:root {
  --primary: #1D4ED8;
  --primary-dark: #1e40af;
  --primary-light: #EFF6FF;
  --accent: #F97316;
  --accent-dark: #ea580c;
  --text: #111827;
  --text-secondary: #6B7280;
  --border: #E5E7EB;
  --bg: #F9FAFB;
  --white: #ffffff;
  --success: #059669;
  --success-bg: #ECFDF5;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0,0,0,.07), 0 1px 2px rgba(0,0,0,.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.05);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; color: var(--text); background: var(--bg); font-size: 16px; line-height: 1.6; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* NAV */
nav { background: var(--white); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.nav-inner { max-width: 1100px; margin: 0 auto; padding: 0 20px; display: flex; align-items: center; justify-content: space-between; height: 58px; }
.nav-logo { font-size: 18px; font-weight: 700; color: var(--primary); display: flex; align-items: center; gap: 8px; }
.nav-logo span { color: var(--accent); }
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a { font-size: 14px; color: var(--text-secondary); font-weight: 500; }
.nav-links a:hover { color: var(--primary); text-decoration: none; }
.nav-cta { background: var(--accent); color: white !important; padding: 7px 16px; border-radius: 8px; font-size: 13px; font-weight: 600; }
.nav-cta:hover { background: var(--accent-dark); }

/* AD BANNER - Promotion 3tranx services */
.ad-banner { background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%); color: white; padding: 14px 20px; }
.ad-banner-inner { max-width: 1100px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.ad-banner-text { font-size: 14px; opacity: .95; }
.ad-banner-text strong { display: block; font-size: 15px; margin-bottom: 2px; }
.ad-banner-btn { background: white; color: var(--primary); padding: 8px 18px; border-radius: 7px; font-size: 13px; font-weight: 700; white-space: nowrap; flex-shrink: 0; }
.ad-banner-btn:hover { text-decoration: none; background: #f1f5f9; }

/* PAGE HEADER */
.page-header { background: var(--white); border-bottom: 1px solid var(--border); padding: 28px 20px 24px; }
.page-header-inner { max-width: 1100px; margin: 0 auto; }
.breadcrumb { font-size: 13px; color: var(--text-secondary); margin-bottom: 10px; }
.breadcrumb a { color: var(--text-secondary); }
.breadcrumb span { margin: 0 6px; }
h1.tool-title { font-size: 28px; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.tool-desc { font-size: 16px; color: var(--text-secondary); }

/* MAIN LAYOUT */
.main { max-width: 1100px; margin: 0 auto; padding: 30px 20px; display: grid; grid-template-columns: 1fr 300px; gap: 28px; }
@media(max-width: 768px) { .main { grid-template-columns: 1fr; } }
.tool-area { }
.sidebar { }

/* TOOL CARD */
.tool-card { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow); margin-bottom: 20px; }
.tool-card h2 { font-size: 18px; font-weight: 600; margin-bottom: 20px; color: var(--text); }

/* FORM ELEMENTS */
label { display: block; font-size: 14px; font-weight: 500; color: var(--text); margin-bottom: 6px; margin-top: 16px; }
label:first-child { margin-top: 0; }
input[type="text"], input[type="number"], input[type="email"], select, textarea {
  width: 100%; padding: 10px 14px; border: 1px solid var(--border); border-radius: 8px;
  font-size: 15px; color: var(--text); background: var(--white);
  transition: border-color .15s; outline: none;
}
input:focus, select:focus, textarea:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(29,78,216,.1); }
textarea { resize: vertical; min-height: 100px; }
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media(max-width: 500px) { .row { grid-template-columns: 1fr; } }
.row3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 14px; }
@media(max-width: 600px) { .row3 { grid-template-columns: 1fr; } }

/* BUTTONS */
.btn { display: inline-flex; align-items: center; gap: 6px; padding: 11px 22px; border-radius: 8px; font-size: 15px; font-weight: 600; cursor: pointer; border: none; transition: all .15s; }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-accent { background: var(--accent); color: white; }
.btn-accent:hover { background: var(--accent-dark); }
.btn-outline { background: white; color: var(--primary); border: 1px solid var(--primary); }
.btn-outline:hover { background: var(--primary-light); }
.btn-success { background: var(--success); color: white; }
.btn-block { width: 100%; justify-content: center; margin-top: 18px; }
.btn-sm { padding: 7px 14px; font-size: 13px; }
.btns { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 18px; }

