:root {
  --ink: #172033;
  --muted: #667085;
  --line: #d8dee9;
  --paper: #ffffff;
  --soft: #f4f7fb;
  --primary: #0b7a75;
  --primary-dark: #075c59;
  --accent: #f6b743;
  --danger: #c2410c;
  --shadow: 0 20px 60px rgba(23, 32, 51, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", Arial, sans-serif;
  color: var(--ink);
  background: var(--soft);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(18px, 5vw, 72px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  color: #ffffff;
  background: var(--primary);
  border-radius: 8px;
  font-weight: 800;
}

.brand strong,
.brand small {
  display: block;
}

.brand small,
.main-nav a,
.action-item small {
  color: var(--muted);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 10px;
}

.main-nav a {
  padding: 8px 12px;
  border-radius: 8px;
  font-weight: 700;
}

.main-nav a:hover {
  background: #e8f3f2;
  color: var(--primary-dark);
}

main {
  overflow: hidden;
}

.hero-section {
  display: grid;
  min-height: 620px;
  grid-template-columns: minmax(0, 1.2fr) minmax(320px, 0.8fr);
  align-items: center;
  gap: 40px;
  padding: clamp(44px, 7vw, 92px) clamp(18px, 5vw, 72px) 34px;
  background:
    linear-gradient(120deg, rgba(11, 122, 117, 0.94), rgba(23, 32, 51, 0.88)),
    url("https://images.unsplash.com/photo-1523240795612-9a054b0db644?auto=format&fit=crop&w=1800&q=80");
  background-position: center;
  background-size: cover;
  color: #ffffff;
}

.hero-content {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 20px;
  font-size: clamp(2.7rem, 6vw, 5.8rem);
  line-height: 0.98;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(1.55rem, 3vw, 2.3rem);
  line-height: 1.15;
}

.hero-copy {
  max-width: 640px;
  color: rgba(255, 255, 255, 0.88);
  font-size: 1.12rem;
}

.hero-actions,
.action-strip,
.status-list,
.button-row {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 12px 18px;
  border: 0;
  border-radius: 8px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 28px rgba(23, 32, 51, 0.18);
}

.primary {
  color: #ffffff;
  background: var(--primary);
}

.secondary {
  color: var(--ink);
  background: #ffffff;
}

.dark {
  color: #ffffff;
  background: var(--ink);
}

.full-width {
  width: 100%;
}

.quick-panel {
  padding: 24px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(255, 255, 255, 0.6);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.qr-card {
  display: grid;
  grid-template-columns: 132px 1fr;
  align-items: center;
  gap: 20px;
}

.qr-image {
  display: block;
  width: min(100%, 260px);
  aspect-ratio: 1;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
  object-fit: contain;
}

.qr-image.small {
  width: 132px;
  padding: 8px;
}

.status-list {
  margin-top: 24px;
}

.status-list div {
  display: flex;
  min-width: 150px;
  align-items: center;
  gap: 9px;
  padding: 10px 12px;
  background: #f7fafc;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.status-list p {
  margin: 0;
  font-size: 0.9rem;
  font-weight: 700;
}

.status-dot {
  width: 10px;
  height: 10px;
  background: var(--primary);
  border-radius: 999px;
}

.status-dot.green {
  background: #16a34a;
}

.status-dot.yellow {
  background: var(--accent);
}

.action-strip {
  position: relative;
  z-index: 2;
  max-width: 1180px;
  margin: -34px auto 0;
  padding: 0 18px;
}

.action-item {
  flex: 1 1 250px;
  padding: 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 12px 32px rgba(23, 32, 51, 0.08);
}

.action-item span,
.block-icon {
  display: inline-flex;
  min-width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
  color: var(--primary-dark);
  background: #dff3f1;
  border-radius: 8px;
  font-weight: 800;
}

.action-item strong,
.action-item small {
  display: block;
}

.content-grid {
  display: grid;
  max-width: 1180px;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: 28px;
  margin: 54px auto;
  padding: 0 18px;
}

.register-section,
.info-block,
.qr-section,
.setup-section {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 12px 32px rgba(23, 32, 51, 0.06);
}

