/* ============================================================
   怀柔板栗·乡村振兴实践行 - 主样式表
   Color Palette:
   - Primary (Deep Green):    #267326
   - Primary Dark:            #1C5E1E
   - Primary Light:           #2E7D32
   - Background (Light Green): #E8F5E9
   - Accent (Chestnut Brown):  #8B4513
   - Text Dark:               #333333
   - Text Light:              #666666
   - White:                   #FFFFFF
   ============================================================ */

/* ===== CSS Variables ===== */
:root {
  --green-dark: #267326;
  --green-darker: #1C5E1E;
  --green-light: #2E7D32;
  --green-bg: #E8F5E9;
  --green-bg-alt: #C8E6C9;
  --brown: #8B4513;
  --brown-light: #A0522D;
  --brown-bg: #FFF3E0;
  --text-dark: #333333;
  --text-light: #666666;
  --text-muted: #999999;
  --white: #FFFFFF;
  --shadow: 0 2px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
  --radius: 0;
  --radius-sm: 0;
  --transition: all 0.3s ease;
  --max-width: 1200px;
  --nav-height: 70px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", Arial, sans-serif;
  color: var(--text-dark);
  line-height: 1.7;
  background-color: var(--white);
  overflow-x: hidden;
}

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

ul, ol {
  list-style: none;
}

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

/* ===== Navigation Bar ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  background: var(--green-dark);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 40px;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.15);
  transition: var(--transition);
}

.navbar.scrolled {
  height: 60px;
  background: rgba(38, 115, 38, 0.97);
  backdrop-filter: blur(10px);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-logo .logo-icon {
  width: 54px;
  height: 54px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}

.nav-logo .logo-text {
  color: var(--white);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 1px;
  white-space: nowrap;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-menu a {
  color: var(--white);
  padding: 8px 16px;
  border-radius: 0;
  font-size: 15px;
  font-weight: 500;
  transition: var(--transition);
  white-space: nowrap;
}

.nav-menu a:hover,
.nav-menu a.active {
  background: rgba(255,255,255,0.15);
}

/* Hamburger Menu Button */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 8px;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--white);
  border-radius: 3px;
  transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 6px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -6px);
}

/* Mobile Nav */
.mobile-nav {
  position: fixed;
  top: 0;
  right: -100%;
  width: 280px;
  height: 100vh;
  background: var(--green-darker);
  padding: 90px 30px 30px;
  z-index: 999;
  transition: right 0.4s ease;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.mobile-nav.open {
  right: 0;
}

.mobile-nav a {
  color: var(--white);
  padding: 14px 20px;
  border-radius: 0;
  font-size: 16px;
  transition: var(--transition);
}

.mobile-nav a:hover,
.mobile-nav a.active {
  background: rgba(255,255,255,0.12);
}

.mobile-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 998;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.mobile-overlay.show {
  opacity: 1;
  pointer-events: auto;
}

/* ===== Hero Section ===== */
.hero {
  position: relative;
  width: 100%;
  height: 100vh;
  min-height: 600px;
  overflow: hidden;
  margin-top: 0;
}

.hero-slides {
  position: relative;
  width: 100%;
  height: 100%;
}

.hero-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 1s ease;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.hero-slide.active {
  opacity: 1;
}

.hero-slide::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(0,0,0,0.3) 0%,
    rgba(0,0,0,0.15) 50%,
    rgba(0,0,0,0.5) 100%
  );
}

/* Hero slide images set via inline style in index.html */

.hero-content {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  z-index: 2;
  width: 90%;
  max-width: 900px;
}

.hero-content h1 {
  color: var(--white);
  font-size: clamp(28px, 5vw, 52px);
  font-weight: 700;
  text-shadow: 0 2px 20px rgba(0,0,0,0.4);
  margin-bottom: 16px;
  letter-spacing: 2px;
}

.hero-content p {
  color: rgba(255,255,255,0.92);
  font-size: clamp(16px, 2.5vw, 22px);
  text-shadow: 0 1px 10px rgba(0,0,0,0.3);
  line-height: 1.6;
}

