:root{--body-bg:#f0f2f8;--surface:#ffffff;--surface-alt:#f8fafc;--border:#e2e8f0;--border-light:#f1f5f9;--text-primary:#0f172a;--text-secondary:#475569;--text-muted:#94a3b8;--accent:#f97316;--accent-dark:#ea580c;--accent-bg:#fff7ed;--blue:#2563eb;--blue-dark:#1d4ed8;--blue-bg:#eff6ff;--green:#16a34a;--green-bg:#f0fdf4;--red:#dc2626;--yellow:#d97706;--header-bg:#0f172a;--footer-bg:#0f172a;--hero-bg:linear-gradient(135deg,#0f172a 0%,#1e3a5f 60%,#1e4080 100%);--font-heading:'Inter',system-ui,sans-serif;--font-mono:'Roboto Mono',monospace;--radius-xs:6px;--radius-sm:10px;--radius:16px;--radius-lg:24px;--shadow-xs:0 1px 2px rgba(0,0,0,.06);--shadow-sm:0 2px 8px rgba(0,0,0,.07),0 1px 2px rgba(0,0,0,.04);--shadow:0 4px 20px rgba(0,0,0,.09),0 2px 6px rgba(0,0,0,.05);--shadow-lg:0 12px 48px rgba(0,0,0,.12),0 4px 16px rgba(0,0,0,.06);--transition:.2s cubic-bezier(.4,0,.2,1);--chalk-white:#f1f5f9;--chalk-black:#cbd5e1;--chalk-yellow:#fbbf24;--chalk-blue:#60a5fa;--chalk-green:#4ade80;--chalk-red:#f87171;--font-chalk:'Caveat',var(--font-mono),cursive}*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}html,body{overflow-x:clip;width:100%}body{font-family:var(--font-heading);background:var(--body-bg);color:var(--text-primary);line-height:1.65}a{text-decoration:none;color:inherit}img{max-width:100%;display:block}button{font-family:var(--font-heading)}a:focus-visible,button:focus-visible,summary:focus-visible,.tool-card:focus-visible,details:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:6px}@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:0.01ms !important;animation-iteration-count:1 !important;transition-duration:0.01ms !important;scroll-behavior:auto !important}}.site-header{background:var(--header-bg);border-bottom:2px solid #ffffff;position:sticky;top:0;z-index:1000;box-shadow:0 2px 24px rgba(0,0,0,.28)}.header-inner{max-width:1200px;margin:0 auto;padding:0 24px;height:64px;display:flex;align-items:center;gap:16px}.site-logo{display:flex;align-items:center;gap:10px;flex-shrink:0}.site-logo img{height:38px;width:38px;border-radius:9px;object-fit:cover}.site-logo span{font-size:1.02rem;font-weight:700;color:#fff;white-space:nowrap;letter-spacing:-.01em}.site-nav{display:flex;align-items:center;gap:2px;margin-left:auto}.site-nav a,.nav-dropdown-btn{color:#94a3b8;font-size:.9rem;font-weight:500;padding:7px 13px;border-radius:var(--radius-sm);transition:color var(--transition),background var(--transition);background:none;border:none;cursor:pointer;white-space:nowrap;letter-spacing:-.005em}.site-nav a:hover,.nav-dropdown-btn:hover{color:#fff;background:rgba(255,255,255,.08)}.site-nav a.active{color:var(--accent);font-weight:600}.nav-dropdown{position:relative}.nav-dropdown-menu{display:none;position:absolute;top:calc(100% + 10px);right:0;background:#1a2744;border:1px solid rgba(255,255,255,.1);border-radius:var(--radius);padding:8px;min-width:248px;box-shadow:0 16px 48px rgba(0,0,0,.5);z-index:200}.nav-dropdown.open .nav-dropdown-menu{display:flex;flex-direction:column}.nav-dropdown-menu a{color:#94a3b8;padding:9px 14px;border-radius:var(--radius-sm);font-size:.88rem;font-weight:500;display:flex;align-items:center;gap:10px;transition:background var(--transition),color var(--transition)}.nav-dropdown-menu a:hover{background:rgba(255,255,255,.08);color:#fff}.header-actions{display:flex;align-items:center;gap:8px;flex-shrink:0;margin-left:auto}.hamburger-btn{display:none;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.1);border-radius:var(--radius-sm);padding:8px 12px;color:#fff;font-size:1.1rem;cursor:pointer;transition:background var(--transition)}.hamburger-btn:hover{background:rgba(255,255,255,.14)}.mobile-nav{display:none;flex-direction:column;background:#131f36;border-top:1px solid rgba(255,255,255,.07);padding:10px;gap:2px}.mobile-nav.open{display:flex}.mobile-nav a,.mobile-nav button{color:#94a3b8;font-size:.92rem;font-weight:500;padding:10px 14px;border-radius:var(--radius-sm);border:none;background:none;text-align:left;cursor:pointer;transition:background