/* === RESET & BASE === */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;color:#1f2937;background:#fff;line-height:1.6}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}
button{cursor:pointer;font-family:inherit}
input,select,textarea{font-family:inherit}

/* === NAVBAR === */
.navbar{position:sticky;top:0;z-index:100;background:#fff;border-bottom:1px solid #e5e7eb;backdrop-filter:blur(8px);background:rgba(255,255,255,.95)}
.nav-inner{max-width:1140px;margin:0 auto;padding:0 1rem;display:flex;align-items:center;justify-content:space-between;height:56px}
.nav-logo{display:flex;align-items:center;gap:.5rem;font-weight:700;font-size:1.1rem;color:#0284c7}
.nav-logo .logo-box{display:flex;align-items:center;justify-content:center;width:32px;height:32px;border-radius:8px;background:#0284c7;color:#fff;font-size:.85rem;font-weight:700}
.nav-links{display:flex;align-items:center;gap:.25rem}
.nav-links a{padding:.5rem .75rem;border-radius:6px;font-size:.875rem;font-weight:500;color:#6b7280;transition:all .2s}
.nav-links a:hover{color:#0284c7;background:#f0f9ff}
.nav-hamburger{display:none;background:none;border:none;font-size:1.5rem;color:#374151;padding:.25rem}

/* === HERO === */
.hero{background:linear-gradient(to bottom,#f0f9ff,#fff);padding:4rem 1rem 3rem;text-align:center}
.hero h1{font-size:2rem;font-weight:700;color:#111827;max-width:600px;margin:0 auto .75rem}
@media(min-width:640px){.hero h1{font-size:2.75rem}}
.hero p{color:#6b7280;font-size:1.05rem;margin-bottom:2rem}
.search-box{position:relative;max-width:440px;margin:0 auto}
.search-box input{width:100%;padding:.75rem 1rem .75rem 2.75rem;border:1px solid #e5e7eb;border-radius:12px;font-size:.95rem;background:#fff;outline:none;transition:border .2s}
.search-box input:focus{border-color:#38bdf8;box-shadow:0 0 0 3px rgba(56,189,248,.15)}
.search-icon{position:absolute;left:.85rem;top:50%;transform:translateY(-50%);color:#9ca3af}

/* === SECTION === */
.section{padding:3rem 1rem}
.section-inner{max-width:1140px;margin:0 auto}
.section-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:2rem;flex-wrap:wrap;gap:.5rem}
.section-header h2{font-size:1.5rem;font-weight:700;color:#111827}
.view-all{font-size:.875rem;font-weight:500;color:#0284c7;background:none;border:none;transition:color .2s;display:flex;align-items:center;gap:.25rem}
.view-all:hover{color:#0369a1}

/* === GRID === */
.tools-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:1rem}
.tool-card{border:1px solid #f3f4f6;background:#fff;border-radius:12px;padding:1.25rem;transition:all .2s;cursor:pointer;box-shadow:0 1px 2px rgba(0,0,0,.04)}
.tool-card:hover{border-color:#bae6fd;box-shadow:0 4px 12px rgba(0,0,0,.07);transform:translateY(-1px)}
.tool-card .card-icon{width:40px;height:40px;border-radius:10px;background:#f0f9ff;color:#0284c7;display:flex;align-items:center;justify-content:center;margin-bottom:.75rem;font-size:1.15rem}
.tool-card h3{font-size:.95rem;font-weight:600;color:#111827;margin-bottom:.25rem}
.tool-card p{font-size:.82rem;color:#6b7280;line-height:1.5;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.tool-card .card-link{margin-top:.75rem;font-size:.82rem;font-weight:600;color:#0284c7}
.tool-card:hover .card-link{color:#0369a1}

/* === CTA === */
.cta-center{text-align:center;margin-top:2.5rem}
.btn-primary{display:inline-block;padding:.7rem 1.75rem;background:#0284c7;color:#fff;border:none;border-radius:12px;font-size:.9rem;font-weight:600;transition:background .2s}
.btn-primary:hover{background:#0369a1}
.btn-secondary{display:inline-block;padding:.7rem 1.75rem;background:#fff;color:#0284c7;border:1px solid #e5e7eb;border-radius:12px;font-size:.9rem;font-weight:600;transition:all .2s}
.btn-secondary:hover{background:#f0f9ff;border-color:#bae6fd}