/* RESULT BOX */
.result-box { background: var(--primary-light); border: 1px solid #BFDBFE; border-radius: var(--radius); padding: 20px; margin-top: 20px; display: none; }
.result-box.show { display: block; }
.result-big { font-size: 32px; font-weight: 700; color: var(--primary); }
.result-label { font-size: 13px; color: var(--text-secondary); margin-bottom: 4px; }
.result-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 8px; }
.result-item { background: white; border-radius: 8px; padding: 12px 16px; }
.result-item .val { font-size: 22px; font-weight: 700; color: var(--primary); }
.result-item .lbl { font-size: 12px; color: var(--text-secondary); margin-top: 2px; }

/* TEXT OUTPUT */
.text-output { width: 100%; padding: 14px; border: 1px solid var(--border); border-radius: 8px; font-size: 14px; background: #FAFAFA; white-space: pre-wrap; min-height: 120px; display: none; margin-top: 16px; font-family: inherit; }
.text-output.show { display: block; }
.copy-btn { margin-top: 8px; }

/* SIDEBAR AD */
.sidebar-ad { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; margin-bottom: 20px; box-shadow: var(--shadow); }
.sidebar-ad-header { background: var(--primary); color: white; padding: 12px 16px; font-size: 13px; font-weight: 600; }
.sidebar-ad-body { padding: 16px; }
.sidebar-ad-body p { font-size: 13px; color: var(--text-secondary); line-height: 1.6; margin-bottom: 12px; }
.sidebar-ad-body .btn { font-size: 13px; padding: 8px 16px; }
.sidebar-service { padding: 12px 16px; border-bottom: 1px solid var(--border); display: flex; gap: 10px; align-items: flex-start; }
.sidebar-service:last-child { border-bottom: none; }
.sidebar-service-icon { font-size: 20px; flex-shrink: 0; margin-top: 2px; }
.sidebar-service-text strong { font-size: 13px; display: block; color: var(--text); }
.sidebar-service-text span { font-size: 12px; color: var(--text-secondary); }

/* BOTTOM AD */
.bottom-ad { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px 28px; margin-top: 8px; display: grid; grid-template-columns: 1fr auto; gap: 20px; align-items: center; box-shadow: var(--shadow); }
@media(max-width: 600px) { .bottom-ad { grid-template-columns: 1fr; } }
.bottom-ad-text h3 { font-size: 17px; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.bottom-ad-text p { font-size: 14px; color: var(--text-secondary); }
.bottom-ad-badges { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.badge { background: var(--primary-light); color: var(--primary); font-size: 12px; font-weight: 500; padding: 3px 10px; border-radius: 99px; }

/* RELATED TOOLS */
.related-tools { margin-top: 8px; }
.related-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 12px; }
.related-card { background: white; border: 1px solid var(--border); border-radius: 8px; padding: 14px 16px; text-decoration: none; display: flex; align-items: center; gap: 10px; }
.related-card:hover { border-color: var(--primary); background: var(--primary-light); text-decoration: none; }
.related-card .icon { font-size: 20px; }
.related-card .name { font-size: 13px; font-weight: 500; color: var(--text); }

/* HOMEPAGE */
.hero { background: white; border-bottom: 1px solid var(--border); padding: 52px 20px 44px; text-align: center; }
.hero h1 { font-size: 38px; font-weight: 800; color: var(--text); margin-bottom: 14px; }
.hero h1 em { color: var(--primary); font-style: normal; }
.hero p { font-size: 18px; color: var(--text-secondary); max-width: 520px; margin: 0 auto 24px; }
.search-bar { max-width: 520px; margin: 0 auto; position: relative; }
.search-bar input { padding: 14px 20px; font-size: 16px; border: 2px solid var(--border); border-radius: 12px; }
.search-bar input:focus { border-color: var(--primary); }
.search-icon { position: absolute; right: 16px; top: 50%; transform: translateY(-50%); color: var(--text-secondary); pointer-events: none; }
.hero-stats { display: flex; gap: 32px; justify-content: center; margin-top: 28px; flex-wrap: wrap; }
.hero-stat { text-align: center; }
.hero-stat strong { display: block; font-size: 24px; font-weight: 800; color: var(--primary); }
.hero-stat span { font-size: 13px; color: var(--text-secondary); }

