/* ===========================================
   10 BRIDGE CHALLENGE — Stylesheet

   Table of Contents:
   1. Design Tokens
   2. Reset & Base
   3. Layout
   4. Hero Section
   5. Section Shared
   6. Challenge Section (horizontal items)
   7. Bridges Section (full-width text + gallery)
   8. Latest / Posts Section
   9. Footer
   10. Animations
   11. Responsive
   =========================================== */

/* -------------------------------------------
   1. DESIGN TOKENS
   ------------------------------------------- */
:root {
  --clr-bg:          #FAF9F7;
  --clr-surface:     #FFFFFF;
  --clr-surface-alt: #F3F1EE;
  --clr-border:      #E5E2DC;
  --clr-border-light:#EFECEA;

  --clr-text:        #1A1917;
  --clr-text-muted:  #6B6660;
  --clr-text-faint:  #9E9891;

  --clr-accent:      #2563EB;
  --clr-accent-soft: #DBEAFE;
  --clr-accent-dark: #1E40AF;

  --clr-success:     #16A34A;
  --clr-success-soft:#DCFCE7;

  --ff-sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --ff-mono:  'IBM Plex Mono', 'SF Mono', 'Fira Code', monospace;

  --fs-xs:    0.75rem;
  --fs-sm:    0.875rem;
  --fs-base:  1rem;
  --fs-lg:    1.125rem;
  --fs-xl:    1.25rem;
  --fs-2xl:   1.5rem;
  --fs-3xl:   2rem;
  --fs-4xl:   2.75rem;
  --fs-hero:  clamp(2.5rem, 6vw, 5rem);

  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.25rem;
  --sp-6: 1.5rem;
  --sp-8: 2rem;
  --sp-10: 2.5rem;
  --sp-12: 3rem;
  --sp-16: 4rem;
  --sp-20: 5rem;
  --sp-24: 6rem;
  --sp-32: 8rem;

  --max-w: 72rem;
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  --shadow-sm:  0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:  0 2px 8px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-lg:  0 8px 24px rgba(0,0,0,0.08), 0 2px 8px rgba(0,0,0,0.04);

  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --duration: 0.25s;
}


/* -------------------------------------------
   2. RESET & BASE
   ------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--ff-sans);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--clr-text);
  background-color: var(--clr-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--clr-accent);
  text-decoration: none;
}

a:hover {
  color: var(--clr-accent-dark);
}

::selection {
  background: var(--clr-accent-soft);
  color: var(--clr-accent-dark);
}


/* -------------------------------------------
   3. LAYOUT
   ------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--sp-6);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--sp-10);
  }
}


/* -------------------------------------------
   4. HERO SECTION
   ------------------------------------------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  padding: var(--sp-16) 0 var(--sp-12);
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero__grid {
  position: absolute;
  inset: 0;
  color: var(--clr-border-light);
  opacity: 0.6;
}

.hero__gradient {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% 0%, var(--clr-accent-soft) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 100%, #FEF3C7 0%, transparent 50%),
    linear-gradient(180deg, var(--clr-bg) 0%, transparent 30%, transparent 70%, var(--clr-bg) 100%);
}

.hero__inner {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero__title {
  font-size: var(--fs-hero);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--clr-text);
  margin-bottom: var(--sp-6);
  animation: fadeInDown 0.6s 0.1s var(--ease) both;
}

.hero__sub {
  font-size: clamp(var(--fs-lg), 2.5vw, var(--fs-xl));
  color: var(--clr-text-muted);
  line-height: 1.7;
  max-width: 36rem;
  margin: 0 auto var(--sp-12);
  animation: fadeInDown 0.6s 0.2s var(--ease) both;
}

/* Stats — single days counter */
.hero__stats {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--sp-10);
  animation: fadeInDown 0.6s 0.3s var(--ease) both;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-1);
}

.stat__number {
  font-family: var(--ff-mono);
  font-size: var(--fs-3xl);
  font-weight: 600;
  color: var(--clr-text);
  line-height: 1;
}