var(--transition),color var(--transition)}.mobile-nav a:hover,.mobile-nav button:hover{background:rgba(255,255,255,.07);color:#fff}.mobile-nav .mobile-tools{padding-left:12px;display:flex;flex-direction:column;gap:2px}.mobile-nav .mobile-tools a{width:100%}.page-hero{background:var(--hero-bg);color:#fff;text-align:center;padding:56px 24px 48px;position:relative;overflow:hidden}.page-hero::before{content:'';position:absolute;inset:0;background-image:radial-gradient(circle at 20% 50%,rgba(249,115,22,.08) 0%,transparent 60%),radial-gradient(circle at 80% 50%,rgba(37,99,235,.08) 0%,transparent 60%)}.page-hero>*{position:relative}.page-hero h1{font-size:2.5rem;font-weight:800;margin-bottom:12px;line-height:1.18;letter-spacing:-.02em}.page-hero p{font-size:1.05rem;color:#94a3b8;max-width:560px;margin:0 auto;line-height:1.6}.hero-badge{display:inline-flex;align-items:center;gap:6px;background:rgba(249,115,22,.15);border:1px solid rgba(249,115,22,.28);color:#fb923c;font-size:.76rem;font-weight:700;padding:4px 14px;border-radius:100px;margin-bottom:14px;letter-spacing:.6px;text-transform:uppercase}main{max-width:1100px;margin:0 auto;padding:40px 24px 60px;display:flex;flex-direction:column;gap:36px}.page-main{max-width:1100px;margin:0 auto;padding:40px 24px 60px}.calculator-section{display:flex;gap:44px;align-items:flex-start;flex-wrap:wrap}.calculator-container{flex:0 0 360px;max-width:360px}.calculator-intro{flex:1;min-width:280px;padding-top:4px}.calculator-intro h2{font-size:2rem;font-weight:800;color:var(--text-primary);margin-bottom:14px;line-height:1.18;letter-spacing:-.03em}.calculator-intro p{color:var(--text-secondary);margin-bottom:12px;font-size:1rem}.intro-badges{display:flex;flex-wrap:wrap;gap:8px;margin-top:22px}.intro-badge{background:var(--surface);border:1.5px solid var(--border);border-radius:100px;padding:6px 16px;font-size:.82rem;font-weight:600;color:var(--blue);box-shadow:var(--shadow-xs)}.stats-strip{display:flex;gap:0;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow-sm)}.stat-item{flex:1;text-align:center;padding:18px 12px;border-right:1px solid var(--border)}.stat-item:last-child{border-right:none}.stat-number{font-size:1.6rem;font-weight:800;color:var(--accent);letter-spacing:-.02em;display:block}.stat-label{font-size:.78rem;font-weight:600;color:var(--text-muted);text-transform:uppercase;letter-spacing:.4px}.calculator-board{background:var(--surface);border-radius:var(--radius-lg);border:1.5px solid var(--border);box-shadow:var(--shadow-lg);padding:16px;position:relative;overflow:hidden}.calculator-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}.brand-text{font-weight:600;color:var(--text-secondary);font-size:.88rem}.calculator-display{background:#1a1f2e;border-radius:12px;padding:12px 14px;margin-bottom:14px;display:flex;flex-direction:column;justify-content:flex-end;min-height:82px;transition:min-height .3s ease}.calculator-display.expanded-view{height:350px;max-height:350px;justify-content:center}.calculator-display.expanded-view .step-by-step-area{display:flex;flex-direction:column;flex:1 1 0}.step-by-step-area{font-family:var(--font-mono);color:#94a3b8;min-height:44px;overflow-x:auto;overflow-y:hidden;padding:4px 0;direction:rtl;text-align:right;font-size:1rem}.step-by-step-area>*{direction:ltr;display:inline-block;min-width:100%}.step-carry{color:#f87171;font-size:.78rem;vertical-align:super}.step-math-line{border-bottom:2px solid #f1f5f9;display:inline-block}.step-operator{color:#fbbf24;margin-right:.5rem}.main-result{font-family:var(--font-mono);font-size:2.4rem;font-weight:700;color:#fff;text-align:right;white-space:nowrap;overflow-x:auto;overflow-y:hidden;line-height:1.2;direction:rtl}.main-result>*{direction:ltr;display:inline-block}.history-panel{position:absolute;top:0;left:0;right:0;bottom:0;height:100%;width:100%;background:var(--surface);z-index:100;padding:20px;overflow-y:auto;border-radius:var(--radius-lg);display:flex;flex-direction:column}.history-panel h3{color:var(--text-primary);margin-bottom:14px;text-align:center;border-bottom:1px