/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s-2);
  font-size: 15px;
  font-weight: 500;
  padding: 12px 22px;
  border-radius: var(--r-full);
  border: 1px solid transparent;
  transition: transform .18s ease, box-shadow .25s ease, background .25s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn-primary {
  background: linear-gradient(135deg, var(--c-primary-400), var(--c-primary-600));
  color: #fff;
  box-shadow: var(--sh-brand);
}
.btn-primary:hover { box-shadow: 0 16px 38px rgba(37,99,235,.35); color:#fff; }
.btn-ghost {
  background: var(--c-surface);
  color: var(--c-primary);
  border-color: var(--c-border-strong);
}
.btn-ghost:hover { border-color: var(--c-primary); color: var(--c-primary-600); }
.btn-lg { padding: 15px 30px; font-size: 16px; }
.btn-block { width: 100%; }

/* ============================================================
   Header / Nav
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,.82);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--c-border);
}
.nav {
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-4);
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 19px; color: var(--c-text);
}
.brand .logo {
  width: 36px; height: 36px; border-radius: 10px;
  background: linear-gradient(135deg, var(--c-primary-400), var(--c-primary-600));
  display: grid; place-items: center; color: #fff; font-size: 18px;
  box-shadow: var(--sh-brand);
}
.brand:hover { color: var(--c-text); }

.nav-links { display: flex; align-items: center; gap: var(--s-2); }
.nav-links a {
  color: var(--c-text-muted);
  font-weight: 500;
  font-size: 15px;
  padding: 9px 14px;
  border-radius: var(--r-full);
  transition: background .2s ease, color .2s ease;
}
.nav-links a:hover { background: var(--c-primary-soft); color: var(--c-primary-600); }
.nav-links a.active { color: var(--c-primary-600); background: var(--c-primary-soft); }

/* Dropdown */
.dropdown { position: relative; }
.dropdown-toggle { display: inline-flex; align-items: center; gap: 6px; }
.dropdown-menu {
  position: absolute;
  z-index: 100;
  top: calc(100% + 10px);
  left: 0;
  min-width: 240px;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  box-shadow: var(--sh-lg);
  padding: var(--s-2);
  opacity: 0; visibility: hidden; transform: translateY(8px);
  transition: opacity .2s ease, transform .2s ease, visibility .2s;
}
.dropdown:hover .dropdown-menu,
.dropdown:focus-within .dropdown-menu {
  opacity: 1; visibility: visible; transform: translateY(0);
}
.dropdown-menu a {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 12px; border-radius: var(--r-sm); color: var(--c-text-muted);
}
.dropdown-menu a:hover { background: var(--c-bg); color: var(--c-primary-600); }
.dropdown-menu .ico { font-size: 18px; }

.nav-toggle { display: none; background: none; border: 0; font-size: 24px; color: var(--c-text); }

@media (max-width: 860px) {
  .nav-links {
    position: fixed; inset: var(--nav-h) 0 auto 0;
    z-index: 60;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--c-surface);
    border-bottom: 1px solid var(--c-border);
    box-shadow: var(--sh-md);
    padding: var(--s-3);
    transform: translateY(-120%);
    transition: transform .3s ease;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 14px; }
  .dropdown-menu { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; border: 0; padding: 0 0 0 var(--s-4); }
  .nav-toggle { display: block; }
}

/* ============================================================
   Hero
   ============================================================ */
.hero {
  position: relative;
  padding: var(--s-9) 0 var(--s-8);
  background:
    radial-gradient(900px 420px at 12% -10%, rgba(59,130,246,.18), transparent 60%),
    radial-gradient(800px 420px at 100% 0%, rgba(37,99,235,.12), transparent 55%),
    var(--c-surface);
  overflow: hidden;
}
.hero-grid {
  display: grid; grid-template-columns: 1.1fr .9fr; gap: var(--s-7); align-items: center;
}
@media (max-width: 900px) { .hero-grid { grid-template-columns: 1fr; } }
.hero h1 { font-size: clamp(34px, 5vw, 52px); margin-bottom: var(--s-4); }
.hero .lead { font-size: 18px; color: var(--c-text-muted); max-width: 540px; margin-bottom: var(--s-5); }
.hero-cta { display: flex; gap: var(--s-3); flex-wrap: wrap; }
.hero-art {
  background: linear-gradient(135deg, #EFF6FF, #DBEAFE);
  border-radius: var(--r-xl);
  border: 1px solid var(--c-border);
  padding: var(--s-6);
  box-shadow: var(--sh-lg);
  position: relative;
}
.hero-art .float-card {
  background: #fff; border-radius: var(--r-md); box-shadow: var(--sh-md);
  padding: var(--s-4); display: flex; align-items: center; gap: 12px; margin-bottom: var(--s-3);
  animation: floaty 5s ease-in-out infinite;
}
.hero-art .float-card:nth-child(2) { animation-delay: .6s; margin-left: 28px; }
.hero-art .float-card:nth-child(3) { animation-delay: 1.2s; margin-left: 12px; }
@keyframes floaty { 0%,100%{ transform: translateY(0); } 50%{ transform: translateY(-8px); } }

