@import url("https://fonts.googleapis.com/css?family=Inter:400,500,600,700,800");

:root {
  --bg: #f7fbff;
  --bg-soft: #eef7ff;
  --bg-panel: rgba(255, 255, 255, 0.9);

  --text: #0b1f33;
  --text-soft: #4b6480;
  --text-muted: #6b84a0;

  --line: #d6e7f5;
  --line-strong: #c4dbef;

  --blue-deep: #0d4d8b;
  --blue-main: #1f78c8;
  --blue-mid: #3ea4e6;
  --blue-light: #dff3ff;
  --blue-ice: #f3fbff;

  --shadow: 0 24px 60px rgba(13, 77, 139, 0.08);
  --button-shadow: 0 14px 28px rgba(31, 120, 200, 0.24);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, sans-serif;
  color: var(--text);
  background: var(--bg);
  position: relative;
}

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

button,
input,
textarea {
  font: inherit;
}

img {
  max-width: 100%;
}

.site-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(circle at top right, rgba(62, 164, 230, 0.14), transparent 24%),
    radial-gradient(circle at top left, rgba(13, 77, 139, 0.08), transparent 28%),
    linear-gradient(180deg, #ffffff 0%, #f8fcff 45%, #edf7ff 100%);
}

.container {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
}

.topbar,
.hero,
.section {
  position: relative;
  z-index: 1;
}

.topbar {
  padding: 24px 0 8px;
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-logo {
  width: 48px;
  height: 48px;
  object-fit: contain;
  display: block;
  flex: 0 0 48px;
}

.brand-text {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1;
  white-space: nowrap;
  color: var(--text);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-link-button,
.nav-cta,
.reveal-button,
.primary-button {
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
}

.nav-link-button {
  padding: 10px 14px;
  background: transparent;
  color: var(--text-soft);
}

.nav-cta,
.reveal-button,
.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 22px;
  background: linear-gradient(135deg, var(--blue-deep), var(--blue-main) 55%, var(--blue-mid));
  color: #fff;
  font-weight: 700;
  box-shadow: var(--button-shadow);
}

.nav-cta {
  padding: 12px 18px;
  font-weight: 600;
}

.nav-link-button:hover,
.nav-cta:hover,
.reveal-button:hover,
.primary-button:hover {
  transform: translateY(-1px);
}

.hero {
  padding: 12px 0 32px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  justify-items: center;
  align-items: center;
  text-align: center;
}

.hero-copy {
  max-width: 860px;
  margin: 0 auto;
  text-align: center;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--blue-main);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  text-align: center;
}

.side-eyebrow {
  text-align: left;
}

.hero-copy h1,
.panel-header h2,
.side-card h3 {
  margin: 0;
}

.hero-copy h1 {
  font-size: clamp(2.6rem, 5vw, 4.4rem);
  line-height: 1.02;
  letter-spacing: -0.05em;
  color: var(--text);
}

.hero-text {
  max-width: 54ch;
  margin: 16px auto 0;
  color: var(--text-soft);
  font-size: 1.05rem;
  line-height: 1.7;
}

.section {
  padding: 20px 0 38px;
}

.challenge-layout {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 22px;
  align-items: start;
}

.challenge-panel,
.side-card {
  padding: 22px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.panel-badge {
  padding: 10px 14px;
  background: var(--blue-ice);
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--blue-deep);
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
}

.image-stage {
  position: relative;
  min-height: 460px;
  overflow: hidden;
  background: linear-gradient(180deg, #edf8ff 0%, #f9fdff 100%);
  border: 1px solid var(--line);
  border-radius: 24px;
}

.daily-image {
  display: block;
  width: 100%;
  height: 460px;
  object-fit: cover;
  filter: blur(18px) saturate(0.8) brightness(0.95);
  transform: scale(1.04);
  transition: all 0.45s ease;
}

.conceal-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.12),
    rgba(223, 243, 255, 0.62)
  );
  transition: opacity 0.3s ease;
}

#state-toggle:checked ~ .image-stage .daily-image {
  filter: blur(0) saturate(1) brightness(1);
  transform: scale(1);
}

#state-toggle:checked ~ .image-stage .conceal-layer {
  opacity: 0;
}

.reveal-button {
  margin-top: 18px;
}

.side-stack {
  display: grid;
  gap: 22px;
}

.stack-form {
  display: grid;
  gap: 14px;
}

.stack-form label {
  display: grid;
  gap: 8px;
}

.stack-form span {
  color: var(--text-soft);
  font-size: 0.94rem;
  font-weight: 600;
}

.stack-form input,
.stack-form textarea {
  width: 100%;
  padding: 14px 16px;
  background: #fbfeff;
  border: 1px solid var(--line);
  border-radius: 16px;
  color: var(--text);
  outline: none;
}

.stack-form input:focus,
.stack-form textarea:focus {
  border-color: rgba(31, 120, 200, 0.6);
  box-shadow: 0 0 0 4px rgba(62, 164, 230, 0.14);
}

.full-width {
  width: 100%;
}

.status-message {
  min-height: 24px;
  margin: 12px 0 0;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  line-height: 1.5;
}

button:disabled,
.primary-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

@media (max-width: 980px) {
  .topbar-actions {
    display: none;
  }

  .challenge-layout {
    grid-template-columns: 1fr;
  }

  .image-stage,
  .daily-image {
    min-height: 320px;
    height: 320px;
  }
}