solid var(--border);padding-bottom:10px;flex-shrink:0;font-size:1rem}#history-list{flex-grow:1;overflow-y:auto;margin-bottom:14px;list-style:none;font-family:var(--font-mono);font-size:1rem}#history-list li{padding:10px;cursor:pointer;border-bottom:1px solid var(--border-light);transition:color var(--transition),background var(--transition);color:var(--text-primary);border-radius:var(--radius-xs)}#history-list li:hover{color:var(--blue);background:var(--blue-bg)}.hidden{display:none !important}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#cbd5e1;border-radius:10px}::-webkit-scrollbar-thumb:hover{background:#94a3b8}.calculator-keypad{display:grid;grid-template-columns:repeat(4,1fr) 1.2fr;gap:8px}.btn-chalk{font-family:var(--font-heading);font-size:1.3rem;font-weight:700;padding:11px 6px;min-height:44px;border:none;border-radius:10px;background:#f1f5f9;color:#1e293b;cursor:pointer;transition:filter var(--transition),transform .1s;box-shadow:0 2px 4px rgba(0,0,0,.12),0 1px 0 rgba(255,255,255,.8) inset;user-select:none;touch-action:manipulation;-webkit-tap-highlight-color:transparent}.btn-chalk:hover{filter:brightness(.94)}.btn-chalk:active{transform:scale(.95);filter:brightness(.90);box-shadow:0 1px 2px rgba(0,0,0,.12)}.btn-operator{background:#f97316;color:#fff;box-shadow:0 2px 4px rgba(249,115,22,.35)}.btn-func{background:#dc2626;color:#fff;font-size:1.15rem;box-shadow:0 2px 4px rgba(220,38,38,.35)}.btn-adv{background:#2563eb;color:#fff;font-size:1.15rem;box-shadow:0 2px 4px rgba(37,99,235,.35)}.btn-yellow{background:var(--yellow);color:#fff;box-shadow:0 2px 4px rgba(217,119,6,.35)}.btn-blue{background:var(--blue);color:#fff;box-shadow:0 2px 4px rgba(37,99,235,.35)}.btn-green{background:var(--green);color:#fff;box-shadow:0 2px 4px rgba(22,163,74,.35)}.btn-red{background:var(--red);color:#fff;box-shadow:0 2px 4px rgba(220,38,38,.35)}.btn-equal{background:#16a34a;color:#fff;font-size:1.5rem;grid-column:5;grid-row:4 / span 2;box-shadow:0 2px 4px rgba(22,163,74,.35)}.btn-action{font-size:.85rem;padding:9px 12px;background:#fef3c7;color:#92400e;border:1px solid #fde68a}.btn-danger{font-size:.85rem;padding:9px;background:#fef2f2;color:var(--red);border:1px solid #fecaca;width:100%;margin-top:10px}.cell-2{grid-column:span 2}.cell-4{grid-column:span 4}.result-actions{display:flex;flex-direction:column;gap:8px;margin-top:12px}#keypad-container{position:relative;z-index:1}.section-header{margin-bottom:28px}.section-title{font-size:1.75rem;font-weight:800;color:var(--text-primary);margin-bottom:6px;letter-spacing:-.02em}.section-subtitle{color:var(--text-secondary);font-size:.98rem}.tools-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:16px}.tool-card{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius);padding:24px 20px 20px;text-align:center;transition:transform var(--transition),box-shadow var(--transition),border-color var(--transition);cursor:pointer;display:flex;flex-direction:column;align-items:center;gap:10px;box-shadow:var(--shadow-xs)}.tool-card:hover{transform:translateY(-5px);box-shadow:var(--shadow);border-color:var(--accent)}.tool-card .tool-icon{font-size:1.9rem;width:58px;height:58px;border-radius:16px;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#fff7ed,#fef3c7)}.tool-card h3{font-size:.95rem;font-weight:700;color:var(--text-primary)}.tool-card p{font-size:.8rem;color:var(--text-secondary);line-height:1.4}.tool-card .tool-tag{background:var(--blue-bg);border-radius:100px;padding:3px 10px;font-size:.73rem;font-weight:700;color:var(--blue);letter-spacing:.2px}.content-section{width:100%;background:var(--surface);padding:36px;border-radius:var(--radius);box-shadow:var(--shadow-sm);border:1.5px solid var(--border)}.content-section h2{color:var(--text-primary);margin-bottom:18px;font-size:1.5rem;font-weight:800;border-bottom:2px solid var(--border-light);padding-bottom:14px;letter-spacing:-.02em}.content-section h2 span.accent{color:var(--accent)}.content-section h3{color:var(--blue);margin-bottom:10px;font-size:1.08rem;font-weight:700;margin-top:22px}.content-section