/* Hero Indicators */
.hero-indicators {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 12px;
  z-index: 3;
}

.hero-indicators span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255,255,255,0.5);
  cursor: pointer;
  transition: var(--transition);
}

.hero-indicators span.active {
  background: var(--white);
  transform: scale(1.2);
}

/* Hero Arrows */
.hero-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(255,255,255,0.2);
  border: 2px solid rgba(255,255,255,0.4);
  color: var(--white);
  font-size: 20px;
  cursor: pointer;
  z-index: 3;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}

.hero-arrow:hover {
  background: rgba(255,255,255,0.35);
  border-color: rgba(255,255,255,0.7);
}

.hero-arrow.left {
  left: 24px;
}

.hero-arrow.right {
  right: 24px;
}

/* ===== Section Common ===== */
.section {
  padding: 80px 40px;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: clamp(24px, 4vw, 36px);
  color: var(--green-dark);
  margin-bottom: 12px;
  position: relative;
  display: inline-block;
}

.section-header p {
  color: var(--text-light);
  font-size: 16px;
  margin-top: 8px;
}

.section-bg {
  background: var(--green-bg);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

/* ===== Quick Nav Cards (Home) ===== */
.quick-nav {
  padding: 80px 40px;
  background: var(--green-bg);
}

.quick-nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.nav-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  cursor: pointer;
  display: block;
}

.nav-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.nav-card-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
}

.nav-card-body {
  padding: 20px 24px;
}

.nav-card-body h3 {
  font-size: 18px;
  color: var(--green-dark);
  margin-bottom: 8px;
}

.nav-card-body p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.6;
}

/* ===== Card Grid Layouts ===== */
.card-grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  align-items: start;
}

.card-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.card-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

/* ===== Content Cards ===== */
.content-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: var(--transition);
}

.content-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.content-card.green-bg {
  background: var(--green-bg);
}

.content-card.brown-bg {
  background: var(--brown-bg);
}

.content-card-img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  background: linear-gradient(135deg, var(--green-light), var(--brown-light));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 40px;
  color: var(--white);
}

.content-card-body {
  padding: 24px;
}

.content-card-body h3 {
  font-size: 18px;
  color: var(--green-dark);
  margin-bottom: 10px;
}

.content-card-body h4 {
  font-size: 16px;
  color: var(--brown);
  margin-bottom: 8px;
}

.content-card-body p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}

/* ===== Image + Text Layout ===== */
.img-text-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.img-text-row.reverse {
  direction: rtl;
}

.img-text-row.reverse > * {
  direction: ltr;
}

.img-text-img {
  width: 100%;
  height: 350px;
  border-radius: var(--radius);
  object-fit: cover;
  background: linear-gradient(135deg, var(--green-light), var(--brown));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  color: var(--white);
  box-shadow: var(--shadow);
}

.img-stack {
  display: flex;
  flex-direction: column;
}

/* ===== Feature List ===== */
.feature-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.feature-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--brown);
  flex-shrink: 0;
  margin-top: 6px;
}

.feature-item strong {
  font-size: 16px;
  color: var(--green-dark);
  display: block;
  margin-bottom: 2px;
}

.feature-item p {
  font-size: 14px;
  color: var(--text-light);
  margin: 0;
  line-height: 1.6;
}

.img-text-content h3 {
  font-size: 22px;
  color: var(--green-dark);
  margin-bottom: 16px;
}

.img-text-content p {
  color: var(--text-light);
  margin-bottom: 12px;
  line-height: 1.8;
}

/* ===== Text Intro Block ===== */
.text-intro-block {
  background: var(--green-bg);
  border-radius: var(--radius);
  padding: 28px 32px;
}

.text-intro-block p {
  font-size: 15px;
  color: var(--text-dark);
  line-height: 2;
  text-indent: 2em;
  margin: 0;
}

/* ===== Data Cards Grid ===== */
.data-card {
  background: var(--green-bg);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  transition: var(--transition);
}

