/* ==========================================================================
   VKI Design system — premium, mobile-first, accessible
   ========================================================================== */

:root{
  --c-bg: #0B1220;
  --c-surface: #0F1A2E;
  --c-card: #FFFFFF;
  --c-card-2: #F6F8FC;
  --c-text: #0B1220;
  --c-muted: #4B5565;
  --c-border: #E6EAF2;
  --c-primary: #0E5CAD;
  --c-primary-2: #0A4A8B;
  --c-accent: #0B7A66;
  --c-danger: #B42318;
  --c-warning: #9A6700;
  --c-success: #0B7A66;
  --c-info: #4B7BF5;
  --c-focus: #1D4ED8;

  --ff: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  --fs-0: 0.875rem;
  --fs-1: 1rem;
  --fs-2: 1.125rem;
  --fs-3: 1.25rem;
  --fs-4: 1.5rem;
  --fs-5: 2rem;
  --lh: 1.6;

  --s-1: .25rem;
  --s-2: .5rem;
  --s-3: .75rem;
  --s-4: 1rem;
  --s-5: 1.25rem;
  --s-6: 1.5rem;
  --s-8: 2rem;
  --s-10: 2.5rem;
  --s-12: 3rem;

  --r-1: .5rem;
  --r-2: .75rem;
  --r-3: 1rem;

  --sh-1: 0 8px 30px rgba(2, 8, 23, .08);
  --sh-2: 0 16px 40px rgba(2, 8, 23, .12);

  --container: 1120px;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
body{
  margin:0;
  font-family: var(--ff);
  line-height: var(--lh);
  color: var(--c-text);
  background: #F3F6FB;
}

img{ max-width:100%; height:auto; }
a{ color: var(--c-primary); text-underline-offset: 3px; }
a:hover{ color: var(--c-primary-2); }

.skip-link{
  position:absolute;
  left: -9999px;
  top: var(--s-3);
  background:#fff;
  color:#000;
  padding: var(--s-3) var(--s-4);
  border-radius: var(--r-1);
  z-index: 999;
}
.skip-link:focus{ left: var(--s-3); outline: 3px solid var(--c-focus); }

.container{
  width: min(var(--container), calc(100% - 2*var(--s-4)));
  margin-inline: auto;
}

/* Header */
.site-header{
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11,18,32,.78);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.brand{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: var(--s-4);
  padding: var(--s-4) 0;
}
.brand__link{
  display:flex;
  align-items:center;
  gap: var(--s-3);
  color:#fff;
  text-decoration:none;
  font-weight: 650;
}
.brand__mark{
  width: 28px;
  height: 28px;
  border-radius: 10px;
  background:
    radial-gradient(circle at 30% 30%, rgba(255,255,255,.9), rgba(255,255,255,.25) 35%, transparent 60%),
    linear-gradient(135deg, rgba(14,92,173,1), rgba(11,122,102,1));
  box-shadow: 0 10px 30px rgba(0,0,0,.25);
}
.brand__name{ letter-spacing: .2px; }
.topnav{
  display:none;
  gap: var(--s-4);
  flex-wrap: wrap;
}
.topnav a{
  color: rgba(255,255,255,.9);
  text-decoration:none;
  font-size: var(--fs-0);
  padding: .35rem .5rem;
  border-radius: .6rem;
}
.topnav a:hover{ background: rgba(255,255,255,.08); }

/* Page */
.page{
  padding: var(--s-10) 0 var(--s-12);
  position: relative;
  z-index: 0;
}
.section{
  margin-top: var(--s-10);
  position: relative;
  z-index: 1;
}
.section__head{
  display:grid;
  gap: var(--s-2);
  margin-bottom: var(--s-5);
}
h1,h2,h3{ line-height: 1.15; margin: 0; }
h1{ font-size: clamp(1.8rem, 2.6vw, 2.6rem); color: var(--c-text); letter-spacing:-.02em; }
h2{ font-size: clamp(1.35rem, 1.8vw, 1.8rem); }
h3{ font-size: 1.1rem; }
.h4{ font-size: 1.05rem; }