.tools-section { max-width: 1100px; margin: 0 auto; padding: 40px 20px; }
.cat-tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 28px; }
.cat-tab { padding: 7px 16px; border-radius: 99px; border: 1px solid var(--border); background: white; font-size: 14px; cursor: pointer; color: var(--text-secondary); font-weight: 500; }
.cat-tab.active, .cat-tab:hover { background: var(--primary); color: white; border-color: var(--primary); }
.tools-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 14px; }
.tool-grid-card { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; text-decoration: none; display: flex; flex-direction: column; gap: 8px; transition: all .15s; box-shadow: var(--shadow); }
.tool-grid-card:hover { border-color: var(--primary); box-shadow: var(--shadow-md); transform: translateY(-1px); text-decoration: none; }
.tool-grid-card .ticon { font-size: 24px; }
.tool-grid-card .tname { font-size: 14px; font-weight: 600; color: var(--text); }
.tool-grid-card .tdesc { font-size: 12px; color: var(--text-secondary); line-height: 1.5; }
.viral-tag { background: #FEF2F2; color: #DC2626; font-size: 10px; font-weight: 600; padding: 2px 8px; border-radius: 99px; width: fit-content; }

/* FOOTER */
footer { background: #111827; color: #9CA3AF; padding: 40px 20px 24px; margin-top: 40px; }
.footer-inner { max-width: 1100px; margin: 0 auto; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px; margin-bottom: 32px; }
@media(max-width: 600px) { .footer-grid { grid-template-columns: 1fr; } }
.footer-logo { font-size: 18px; font-weight: 700; color: white; margin-bottom: 10px; }
.footer-logo span { color: var(--accent); }
.footer-about { font-size: 13px; line-height: 1.7; max-width: 280px; }
footer h4 { color: white; font-size: 14px; font-weight: 600; margin-bottom: 12px; }
footer ul { list-style: none; }
footer ul li { margin-bottom: 8px; }
footer ul li a { font-size: 13px; color: #9CA3AF; }
footer ul li a:hover { color: white; }
.footer-bottom { border-top: 1px solid #374151; padding-top: 20px; display: flex; justify-content: space-between; align-items: center; font-size: 13px; flex-wrap: wrap; gap: 10px; }
.footer-bottom a { color: #9CA3AF; }

/* ALERTS */
.alert { padding: 12px 16px; border-radius: 8px; font-size: 14px; margin-top: 14px; }
.alert-info { background: #EFF6FF; border: 1px solid #BFDBFE; color: #1D4ED8; }
.alert-success { background: var(--success-bg); border: 1px solid #A7F3D0; color: var(--success); }
.alert-warning { background: #FFFBEB; border: 1px solid #FDE68A; color: #92400E; }

/* UTILITY */
.mt-4 { margin-top: 16px; }
.hidden { display: none; }
.text-center { text-align: center; }
.text-muted { color: var(--text-secondary); font-size: 14px; }
table { width: 100%; border-collapse: collapse; font-size: 14px; margin-top: 14px; }
th { background: var(--bg); padding: 10px 12px; text-align: left; font-weight: 600; border-bottom: 2px solid var(--border); }
td { padding: 9px 12px; border-bottom: 1px solid var(--border); }
tr:last-child td { border-bottom: none; }

/* RANGE SLIDER */
input[type="range"] { width: 100%; -webkit-appearance: none; height: 6px; background: var(--border); border-radius: 3px; outline: none; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 18px; height: 18px; background: var(--primary); border-radius: 50%; cursor: pointer; }
.range-labels { display: flex; justify-content: space-between; font-size: 12px; color: var(--text-secondary); margin-top: 4px; }

/* CHECKBOX / RADIO */
.check-group { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; }
.check-item { display: flex; align-items: center; gap: 6px; cursor: pointer; font-size: 14px; }
.check-item input { width: auto; }

@media(max-width: 480px) {
  h1.tool-title { font-size: 22px; }
  .result-grid { grid-template-columns: 1fr; }
  .related-grid { grid-template-columns: 1fr; }
}