/* =========================================
   RESET & BASE
   ========================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --bg-deep:    #0a0e1a;
    --bg-card:    #111827;
    --bg-card2:   #1a2235;
    --border:     #1e2d45;
    --text:       #e2e8f0;
    --text-muted: #94a3b8;
    --accent:     #f59e0b;
    --accent2:    #3b82f6;
    --success:    #22c55e;
    --danger:     #ef4444;
    --warning:    #f59e0b;
    --radius:     12px;
    --shadow:     0 4px 24px rgba(0,0,0,0.5);
}

html { scroll-behavior: smooth; }

body {
    background: var(--bg-deep);
    color: var(--text);
    font-family: 'Poppins', sans-serif;
    font-size: 15px;
    line-height: 1.6;
    min-height: 100vh;
    background-image:
        radial-gradient(ellipse at 20% 50%, rgba(59,130,246,0.04) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(245,158,11,0.03) 0%, transparent 40%);
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* =========================================
   NAVBAR
   ========================================= */
.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10,14,26,0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-brand {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    letter-spacing: 1px;
}

.sun-icon {
    font-size: 1.4rem;
    animation: spin 20s linear infinite;
    display: inline-block;
}

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

.nav-links {
    list-style: none;
    display: flex;
    gap: 0.25rem;
}

.nav-links a {
    padding: 0.45rem 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-muted);
    transition: all 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    background: var(--bg-card2);
    color: var(--text);
}

.nav-links a.active {
    color: var(--accent);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text);
    font-size: 1.4rem;
    cursor: pointer;
}

/* =========================================
   FOOTER
   ========================================= */
.footer {
    border-top: 1px solid var(--border);
    padding: 2rem 1.5rem;
    text-align: center;
    background: var(--bg-card);
}

.footer-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 1rem;
    color: var(--accent);
    margin-bottom: 0.25rem;
}

.footer-sub {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 0.5rem;
}

.footer-copy {
    color: var(--text-muted);
    font-size: 0.8rem;
    opacity: 0.6;
}

/* =========================================
   SOLAR SYSTEM ANIMATION
   ========================================= */
.solar-system {
    position: relative;
    width: 420px;
    height: 420px;
    flex-shrink: 0;
}

.solar-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.sun {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: radial-gradient(circle at 40% 40%, #fff7a0, #fbbf24, #f97316, #b45309);
    box-shadow:
        0 0 20px 6px rgba(251,191,36,0.6),
        0 0 60px 20px rgba(251,191,36,0.25),
        0 0 100px 40px rgba(251,191,36,0.1);
    animation: pulse-sun 3s ease-in-out infinite;
}

@keyframes pulse-sun {
    0%, 100% { box-shadow: 0 0 20px 6px rgba(251,191,36,0.6), 0 0 60px 20px rgba(251,191,36,0.25), 0 0 100px 40px rgba(251,191,36,0.1); }
    50%       { box-shadow: 0 0 28px 10px rgba(251,191,36,0.75), 0 0 80px 30px rgba(251,191,36,0.35), 0 0 130px 55px rgba(251,191,36,0.15); }
}

.orbit {
    position: absolute;
    top: 50%;
    left: 50%;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.07);
    transform: translate(-50%, -50%);
}

.planet-wrapper {
    position: absolute;
    top: 50%;
    left: 50%;
    transform-origin: 0 0;
    animation: orbit-anim linear infinite;
}

.planet-dot {
    position: absolute;
    border-radius: 50%;
    transform: translate(-50%, -50%);
    box-shadow: 0 0 8px 2px rgba(255,255,255,0.15);
}

/* orbit sizes */
.orbit-1  { width:  96px; height:  96px; }
.orbit-2  { width: 140px; height: 140px; }
.orbit-3  { width: 184px; height: 184px; }
.orbit-4  { width: 228px; height: 228px; }
.orbit-5  { width: 280px; height: 280px; }
.orbit-6  { width: 330px; height: 330px; }
.orbit-7  { width: 376px; height: 376px; }
.orbit-8  { width: 418px; height: 418px; }

