/* ═══════════════════════════════════════════════════════════════
   KC Web App — Professional UI
   ═══════════════════════════════════════════════════════════════ */

:root {
  --navy: #0f2744;
  --blue: #1a6dd4;
  --blue-light: #e8f1fc;
  --green: #16a34a;
  --green-bg: #dcfce7;
  --amber: #ca8a04;
  --amber-bg: #fef9c3;
  --red: #dc2626;
  --red-bg: #fee2e2;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-500: #6b7280;
  --gray-700: #374151;
  --gray-900: #111827;
  --radius: 10px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
  --transition: 0.2s ease;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; color: var(--gray-900); background: var(--gray-50); line-height: 1.6; -webkit-font-smoothing: antialiased; }

/* ── Nav ─────────────────────────────────────────────────────── */
.nav { background: var(--navy); padding: 0; position: sticky; top: 0; z-index: 100; box-shadow: 0 2px 8px rgba(0,0,0,0.15); }
.nav-inner { max-width: 1100px; margin: 0 auto; padding: 0 24px; display: flex; justify-content: space-between; align-items: center; height: 56px; }
.logo { color: #fff; font-size: 1.2rem; font-weight: 800; text-decoration: none; letter-spacing: 2px; }
.logo span { color: var(--blue); }
.nav-links { display: flex; gap: 6px; align-items: center; }
.nav-link { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.85rem; padding: 6px 14px; border-radius: 6px; transition: var(--transition); font-weight: 500; }
.nav-link:hover, .nav-link.active { color: #fff; background: rgba(255,255,255,0.1); }
.nav-cta { background: var(--blue); color: #fff !important; font-weight: 600; border-radius: 6px; padding: 7px 18px; font-size: 0.85rem; text-decoration: none; transition: var(--transition); }
.nav-cta:hover { background: #1558b0; }


/* ── Hero ────────────────────────────────────────────────────── */
.hero { text-align: center; padding: 90px 24px 70px; background: linear-gradient(160deg, var(--navy) 0%, #1a3a5c 50%, var(--blue) 100%); color: #fff; position: relative; overflow: hidden; }
.hero::after { content: ''; position: absolute; bottom: -2px; left: 0; right: 0; height: 60px; background: var(--gray-50); clip-path: ellipse(55% 100% at 50% 100%); }
.hero h1 { font-size: 2.8rem; font-weight: 800; line-height: 1.15; margin-bottom: 18px; letter-spacing: -0.5px; }
.hero h1 span { color: #60a5fa; }
.hero-sub { font-size: 1.1rem; opacity: 0.8; max-width: 580px; margin: 0 auto 32px; line-height: 1.6; font-weight: 400; }
.hero-badges { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-bottom: 32px; }
.hero-badge { background: rgba(255,255,255,0.12); border: 1px solid rgba(255,255,255,0.2); padding: 5px 14px; border-radius: 20px; font-size: 0.8rem; font-weight: 500; }

/* ── Buttons ─────────────────────────────────────────────────── */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px; background: var(--blue); color: #fff; border: none; border-radius: 8px; font-size: 0.95rem; font-weight: 600; cursor: pointer; text-decoration: none; transition: var(--transition); }
.btn:hover { background: #1558b0; transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-lg { padding: 14px 36px; font-size: 1.05rem; }
.btn-full { width: 100%; justify-content: center; }
.btn-white { background: #fff; color: var(--navy); }
.btn-white:hover { background: var(--gray-100); }
.btn-download { background: var(--green); padding: 16px 40px; font-size: 1.1rem; }
.btn-download:hover { background: #15803d; }
.btn:disabled { background: var(--gray-300); cursor: not-allowed; transform: none; box-shadow: none; }
.btn-outline { background: transparent; border: 2px solid var(--blue); color: var(--blue); }
.btn-outline:hover { background: var(--blue-light); }