p,.content-section ul{margin-bottom:14px;font-size:.97rem;color:var(--text-secondary)}.content-section ul{padding-left:1.6rem}.content-section li{margin-bottom:.5rem}.feature-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;padding-bottom:20px}.feature-card{background:var(--surface-alt);padding:20px;border-radius:var(--radius-sm);border:1px solid var(--border);border-left:4px solid var(--blue);transition:transform var(--transition),box-shadow var(--transition)}.feature-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-sm)}.feature-card h3{color:var(--blue);margin-bottom:6px;font-size:.95rem;margin-top:0}.feature-card p{font-size:.88rem;color:var(--text-secondary);margin:0}details{background:var(--surface-alt);margin-bottom:.625rem;border-radius:var(--radius-sm);border:1.5px solid var(--border);overflow:hidden;transition:box-shadow var(--transition)}details:hover{box-shadow:var(--shadow-xs)}summary{padding:1rem 1.2rem;font-weight:600;cursor:pointer;font-size:.95rem;color:var(--text-primary);list-style:none;display:flex;justify-content:space-between;align-items:center;transition:background var(--transition);user-select:none}summary::-webkit-details-marker{display:none}summary::after{content:'+';font-size:1.2rem;color:var(--blue);font-weight:400;flex-shrink:0;margin-left:12px}details[open] summary::after{content:'−'}summary:hover{background:var(--blue-bg);color:var(--blue)}details[open] summary{background:var(--blue-bg);color:var(--blue);border-bottom:1px solid var(--border)}details p{padding:1rem 1.2rem;margin-bottom:0;color:var(--text-secondary);font-size:.93rem;line-height:1.65}.action-guides-container{display:grid;grid-template-columns:repeat(2,1fr);gap:20px;margin:24px 0}.action-card{background:var(--surface);border-radius:var(--radius);border:1.5px solid var(--border);padding:20px;display:flex;flex-direction:column;align-items:center;box-shadow:var(--shadow-xs);transition:transform var(--transition),box-shadow var(--transition)}.action-card:hover{transform:translateY(-3px);box-shadow:var(--shadow)}.action-card:nth-child(5){grid-column:1 / -1;justify-self:center;width:calc(50% - 10px)}.action-card h3{color:var(--text-primary);font-size:1rem;margin-top:14px;font-weight:700}.mock-display-screen{background:#1a1f2e;width:100%;aspect-ratio:1/1;border-radius:10px;padding:14px;display:flex;flex-direction:column;justify-content:center;position:relative;overflow:hidden}.mock-display-screen::before{content:'Calculadora de Alicia';position:absolute;top:10px;left:0;width:100%;text-align:center;color:#94a3b8;font-family:var(--font-mono);font-weight:600;font-size:1rem}.guide-svg-container{display:none}.guia-responsive{position:relative;max-width:400px;margin:2rem auto;width:100%}.guia-label{position:absolute;color:var(--red);font-weight:700;font-size:.9rem;white-space:nowrap;display:flex;align-items:center;z-index:10;transform:translateY(-50%)}.guia-label.left{right:110%;justify-content:flex-end}.guia-label.right{left:110%}.tool-section{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-sm);padding:32px;margin-bottom:24px}.tool-section h2{font-size:1.4rem;font-weight:800;color:var(--text-primary);margin-bottom:24px;letter-spacing:-.02em}.input-row{display:flex;align-items:center;gap:14px;flex-wrap:wrap;margin-bottom:20px}.input-group{display:flex;flex-direction:column;gap:6px;flex:1;min-width:100px}.input-group label{font-size:.82rem;font-weight:700;color:var(--text-secondary);letter-spacing:.2px;text-transform:uppercase}.input-group input,.input-group select{border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:10px 14px;font-size:1rem;font-family:var(--font-heading);background:var(--surface-alt);color:var(--text-primary);transition:border-color var(--transition),box-shadow var(--transition);width:100%}.input-group input:focus,.input-group select:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.12);background:#fff}.fraction-display{display:inline-flex;flex-direction:column;align-items:center;font-family:var(--font-mono);font-size:1.4rem;font-weight:700}.fraction-display .frac-line{width:100%;height:2px;background:var(--text-primary);margin:2px 0}.fraction-input-group{display:flex;flex-direction:column;align-items:center;gap:4px}.fraction-input-group input{width:80px;text-align:center;border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:8px;font-size:1.1rem;font-family:var(--font-mono);background:var(--surface-alt);color:var(--text-primary);transition:border-color var(--transition)}.fraction-input-group input:focus{outline:none;border-color:var(--blue)}.frac-divider{width:60px;height:3px;background:var(--text-primary);border-radius:2px}.op-selector{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:20px}.op-btn{padding:9px 18px;border:1.5px solid var(--border);border-radius:var(--radius-sm);background:var(--surface);color:var(--text-secondary);font-size:1.05rem;font-weight:700;cursor:pointer;transition:all var(--transition);font-family:var(--font-mono)}.op-btn:hover{border-color:var(--accent);color:var(--accent);background:var(--accent-bg)}.op-btn.active{background:var(--accent);border-color:var(--accent);color:#fff;box-shadow:0 2px 8px rgba(249,115,22,.3)}.calc-btn{background:linear-gradient(135deg,#f97316,#ea580c);color:#fff;border:none;border-radius:var(--radius-sm);padding:12px 32px;font-size:.95rem;font-weight:700;cursor:pointer;transition:opacity var(--transition),transform .15s,box-shadow var(--transition);box-shadow:0 2px 8px rgba(249,115,22,.35);letter-spacing:.01em}.calc-btn:hover{opacity:.93;transform:translateY(-1px);box-shadow:0 4px 16px rgba(249,115,22,.4)}.calc-btn:active{transform:scale(.97)}.calc-btn-blue{background:linear-gradient(135deg,#2563eb,#1d4ed8);box-shadow:0 2px 8px rgba(37,99,235,.35)}.calc-btn-green{background:linear-gradient(135deg,#16a34a,#15803d);box-shadow:0 2px 8px rgba(22,163,74,.35)}.result-box{background:linear-gradient(135deg,#0f172a 0%,#1e3359 100%);border-radius:var(--radius);padding:24px 28px;margin-top:22px;color:#fff;display:none;box-shadow:var(--shadow)}.result-box.show{display:block}.result-box .result-label{font-size:.78rem;color:#64748b;margin-bottom:4px;font-weight:700;text-transform:uppercase;letter-spacing:.6px}.result-box .result-value{font-size:2.1rem;font-weight:800;color:#fff;margin-bottom:18px;font-family:var(--font-mono);letter-spacing:-.01em}.result-box .steps-title{font-size:.75rem;color:#64748b;margin-bottom:10px;font-weight:700;text-transform:uppercase;letter-spacing:.6px}.result-box .step-item{background:rgba(255,255,255,.06);border-left:3px solid var(--accent);border-radius:0 var(--radius-xs) var(--radius-xs) 0;padding:10px 14px;margin-bottom:8px;font-size:.9rem;line-height:1.55;color:#94a3b8}.result-box .step-item strong{color:#fff}.result-box .step-highlight{color:#fbbf24;font-family:var(--font-mono);font-weight:700}.shape-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:10px;margin-bottom:20px}.shape-btn{border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:14px 8px;background:var(--surface-alt);cursor:pointer;text-align:center;transition:all var(--transition)}.shape-btn span{display:block;font-size:1.5rem;margin-bottom:4px}.shape-btn small{font-size:.76rem;font-weight:600;color:var(--text-muted)}.shape-btn:hover{border-color:var(--accent);background:var(--accent-bg)}.shape-btn.active{border-color:var(--blue);background:var(--blue-bg);box-shadow:0 0 0 2px rgba(37,99,235,.12)}.shape-btn.active small{color:var(--blue)}.sci-display{background:#1a1f2e;border-radius:12px;padding:18px 18px;margin-bottom:14px;min-height:90px;display:flex;flex-direction:column;justify-content:flex-end;align-items:flex-end}.sci-display .sci-expression{font-family:var(--font-mono);font-size:1rem;color:#cbd5e1;word-break:break-all;text-align:right;min-height:22px}.sci-display .sci-result{font-family:var(--font-mono);font-size:2.2rem;font-weight:700;color:#fff;word-break:break-all;text-align:right}.sci-keypad{display:grid;grid-template-columns:repeat(5,1fr);gap:6px}.sci-btn{padding:11px 