/* ── Space Invaders — Emerald Theme ── */
:root {
    --si-accent: #10B981;
    --si-accent-light: #6EE7B7;
    --si-accent-dark: #047857;
    --si-glow: rgba(16, 185, 129, 0.55);
    --si-bg: #021510;
    --si-surface: #04221A;
    --si-surface-light: #0A3527;
    --si-text: #D1FAE5;
    --si-text-dim: #6CA398;
    --si-gold: #FACC15;
    --si-danger: #F87171;
    --si-magenta: #EC4899;
}

.si-layout {
    display: flex; justify-content: center; gap: 20px;
    max-width: 1200px; margin: 0 auto;
    padding: 20px; min-height: calc(100vh - 80px);
}
.ad-slot { width: 160px; flex-shrink: 0; }
.ad-slot--left, .ad-slot--right { display: flex; align-items: flex-start; }
.ad-placeholder--vertical {
    width: 160px; height: 600px;
    background: var(--si-surface);
    border: 1px dashed var(--si-text-dim);
    display: flex; align-items: center; justify-content: center;
    color: var(--si-text-dim); font-size: 12px; border-radius: 8px;
}

#spaceinvaders-app {
    flex: 1; max-width: 760px; min-width: 320px;
    color: var(--si-text);
}

.screen { display: none; }
.screen.active { display: block; animation: siFade 0.3s ease; }
@keyframes siFade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

.si-header { text-align: center; padding: 36px 0 24px; }
.si-logo {
    display: inline-block;
    padding: 16px 20px;
    background: var(--si-surface);
    border-radius: 12px;
    border: 1px solid var(--si-surface-light);
    margin-bottom: 14px;
}
.si-invader {
    width: 48px; height: 36px;
    background:
        radial-gradient(circle at 25% 35%, var(--si-accent) 22%, transparent 24%),
        radial-gradient(circle at 75% 35%, var(--si-accent) 22%, transparent 24%),
        linear-gradient(var(--si-accent), var(--si-accent));
    mask: linear-gradient(#000,#000);
    box-shadow: 0 0 18px var(--si-glow);
    border-radius: 6px;
    animation: siPulse 1.6s ease-in-out infinite alternate;
}
@keyframes siPulse { from { transform: translateY(0); } to { transform: translateY(-4px); } }

.si-header h1 {
    font-family: 'Syne', sans-serif;
    font-size: 2.6rem; font-weight: 800;
    color: var(--si-accent-light);
    letter-spacing: 4px; margin: 0;
    text-shadow: 0 0 26px var(--si-glow);
}
.subtitle { color: var(--si-text-dim); font-size: 1rem; margin-top: 8px; }

.card {
    background: var(--si-surface);
    border-radius: 14px; padding: 20px;
    margin-bottom: 16px;
    border: 1px solid var(--si-surface-light);
}
.card__title {
    font-family: 'Syne', sans-serif;
    font-size: 0.85rem; text-transform: uppercase;
    letter-spacing: 2px; color: var(--si-accent-light);
    margin-bottom: 14px;
}

.difficulty-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.diff-btn {
    background: var(--si-surface-light); border: 1.5px solid transparent;
    color: var(--si-text); padding: 14px 8px; border-radius: 10px;
    cursor: pointer; display: flex; flex-direction: column;
    align-items: center; gap: 4px;
    transition: transform 0.15s ease, border-color 0.15s ease, background 0.15s ease;
    font-family: 'DM Sans', sans-serif; font-size: 0.85rem;
}
.diff-btn:hover { transform: translateY(-2px); border-color: var(--si-accent); }
.diff-btn.selected {
    background: linear-gradient(135deg, var(--si-accent-dark), var(--si-accent));
    border-color: var(--si-accent-light);
    box-shadow: 0 0 16px var(--si-glow);
}
.diff-icon { font-family: 'JetBrains Mono', monospace; font-size: 0.9rem; font-weight: 700; color: var(--si-accent-light); }
.diff-btn.selected .diff-icon { color: #fff; }
.diff-desc { font-size: 0.72rem; color: var(--si-text-dim); }
.diff-btn.selected .diff-desc { color: rgba(255,255,255,0.85); }

.si-rules { margin: 0; padding-left: 1.1rem; color: var(--si-text-dim); font-size: 0.92rem; line-height: 1.6; }
.si-rules li + li { margin-top: 6px; }

.btn { font-family: 'DM Sans', sans-serif; font-weight: 600; border-radius: 10px; border: none; cursor: pointer; padding: 12px 22px; transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.15s ease; font-size: 0.95rem; }
.btn:hover { transform: translateY(-1px); }
.btn--primary { background: linear-gradient(135deg, var(--si-accent), var(--si-accent-light)); color: #021510; box-shadow: 0 6px 18px var(--si-glow); }
.btn--primary:hover { box-shadow: 0 10px 24px var(--si-glow); }
.btn--outline { background: transparent; border: 1.5px solid var(--si-accent); color: var(--si-accent-light); }
.btn--outline:hover { background: rgba(16, 185, 129, 0.12); }
.btn--ghost { background: transparent; color: var(--si-text-dim); }
.btn--ghost:hover { color: var(--si-accent-light); }
.btn--lg { padding: 16px 36px; font-size: 1.05rem; }
.btn--sm { padding: 8px 14px; font-size: 0.85rem; }
.menu-actions { display: flex; flex-direction: column; align-items: center; gap: 8px; margin-top: 18px; }