/* ============================================================
   Feature pills
   ============================================================ */
.features { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--s-4); }
@media (max-width: 820px) { .features { grid-template-columns: repeat(2, 1fr); } }
.feature {
  display: flex; gap: 12px; align-items: flex-start;
  background: var(--c-surface); border: 1px solid var(--c-border);
  border-radius: var(--r-md); padding: var(--s-4); box-shadow: var(--sh-sm);
}
.feature .f-ico {
  width: 40px; height: 40px; flex: none; border-radius: 10px;
  background: var(--c-primary-soft); color: var(--c-primary);
  display: grid; place-items: center; font-size: 20px;
}
.feature h4 { font-size: 15px; margin-bottom: 2px; }
.feature p { font-size: 13px; color: var(--c-text-muted); }

/* ============================================================
   Cards (tool cards)
   ============================================================ */
.card {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: var(--s-5);
  box-shadow: var(--sh-sm);
  transition: transform .22s ease, box-shadow .25s ease, border-color .25s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--sh-lg); border-color: var(--c-primary-400); }

.tool-card { display: flex; flex-direction: column; gap: var(--s-3); }
.tool-card .t-ico {
  width: 52px; height: 52px; border-radius: 14px;
  background: linear-gradient(135deg, var(--c-primary-400), var(--c-primary-600));
  color: #fff; display: grid; place-items: center; font-size: 26px;
  box-shadow: var(--sh-brand);
}
.tool-card h3 { font-size: 19px; }
.tool-card p { color: var(--c-text-muted); font-size: 14px; flex: 1; }
.tool-card .t-link {
  margin-top: var(--s-2); font-weight: 600; color: var(--c-primary);
  display: inline-flex; align-items: center; gap: 6px;
}
.tool-card:hover .t-link { gap: 10px; }

/* ============================================================
   Tool page components (uploader, options, result)
   ============================================================ */
.panel {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: var(--s-5);
  box-shadow: var(--sh-sm);
}
.panel + .panel { margin-top: var(--s-5); }

.uploader {
  border: 2px dashed var(--c-border-strong);
  border-radius: var(--r-md);
  padding: var(--s-7) var(--s-5);
  text-align: center;
  background: var(--c-bg);
  transition: border-color .2s ease, background .2s ease;
  cursor: pointer;
}
.uploader.drag { border-color: var(--c-primary); background: var(--c-primary-soft); }
.uploader .u-ico { font-size: 40px; }
.uploader .u-title { font-weight: 700; margin: 8px 0 2px; }
.uploader .u-sub { color: var(--c-text-muted); font-size: 14px; }

.field { display: flex; flex-direction: column; gap: 6px; margin-bottom: var(--s-4); }
.field label { font-size: 14px; font-weight: 500; color: var(--c-text-muted); }
.field select, .field input[type="number"], .field input[type="text"] {
  font-family: inherit; font-size: 15px; padding: 11px 14px;
  border: 1px solid var(--c-border-strong); border-radius: var(--r-sm);
  background: var(--c-surface); color: var(--c-text); transition: border-color .2s;
}
.field select:focus, .field input:focus { outline: none; border-color: var(--c-primary); }
.range-row { display: flex; align-items: center; gap: 12px; }
.range-row input[type="range"] { flex: 1; accent-color: var(--c-primary); }

.file-list { display: flex; flex-direction: column; gap: 8px; margin-top: var(--s-3); }
.file-chip {
  display: flex; align-items: center; gap: 10px; justify-content: space-between;
  background: var(--c-bg); border: 1px solid var(--c-border);
  border-radius: var(--r-sm); padding: 10px 12px; font-size: 14px;
}
.file-chip .fc-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.result-preview {
  margin-top: var(--s-4);
  border: 1px solid var(--c-border); border-radius: var(--r-md);
  padding: var(--s-4); background: var(--c-bg);
}
.result-preview img, .result-preview canvas { max-width: 100%; border-radius: var(--r-sm); }