6px;border:none;border-radius:var(--radius-xs);font-size:.85rem;font-weight:700;cursor:pointer;transition:filter var(--transition),transform .1s;font-family:var(--font-heading);background:#f1f5f9;color:#1e293b;box-shadow:0 1px 3px rgba(0,0,0,.1)}.sci-btn:hover{filter:brightness(.93)}.sci-btn:active{transform:scale(.95)}.sci-btn.btn-num-sci{background:#f8fafc;color:#1e293b}.sci-btn.btn-op-sci{background:#f97316;color:#fff}.sci-btn.btn-func-sci{background:#475569;color:#fff;font-size:.78rem}.sci-btn.btn-eq-sci{background:#16a34a;color:#fff;font-size:1.05rem}.sci-btn.btn-ac-sci{background:#dc2626;color:#fff}.sci-btn.btn-adv-sci{background:#2563eb;color:#fff;font-size:.8rem}.tab-bar{display:flex;gap:4px;background:var(--surface-alt);border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:4px;margin-bottom:22px;flex-wrap:wrap}.tab-btn{flex:1;padding:9px 14px;border:none;border-radius:var(--radius-xs);background:none;font-size:.88rem;font-weight:600;color:var(--text-muted);cursor:pointer;transition:all var(--transition);white-space:nowrap}.tab-btn.active{background:#fff;color:var(--text-primary);box-shadow:0 2px 8px rgba(0,0,0,.08)}.tab-btn:not(.active):hover{color:var(--text-primary);background:rgba(0,0,0,.04)}.page-content{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius);padding:44px;box-shadow:var(--shadow-sm)}.page-content h2{font-size:1.25rem;font-weight:700;color:var(--text-primary);margin-top:36px;margin-bottom:10px;padding-bottom:8px;border-bottom:2px solid var(--border-light);letter-spacing:-.01em}.page-content h2:first-child{margin-top:0}.page-content p{color:var(--text-secondary);margin-bottom:14px;font-size:.97rem;line-height:1.72}.page-content ul{padding-left:1.5rem;margin-bottom:14px}.page-content li{color:var(--text-secondary);margin-bottom:6px;font-size:.97rem}.page-content a{color:var(--blue);text-decoration:underline;text-underline-offset:2px}.page-content strong{color:var(--text-primary)}.contact-form{display:flex;flex-direction:column;gap:18px}.contact-form label{font-size:.82rem;font-weight:700;color:var(--text-secondary);margin-bottom:6px;display:block;text-transform:uppercase;letter-spacing:.2px}.contact-form input,.contact-form textarea{width:100%;border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:12px 16px;font-size:.97rem;font-family:var(--font-heading);background:var(--surface-alt);color:var(--text-primary);transition:border-color var(--transition),box-shadow var(--transition);resize:vertical}.contact-form input:focus,.contact-form textarea:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.12);background:#fff}.contact-info-block{background:var(--blue-bg);border:1px solid #bfdbfe;border-radius:var(--radius-sm);padding:18px 22px;margin-bottom:24px}.contact-info-block p{margin-bottom:8px;font-size:.95rem;color:var(--text-secondary)}.contact-info-block strong{color:var(--text-primary)}.site-footer{background:var(--footer-bg);color:#94a3b8;margin-top:40px}.footer-inner{max-width:1200px;margin:0 auto;padding:52px 24px 40px;display:grid;grid-template-columns:1.6fr 1fr 1fr;gap:48px}.footer-brand img{height:42px;width:42px;border-radius:9px;object-fit:cover;margin-bottom:14px}.footer-brand .brand-name{font-size:1rem;font-weight:700;color:#f1f5f9;margin-bottom:8px}.footer-brand .footer-tagline{font-size:.85rem;color:#475569;line-height:1.6}.footer-links h4{color:#f1f5f9;font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.7px;margin-bottom:14px}.footer-links a{display:block;color:#475569;font-size:.88rem;margin-bottom:10px;transition:color var(--transition)}.footer-links a:hover{color:var(--accent)}.footer-bottom{border-top:1px solid #1e293b;padding:18px 24px;text-align:center;font-size:.82rem;color:#334155}@media (max-width:900px){.calculator-section{flex-direction:column;align-items:center}.calculator-container{max-width:100%;width:100%}.footer-inner{grid-template-columns:1fr 1fr}.footer-brand{grid-column:span 2}}@media (max-width:700px){.site-nav{display:none}.hamburger-btn{display:block}.header-inner{gap:12px}.site-logo span{font-size:.9rem}.page-hero