.eyebrow{
  color: var(--c-muted);
  font-size: var(--fs-0);
  margin:0 0 var(--s-2);
}
.lead{
  color: var(--c-text);
  font-size: clamp(1.05rem, 1.2vw, 1.2rem);
  margin: var(--s-3) 0 var(--s-5);
  max-width: 65ch;
}
.muted{ color: var(--c-muted); }
.micro{ font-size: var(--fs-0); }

/* Hero */
.hero{
  display:grid;
  gap: var(--s-6);
  align-items:start;
  position: relative;
  z-index: 2;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(1.25rem, 2.4vw, 2rem);
  border-radius: 1.5rem;
  background:
    radial-gradient(1000px 520px at 10% -10%, rgba(14,92,173,.34), transparent 60%),
    radial-gradient(900px 480px at 90% 0%, rgba(11,122,102,.26), transparent 55%),
    linear-gradient(180deg, #0B1220 0%, #0B1220 100%);
  color: rgba(255,255,255,.92);
  box-shadow: 0 24px 60px rgba(2,8,23,.22);
  border: 1px solid rgba(255,255,255,.10);
}
.hero__content{ padding-top: var(--s-2); }
.hero h1{ color:#fff; }
.hero .lead{ color: rgba(255,255,255,.92); }
.hero .eyebrow{ color: rgba(255,255,255,.82); }
.hero .muted{ color: rgba(255,255,255,.78); }
.hero a{ color: rgba(255,255,255,.92); }
.hero a:hover{ color: #fff; }
.hero__cta{
  display:flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  margin-top: var(--s-4);
}
.trustlist{
  list-style:none;
  padding:0;
  margin: 0;
  display:grid;
  gap: var(--s-2);
  color: rgba(255,255,255,.9);
  max-width: 60ch;
}
.trustlist li{
  display:flex;
  gap: var(--s-2);
}
.trustlist li::before{
  content:"";
  width:.55rem;
  height:.55rem;
  margin-top:.45rem;
  border-radius: 999px;
  background: rgba(11,122,102,.95);
  box-shadow: 0 0 0 4px rgba(11,122,102,.15);
}
.hero__card .card{
  border: 1px solid rgba(255,255,255,.1);
  background: rgba(255,255,255,.06);
  color: rgba(255,255,255,.92);
}

/* Cards */
.card{
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-3);
  padding: var(--s-6);
  box-shadow: var(--sh-1);
}
.card--soft{
  background: rgba(255,255,255,.06);
  border-color: rgba(255,255,255,.12);
  box-shadow: none;
}
.card--result{
  border-color: rgba(14,92,173,.25);
  box-shadow: var(--sh-2);
}
.card__title{ margin: .2rem 0 var(--s-2); }
.card__kicker{ color: var(--c-accent); font-weight: 650; font-size: var(--fs-0); }
.card--mini{ padding: var(--s-5); }
.card--link{
  text-decoration:none;
  display:block;
  transition: transform .12s ease, box-shadow .12s ease;
}
.card--link:hover{
  transform: translateY(-2px);
  box-shadow: var(--sh-2);
}

/* Buttons */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap: .5rem;
  padding: .8rem 1rem;
  border-radius: .95rem;
  border: 1px solid transparent;
  font-weight: 650;
  text-decoration:none;
  cursor:pointer;
  user-select: none;
  min-height: 44px;
}
.btn--primary{
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color:#fff;
  box-shadow: 0 14px 34px rgba(14,92,173,.24);
}
.btn--primary:hover{ filter: brightness(1.02); }
.btn--secondary{
  background: #F4F7FF;
  border-color: #D9E3FF;
  color: #0B2D55;
}
.btn--ghost{
  background: transparent;
  border-color: var(--c-border);
  color: var(--c-primary-2);
}
.btn--ghost:hover{ background: rgba(14,92,173,.06); }
.hero .btn--ghost{
  border-color: rgba(255,255,255,.22);
  color: rgba(255,255,255,.95);
}
.hero .btn--ghost:hover{ background: rgba(255,255,255,.08); }
.iconbtn{
  border: 1px solid var(--c-border);
  background: #fff;
  border-radius: .8rem;
  padding: .55rem .75rem;
  min-height: 40px;
  cursor:pointer;
}