/* Demo / training mode */
.demo-case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 24px;
}
.demo-case-card {
  display: block;
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 18px 18px 16px;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.demo-case-card:hover {
  border-color: var(--blue);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.demo-case-title { font-weight: 700; color: var(--navy); font-size: 1.05rem; margin-bottom: 6px; }
.demo-case-meta { font-size: 0.85rem; color: var(--gray-600); margin-bottom: 8px; }
.demo-case-eyes { font-size: 0.8rem; font-weight: 600; color: var(--blue); margin-bottom: 8px; }
.demo-case-peek { font-size: 0.78rem; color: var(--gray-500); line-height: 1.45; min-height: 2.6em; }
.demo-case-cta { display: inline-block; margin-top: 12px; font-size: 0.85rem; font-weight: 600; color: var(--blue); }

.demo-meta-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 20px 0 8px;
}
.demo-eye-block {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 8px;
  margin-top: 14px;
  box-shadow: var(--shadow-sm);
}
.demo-eye-head {
  font-size: 1rem;
  color: #fff;
  background: var(--navy);
  margin: -8px -8px 8px;
  padding: 10px 14px;
  border-radius: var(--radius) var(--radius) 0 0;
}
.page-section--demo {
  max-width: min(1680px, 100%);
  padding: 24px 12px 48px;
}
.demo-image-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 12px;
}
.demo-image-card {
  border: 1px solid var(--gray-200);
  border-radius: 6px;
  overflow: hidden;
  background: #fff;
}
.demo-image-label {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--gray-600);
  padding: 6px 10px;
  border-bottom: 1px solid var(--gray-200);
}
.demo-image-placeholder {
  min-height: 360px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--gray-500);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 16px;
  background: repeating-linear-gradient(
    -45deg,
    #f8fafc,
    #f8fafc 8px,
    #eef2f7 8px,
    #eef2f7 16px
  );
}
.demo-image-placeholder span { font-weight: 400; font-size: 0.72rem; margin-top: 4px; }
.demo-image {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  background: #fff;
}
a.demo-image-link {
  display: block;
  cursor: zoom-in;
}
a.demo-image-link:hover .demo-image {
  opacity: 0.97;
}
.demo-refraction {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  padding: 4px 2px 6px;
}
.demo-refraction-field label {
  display: block;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 6px;
}
.demo-refraction-field input {
  width: 100%;
  border: 1px solid var(--gray-300);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--gray-800, #1f2937);
  background: #fff;
}
.demo-refraction-field input:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}
.demo-field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 10px 12px;
}
.demo-actions { display: flex; gap: 12px; flex-wrap: wrap; margin: 24px 0 8px; }

.demo-reason-block {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}
.demo-reason-h { font-size: 0.95rem; color: var(--navy); margin: 18px 0 10px; }
.demo-reason-table td, .demo-reason-table th { font-size: 0.8rem; }
.demo-reason-text { color: var(--gray-600); max-width: 320px; }
.demo-proc-card {
  border: 1px solid var(--gray-200);
  border-radius: 8px;
  padding: 12px;
  margin-bottom: 12px;
  background: #fafbfc;
}
.demo-proc-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
}
.verdict-normal { background: var(--green-bg); color: var(--green); }
.verdict-suspicious { background: var(--amber-bg); color: var(--amber); }
.verdict-abnormal, .verdict-critical { background: var(--red-bg); color: var(--red); }
.diag-suspect { background: var(--amber-bg); color: var(--amber); }
.diag-ectasia { background: var(--red-bg); color: var(--red); }
.diag-normal { background: var(--green-bg); color: var(--green); }

@media (max-width: 720px) {
  .demo-meta-row, .demo-image-row { grid-template-columns: 1fr; }
}