.status {
  margin-top: var(--s-3); padding: 10px 14px; border-radius: var(--r-sm);
  font-size: 14px; display: none;
}
.status.show { display: block; }
.status.info { background: var(--c-primary-soft); color: var(--c-primary-600); }
.status.ok { background: #ECFDF5; color: #047857; }
.status.err { background: #FEF2F2; color: #B91C1C; }

.progress { height: 8px; background: var(--c-border); border-radius: var(--r-full); overflow: hidden; margin-top: var(--s-3); display: none; }
.progress.show { display: block; }
.progress > span { display: block; height: 100%; width: 0; background: linear-gradient(90deg,var(--c-primary-400),var(--c-primary-600)); transition: width .2s ease; }

/* ============================================================
   Unit converter tabs
   ============================================================ */
.tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: var(--s-5); }
.tab {
  padding: 10px 18px; border-radius: var(--r-full); border: 1px solid var(--c-border-strong);
  background: var(--c-surface); font-weight: 500; font-size: 14px; color: var(--c-text-muted);
  transition: all .2s;
}
.tab.active { background: var(--c-primary); color: #fff; border-color: var(--c-primary); }

.two-input { display: grid; grid-template-columns: 1fr auto 1fr; gap: var(--s-3); align-items: end; }
@media (max-width: 640px){ .two-input { grid-template-columns: 1fr; } }
.swap-btn {
  width: 44px; height: 44px; border-radius: var(--r-full); border: 1px solid var(--c-border-strong);
  background: var(--c-surface); color: var(--c-primary); font-size: 18px;
  display: grid; place-items: center; transition: transform .3s ease, box-shadow .2s;
}
.swap-btn:hover { transform: rotate(180deg); box-shadow: var(--sh-md); }

/* ============================================================
   Contact
   ============================================================ */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s-6); }
@media (max-width: 820px){ .contact-grid { grid-template-columns: 1fr; } }
.form-field { display: flex; flex-direction: column; gap: 6px; margin-bottom: var(--s-4); }
.form-field label { font-size: 14px; font-weight: 500; color: var(--c-text-muted); }
.form-field input, .form-field textarea {
  font-family: inherit; font-size: 15px; padding: 11px 14px;
  border: 1px solid var(--c-border-strong); border-radius: var(--r-sm); background: var(--c-surface);
  color: var(--c-text); transition: border-color .2s;
}
.form-field input:focus, .form-field textarea:focus { outline: none; border-color: var(--c-primary); }
.contact-info .ci {
  display: flex; gap: 12px; align-items: center; padding: var(--s-3) 0;
  border-bottom: 1px solid var(--c-border);
}
.contact-info .ci .ci-ico { width: 40px; height: 40px; border-radius: 10px; background: var(--c-primary-soft); color: var(--c-primary); display: grid; place-items: center; }

/* ============================================================
   Footer
   ============================================================ */
.site-footer { background: #0F172A; color: #CBD5E1; margin-top: var(--s-8); }
.site-footer a { color: #CBD5E1; }
.site-footer a:hover { color: #fff; }
.footer-grid { display: grid; grid-template-columns: 1.4fr repeat(2, 1fr); gap: var(--s-6); padding-top: var(--s-7); padding-bottom: var(--s-7); }
@media (max-width: 820px){ .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px){ .footer-grid { grid-template-columns: 1fr; gap: var(--s-5); padding-top: var(--s-5); padding-bottom: var(--s-5); } }
.footer-grid h4 { color: #fff; font-size: 15px; margin-bottom: var(--s-3); }
.footer-grid ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.footer-grid li a { font-size: 14px; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1); padding-top: var(--s-4); padding-bottom: var(--s-4);
  display: flex; justify-content: space-between; gap: var(--s-3); flex-wrap: wrap;
  font-size: 13px; color: #94A3B8;
}
@media (max-width: 480px) {
  .footer-bottom { flex-direction: column; text-align: center; gap: var(--s-2); }
}

/* ============================================================
   Section heading
   ============================================================ */
.sec-head { text-align: center; max-width: 640px; margin: 0 auto var(--s-6); }
.sec-head h2 { margin: var(--s-3) 0; }
.sec-head p { color: var(--c-text-muted); }