.stat__label {
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--clr-text-faint);
  font-weight: 500;
}

/* Punch card */
.punchcard {
  margin-bottom: var(--sp-10);
  animation: fadeInDown 0.6s 0.35s var(--ease) both;
}

.punchcard__card {
  display: inline-flex;
  gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-5);
  background: var(--clr-surface);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.punchcard__stamp {
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  border: 1.5px dashed var(--clr-border);
  background: var(--clr-surface-alt);
  transition: all 0.4s var(--ease);
}

.punchcard__stamp span {
  font-family: var(--ff-mono);
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--clr-text-faint);
  line-height: 1;
}

.punchcard__stamp.punched {
  border-style: solid;
  border-color: var(--clr-success);
  background: var(--clr-success-soft);
}

.punchcard__stamp.punched span {
  color: var(--clr-success);
  font-weight: 700;
}

/* Nav buttons */
.hero__nav {
  display: flex;
  gap: var(--sp-3);
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInDown 0.6s 0.4s var(--ease) both;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--ff-sans);
  font-size: var(--fs-sm);
  font-weight: 600;
  padding: var(--sp-3) var(--sp-6);
  border-radius: var(--radius);
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: all var(--duration) var(--ease);
}

.btn--primary {
  background: var(--clr-text);
  color: var(--clr-bg);
  border-color: var(--clr-text);
}

.btn--primary:hover {
  background: transparent;
  color: var(--clr-text);
}

.btn--ghost {
  background: transparent;
  color: var(--clr-text-muted);
  border-color: var(--clr-border);
}

.btn--ghost:hover {
  border-color: var(--clr-text);
  color: var(--clr-text);
}

/* Scroll indicator */
.hero__scroll {
  position: absolute;
  bottom: var(--sp-8);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-2);
  color: var(--clr-text-faint);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  animation: fadeInDown 0.6s 0.5s var(--ease) both;
}

.hero__scroll-dot {
  animation: scrollBounce 2s ease-in-out infinite;
}


/* -------------------------------------------
   5. SECTION SHARED
   ------------------------------------------- */
.section {
  padding: var(--sp-24) 0;
  border-top: 1px solid var(--clr-border-light);
}

.section__header {
  margin-bottom: var(--sp-12);
}

.section__number {
  display: inline-block;
  font-family: var(--ff-mono);
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--clr-accent);
  letter-spacing: 0.1em;
  margin-bottom: var(--sp-3);
}

.section__title {
  font-size: var(--fs-4xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.section__desc {
  margin-top: var(--sp-4);
  color: var(--clr-text-muted);
  max-width: 40rem;
  font-size: var(--fs-lg);
}


/* -------------------------------------------
   6. CHALLENGE SECTION — Horizontal items
   ------------------------------------------- */
.challenge__list {
  display: flex;
  flex-direction: column;
  gap: var(--sp-5);
}

.challenge-item {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-4);
  padding: var(--sp-5) var(--sp-6);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border-light);
  border-radius: var(--radius-lg);
  transition: all var(--duration) var(--ease);
}

.challenge-item:hover {
  border-color: var(--clr-border);
  box-shadow: var(--shadow-sm);
}

.challenge-item__icon {
  flex-shrink: 0;
  width: 2.25rem;
  height: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--clr-accent-soft);
  color: var(--clr-accent);
  border-radius: var(--radius);
}

.challenge-item__info {
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
}

.challenge-item__info strong {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--clr-text);
}

.challenge-item__info span {
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.6;
}


/* -------------------------------------------
   7. BRIDGES SECTION — Full-width text + gallery
   ------------------------------------------- */
.bridges__text {
  column-count: 1;
  column-gap: var(--sp-12);
  margin-bottom: var(--sp-16);
}