/* Forms */
.form{ display:grid; gap: var(--s-5); }
.fieldset{ border:0; padding:0; margin:0; }
.field{ display:grid; gap: var(--s-2); }
label,.label{ font-weight: 650; }
input,select{
  width:100%;
  padding: .85rem .9rem;
  border-radius: .9rem;
  border: 1px solid var(--c-border);
  background: #fff;
  font: inherit;
  min-height: 48px;
}
input:focus,select:focus,button:focus,a:focus,summary:focus{
  outline: 3px solid rgba(29,78,216,.25);
  outline-offset: 2px;
}
input[aria-invalid="true"],select[aria-invalid="true"]{
  border-color: rgba(180,35,24,.55);
  box-shadow: 0 0 0 4px rgba(180,35,24,.12);
}
.help{ font-size: var(--fs-0); color: var(--c-muted); }
.error{
  font-size: var(--fs-0);
  color: var(--c-danger);
  padding: .55rem .75rem;
  background: rgba(180,35,24,.06);
  border: 1px solid rgba(180,35,24,.18);
  border-radius: .75rem;
}
.actions{ display:flex; gap: var(--s-3); flex-wrap: wrap; }

.optional-field label::after {
  content: " (opsiyonel)";
  font-weight: normal;
  color: var(--c-muted);
  font-size: var(--fs-0);
}

.segmented{
  display:flex;
  gap: var(--s-2);
  background: #F6F8FC;
  padding: var(--s-2);
  border-radius: 1rem;
  border: 1px solid var(--c-border);
}
.segmented__item{
  flex:1;
  display:flex;
  align-items:center;
  justify-content:center;
  gap: .5rem;
  padding: .6rem .7rem;
  border-radius: .85rem;
  cursor:pointer;
  user-select:none;
}
.segmented__item input{ width:auto; min-height:auto; }

/* Result */
.result-head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: var(--s-3);
  margin-bottom: var(--s-4);
}
.result-actions{ display:flex; gap: var(--s-2); }
.metric{
  padding: var(--s-5);
  border-radius: 1.25rem;
  background: linear-gradient(135deg, rgba(14,92,173,.10), rgba(11,122,102,.10));
  border: 1px solid rgba(14,92,173,.18);
}
.metric__label{ color: var(--c-muted); font-weight:650; }
.metric__value{
  font-size: clamp(2.2rem, 3vw, 3rem);
  font-weight: 800;
  letter-spacing: -.02em;
  margin-top: var(--s-2);
}

/* Category Badge */
.category-badge{
  margin: var(--s-4) 0;
  padding: var(--s-4) var(--s-5);
  border-radius: 1rem;
  text-align: center;
}
.category-badge__label{
  font-size: var(--fs-4);
  font-weight: 800;
}
.category-badge__range{
  font-size: var(--fs-0);
  margin-top: var(--s-1);
  opacity: 0.9;
}
.category--info {
  background: linear-gradient(135deg, rgba(75,123,245,.15), rgba(75,123,245,.08));
  border: 2px solid rgba(75,123,245,.35);
  color: #2E4DB5;
}
.category--success {
  background: linear-gradient(135deg, rgba(11,122,102,.15), rgba(11,122,102,.08));
  border: 2px solid rgba(11,122,102,.35);
  color: #0B5A4A;
}
.category--warning {
  background: linear-gradient(135deg, rgba(154,103,0,.15), rgba(154,103,0,.08));
  border: 2px solid rgba(154,103,0,.35);
  color: #7A5200;
}
.category--danger {
  background: linear-gradient(135deg, rgba(180,35,24,.15), rgba(180,35,24,.08));
  border: 2px solid rgba(180,35,24,.35);
  color: #8B2318;
}