/* ── Features ────────────────────────────────────────────────── */
.features { max-width: 1100px; margin: 0 auto; padding: 70px 24px 50px; }
.features-title { text-align: center; font-size: 1.6rem; font-weight: 700; color: var(--navy); margin-bottom: 8px; }
.features-sub { text-align: center; font-size: 0.95rem; color: var(--gray-500); margin-bottom: 40px; }
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; }
.feature-card { background: #fff; border-radius: var(--radius); padding: 28px 24px; box-shadow: var(--shadow-sm); border: 1px solid var(--gray-200); transition: var(--transition); }
.feature-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.feature-icon { width: 44px; height: 44px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 1.3rem; margin-bottom: 14px; }
.fi-blue { background: var(--blue-light); }
.fi-green { background: var(--green-bg); }
.fi-amber { background: var(--amber-bg); }
.fi-red { background: var(--red-bg); }
.feature-card h3 { font-size: 0.95rem; color: var(--gray-900); margin-bottom: 6px; font-weight: 700; }
.feature-card p { font-size: 0.85rem; color: var(--gray-500); line-height: 1.5; }

/* ── How it works ────────────────────────────────────────────── */
.how-section { background: #fff; padding: 70px 24px; border-top: 1px solid var(--gray-200); }
.how-section h2 { text-align: center; font-size: 1.6rem; font-weight: 700; color: var(--navy); margin-bottom: 40px; }
.steps-grid { display: flex; gap: 24px; justify-content: center; flex-wrap: wrap; max-width: 900px; margin: 0 auto; }
.step { flex: 1; min-width: 220px; max-width: 280px; text-align: center; position: relative; }
.step-num { width: 48px; height: 48px; background: var(--navy); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 1.2rem; margin: 0 auto 14px; }
.step h3 { font-size: 0.95rem; color: var(--gray-900); margin-bottom: 6px; font-weight: 700; }
.step p { font-size: 0.85rem; color: var(--gray-500); line-height: 1.5; }
.step-arrow { display: none; }
@media (min-width: 700px) {
  .step-arrow { display: block; position: absolute; right: -18px; top: 22px; color: var(--gray-300); font-size: 1.4rem; }
}


/* ── Trust bar ───────────────────────────────────────────────── */
.trust-bar { background: var(--gray-100); padding: 28px 24px; text-align: center; border-top: 1px solid var(--gray-200); }
.trust-bar p { font-size: 0.8rem; color: var(--gray-500); max-width: 700px; margin: 0 auto; }
.trust-badges { display: flex; gap: 24px; justify-content: center; flex-wrap: wrap; margin-top: 10px; }
.trust-badges span { font-size: 0.78rem; color: var(--gray-500); font-weight: 600; }

/* ── Upload page ─────────────────────────────────────────────── */
.page-section { max-width: 820px; margin: 0 auto; padding: 40px 24px 60px; }
.page-section h1 { font-size: 1.5rem; color: var(--navy); margin-bottom: 4px; font-weight: 700; }
.page-sub { font-size: 0.9rem; color: var(--gray-500); margin-bottom: 28px; }
.upload-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 28px; }
.upload-card { background: #fff; border-radius: var(--radius); padding: 16px; border: 1px solid var(--gray-200); }
.upload-card label { display: block; font-weight: 600; font-size: 0.82rem; color: var(--navy); margin-bottom: 8px; }
.drop-zone { border: 2px dashed var(--gray-300); border-radius: 8px; padding: 24px 12px; text-align: center; cursor: pointer; transition: var(--transition); min-height: 90px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px; background: var(--gray-50); }
.drop-zone:hover { border-color: var(--blue); background: var(--blue-light); }
.drop-zone.has-file { border-color: var(--green); background: var(--green-bg); }
.drop-zone input { display: none; }