@media (min-width: 768px) {
  .bridges__text {
    column-count: 2;
  }
}

.bridges__text p {
  color: var(--clr-text-muted);
  line-height: 1.8;
  font-size: var(--fs-base);
  break-inside: avoid;
}

.bridges__text p + p {
  margin-top: var(--sp-6);
}

.bridges__cta {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  margin-top: var(--sp-8);
  margin-bottom: var(--sp-8);
  padding: var(--sp-5) var(--sp-6);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border-light);
  border-radius: var(--radius);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.5;
}

.bridges__cta svg {
  flex-shrink: 0;
  color: var(--clr-text-faint);
}

.bridges__cta a {
  font-weight: 500;
}

/* Slider */
.slider {
  position: relative;
  overflow: hidden;
  border-radius: 2px;
  background: var(--clr-surface-alt);
  border: 1px solid var(--clr-border-light);
}

.slider__track {
  display: flex;
  transition: transform 0.5s var(--ease);
}

.slider__slide {
  flex: 0 0 100%;
  min-width: 0;
}

.slider__image {
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--clr-surface-alt);
  overflow: hidden;
}

.slider__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Placeholder for missing images */
.slider__image--placeholder::after {
  content: 'Add image';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-sm);
  color: var(--clr-text-faint);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 500;
}

.slider__caption {
  padding: var(--sp-4) var(--sp-6) var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.5;
  text-align: center;
}

/* Arrow buttons */
.slider__btn {
  position: absolute;
  top: 50%;
  transform: translateY(calc(-50% - 1.75rem)); /* offset for caption + dots */
  width: 2.75rem;
  height: 2.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(4px);
  border: 1px solid var(--clr-border);
  border-radius: 50%;
  color: var(--clr-text);
  cursor: pointer;
  opacity: 0.7;
  transition: opacity var(--duration) var(--ease), background var(--duration) var(--ease);
  z-index: 2;
}

.slider__btn:hover {
  opacity: 1;
  background: rgba(255,255,255,0.95);
}

.slider__btn--prev {
  left: var(--sp-4);
}

.slider__btn--next {
  right: var(--sp-4);
}

/* Dots */
.slider__dots {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  padding: var(--sp-4) 0 var(--sp-2);
}

.slider__dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--clr-border);
  border: none;
  padding: 0;
  cursor: pointer;
  transition: background var(--duration) var(--ease), transform var(--duration) var(--ease);
  flex-shrink: 0;
}

.slider__dot:hover {
  background: var(--clr-text-faint);
}

.slider__dot.active {
  background: var(--clr-text);
  transform: scale(1.3);
}

/* Counter */
.slider__counter {
  position: absolute;
  bottom: 3.75rem; /* just above caption */
  right: var(--sp-5);
  font-family: var(--ff-mono);
  font-size: var(--fs-xs);
  color: var(--clr-text-faint);
  background: rgba(255,255,255,0.8);
  backdrop-filter: blur(4px);
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--radius);
  z-index: 2;
}

@media (max-width: 639px) {
  .slider__btn {
    width: 2.25rem;
    height: 2.25rem;
  }

  .slider__btn--prev {
    left: var(--sp-2);
  }

  .slider__btn--next {
    right: var(--sp-2);
  }

  .slider__caption {
    padding: var(--sp-4) var(--sp-5);
    font-size: var(--fs-xs);
  }
}


/* -------------------------------------------
   8. LATEST / POSTS SECTION
   ------------------------------------------- */
.posts__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-5);
  align-items: start;
}

@media (min-width: 768px) {
  .posts__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Individual post card */
.post {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border-light);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all var(--duration) var(--ease);
}

.post:hover {
  border-color: var(--clr-border);
  box-shadow: var(--shadow-md);
}

.post__header {
  padding: var(--sp-6);
  cursor: pointer;
  position: relative;
  user-select: none;
}

.post__header:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: -2px;
  border-radius: var(--radius-xl);
}

.post__meta {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  margin-bottom: var(--sp-3);
}