.data-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

.data-card .data-icon {
  font-size: 32px;
  margin-bottom: 12px;
}

.data-card .data-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--green-dark);
  margin-bottom: 4px;
}

.data-card .data-label {
  font-size: 13px;
  color: var(--text-light);
}

/* ===== Timeline Layout ===== */
.timeline {
  position: relative;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 16px;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--green-light);
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  margin-bottom: 32px;
  padding-left: 24px;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -28px;
  top: 8px;
  width: 14px;
  height: 14px;
  background: var(--brown);
  border-radius: 50%;
  border: 3px solid var(--green-bg);
}

.timeline-item .time-label {
  font-size: 14px;
  color: var(--brown);
  font-weight: 600;
  margin-bottom: 4px;
}

.timeline-item h4 {
  font-size: 17px;
  color: var(--green-dark);
  margin-bottom: 6px;
}

.timeline-item p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}

/* ===== Process / Flow Chart ===== */
.process-flow {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  padding: 20px 0;
}

.process-step {
  background: var(--white);
  border-radius: var(--radius);
  padding: 20px 28px;
  text-align: center;
  box-shadow: var(--shadow);
  min-width: 160px;
  transition: var(--transition);
  position: relative;
}

.process-step:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.process-step .step-number {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--green-dark);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  margin: 0 auto 10px;
}

.process-step h4 {
  font-size: 15px;
  color: var(--green-dark);
  margin-bottom: 4px;
}

.process-step p {
  font-size: 12px;
  color: var(--text-light);
}

.process-arrow {
  font-size: 24px;
  color: var(--brown);
  flex-shrink: 0;
}

/* ===== Video Section ===== */
.video-container {
  position: relative;
  width: 100%;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  background: #000;
}

.video-container video {
  width: 100%;
  display: block;
}

.video-placeholder {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, #263238, #37474F);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--white);
  gap: 12px;
  cursor: pointer;
  transition: var(--transition);
}

.video-placeholder:hover {
  background: linear-gradient(135deg, #37474F, #455A64);
}

.video-placeholder .play-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: rgba(255,255,255,0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  border: 2px solid rgba(255,255,255,0.5);
  transition: var(--transition);
}

.video-placeholder:hover .play-icon {
  background: rgba(255,255,255,0.3);
  transform: scale(1.1);
}

.video-placeholder p {
  font-size: 14px;
  opacity: 0.8;
}

/* ===== Photo Gallery Grid ===== */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 16px;
}

.gallery-item {
  position: relative;
  border-radius: var(--radius-sm);
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 4 / 3;
}

.gallery-item .gallery-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: linear-gradient(135deg, var(--green-light), var(--brown));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 32px;
  transition: transform 0.5s ease;
}

.gallery-item:hover .gallery-img {
  transform: scale(1.08);
}

.gallery-item .gallery-caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 12px 16px;
  background: linear-gradient(to top, rgba(0,0,0,0.7), transparent);
  color: var(--white);
  font-size: 13px;
  opacity: 0;
  transition: var(--transition);
}

.gallery-item:hover .gallery-caption {
  opacity: 1;
}

/* ===== Lightbox ===== */
.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.92);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.lightbox.open {
  opacity: 1;
  pointer-events: auto;
}

.lightbox-img {
  max-width: 90vw;
  max-height: 85vh;
  border-radius: 0;
  object-fit: contain;
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 30px;
  font-size: 36px;
  color: var(--white);
  cursor: pointer;
  background: none;
  border: none;
  z-index: 2001;
}

.lightbox-caption {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--white);
  font-size: 15px;
}

/* ===== Challenge & Solution Cards ===== */
.challenge-solution {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
}

.challenge-card,
.solution-card {
  border-radius: var(--radius);
  padding: 28px;
}

.challenge-card {
  background: #FFF3E0;
}

.solution-card {
  background: var(--green-bg);
}

.challenge-card h4,
.solution-card h4 {
  font-size: 18px;
  margin-bottom: 14px;
}

