:root {
    --scale-width-1: clamp(260px, 90vw, 420px);
    --purple-main: #4b44d4;
    --purple-dark: #312ba1;
    --gold: #fbc02d;
    --bg-black: #0a1b2e;
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--bg-black);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-family: 'Segoe UI', Arial, sans-serif;
    overflow-x: hidden;
}

/* NAVIGATION */
.scale-selector {
    margin-bottom: 30px;
    display: flex;
    gap: 10px;
}

.tab-btn {
    padding: 10px 20px;
    border: 2px solid var(--purple-main);
    background: transparent;
    color: white;
    cursor: pointer;
    border-radius: 20px;
    font-weight: bold;
    transition: 0.3s;
}

.tab-btn.active { background: var(--purple-main); }

.scale-view {
    display: none;
    flex-direction: column;
    align-items: center;
    width: 100%;
}

.scale-view.active { display: flex; }

/* --- SCALE 1 (SIMPLE) --- */
.beam-wrapper-1 {
    width: var(--scale-width-1);
    height: 40px;
    position: relative;
    margin-bottom: 25px;
}
.beam-1 {
    width: 100%; height: 10px;
    background: #00cde8; border-radius: 5px;
    transform-origin: center;
    transition: transform 0.4s ease;
}
.pivot-1 {
    position: absolute; left: 50%; top: -18px;
    transform: translateX(-50%);
    width: 36px; height: 36px;
    background: #fff; border-radius: 50%;
}
.plate-1 {
    width: clamp(80px, 22vw, 140px); height: 22px;
    background: #ffc93c; border-radius: 0 0 50px 50px;
    position: absolute; top: -12px;
}
.left-1 { left: -6px; }
.right-1 { right: -6px; }
.base-1 {
    width: 120px; height: 70px;
    background: #00cde8;
    clip-path: polygon(15% 100%, 85% 100%, 65% 0%, 35% 0%);
}

/* --- SCALE 2 (3D) --- */
.scale-stage-2 {
    position: relative;
    width: 100%; max-width: 500px;
    height: 380px;
    display: flex; justify-content: center; align-items: flex-end;
}
.pillar-assembly-2 {
    position: absolute; bottom: 40px;
    display: flex; flex-direction: column; align-items: center;
    z-index: 1;
}
.finial-top-2 {
    width: 16px; height: 26px;
    background: var(--gold); border-radius: 50% 50% 20% 20%;
    margin-bottom: -5px; box-shadow: inset -2px -2px 5px rgba(0,0,0,0.3);
}
.vertical-stick-2 {
    width: 20px; height: 210px;
    background: linear-gradient(to right, var(--purple-dark), var(--purple-main), #6b64f0);
    border-radius: 10px;
}
.base-bottom-2 {
    width: 140px; height: 40px;
    background: var(--purple-dark);
    border-radius: 50% / 15px;
    margin-top: -15px; box-shadow: 0 5px 15px rgba(0,0,0,0.8);
}
.beam-pivot-2 {
    position: absolute; bottom: 225px;
    width: 440px; height: 100px;
    transform-origin: center 15px;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 2; display: flex; justify-content: center;
}
.beam-svg-2 { width: 100%; filter: drop-shadow(0 5px 5px rgba(0,0,0,0.4)); }
.hanging-pan-2 {
    position: absolute; top: 35px;
    display: flex; flex-direction: column; align-items: center;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}
.left-pan-2 { left: 5px; }
.right-pan-2 { right: 5px; }
.chain-links-2 {
    width: 80px; height: 130px;
    stroke: #e0e0e0; stroke-width: 1.5; fill: none; stroke-dasharray: 2, 2;
}
.gold-bowl-2 {
    width: 135px; height: 45px;
    background: linear-gradient(180deg, var(--gold) 0%, #d4a017 100%);
    border-radius: 5px 5px 60px 60px;
    margin-top: -5px;
}

/* --- CONTROLS --- */
.controls-panel {
    background: #0d1526; padding: 20px; border-radius: 20px;
    display: grid; grid-template-columns: 1fr 1fr; gap: 20px;
    width: 85%; max-width: 400px; margin-top: 30px; border: 1px solid #1e2a44;
}
.control-unit { display: flex; flex-direction: column; align-items: center; gap: 10px; }
.action-btn {
    background: #3a4252; color: white; border: none;
    width: 45px; height: 45px; border-radius: 10px;
    font-size: 22px; cursor: pointer;
}
.action-btn:active { transform: scale(0.9); }
.mass-val { font-size: 20px; font-weight: bold; }

@media (max-width: 480px) {
    .scale-stage-2 { transform: scale(0.75); height: 300px; }
}