.register-section {
  padding: clamp(22px, 4vw, 34px);
}

.section-heading p {
  color: var(--muted);
}

.qr-section {
  max-width: 1180px;
  margin: 54px auto 0;
  padding: clamp(22px, 4vw, 34px);
}

.qr-generator {
  display: grid;
  grid-template-columns: minmax(220px, 0.75fr) minmax(0, 1.25fr);
  gap: 28px;
  align-items: center;
}

.qr-preview {
  display: grid;
  justify-items: center;
  gap: 14px;
  padding: 22px;
  background: #f7fafc;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.qr-text {
  width: 100%;
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
  overflow-wrap: anywhere;
  text-align: center;
}

.qr-controls {
  display: grid;
  gap: 12px;
}

.qr-controls small {
  color: var(--muted);
  font-weight: 700;
}

.student-form {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.form-row {
  display: grid;
  gap: 7px;
}

.form-row.full-span,
.form-button,
.form-status {
  grid-column: 1 / -1;
}

label {
  font-weight: 800;
}

input,
select,
textarea {
  width: 100%;
  min-height: 48px;
  padding: 12px 13px;
  color: var(--ink);
  background: #fbfcfe;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font: inherit;
}

textarea {
  resize: vertical;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--primary);
  outline: 3px solid rgba(11, 122, 117, 0.16);
}

input[aria-invalid="true"],
select[aria-invalid="true"] {
  border-color: var(--danger);
  background: #fff7ed;
}

.error-message {
  min-height: 18px;
  color: var(--danger);
  font-weight: 700;
}

.form-status {
  min-height: 24px;
  margin: 0;
  color: var(--primary-dark);
  font-weight: 800;
}

.info-column {
  display: grid;
  gap: 22px;
  align-content: start;
}

.info-block {
  padding: 26px;
}

.info-block p {
  color: var(--muted);
}

.info-block.accent {
  background: #fff7e8;
}

.setup-section {
  display: grid;
  max-width: 1180px;
  grid-template-columns: minmax(0, 0.7fr) minmax(280px, 1fr);
  gap: 28px;
  margin: 0 auto 54px;
  padding: 28px;
}

.setup-section ol {
  margin: 0;
  padding-left: 22px;
}

.setup-section li + li {
  margin-top: 8px;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 24px clamp(18px, 5vw, 72px);
  color: #ffffff;
  background: var(--ink);
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  font-weight: 800;
}

.footer-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.admin-page {
  min-height: 100vh;
  padding: clamp(22px, 5vw, 54px);
  background: var(--soft);
}

.admin-panel {
  max-width: 1180px;
  margin: 0 auto;
  padding: clamp(22px, 4vw, 34px);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.admin-panel h1 {
  margin-bottom: 12px;
  font-size: clamp(2rem, 4vw, 3.2rem);
  line-height: 1.08;
}

.admin-login {
  display: grid;
  max-width: 420px;
  gap: 14px;
}

.admin-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin: 24px 0;
  flex-wrap: wrap;
}

.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.registrations-table {
  width: 100%;
  min-width: 980px;
  border-collapse: collapse;
  background: #ffffff;
}

.registrations-table th,
.registrations-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.registrations-table th {
  color: var(--ink);
  background: #eef7f6;
  font-size: 0.85rem;
  text-transform: uppercase;
}

.registrations-table td {
  color: var(--muted);
  font-size: 0.92rem;
}

@media (max-width: 860px) {
  .site-header,
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .main-nav {
    width: 100%;
    justify-content: space-between;
  }

  .hero-section,
  .content-grid,
  .qr-generator,
  .setup-section {
    grid-template-columns: 1fr;
  }

  .hero-section {
    min-height: auto;
  }

  .student-form {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .main-nav a {
    padding: 8px 6px;
    font-size: 0.9rem;
  }

  .hero-actions .button,
  .form-button {
    width: 100%;
  }

  .quick-panel {
    padding: 18px;
  }

  .qr-card {
    grid-template-columns: 1fr;
  }

  .qr-image.small {
    width: min(100%, 180px);
  }

  .button-row .button {
    width: 100%;
  }
}