/* =========================
   Global Styles
========================= */
:root {
  --bg-primary: #f5f5f7;
  --bg-card: rgba(255, 255, 255, 0.92);
  --text-primary: #1d1d1f;
  --text-secondary: #424245;
  --text-muted: #6e6e73;
  --accent: #0071e3;
  --accent-hover: #2997ff;
  --border: #d2d2d7;
  --shadow-light: 0 4px 20px rgba(0, 0, 0, 0.06);
  --shadow-hover: 0 10px 30px rgba(0, 0, 0, 0.1);
  --radius-main: 22px;
  --radius-small: 14px;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", sans-serif;
  margin: 0;
  background: linear-gradient(to bottom, #f5f5f7, #ebebee);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  line-height: 1.6;
}

/* =========================
   Header
========================= */
header {
  background: linear-gradient(135deg, #000000, #1c1c1e);
  color: white;
  padding: 60px 20px 50px;
  text-align: center;
  box-shadow: var(--shadow-light);
}

header h1 {
  margin: 0;
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -1px;
}

header p {
  margin-top: 10px;
  font-size: 1.05rem;
  color: #b0b0b5;
  font-weight: 400;
}

/* =========================
   Navigation
========================= */
nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(20, 20, 20, 0.88);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

nav a {
  color: #f5f5f7;
  padding: 16px 22px;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.25s ease;
  border-bottom: 2px solid transparent;
}

nav a:hover {
  color: var(--accent-hover);
  border-bottom: 2px solid var(--accent-hover);
}

/* =========================
   Main Sections
========================= */
section {
  max-width: var(--max-width);
  margin: 28px auto;
  padding: 50px 60px;
  background: var(--bg-card);
  border-radius: var(--radius-main);
  box-shadow: var(--shadow-light);
  backdrop-filter: blur(18px);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

section:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

/* =========================
   Typography
========================= */
h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 30px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--border);
  letter-spacing: -0.5px;
}

h3 {
  font-size: 1.3rem;
  font-weight: 650;
  margin-top: 30px;
  margin-bottom: 14px;
}

h4 {
  font-size: 1.05rem;
  font-weight: 650;
  margin-bottom: 8px;
  color: var(--text-primary);
}

p {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 16px;
}

/* =========================
   Team Section
========================= */
.team {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 40px;
}

.member {
  text-align: center;
  transition: transform 0.3s ease;
}

.member:hover {
  transform: translateY(-6px);
}

.member img {
  width: 190px;
  height: 190px;
  object-fit: cover;
  border-radius: 50%;
  border: 4px solid white;
  box-shadow: var(--shadow-light);
}

.member p {
  margin-top: 14px;
  font-weight: 600;
  font-size: 1rem;
}

/* =========================
   Solutions / Existing Solutions
========================= */
.solutions {
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.solution {
  background: #f9f9fb;
  padding: 24px;
  border-radius: var(--radius-small);
  border: 1px solid rgba(0,0,0,0.04);
}

.solution h4 {
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.6px;
  font-size: 0.8rem;
}

.solution ul {
  padding-left: 22px;
}

.solution li {
  margin-bottom: 8px;
  color: var(--text-secondary);
}

.solution img {
  display: block;
  margin: 18px auto 0;
  max-width: 100%;
  border-radius: 12px;
  box-shadow: var(--shadow-light);
}

/* =========================
   Solution Concept Images
========================= */
.solution-images {
  display: flex;
  gap: 28px;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
}

.solution-img {
  flex: 1 1 320px;
  text-align: center;
}

.solution-img img {
  width: 100%;
  max-width: 420px;
  border-radius: 16px;
  box-shadow: var(--shadow-light);
}

.solution-img em {
  display: block;
  margin-top: 10px;
  color: var(--text-muted);
}

/* =========================
   Layer Cards
========================= */
ul.layers {
  list-style: none;
  padding: 0;
}

ul.layers li {
  background: #f8f8fa;
  border-left: 4px solid var(--accent);
  padding: 16px 18px;
  margin-bottom: 12px;
  border-radius: 12px;
  color: var(--text-secondary);
}

ul.layers li strong {
  color: var(--text-primary);
}

/* =========================
   Lists
========================= */
ul {
  padding-left: 28px;
}

li {
  margin-bottom: 10px;
}

/* =========================
   Block Diagram + PCB + Poster
========================= */
.block-diagram,
.pcb-diagram,
#Poster,
#Video {
  text-align: center;
}

.block-diagram img,
.pcb-diagram img,
#Poster img {
  max-width: 100%;
  height: auto;
  border-radius: 16px;
  box-shadow: var(--shadow-light);
  margin-top: 15px;
}

.block-diagram em {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* =========================
   Links
========================= */
a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* =========================
   Timeline Table
========================= */
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 22px;
  overflow: hidden;
  border-radius: 14px;
}

table th {
  background: linear-gradient(135deg, #1d1d1f, #2c2c2e);
  color: white;
  padding: 16px;
  text-align: left;
  font-size: 0.95rem;
}

table td {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  background: white;
}

table tr:nth-child(even) td {
  background: #f8f8fa;
}

table tr:hover td {
  background: #eef5ff;
}

/* =========================
   Footer
========================= */
footer {
  text-align: center;
  padding: 35px 20px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* =========================
   Responsive Design
========================= */
@media (max-width: 900px) {
  section {
    padding: 35px 28px;
    margin: 18px 14px;
  }

  header h1 {
    font-size: 2.3rem;
  }

  nav a {
    padding: 14px 14px;
    font-size: 0.82rem;
  }
}

@media (max-width: 700px) {
  .solution-images {
    flex-direction: column;
    align-items: center;
  }

  .team {
    flex-direction: column;
    align-items: center;
  }

  table,
  table thead,
  table tbody,
  table th,
  table td,
  table tr {
    display: block;
    width: 100%;
  }

  table thead {
    display: none;
  }

  table tr {
    margin-bottom: 18px;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-light);
    padding: 10px;
  }

  table td {
    border: none;
    padding: 10px;
    position: relative;
  }
}

@media (max-width: 500px) {
  header {
    padding: 45px 15px;
  }

  header h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.6rem;
  }

  h3 {
    font-size: 1.15rem;
  }

  section {
    padding: 28px 18px;
  }
}