/* planet wrappers */
.pw-1 { width:  48px; height:  48px; margin: -24px 0 0 -24px; animation-duration:  4s; }
.pw-2 { width:  70px; height:  70px; margin: -35px 0 0 -35px; animation-duration:  7s; }
.pw-3 { width:  92px; height:  92px; margin: -46px 0 0 -46px; animation-duration: 10s; }
.pw-4 { width: 114px; height: 114px; margin: -57px 0 0 -57px; animation-duration: 16s; }
.pw-5 { width: 140px; height: 140px; margin: -70px 0 0 -70px; animation-duration: 38s; }
.pw-6 { width: 165px; height: 165px; margin: -82px 0 0 -82px; animation-duration: 62s; }
.pw-7 { width: 188px; height: 188px; margin: -94px 0 0 -94px; animation-duration: 90s; }
.pw-8 { width: 209px; height: 209px; margin: -104px 0 0 -104px; animation-duration:140s; }

/* planet dot sizes */
.pd-1  { width:  7px; height:  7px;  top:  48px; left: 50%; }
.pd-2  { width: 11px; height: 11px; top:  70px; left: 50%; }
.pd-3  { width: 12px; height: 12px; top:  92px; left: 50%; }
.pd-4  { width:  9px; height:  9px;  top: 114px; left: 50%; }
.pd-5  { width: 22px; height: 22px; top: 140px; left: 50%; }
.pd-6  { width: 20px; height: 20px; top: 165px; left: 50%; }
.pd-7  { width: 16px; height: 16px; top: 188px; left: 50%; }
.pd-8  { width: 15px; height: 15px; top: 209px; left: 50%; }

@keyframes orbit-anim {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}

/* =========================================
   HERO SECTION
   ========================================= */
.hero {
    min-height: calc(100vh - 64px);
    display: flex;
    align-items: center;
    padding: 3rem 1.5rem;
    overflow: hidden;
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, rgba(59,130,246,0.06) 0%, transparent 60%);
    pointer-events: none;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: flex;
    align-items: center;
    gap: 4rem;
    flex-wrap: wrap;
}

.hero-text { flex: 1; min-width: 280px; }

.hero-badge {
    display: inline-block;
    background: rgba(245,158,11,0.1);
    color: var(--accent);
    border: 1px solid rgba(245,158,11,0.3);
    padding: 0.3rem 1rem;
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 500;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 1.25rem;
}

.hero-title {
    font-family: 'Orbitron', sans-serif;
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #ffffff 30%, #fbbf24);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.05rem;
    color: var(--text-muted);
    max-width: 500px;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* =========================================
   BUTTONS
   ========================================= */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.7rem 1.6rem;
    border-radius: 999px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s;
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: #1a1a1a;
    box-shadow: 0 4px 20px rgba(245,158,11,0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 28px rgba(245,158,11,0.45);
}

.btn-outline {
    background: transparent;
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-outline:hover {
    background: var(--bg-card2);
    border-color: var(--accent2);
    color: var(--accent2);
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--bg-card2);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--border);
    transform: translateY(-2px);
}

.btn-danger {
    background: var(--danger);
    color: #fff;
}

.btn-success {
    background: var(--success);
    color: #fff;
}

/* =========================================
   SECTION STYLES
   ========================================= */
.section {
    padding: 5rem 1.5rem;
}

.section-container {
    max-width: 1200px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

.section-title {
    font-family: 'Orbitron', sans-serif;
    font-size: clamp(1.5rem, 3vw, 2.25rem);
    font-weight: 700;
    color: var(--text);
    margin-bottom: 0.75rem;
}

.section-desc {
    color: var(--text-muted);
    font-size: 0.95rem;
    max-width: 500px;
    margin: 0 auto;
}

/* =========================================
   CARDS
   ========================================= */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: all 0.3s;
}

.card:hover {
    border-color: rgba(245,158,11,0.3);
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

/* =========================================
   PLANET GRID
   ========================================= */
.planets-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.25rem;
}

.planet-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem 1rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    color: inherit;
    display: block;
}

.planet-card:hover {
    transform: translateY(-6px);
    border-color: var(--planet-color, var(--accent));
    box-shadow: 0 8px 32px rgba(0,0,0,0.4);
}

.planet-orb {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    margin: 0 auto 1rem;
    position: relative;
    box-shadow: 0 4px 16px rgba(0,0,0,0.4);
}

.planet-card-name {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.85rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.planet-card-subtitle {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.planet-card-order {
    display: inline-block;
    font-size: 0.7rem;
    color: var(--text-muted);
    background: var(--bg-card2);
    border-radius: 4px;
    padding: 0.15rem 0.5rem;
}

/* =========================================
   PLANET DETAIL
   ========================================= */
.planet-detail-hero {
    padding: 4rem 1.5rem 2rem;
    text-align: center;
    background: linear-gradient(to bottom, var(--bg-card2) 0%, transparent 100%);
}