.bulk-zone {
  position: relative;
  border: 2px dashed var(--blue);
  border-radius: var(--radius);
  padding: 36px 20px;
  text-align: center;
  cursor: pointer;
  background: var(--blue-light);
  margin-bottom: 16px;
  transition: var(--transition);
}
.bulk-zone:hover, .bulk-zone.drag-over { background: #d6e8fb; border-color: #1558b0; }
.bulk-zone.has-file { border-color: var(--green); background: var(--green-bg); }
.bulk-zone input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.bulk-title { font-weight: 700; color: var(--navy); margin: 8px 0 4px; font-size: 1.05rem; }
.bulk-hint { color: var(--gray-500); font-size: 0.85rem; margin-bottom: 8px; }
.bulk-examples { color: var(--gray-700); font-size: 0.75rem; line-height: 1.5; }
.bulk-examples code {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 0.7rem;
}
.alloc-msg {
  margin-bottom: 16px;
  padding: 12px 14px;
  border-radius: 8px;
  font-size: 0.88rem;
  line-height: 1.5;
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
}
.alloc-msg.alloc-ok { background: var(--green-bg); border-color: #86efac; color: #166534; }
.alloc-msg.alloc-warn { background: var(--amber-bg); border-color: #fde047; color: #854d0e; }
.alloc-actions { margin: -8px 0 16px; text-align: right; }
.btn-clear {
  background: transparent;
  border: 1px solid var(--gray-300);
  color: var(--gray-700);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
}
.btn-clear:hover { border-color: var(--red); color: var(--red); background: var(--red-bg); }
.slot-zone .file-name { font-size: 0.72rem; color: var(--gray-700); word-break: break-all; max-width: 100%; padding: 0 4px; }
#submitBtn:disabled { opacity: 0.55; cursor: not-allowed; }
.drop-icon { font-size: 1.4rem; opacity: 0.5; }
.drop-text { font-size: 0.8rem; color: var(--gray-500); }
.file-name { font-size: 0.78rem; color: var(--green); font-weight: 600; word-break: break-all; }

.form-section { background: #fff; border-radius: var(--radius); padding: 20px; border: 1px solid var(--gray-200); margin-bottom: 24px; }
.form-section h3 { font-size: 0.9rem; color: var(--navy); margin-bottom: 14px; font-weight: 700; }
.input-row { display: flex; gap: 16px; }

.eye-select { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.eye-option {
  display: flex; flex-direction: column; gap: 2px;
  border: 1px solid var(--gray-200); border-radius: 8px;
  padding: 12px 14px; cursor: pointer; background: var(--gray-50);
  transition: var(--transition);
}
.eye-option:hover { border-color: var(--blue); background: var(--blue-light); }
.eye-option:has(input:checked) { border-color: var(--blue); background: var(--blue-light); box-shadow: inset 0 0 0 1px var(--blue); }
.eye-option input { margin-bottom: 4px; }
.eye-option span { font-weight: 700; color: var(--navy); font-size: 0.9rem; }
.eye-option small { color: var(--gray-500); font-size: 0.75rem; }

.refraction-block {
  border: 1px solid var(--gray-200);
  border-radius: 8px;
  padding: 14px;
  margin-bottom: 12px;
  background: var(--gray-50);
}
.refraction-block:last-child { margin-bottom: 0; }
.refraction-block h4 {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.input-group { flex: 1; }
.input-group label { display: block; font-weight: 600; font-size: 0.82rem; color: var(--gray-700); margin-bottom: 4px; }
.input-group input { width: 100%; padding: 10px 12px; border: 1px solid var(--gray-300); border-radius: 8px; font-size: 0.9rem; transition: var(--transition); background: #fff; }
.input-group input:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(26,109,212,0.1); }
.input-hint { font-size: 0.75rem; color: var(--gray-500); margin-top: 2px; }

.error-box { background: var(--red-bg); border-left: 4px solid var(--red); color: var(--red); padding: 12px 16px; border-radius: 6px; margin-bottom: 20px; font-size: 0.88rem; font-weight: 500; }