.split{ display:grid; gap: var(--s-3); margin-top: var(--s-4); }
.subcard{
  border: 1px solid var(--c-border);
  background: var(--c-card-2);
  border-radius: 1rem;
  padding: var(--s-4);
}
.subcard__title{ font-weight: 750; }
.subcard__value{ font-weight: 800; margin-top: var(--s-1); font-size: var(--fs-3); }
.callout{
  margin-top: var(--s-4);
  padding: var(--s-4);
  border-radius: 1rem;
  border: 1px solid rgba(14,92,173,.18);
  background: #F4F9FF;
}
.callout--secondary {
  background: #F6FFFB;
  border-color: rgba(11,122,102,.18);
}
.callout__title{ font-weight: 800; }
.callout__text{ margin: var(--s-2) 0 0; color: #0B2D55; }
.disclaimer{
  margin-top: var(--s-4);
  padding: var(--s-4);
  border-radius: 1rem;
  border: 1px dashed rgba(154,103,0,.45);
  background: rgba(154,103,0,.06);
  color: #4A3200;
}
.sharebox{
  margin-top: var(--s-4);
  border-radius: 1rem;
  border: 1px solid var(--c-border);
  overflow:hidden;
}
.sharebox__title{
  padding: var(--s-3) var(--s-4);
  background: #F8FAFF;
  font-weight: 750;
}
.sharebox__text{
  margin:0;
  padding: var(--s-4);
  background:#fff;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: .92rem;
  white-space: pre-wrap;
  word-break: break-word;
}
.next{ display:flex; flex-wrap:wrap; gap: var(--s-2); margin-top: var(--s-4); }
.empty ul{ margin: var(--s-3) 0 0; }
.checklist{
  padding-left: 1.1rem;
  color: var(--c-muted);
}

/* Category Cards */
.category-card {
  border-left: 4px solid;
}
.category-card--info { border-left-color: var(--c-info); }
.category-card--success { border-left-color: var(--c-success); }
.category-card--warning { border-left-color: var(--c-warning); }
.category-card--danger { border-left-color: var(--c-danger); }
.category-card__range {
  font-size: var(--fs-2);
  font-weight: 800;
  color: var(--c-muted);
  margin-bottom: var(--s-2);
}

/* Content */
.prose{ max-width: 78ch; }
.prose p{ margin: .6rem 0; }
.prose h3{ margin-top: var(--s-6); }
.snippet{
  border-radius: 1rem;
  padding: var(--s-4);
  background: #FFFFFF;
  border: 1px solid rgba(14,92,173,.18);
  box-shadow: 0 10px 25px rgba(2,8,23,.06);
}
.snippet__title{ font-weight: 800; color: #0B2D55; }
.bullets{ margin:0; padding-left: 1.2rem; }
.bullets li{ margin: .25rem 0; }
.dl{ display:grid; gap: var(--s-2); margin-top: var(--s-3); }
.dl dt{ font-weight: 800; }
.dl dd{ margin: 0; color: var(--c-muted); }
.refs{ margin: 0; padding-left: 1.2rem; }
.refs li{ margin: .35rem 0; }

/* Tables (responsive) */
.table-wrap{
  overflow:auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--c-border);
  border-radius: 1rem;
  background:#fff;
}
.table{
  width: 100%;
  border-collapse: collapse;
  min-width: 800px;
}
.table th,
.table td{
  padding: .6rem .5rem;
  border-bottom: 1px solid var(--c-border);
  text-align: center;
  white-space: nowrap;
}
.table th{
  position: sticky;
  top: 0;
  background: #F8FAFF;
  z-index: 1;
  font-size: var(--fs-0);
  letter-spacing: .2px;
}
.table td{ font-variant-numeric: tabular-nums; }
.table tbody th {
  text-align: left;
  background: #F8FAFF;
  font-weight: 650;
}

/* VKI Table Colors */
.vki-under { background: rgba(75,123,245,.12); color: #2E4DB5; font-weight: 600; }
.vki-normal { background: rgba(11,122,102,.12); color: #0B5A4A; font-weight: 600; }
.vki-over { background: rgba(154,103,0,.12); color: #7A5200; font-weight: 600; }
.vki-obese { background: rgba(180,35,24,.12); color: #8B2318; font-weight: 600; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  margin-top: var(--s-4);
}
.legend__item {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  font-size: var(--fs-0);
}
.legend__dot {
  width: 1rem;
  height: 1rem;
  border-radius: 3px;
}

