    padding: 0.75rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.modal-stat-label {
    font-size: 0.72rem;
    color: #5a6075;
    font-weight: 500;
}

.modal-stat-value {
    font-size: 0.95rem;
    color: #e8eaf0;
    font-weight: 600;
}

/* Seznam zajímavostí */
.modal-facts-list {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.modal-fact {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.65rem 0.9rem;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    font-size: 0.875rem;
    color: #b0b8cc;
    line-height: 1.5;
}

.modal-fact-icon {
    font-size: 1.1rem;
    flex-shrink: 0;
    margin-top: 0.05rem;
}

/* Responzivita */
@media (max-width: 600px) {
    .modal-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
        padding: 1.5rem;
    }

    .modal-header-text h2 {
        font-size: 1.6rem;
    }

    .modal-body {
        padding: 1.25rem;
    }

    .modal-stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .modal-close {
        top: 0.75rem;
        right: 0.75rem;
    }
}
/* ==========================================
   DOPLNĚK – Nové planety + modální dialog
   Přidat na konec souboru css/style.css
   ========================================== */

/* Grid planet – 3 sloupce na desktopu, 2 na tabletu, 1 na mobilu */
.planets-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 2.5rem;
}

@media (max-width: 900px) {
    .planets-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 560px) {
    .planets-grid {
        grid-template-columns: 1fr;
    }
}

/* Karta planety */
.planet-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.07);
    border-radius: 16px;
    overflow: hidden;
    transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
    display: flex;
    flex-direction: column;
}

.planet-card:hover {
    transform: translateY(-6px);
    border-color: rgba(255, 255, 255, 0.18);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}

.planet-card img {
    width: 100%;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    display: block;
    background: #0a0c14;
}

.card-body {
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    flex: 1;
    gap: 0.6rem;
}

.card-body h3 {
    margin: 0;
    font-size: 1.25rem;
    color: #ffffff;
}

.card-body p {
    margin: 0;
    font-size: 0.875rem;
    line-height: 1.6;
    color: #9aa0b0;
    flex: 1;
}

/* Tlačítko Detail planety */
.btn-secondary {
    margin-top: auto;
    padding: 0.55rem 1.1rem;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.15);
    background: rgba(255, 255, 255, 0.05);
    color: #e0e4f0;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s, transform 0.15s;
    align-self: flex-start;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.28);
    transform: scale(1.03);
}

.btn-secondary:active {
    transform: scale(0.97);
}

/* ==========================================
   MODÁLNÍ DIALOG – Detail planety
   ========================================== */

#planet-modal {
    border: none;
    border-radius: 20px;
    padding: 0;
    background: #0f1117;
    color: #e8eaf0;
    max-width: 680px;
    width: calc(100% - 2rem);
    max-height: 90vh;
    overflow: hidden;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.7), 0 0 0 1px rgba(255, 255, 255, 0.06);
    opacity: 0;
    transform: translateY(24px) scale(0.97);
    transition: opacity 0.28s ease, transform 0.28s ease;
}

#planet-modal.modal-open {
    opacity: 1;
    transform: translateY(0) scale(1);
}

#planet-modal::backdrop {
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
}

.modal-inner {
    display: flex;
    flex-direction: column;
    max-height: 90vh;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(255, 255, 255, 0.1) transparent;
}

.modal-header {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 2rem;
    background: var(--planet-color-light, rgba(193, 68, 14, 0.12));
    border-bottom: 1px solid rgba(255, 255, 255, 0.07);
    position: relative;
}

.modal-planet-visual {
    position: relative;
    flex-shrink: 0;
}

.modal-planet-orb {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    box-shadow:
        inset -12px -12px 24px rgba(0, 0, 0, 0.5),
        0 0 30px rgba(100, 100, 255, 0.2),
        0 0 60px rgba(100, 100, 255, 0.08);
    animation: planetFloat 4s ease-in-out infinite;
}

.modal-planet-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) rotateX(75deg);
    width: 120px;
    height: 120px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.1);
    pointer-events: none;
}

@keyframes planetFloat {
    0%, 100% { transform: translateY(0px); }
    50%       { transform: translateY(-6px); }
}

.modal-header-text {
    flex: 1;
    min-width: 0;
}

.modal-subtitle {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--planet-color, #888);
    margin: 0 0 0.25rem;
}

.modal-header-text h2 {
    font-size: 2rem;
    font-weight: 700;
    margin: 0 0 0.75rem;
    color: #ffffff;
    line-height: 1.1;
}

.modal-description {
    font-size: 0.9rem;
    line-height: 1.6;
    color: #9aa0b0;
    margin: 0;
}

.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: #9aa0b0;
    font-size: 0.85rem;
    transition: background 0.2s, color 0.2s;
    flex-shrink: 0;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.12);
    color: #ffffff;
}

.modal-body {
    padding: 1.75rem 2rem 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

.modal-section-title {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #5a6075;
    margin: 0 0 1rem;
}

.modal-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 0.5rem;
}

.modal-stat {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 10px;
    padding: 0.75rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.modal-stat-label {
    font-size: 0.72rem;
    color: #5a6075;
    font-weight: 500;
}

.modal-stat-value {
    font-size: 0.95rem;
    color: #e8eaf0;
    font-weight: 600;
}

.modal-facts-list {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.modal-fact {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.65rem 0.9rem;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    font-size: 0.875rem;
    color: #b0b8cc;
    line-height: 1.5;
}

.modal-fact-icon {
    font-size: 1.1rem;
    flex-shrink: 0;
    margin-top: 0.05rem;
}

@media (max-width: 600px) {
    .modal-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
        padding: 1.5rem;
    }

    .modal-header-text h2 {
        font-size: 1.6rem;
    }

    .modal-body {
        padding: 1.25rem;
    }

    .modal-stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .modal-close {
        top: 0.75rem;
        right: 0.75rem;
    }
}