.post__date {
  font-family: var(--ff-mono);
  font-size: var(--fs-xs);
  color: var(--clr-text-faint);
}

.post__tag {
  font-family: var(--ff-mono);
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--clr-accent);
  background: var(--clr-accent-soft);
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--radius);
}

.post__tag--video {
  color: #DC2626;
  background: #FEE2E2;
}

.post__tag--image {
  color: #7C3AED;
  background: #EDE9FE;
}

.post__title {
  font-size: var(--fs-lg);
  font-weight: 600;
  margin-bottom: var(--sp-2);
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.post__preview {
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post__toggle {
  position: absolute;
  top: var(--sp-6);
  right: var(--sp-6);
  width: 1.75rem;
  height: 1.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--clr-text-faint);
  transition: transform var(--duration) var(--ease);
}

.post.expanded .post__toggle {
  transform: rotate(180deg);
}

/* Expandable body */
.post__body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s var(--ease);
}

.post.expanded .post__body {
  max-height: 2000px;
}

.post__content {
  padding: 0 var(--sp-6) var(--sp-6);
}

.post__content p {
  color: var(--clr-text-muted);
  font-size: var(--fs-sm);
  line-height: 1.7;
}

.post__content p + p {
  margin-top: var(--sp-4);
}

.post__content a {
  color: var(--clr-accent);
  text-decoration: underline;
  text-decoration-color: var(--clr-accent-soft);
  text-underline-offset: 2px;
}

.post__content a:hover {
  text-decoration-color: var(--clr-accent);
}

/* Video embed */
.post__embed {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 */
  height: 0;
  margin: 0 var(--sp-6) var(--sp-4);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--clr-text);
}

.post__embed iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* Image in post */
.post__media {
  margin: 0 var(--sp-6) var(--sp-4);
  border-radius: var(--radius);
  overflow: hidden;
}

.post__media img {
  width: 100%;
  height: auto;
}

/* When expanded, hide preview */
.post.expanded .post__preview {
  display: none;
}

/* Empty state */
.posts__empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--sp-16) var(--sp-8);
  color: var(--clr-text-faint);
}

.posts__empty-icon {
  margin: 0 auto var(--sp-5);
  opacity: 0.4;
}

.posts__empty-title {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--clr-text-muted);
  margin-bottom: var(--sp-2);
}

.posts__empty-text {
  font-size: var(--fs-sm);
}


/* -------------------------------------------
   9. FOOTER
   ------------------------------------------- */
.footer {
  border-top: 1px solid var(--clr-border-light);
  padding: var(--sp-10) 0;
}

.footer__inner {
  text-align: center;
}

.footer__text {
  font-size: var(--fs-sm);
  color: var(--clr-text-muted);
}

.footer__text--muted {
  color: var(--clr-text-faint);
  margin-top: var(--sp-2);
  font-size: var(--fs-xs);
}

.footer__text--sub {
  color: var(--clr-text-faint);
  margin-top: var(--sp-2);
  font-size: var(--fs-xs);
}


/* -------------------------------------------
   10. ANIMATIONS
   ------------------------------------------- */
@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes scrollBounce {
  0%, 100% { cy: 8; }
  50% { cy: 16; }
}

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}


/* -------------------------------------------
   11. RESPONSIVE
   ------------------------------------------- */
@media (max-width: 639px) {
  .stat__number {
    font-size: var(--fs-2xl);
  }

  .punchcard__card {
    gap: var(--sp-1);
    padding: var(--sp-2) var(--sp-3);
  }

  .punchcard__stamp {
    width: 1.6rem;
    height: 1.6rem;
  }

  .punchcard__stamp span {
    font-size: 0.625rem;
  }

  .section {
    padding: var(--sp-16) 0;
  }

  .section__title {
    font-size: var(--fs-3xl);
  }

  .challenge-item {
    padding: var(--sp-4) var(--sp-5);
  }
}

@media (max-width: 400px) {
  .hero__nav {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    justify-content: center;
  }
}