.processing-overlay { display: none; position: fixed; inset: 0; background: rgba(15,39,68,0.7); z-index: 200; align-items: center; justify-content: center; }
.processing-overlay.active { display: flex; }
.processing-card { background: #fff; border-radius: 16px; padding: 40px 48px; text-align: center; box-shadow: var(--shadow-lg); max-width: 400px; }
.processing-card h3 { color: var(--navy); margin-bottom: 8px; }
.processing-card p { color: var(--gray-500); font-size: 0.88rem; }
.spinner { width: 40px; height: 40px; border: 4px solid var(--gray-200); border-top-color: var(--blue); border-radius: 50%; animation: spin 0.8s linear infinite; margin: 0 auto 16px; }
@keyframes spin { to { transform: rotate(360deg); } }


/* ── Result page ─────────────────────────────────────────────── */
.result-hero { text-align: center; padding: 40px 24px 30px; background: linear-gradient(160deg, #0d3320 0%, var(--green) 100%); color: #fff; }
.result-hero h1 { font-size: 1.6rem; font-weight: 700; margin-bottom: 4px; }
.result-hero p { opacity: 0.8; font-size: 0.95rem; }
.result-content { max-width: 900px; margin: -20px auto 0; padding: 0 24px 60px; position: relative; z-index: 1; }
.result-content--demo { max-width: 1100px; }
.demo-pdf-preview {
  background: #fff;
  border-radius: var(--radius);
  padding: 16px 16px 12px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
  margin-bottom: 24px;
}
.demo-pdf-preview h3 {
  font-size: 0.95rem;
  color: var(--navy);
  margin-bottom: 12px;
}
.demo-pdf-preview iframe {
  width: 100%;
  height: min(82vh, 1100px);
  min-height: 780px;
  border: 1px solid var(--gray-200);
  border-radius: 8px;
  background: #525659;
}
.download-bar { background: #fff; border-radius: var(--radius); padding: 20px 24px; box-shadow: var(--shadow-md); text-align: center; margin-bottom: 24px; }
.eyes-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.eye-card { background: #fff; border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow-sm); border: 1px solid var(--gray-200); }
.eye-card h2 { font-size: 1rem; color: var(--navy); margin-bottom: 12px; font-weight: 700; }
.diag-badge { display: inline-block; padding: 6px 16px; border-radius: 20px; font-weight: 700; font-size: 0.85rem; margin-bottom: 16px; }
.diag-normal { background: var(--green-bg); color: var(--green); }
.diag-suspect { background: var(--amber-bg); color: var(--amber); }
.diag-ectasia { background: var(--red-bg); color: var(--red); }
.summary-table { width: 100%; border-collapse: collapse; }
.summary-table th { text-align: left; padding: 8px 10px; font-size: 0.78rem; color: var(--gray-500); border-bottom: 2px solid var(--gray-200); text-transform: uppercase; letter-spacing: 0.5px; }
.summary-table td { padding: 8px 10px; font-size: 0.88rem; border-bottom: 1px solid var(--gray-100); }
.verdict-badge { display: inline-block; padding: 3px 12px; border-radius: 20px; font-size: 0.78rem; font-weight: 600; }
.verdict-safe { background: var(--green-bg); color: var(--green); }
.verdict-caution { background: var(--amber-bg); color: var(--amber); }
.verdict-contraindicated { background: var(--red-bg); color: var(--red); }
.result-actions { text-align: center; margin-top: 28px; }

/* ── Footer ──────────────────────────────────────────────────── */
.footer { text-align: center; padding: 28px 24px; font-size: 0.78rem; color: var(--gray-500); border-top: 1px solid var(--gray-200); margin-top: 40px; background: #fff; }
.footer p { margin: 2px 0; }
.footer a { color: var(--blue); text-decoration: none; }

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 700px) {
  .hero h1 { font-size: 1.8rem; }
  .upload-grid { grid-template-columns: 1fr; }
  .input-row { flex-direction: column; }
  .eye-select { grid-template-columns: 1fr; }
  .steps-grid { flex-direction: column; align-items: center; }
  .eyes-grid { grid-template-columns: 1fr; }
  .nav-inner { padding: 0 16px; }
}