#game-hud {
    display: grid; grid-template-columns: repeat(4, 1fr);
    gap: 10px; background: var(--si-surface); padding: 14px;
    border-radius: 12px; border: 1px solid var(--si-surface-light);
    margin-bottom: 14px;
}
.hud__cell { display: flex; flex-direction: column; align-items: center; gap: 2px; }
.hud__label { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 1.5px; color: var(--si-text-dim); }
.hud__value { font-family: 'JetBrains Mono', monospace; font-size: 1.4rem; font-weight: 700; color: var(--si-accent-light); }

.si-canvas-wrap {
    display: flex; justify-content: center;
    background: var(--si-surface); border: 1px solid var(--si-surface-light);
    border-radius: 14px; padding: 12px;
    box-shadow: 0 12px 36px rgba(0,0,0,0.45);
}
#si-canvas {
    background: radial-gradient(ellipse at center, #022D20 0%, #010906 90%);
    border-radius: 8px; max-width: 100%; height: auto; display: block;
}

.si-touch { display: none; gap: 12px; justify-content: center; margin-top: 14px; }
.touch-btn {
    width: 70px; height: 60px; background: var(--si-surface);
    border: 1.5px solid var(--si-accent); color: var(--si-accent-light);
    border-radius: 12px; font-size: 1.3rem; cursor: pointer; user-select: none;
    -webkit-tap-highlight-color: transparent;
}
.touch-btn--fire { background: var(--si-accent); color: #021510; font-weight: 700; border-color: var(--si-accent-light); }
.touch-btn:active { transform: scale(0.92); }
.si-actions { display: flex; justify-content: center; margin-top: 16px; }

.result-card, .lb-card {
    background: var(--si-surface); border-radius: 16px;
    padding: 36px 28px; border: 1px solid var(--si-surface-light);
    text-align: center; max-width: 480px; margin: 40px auto;
    box-shadow: 0 18px 36px rgba(0,0,0,0.4);
}
.result-card h2 {
    font-family: 'Syne', sans-serif; font-size: 2rem; color: var(--si-accent-light);
    letter-spacing: 4px; margin: 0 0 12px; text-shadow: 0 0 24px var(--si-glow);
}
.result-score { font-family: 'JetBrains Mono', monospace; font-size: 3rem; font-weight: 700; color: var(--si-gold); margin: 8px 0; }
.result-detail { color: var(--si-text-dim); font-size: 0.95rem; margin-bottom: 18px; line-height: 1.6; }
#nickname {
    width: 100%; padding: 12px 14px; border-radius: 10px;
    background: var(--si-bg); color: var(--si-text);
    border: 1.5px solid var(--si-surface-light);
    font-family: 'DM Sans', sans-serif; font-size: 0.95rem;
    margin-bottom: 12px; box-sizing: border-box;
}
#nickname:focus { outline: none; border-color: var(--si-accent); }
.result-actions { display: flex; gap: 10px; justify-content: center; margin-bottom: 10px; }

.lb-card h2 { font-family: 'Syne', sans-serif; color: var(--si-accent-light); letter-spacing: 4px; margin-bottom: 18px; text-shadow: 0 0 24px var(--si-glow); }
#leaderboard-list { list-style: none; padding: 0; margin: 0 0 16px; text-align: left; counter-reset: lb; }
#leaderboard-list li {
    counter-increment: lb; display: flex; justify-content: space-between;
    padding: 10px 14px; background: var(--si-bg);
    margin-bottom: 6px; border-radius: 8px;
    border: 1px solid var(--si-surface-light);
    font-family: 'DM Sans', sans-serif;
}
#leaderboard-list li::before { content: counter(lb); color: var(--si-accent-light); font-weight: 700; margin-right: 10px; min-width: 24px; }
#leaderboard-list li:nth-child(1) { border-color: var(--si-gold); }
#leaderboard-list li:nth-child(1)::before { color: var(--si-gold); }
#leaderboard-list .lb-score { font-family: 'JetBrains Mono', monospace; color: var(--si-accent-light); font-weight: 600; }

@media (max-width: 900px) {
    .si-layout { flex-direction: column; padding: 12px; }
    .ad-slot { width: 100%; }
    .ad-placeholder--vertical { width: 100%; height: 90px; }
    .si-header h1 { font-size: 2rem; letter-spacing: 2px; }
    #game-hud { grid-template-columns: repeat(2, 1fr); }
    .si-touch { display: flex; }
}