.challenge-card h4 { color: #E65100; }
.solution-card h4 { color: var(--green-dark); }

.challenge-card li,
.solution-card li {
  padding: 8px 0;
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.6;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.challenge-card li:last-child,
.solution-card li:last-child {
  border-bottom: none;
}

/* ===== Visitor Feedback ===== */
.feedback-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  border-top: 3px solid var(--green-light);
}

.feedback-card .feedback-author {
  font-weight: 600;
  color: var(--green-dark);
  margin-bottom: 8px;
}

.feedback-card .feedback-text {
  font-size: 14px;
  color: var(--text-light);
  font-style: italic;
  line-height: 1.7;
}

/* ===== Page Hero (Sub-pages) ===== */
.page-hero {
  position: relative;
  width: 100%;
  height: 45vh;
  min-height: 350px;
  background-size: cover;
  background-position: center;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: var(--nav-height);
}

.page-hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, rgba(0,0,0,0.35), rgba(0,0,0,0.55));
  z-index: 1;
}

.page-hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  color: var(--white);
}

.page-hero-content h1 {
  font-size: clamp(26px, 4.5vw, 44px);
  font-weight: 700;
  margin-bottom: 10px;
  text-shadow: 0 2px 12px rgba(0,0,0,0.4);
}

.page-hero-content p {
  font-size: clamp(14px, 2vw, 18px);
  opacity: 0.9;
  text-shadow: 0 1px 8px rgba(0,0,0,0.3);
}

/* Sub-page hero background images */
.page-hero.yichan-hero {
  background-image: url('../images/hero/hero2.jpg');
}

.page-hero.erchan-hero {
  background-image: url('../images/hero/hero1.jpg');
}

.page-hero.sanchan-hero {
  background-image: url('../images/hero/3chan.jpg');
}

.page-hero.practice-hero {
  background-image: url('../images/hero/4实践调研.jpg');
}

/* ===== Module Section ===== */
.module {
  margin-bottom: 60px;
}

.module:last-child {
  margin-bottom: 0;
}

.module-title {
  font-size: 22px;
  color: var(--green-dark);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--green-bg-alt);
  display: flex;
  align-items: center;
  gap: 10px;
}

.module-title .module-icon {
  font-size: 24px;
}

/* ===== Footer ===== */
.footer {
  background: var(--green-dark);
  color: var(--white);
  padding: 50px 40px 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 30px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-col h3 {
  font-size: 16px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255,255,255,0.2);
}

.footer-col p,
.footer-col a {
  font-size: 13px;
  color: rgba(255,255,255,0.75);
  line-height: 2;
  display: block;
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--white);
  padding-left: 4px;
}

.footer-bottom {
  text-align: center;
  padding-top: 30px;
  margin-top: 30px;
  border-top: 1px solid rgba(255,255,255,0.15);
  font-size: 13px;
  color: rgba(255,255,255,0.6);
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--green-dark);
  color: var(--white);
  border: none;
  cursor: pointer;
  font-size: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
  z-index: 900;
}

.back-to-top.show {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--brown);
  transform: translateY(-3px);
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  padding: 20px 40px;
  background: var(--green-bg);
  font-size: 13px;
  color: var(--text-light);
}

.breadcrumb a {
  color: var(--green-dark);
  transition: var(--transition);
}

.breadcrumb a:hover {
  color: var(--brown);
}

.breadcrumb span {
  margin: 0 6px;
}

/* ===== Tag / Badge ===== */
.tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 0;
  font-size: 12px;
  font-weight: 500;
  background: var(--green-bg);
  color: var(--green-dark);
}

.tag.brown {
  background: var(--brown-bg);
  color: var(--brown);
}

/* ===== Video List Sidebar ===== */
.video-list-layout {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 24px;
  align-items: start;
}

.video-playlist {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.video-playlist h4 {
  padding: 16px 20px;
  background: var(--green-dark);
  color: var(--white);
  font-size: 15px;
}

.video-playlist-item {
  display: flex;
  gap: 12px;
  padding: 12px 20px;
  cursor: pointer;
  transition: var(--transition);
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.video-playlist-item:hover,
.video-playlist-item.active {
  background: var(--green-bg);
}