.planet-sphere {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    margin: 0 auto 2rem;
    box-shadow: 0 0 40px 10px rgba(255,255,255,0.1), inset -20px -10px 30px rgba(0,0,0,0.5);
    animation: float 4s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50%       { transform: translateY(-12px); }
}

.planet-detail-title {
    font-family: 'Orbitron', sans-serif;
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 900;
    margin-bottom: 0.4rem;
}

.planet-detail-subtitle {
    color: var(--text-muted);
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.planet-type-badge {
    display: inline-block;
    padding: 0.25rem 0.8rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.type-planet { background: rgba(59,130,246,0.15); color: #60a5fa; border: 1px solid rgba(59,130,246,0.3); }
.type-star   { background: rgba(245,158,11,0.15); color: #fbbf24; border: 1px solid rgba(245,158,11,0.3); }
.type-dwarf  { background: rgba(168,85,247,0.15); color: #c084fc; border: 1px solid rgba(168,85,247,0.3); }

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 1rem;
    margin: 2.5rem 0;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1rem;
    text-align: center;
}

.stat-icon {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 0.25rem;
}

.stat-value {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--text);
}

.description-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 1.5rem;
    line-height: 1.9;
    color: var(--text-muted);
}

.fun-facts-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.fun-facts-list li {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1rem 1.25rem;
}

.fact-icon {
    font-size: 1.2rem;
    flex-shrink: 0;
    margin-top: 1px;
}

.planet-nav {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 3rem;
    flex-wrap: wrap;
}

/* =========================================
   FACTS SECTION
   ========================================= */
.facts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 1.25rem;
}

.fact-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: all 0.3s;
}

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

.fact-planet-tag {
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 0.75rem;
}

.fact-text {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.7;
}

/* =========================================
   CTA BANNER
   ========================================= */
.cta-banner {
    background: linear-gradient(135deg, rgba(245,158,11,0.1) 0%, rgba(59,130,246,0.1) 100%);
    border: 1px solid rgba(245,158,11,0.2);
    border-radius: 16px;
    padding: 3rem 2rem;
    text-align: center;
    margin: 0 1.5rem;
}

.cta-title {
    font-family: 'Orbitron', sans-serif;
    font-size: clamp(1.3rem, 3vw, 2rem);
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.cta-desc {
    color: var(--text-muted);
    margin-bottom: 1.75rem;
}

/* =========================================
   QUIZ STYLES
   ========================================= */
.quiz-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

.quiz-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.quiz-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.quiz-desc {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.question-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.75rem;
    margin-bottom: 1.25rem;
}

.question-number {
    font-size: 0.75rem;
    color: var(--accent);
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 0.75rem;
}

.question-text {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 1.25rem;
    line-height: 1.5;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.6rem;
}

.option-label {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    background: var(--bg-card2);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.6rem 1rem;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.88rem;
}

.option-label:hover {
    border-color: var(--accent);
    background: rgba(245,158,11,0.06);
}

.option-label input[type="radio"] {
    accent-color: var(--accent);
    flex-shrink: 0;
}

.option-label input[type="radio"]:checked + span {
    color: var(--accent);
    font-weight: 500;
}

.quiz-submit {
    text-align: center;
    margin-top: 2rem;
}

/* =========================================
   QUIZ RESULT
   ========================================= */
.result-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

.score-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2.5rem;
    text-align: center;
    margin-bottom: 2rem;
}

.score-number {
    font-family: 'Orbitron', sans-serif;
    font-size: 4rem;
    font-weight: 900;
    line-height: 1;
    margin-bottom: 0.25rem;
}

.score-total {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.score-badge {
    display: inline-block;
    padding: 0.4rem 1.2rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.badge-success { background: rgba(34,197,94,0.15);  color: #4ade80; border: 1px solid rgba(34,197,94,0.3); }
.badge-warning { background: rgba(245,158,11,0.15); color: #fbbf24; border: 1px solid rgba(245,158,11,0.3); }
.badge-danger  { background: rgba(239,68,68,0.15);  color: #f87171; border: 1px solid rgba(239,68,68,0.3); }

.score-message {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.progress-bar-wrap {
    height: 8px;
    background: var(--bg-card2);
    border-radius: 4px;
    overflow: hidden;
    margin: 1.25rem 0;
}

.progress-bar-fill {
    height: 100%;
    border-radius: 4px;
    background: linear-gradient(90deg, #3b82f6, #f59e0b);
    transition: width 1s ease;
}