.table-tools{
  display:flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  align-items:center;
  justify-content: space-between;
  margin: var(--s-4) 0;
}
.table-tools__left{
  display:flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  align-items:center;
}

/* Accordion */
.acc{
  border: 1px solid var(--c-border);
  border-radius: 1rem;
  background: #fff;
  padding: var(--s-2) var(--s-4);
  box-shadow: var(--sh-1);
}
.acc + .acc{ margin-top: var(--s-3); }
.acc__sum{
  cursor:pointer;
  font-weight: 800;
  padding: var(--s-3) 0;
  list-style:none;
}
.acc__sum::-webkit-details-marker{ display:none; }
.acc__sum::after{
  content:"+";
  float:right;
  font-weight: 900;
  color: var(--c-primary);
}
details[open] .acc__sum::after{ content:"–"; }
.acc__body{ padding-bottom: var(--s-3); color: var(--c-muted); }

/* Layout grids */
.grid{ display:grid; gap: var(--s-5); }
.grid--two{ grid-template-columns: 1fr; }
.grid--calc{ grid-template-columns: 1fr; }
.cards{ display:grid; gap: var(--s-4); }
.cards--category{ grid-template-columns: 1fr; }
.cards--tools{ grid-template-columns: 1fr; }

/* Footer */
.site-footer{
  margin-top: var(--s-12);
  padding: var(--s-10) 0;
  background: #0B1220;
  color: rgba(255,255,255,.9);
}
.footer-grid{
  display:grid;
  gap: var(--s-6);
}
.footer-title{ font-weight: 800; margin-bottom: var(--s-2); }
.linklist{ list-style:none; padding:0; margin:0; display:grid; gap: var(--s-2); }
.linklist a{ color: rgba(255,255,255,.9); }
.footer-meta{
  margin-top: var(--s-8);
  padding-top: var(--s-4);
  border-top: 1px solid rgba(255,255,255,.12);
  display:flex;
  justify-content:space-between;
  gap: var(--s-4);
  flex-wrap: wrap;
}

/* Footer email */
.emailbox{
  display:grid;
  gap: var(--s-3);
  padding: .75rem .85rem;
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 1rem;
  background: rgba(255,255,255,.06);
  max-width: 34rem;
}
.emailbox__row{
  display:flex;
  flex-wrap: wrap;
  gap: .45rem;
  align-items:center;
}
.emailchip{
  display:inline-flex;
  padding: .35rem .55rem;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.16);
  background: rgba(255,255,255,.08);
  color: rgba(255,255,255,.92);
  font-weight: 700;
  letter-spacing: .2px;
}
.emailsep{
  color: rgba(255,255,255,.72);
  font-weight: 800;
  font-size: var(--fs-0);
}
.emailbox__actions{
  display:flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  align-items:center;
}
.site-footer .iconbtn{
  border-color: rgba(255,255,255,.18);
  background: rgba(255,255,255,.08);
  color: rgba(255,255,255,.92);
}

/* Breakpoints */
@media (min-width: 640px){
  .topnav{ display:flex; }
  .hero{ grid-template-columns: 1.35fr .65fr; }
  .grid--two{ grid-template-columns: 1fr 1fr; }
  .split{ grid-template-columns: 1fr 1fr; }
  .cards--tools{ grid-template-columns: 1fr 1fr; }
  .cards--category{ grid-template-columns: 1fr 1fr; }
  .prose{ max-width: 150ch; }
}
@media (min-width: 900px){
  .grid--calc{ grid-template-columns: 1fr 1fr; align-items:start; }
  .footer-grid{ grid-template-columns: 1.4fr .8fr .8fr; }
}
@media (min-width: 1200px){
  .cards--category{ grid-template-columns: 1fr 1fr 1fr 1fr; }
}

/* Print */
@media print{
  .site-header, .site-footer, .hero__cta, .result-actions, .topnav, .skip-link { display:none !important; }
  body{ background:#fff; }
  .card{ box-shadow:none; }
  a{ color:#000; text-decoration:none; }
}