.video-playlist-item .thumb {
  width: 100px;
  height: 60px;
  border-radius: 0;
  flex-shrink: 0;
  background: linear-gradient(135deg, #555, #333);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: var(--white);
}

.video-playlist-item .info h5 {
  font-size: 13px;
  color: var(--text-dark);
  margin-bottom: 4px;
}

.video-playlist-item .info span {
  font-size: 11px;
  color: var(--text-muted);
}

/* ===== Tab Filter ===== */
.tab-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
  justify-content: center;
}

.tab-btn {
  padding: 8px 20px;
  border-radius: 0;
  border: 1px solid var(--green-light);
  background: var(--white);
  color: var(--green-dark);
  font-size: 14px;
  cursor: pointer;
  transition: var(--transition);
}

.tab-btn:hover,
.tab-btn.active {
  background: var(--green-dark);
  color: var(--white);
  border-color: var(--green-dark);
}

/* ===== Journal Entry ===== */
.journal-entry {
  background: var(--white);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
  border-left: 4px solid var(--green-light);
  transition: var(--transition);
}

.journal-entry:hover {
  box-shadow: var(--shadow-lg);
}

.journal-entry .journal-date {
  font-size: 14px;
  color: var(--brown);
  font-weight: 600;
  margin-bottom: 6px;
}

.journal-entry .journal-location {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.journal-entry h4 {
  font-size: 17px;
  color: var(--green-dark);
  margin-bottom: 8px;
}

.journal-entry p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}

/* ===== Results Summary ===== */
.result-card {
  background: var(--green-bg);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  transition: var(--transition);
}

.result-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

.result-card .result-icon {
  font-size: 36px;
  margin-bottom: 12px;
}

.result-card h4 {
  font-size: 16px;
  color: var(--green-dark);
  margin-bottom: 8px;
}

.result-card p {
  font-size: 13px;
  color: var(--text-light);
}

/* ===== Utility Classes ===== */
.text-center { text-align: center; }
.mt-20 { margin-top: 20px; }
.mt-40 { margin-top: 40px; }
.mb-20 { margin-bottom: 20px; }
.mb-40 { margin-bottom: 40px; }

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
  .card-grid-3 { grid-template-columns: repeat(2, 1fr); }
  .card-grid-4 { grid-template-columns: repeat(2, 1fr); }
  .img-text-row {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .video-list-layout {
    grid-template-columns: 1fr;
  }
  .process-flow {
    flex-direction: column;
    gap: 8px;
  }
  .process-arrow {
    transform: rotate(90deg);
  }
}

@media (max-width: 768px) {
  .navbar {
    padding: 0 20px;
  }

  .nav-menu {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .section {
    padding: 50px 20px;
  }

  .quick-nav {
    padding: 50px 20px;
  }

  .quick-nav-grid {
    grid-template-columns: 1fr;
  }

  .card-grid-2,
  .card-grid-3,
  .card-grid-4 {
    grid-template-columns: 1fr;
  }

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

  .hero-arrow {
    width: 36px;
    height: 36px;
    font-size: 16px;
  }

  .hero-arrow.left { left: 10px; }
  .hero-arrow.right { right: 10px; }

  .hero-content h1 {
    font-size: 24px;
  }

  .hero-content p {
    font-size: 14px;
  }

  .footer {
    padding: 40px 20px 24px;
  }

  .page-hero {
    height: 35vh;
    min-height: 250px;
  }

  .gallery {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }

  .tab-filters {
    gap: 6px;
  }

  .tab-btn {
    padding: 6px 14px;
    font-size: 12px;
  }

  .data-card .data-value {
    font-size: 20px;
  }
}

@media (max-width: 480px) {
  .nav-logo .logo-text {
    font-size: 15px;
  }

  .section-header h2 {
    font-size: 22px;
  }

  .hero-content h1 {
    font-size: 20px;
  }

  .gallery {
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  }
}