.review-section { margin-top: 2rem; }

.review-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.review-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
    margin-bottom: 0.75rem;
}

.review-item.correct  { border-left: 3px solid var(--success); }
.review-item.wrong    { border-left: 3px solid var(--danger);  }

.review-q {
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 0.6rem;
}

.review-answers {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-size: 0.8rem;
}

.answer-tag {
    padding: 0.2rem 0.7rem;
    border-radius: 6px;
    font-size: 0.78rem;
}

.answer-tag.correct-tag { background: rgba(34,197,94,0.15);  color: #4ade80; }
.answer-tag.wrong-tag   { background: rgba(239,68,68,0.15);  color: #f87171; }
.answer-tag.info-tag    { background: var(--bg-card2); color: var(--text-muted); }

/* =========================================
   PAGE HEADER
   ========================================= */
.page-header {
    background: linear-gradient(to bottom, var(--bg-card2), transparent);
    padding: 3rem 1.5rem 2rem;
    text-align: center;
    border-bottom: 1px solid var(--border);
}

.page-header-title {
    font-family: 'Orbitron', sans-serif;
    font-size: clamp(1.6rem, 4vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.page-header-desc {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* =========================================
   ABOUT PAGE
   ========================================= */
.about-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
}

.about-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 1.5rem;
}

.about-card-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 1rem;
}

.about-card p, .about-card li {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.8;
}

.about-card ul {
    padding-left: 1.25rem;
}

/* =========================================
   UTILITY
   ========================================= */
.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }

.divider {
    border: none;
    border-top: 1px solid var(--border);
    margin: 2rem 0;
}

/* =========================================
   RESPONSIVE
   ========================================= */
@media (max-width: 900px) {
    .solar-system { width: 320px; height: 320px; }
    .orbit-8 { width: 318px; height: 318px; }
    .orbit-7 { width: 278px; height: 278px; }
    .orbit-6 { width: 240px; height: 240px; }
    .orbit-5 { width: 200px; height: 200px; }
    .orbit-4 { width: 162px; height: 162px; }
    .orbit-3 { width: 126px; height: 126px; }
    .orbit-2 { width:  98px; height:  98px; }
    .orbit-1 { width:  68px; height:  68px; }
}

@media (max-width: 768px) {
    .nav-toggle { display: block; }
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(10,14,26,0.97);
        flex-direction: column;
        padding: 1rem;
        border-bottom: 1px solid var(--border);
    }
    .nav-links.open { display: flex; }

    .hero-container { flex-direction: column-reverse; align-items: center; text-align: center; gap: 2.5rem; }
    .hero-actions { justify-content: center; }
    .solar-system { width: 280px; height: 280px; }

    .options-grid { grid-template-columns: 1fr; }
    .stats-grid   { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
    .solar-system { display: none; }
    .planets-grid { grid-template-columns: repeat(2, 1fr); }
}

/* Stars background */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image:
        radial-gradient(1px 1px at 10% 15%, rgba(255,255,255,0.4) 0%, transparent 100%),
        radial-gradient(1px 1px at 25% 60%, rgba(255,255,255,0.3) 0%, transparent 100%),
        radial-gradient(1px 1px at 40% 30%, rgba(255,255,255,0.35) 0%, transparent 100%),
        radial-gradient(1px 1px at 55% 80%, rgba(255,255,255,0.25) 0%, transparent 100%),
        radial-gradient(1px 1px at 70% 10%, rgba(255,255,255,0.4) 0%, transparent 100%),
        radial-gradient(1px 1px at 80% 45%, rgba(255,255,255,0.3) 0%, transparent 100%),
        radial-gradient(1px 1px at 90% 70%, rgba(255,255,255,0.35) 0%, transparent 100%),
        radial-gradient(1px 1px at 15% 90%, rgba(255,255,255,0.2) 0%, transparent 100%),
        radial-gradient(1px 1px at 35% 50%, rgba(255,255,255,0.3) 0%, transparent 100%),
        radial-gradient(1px 1px at 60% 25%, rgba(255,255,255,0.25) 0%, transparent 100%),
        radial-gradient(1px 1px at 5%  40%, rgba(255,255,255,0.4) 0%, transparent 100%),
        radial-gradient(1px 1px at 95% 55%, rgba(255,255,255,0.3) 0%, transparent 100%);
    pointer-events: none;
    z-index: 0;
}

main, .navbar, .footer { position: relative; z-index: 1; }