h1{font-size:1.9rem}.tools-grid{grid-template-columns:repeat(2,1fr)}.feature-grid{grid-template-columns:1fr}.action-guides-container{grid-template-columns:1fr}.action-card:nth-child(5){width:100%}.content-section{padding:22px 18px}.tool-section{padding:22px 18px}.page-content{padding:22px 18px}.footer-inner{grid-template-columns:1fr}.footer-brand{grid-column:span 1}.sci-keypad{gap:5px}.sci-btn{padding:9px 3px;font-size:.74rem}.sci-btn.btn-func-sci{font-size:.66rem}.sci-btn.btn-adv-sci{font-size:.68rem}.sci-btn.btn-eq-sci{font-size:.9rem}.input-row{flex-direction:column}.input-group{width:100%}.guia-responsive{zoom:.75}.stats-strip{display:none}}@media (max-width:480px){.tools-grid{grid-template-columns:1fr}.page-hero h1{font-size:1.55rem}.guia-responsive{zoom:.55}.shape-grid{grid-template-columns:repeat(3,1fr)}.shape-btn span{font-size:1.25rem}.shape-btn small{font-size:.68rem}.sci-btn{padding:7px 2px;font-size:.66rem}.sci-btn.btn-func-sci{font-size:.58rem}.sci-btn.btn-adv-sci{font-size:.6rem}}.breadcrumb{display:flex;align-items:center;gap:6px;font-size:.82rem;color:var(--text-muted);padding:20px 0 4px;flex-wrap:wrap}.breadcrumb a{color:var(--text-muted);transition:color var(--transition)}.breadcrumb a:hover{color:var(--accent)}.breadcrumb .bc-sep{color:var(--border)}.breadcrumb .bc-current{color:var(--text-secondary);font-weight:600}.tool-icon.icon-basic{background:linear-gradient(135deg,#fff7ed,#fef3c7)}.tool-icon.icon-intermediate{background:linear-gradient(135deg,#eff6ff,#dbeafe)}.tool-icon.icon-advanced{background:linear-gradient(135deg,#f5f3ff,#ede9fe)}.tool-icon.icon-geometry{background:linear-gradient(135deg,#f0fdf4,#dcfce7)}.tool-tag.tag-basic{background:var(--accent-bg);color:var(--accent-dark)}.tool-tag.tag-intermediate{background:var(--blue-bg);color:var(--blue-dark)}.tool-tag.tag-advanced{background:#f5f3ff;color:#7c3aed}.tool-tag.tag-geometry{background:var(--green-bg);color:var(--green)}.example-box{background:linear-gradient(135deg,#f0fdf4,#ecfdf5);border:1.5px solid #bbf7d0;border-radius:var(--radius-sm);padding:20px 24px;margin:20px 0 0}.example-box .example-label{font-size:.73rem;font-weight:700;color:var(--green);text-transform:uppercase;letter-spacing:.6px;margin-bottom:8px}.example-box p{color:var(--text-secondary);margin-bottom:6px;font-size:.93rem}.example-box p:last-child{margin-bottom:0}.example-box strong{color:var(--text-primary)}.example-box .example-result{display:inline-block;background:var(--green);color:#fff;padding:3px 12px;border-radius:100px;font-weight:700;font-size:.88rem;margin-top:6px;font-family:var(--font-mono)}.related-tools{margin-top:36px}.related-tools-title{font-size:.78rem;font-weight:700;color:var(--text-muted);text-transform:uppercase;letter-spacing:.5px;margin-bottom:14px}.related-tools-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.related-tool-card{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:14px 16px;display:flex;align-items:center;gap:12px;transition:transform var(--transition),box-shadow var(--transition),border-color var(--transition);box-shadow:var(--shadow-xs)}.related-tool-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-sm);border-color:var(--accent)}.rt-icon{font-size:1.2rem;width:38px;height:38px;border-radius:9px;display:flex;align-items:center;justify-content:center;flex-shrink:0;background:var(--surface-alt)}.rt-name{font-size:.88rem;font-weight:700;color:var(--text-primary);line-height:1.3}.rt-desc{font-size:.75rem;color:var(--text-muted);line-height:1.3;margin-top:2px}.audience-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.audience-card{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius);padding:28px 22px;text-align:center;box-shadow:var(--shadow-xs);transition:transform var(--transition),box-shadow var(--transition)}.audience-card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}.audience-icon{font-size:2rem;width:60px;height:60px;border-radius:16px;display:flex;align-items:center;justify-content:center;margin:0 auto 16px}.audience-card