/* === TOOL PAGE === */
.tool-page{max-width:640px;margin:0 auto;padding:2rem 1rem 4rem}
.back-link{display:inline-flex;align-items:center;gap:.35rem;font-size:.85rem;color:#6b7280;margin-bottom:1.5rem;transition:color .2s}
.back-link:hover{color:#0284c7}
.tool-header{display:flex;align-items:center;gap:.75rem;margin-bottom:1.75rem}
.tool-header .th-icon{width:42px;height:42px;border-radius:10px;background:#f0f9ff;color:#0284c7;display:flex;align-items:center;justify-content:center;font-size:1.15rem;flex-shrink:0}
.tool-header h1{font-size:1.25rem;font-weight:700;color:#111827}
.tool-header p{font-size:.82rem;color:#6b7280}
.tool-box{border:1px solid #f3f4f6;border-radius:12px;padding:1.5rem;background:#fff;box-shadow:0 1px 2px rgba(0,0,0,.04)}
.form-group{margin-bottom:1rem}
.form-group label{display:block;font-size:.82rem;font-weight:500;color:#374151;margin-bottom:.35rem}
.form-group input,.form-group select,.form-group textarea{width:100%;padding:.6rem .75rem;border:1px solid #e5e7eb;border-radius:8px;font-size:.9rem;outline:none;transition:border .2s;background:#fff}
.form-group input:focus,.form-group select:focus,.form-group textarea:focus{border-color:#38bdf8;box-shadow:0 0 0 3px rgba(56,189,248,.15)}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:.75rem}
.form-row-3{display:grid;grid-template-columns:1fr 1fr auto;gap:.75rem}
@media(max-width:480px){.form-row,.form-row-3{grid-template-columns:1fr}}
.btn-calc{width:100%;padding:.7rem;background:#0284c7;color:#fff;border:none;border-radius:10px;font-size:.9rem;font-weight:600;transition:background .2s;margin-top:.5rem}
.btn-calc:hover{background:#0369a1}
.btn-calc:disabled{background:#d1d5db;cursor:not-allowed;color:#9ca3af}
.btn-outline{width:100%;padding:.6rem;background:#fff;color:#0284c7;border:1px solid #e5e7eb;border-radius:10px;font-size:.85rem;font-weight:600;transition:all .2s;margin-top:.5rem}
.btn-outline:hover{background:#f0f9ff;border-color:#bae6fd}
.result-box{margin-top:1rem;padding:1rem;background:#f0f9ff;border-radius:10px;text-align:center}
.result-box .result-value{font-size:1.75rem;font-weight:700;color:#0284c7}
.result-box .result-label{font-size:.82rem;color:#6b7280;margin-top:.25rem}
.result-box .result-detail{font-size:.82rem;color:#6b7280;margin-top:.5rem}
.error-msg{color:#ef4444;font-size:.82rem;margin-top:.5rem}
.info-box{margin-top:1rem;padding:1rem;background:#fffbeb;border:1px solid #fde68a;border-radius:10px;text-align:center}
.info-box .info-title{font-size:1rem;font-weight:600;color:#92400e;margin-bottom:.25rem}
.info-box .info-text{font-size:.82rem;color:#a16207}

/* === STATS GRID === */
.stats-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.5rem;margin-top:1rem}
@media(min-width:640px){.stats-grid{grid-template-columns:repeat(5,1fr)}}
.stat-card{padding:.75rem;background:#f0f9ff;border-radius:8px;text-align:center}
.stat-card .stat-num{font-size:1.35rem;font-weight:700;color:#0284c7}
.stat-card .stat-label{font-size:.7rem;color:#6b7280;margin-top:.1rem}

/* === CALCULATOR === */
.calc-display{background:#111827;border-radius:12px;padding:1rem;margin-bottom:.75rem;text-align:right}
.calc-display .calc-text{color:#fff;font-size:1.75rem;font-family:monospace;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.calc-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:.5rem}
.calc-btn{height:52px;border:none;border-radius:10px;font-size:1.05rem;font-weight:500;transition:all .15s;display:flex;align-items:center;justify-content:center}
.calc-btn.num{background:#f9fafb;color:#111827}.calc-btn.num:hover{background:#f3f4f6}
.calc-btn.op{background:#e0f2fe;color:#0369a1;font-weight:700}.calc-btn.op:hover{background:#bae6fd}
.calc-btn.fn{background:#e5e7eb;color:#374151}.calc-btn.fn:hover{background:#d1d5db}
.calc-btn.eq{background:#0284c7;color:#fff;font-weight:700}.calc-btn.eq:hover{background:#0369a1}
.calc-btn.wide{grid-column:span 2}

/* === TIMER === */
.timer-ring-wrap{display:flex;justify-content:center;margin:1.5rem 0}
.timer-ring{position:relative;width:200px;height:200px}
.timer-ring svg{transform:rotate(-90deg)}
.timer-ring .time-text{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.timer-ring .time-digits{font-size:2.25rem;font-weight:700;font-family:monospace;color:#111827}
.timer-ring .time-label{font-size:.8rem;color:#9ca3af;margin-top:.2rem}
.timer-btns{display:flex;justify-content:center;gap:.75rem;margin-top:1rem}