h3{font-size:1rem;font-weight:700;color:var(--text-primary);margin-bottom:8px}.audience-card p{font-size:.87rem;color:var(--text-secondary);line-height:1.55;margin:0}.result-preview-card{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius);padding:16px 20px;box-shadow:var(--shadow);margin-top:20px}.rpc-label{font-size:.72rem;font-weight:700;color:var(--text-muted);text-transform:uppercase;letter-spacing:.5px;margin-bottom:8px}.rpc-equation{font-family:var(--font-mono);font-size:.95rem;color:var(--text-secondary);margin-bottom:8px}.rpc-step{background:var(--surface-alt);border-left:3px solid var(--accent);border-radius:0 var(--radius-xs) var(--radius-xs) 0;padding:6px 10px;font-size:.8rem;color:var(--text-secondary);margin-bottom:4px;font-family:var(--font-mono)}.rpc-answer{margin-top:10px;font-size:1rem;font-weight:800;color:var(--green);font-family:var(--font-mono)}@media (max-width:900px){.audience-grid{grid-template-columns:1fr 1fr}}@media (max-width:700px){.related-tools-grid{grid-template-columns:1fr}.audience-grid{grid-template-columns:1fr}}.eq-input-row{display:flex;align-items:flex-end;gap:10px;flex-wrap:wrap;margin-bottom:8px}.eq-system-block{margin-bottom:8px}.eq-system-row{display:flex;align-items:flex-end;gap:10px;flex-wrap:wrap}.eq-coef-group{display:flex;flex-direction:column;align-items:center;gap:4px}.eq-coef-group label{font-size:.72rem;font-weight:700;color:var(--text-muted);text-transform:uppercase;letter-spacing:.3px}.eq-coef-input{width:72px;border:1.5px solid var(--border);border-radius:var(--radius-sm);padding:9px 8px;font-size:1rem;font-family:var(--font-mono);font-weight:700;text-align:center;background:var(--surface-alt);color:var(--text-primary);transition:border-color var(--transition),box-shadow var(--transition)}.eq-coef-input:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.12);background:#fff}.eq-var{font-family:var(--font-mono);font-size:1rem;font-weight:700;color:var(--text-secondary);padding-bottom:10px}.eq-plus{font-size:1.3rem;font-weight:700;color:var(--text-muted);padding-bottom:10px;user-select:none}.eq-equals{font-size:1.3rem;font-weight:700;color:var(--accent);padding-bottom:10px;padding:0 4px 10px;user-select:none}.eq-sys-label{font-size:.8rem;font-weight:700;color:var(--text-muted);padding-bottom:10px;min-width:50px}@media (max-width:600px){.eq-coef-input{width:58px;font-size:.9rem}.eq-input-row,.eq-system-row{gap:7px}}.tool-infographic{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius-lg);padding:24px;margin:32px 0;box-shadow:var(--shadow-sm);overflow:hidden}.tool-infographic-header{margin-bottom:20px;text-align:center}.tool-infographic-header h3{font-size:1.25rem;font-weight:800;color:var(--text-primary);margin-bottom:4px;display:flex;align-items:center;justify-content:center;gap:8px}.tool-infographic-header p{font-size:.88rem;color:var(--text-muted);margin:0}.tool-infographic svg{width:100%;height:auto;display:block;border-radius:var(--radius-md)}.tool-infographic-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;border-radius:var(--radius-md);scrollbar-width:thin}.tool-infographic-scroll svg{min-width:600px}.tool-infographic-hint{display:none;text-align:center;font-size:.78rem;color:var(--text-muted);margin:10px 0 0}@media (max-width:600px){.tool-infographic{padding:16px;margin:24px 0}.tool-infographic-header h3{font-size:1.1rem}.tool-infographic-hint{display:block}}.back-to-top{position:fixed;bottom:24px;right:24px;width:48px;height:48px;background:var(--blue,#2563eb);color:#ffffff;border:none;border-radius:50%;box-shadow:0 6px 20px rgba(37,99,235,0.45);cursor:pointer;display:flex;align-items:center;justify-content:center;z-index:999;opacity:0;visibility:hidden;transform:translateY(12px);transition:opacity .25s ease,transform .25s ease,background-color .2s ease,box-shadow .2s ease}.back-to-top.visible{opacity:1;visibility:visible;transform:translateY(0)}.back-to-top:hover{background:var(--blue-dark,#1d4ed8);box-shadow:0 8px 26px rgba(37,99,235,0.6);transform:translateY(-2px)}.back-to-top svg{width:22px;height:22px;stroke-width:2.8}