/* === UPLOAD ZONE === */
.upload-zone{border:2px dashed #e5e7eb;border-radius:12px;padding:2rem;text-align:center;cursor:pointer;transition:all .2s}
.upload-zone:hover{border-color:#38bdf8;background:#f0f9ff}
.upload-zone .uz-icon{margin:0 auto .5rem;color:#9ca3af;font-size:1.5rem}
.upload-zone .uz-text{font-size:.85rem;color:#6b7280}
.upload-zone .uz-sub{font-size:.75rem;color:#9ca3af;margin-top:.25rem}
.img-preview-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:.5rem;margin-top:1rem;max-height:240px;overflow-y:auto}
.img-preview-item{position:relative;border-radius:8px;overflow:hidden;border:1px solid #e5e7eb}
.img-preview-item img{width:100%;height:72px;object-fit:cover}
.img-preview-item .remove-img{position:absolute;top:3px;right:3px;width:20px;height:20px;background:#ef4444;color:#fff;border:none;border-radius:50%;font-size:.7rem;display:flex;align-items:center;justify-content:center;cursor:pointer;opacity:0;transition:opacity .2s}
.img-preview-item:hover .remove-img{opacity:1}

/* === STATIC PAGE === */
.static-page{max-width:720px;margin:0 auto;padding:2rem 1rem 4rem}
.static-page h1{font-size:1.75rem;font-weight:700;color:#111827;margin-bottom:1rem}
.static-page h2{font-size:1.15rem;font-weight:700;color:#111827;margin-top:1.5rem;margin-bottom:.5rem}
.static-page p{color:#4b5563;margin-bottom:.75rem;line-height:1.7}
.static-page ul{list-style:disc;padding-left:1.5rem;margin-bottom:1rem;color:#4b5563}
.static-page li{margin-bottom:.35rem}

/* === FOOTER === */
.footer{border-top:1px solid #e5e7eb;background:#f9fafb;margin-top:auto}
.footer-inner{max-width:1140px;margin:0 auto;padding:1.5rem 1rem;display:flex;flex-direction:column;align-items:center;gap:1rem}
.footer-links{display:flex;align-items:center;gap:.75rem;font-size:.85rem;color:#6b7280}
.footer-links a{color:#6b7280;transition:color .2s}
.footer-links a:hover{color:#0284c7}
.footer-links .sep{color:#d1d5db}
.footer-copy{font-size:.75rem;color:#9ca3af}

/* === NO RESULTS === */
.no-results{text-align:center;color:#9ca3af;padding:3rem 0;font-size:.9rem}

/* === CONTACT FORM === */
.form-success{border:1px solid #bbf7d0;background:#f0fdf4;border-radius:12px;padding:1.5rem;text-align:center}
.form-success h3{color:#166534;font-weight:600;margin-bottom:.25rem}
.form-success p{color:#15803d;font-size:.85rem}

/* === NUMBER CHIPS === */
.chip-wrap{display:flex;flex-wrap:wrap;gap:.4rem;margin-top:.5rem;max-height:180px;overflow-y:auto}
.chip{display:inline-block;background:#fff;border:1px solid #bae6fd;padding:.3rem .7rem;border-radius:6px;font-size:.82rem;font-family:monospace;font-weight:600;color:#0369a1}

/* === RESPONSIVE NAV === */
@media(max-width:768px){
  .nav-links{display:none;position:absolute;top:56px;left:0;right:0;background:#fff;border-bottom:1px solid #e5e7eb;flex-direction:column;padding:.5rem 1rem 1rem;gap:0}
  .nav-links.open{display:flex}
  .nav-links a{padding:.65rem .75rem;width:100%;border-radius:6px}
  .nav-hamburger{display:block}
}

/* === PAGE WRAPPER === */
.page-wrapper{min-height:100vh;display:flex;flex-direction:column}

/* === SUBJECT ROW === */
.subject-row{display:grid;grid-template-columns:1fr 70px 70px 36px;gap:.5rem;align-items:end;margin-bottom:.5rem}
@media(max-width:480px){.subject-row{grid-template-columns:1fr 1fr}}
.subject-row .remove-subject{background:none;border:none;color:#9ca3af;font-size:1rem;padding:.3rem;transition:color .2s}
.subject-row .remove-subject:hover{color:#ef4444}

/* === CHECKBOX ROW === */
.checkbox-row{display:flex;align-items:center;gap:.5rem;margin-top:.5rem}
.checkbox-row input[type="checkbox"]{width:16px;height:16px;accent-color:#0284c7}
.checkbox-row label{font-size:.82rem;color:#6b7280}