/* ============================================================
   TELEGRAM.ORG AUTHENTIC STYLESHEET FOR U-CHAT
   Faithfully recreating telegram.org layout, typography and feel
   ============================================================ */

:root {
  --bg-color: #ffffff;
  --bg-secondary: #f4f4f5;
  --card-bg: #ffffff;
  --card-hover: #fcfcfc;
  --border-color: #e5e7eb;
  --border-subtle: #edf0f2;
  --text-primary: #111827;
  --text-secondary: #707579;
  --text-muted: #9ca3af;
  
  /* Telegram signature blue with U-Chat vibrant purple hybrid tone */
  --accent-color: #2481cc;
  --accent-hover: #1e70b3;
  --accent-gradient: linear-gradient(135deg, #2481cc 0%, #7a3ee8 100%);
  --accent-light: rgba(36, 129, 204, 0.08);
  --accent-border: rgba(36, 129, 204, 0.25);
  
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.07);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.1);
  --shadow-badge: 0 10px 24px rgba(36,129,204,0.22);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

[data-theme="dark"] {
  --bg-color: #0e1621;
  --bg-secondary: #17212b;
  --card-bg: #17212b;
  --card-hover: #1c2733;
  --border-color: #242f3d;
  --border-subtle: #1e2936;
  --text-primary: #f5f5f5;
  --text-secondary: #7e8b99;
  --text-muted: #5e6b78;

  --accent-color: #5288c1;
  --accent-hover: #6499d3;
  --accent-gradient: linear-gradient(135deg, #5288c1 0%, #9065ea 100%);
  --accent-light: rgba(82, 136, 193, 0.12);
  --accent-border: rgba(82, 136, 193, 0.3);

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 18px rgba(0,0,0,0.35);
  --shadow-lg: 0 12px 36px rgba(0,0,0,0.45);
  --shadow-badge: 0 10px 24px rgba(0,0,0,0.4);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 70px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: color 0.2s ease, opacity 0.2s ease;
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* Layout Container */
.tl_page {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
  position: relative;
}

/* ============================================================
   TOP NAVBAR (TELEGRAM STYLE)
   ============================================================ */
.tl_header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-color);
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}

.tl_header_wrap {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.tl_header_brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 19px;
  color: var(--text-primary);
}

.tl_header_brand img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
}

.tl_nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.tl_nav_link {
  padding: 8px 14px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 8px;
  transition: all 0.18s ease;
}

.tl_nav_link:hover, .tl_nav_link.active {
  color: var(--text-primary);
  background: var(--bg-secondary);
}

.tl_theme_toggle {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: all 0.2s ease;
  margin-left: 6px;
}

.tl_theme_toggle:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* ============================================================
   HERO / MAIN HEAD SECTION
   ============================================================ */
.tl_main_head {
  padding: 56px 0 36px;
  position: relative;
  text-align: center;
}

/* Side Blog Widget (Telegram's classic right-side box) */
.tl_main_side_blog {
  position: absolute;
  top: 36px;
  right: 0;
  width: 240px;
  text-align: left;
  z-index: 5;
}

.side_blog {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 16px 18px;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.25s, box-shadow 0.25s;
}

.side_blog:hover {
  border-color: var(--accent-border);
  box-shadow: var(--shadow-md);
}

.side_blog_header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 14px;
  font-weight: 700;
  color: var(--accent-color);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
}

.side_blog_header svg {
  width: 16px;
  height: 16px;
}

.side_blog_entries {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.side_blog_entry {
  display: block;
  text-decoration: none;
}

.side_blog_date {
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.4px;
  margin-bottom: 2px;
}

.side_blog_title {
  font-size: 13px;
  line-height: 1.35;
  color: var(--text-primary);
  font-weight: 500;
  transition: color 0.15s;
}

.side_blog_entry:hover .side_blog_title {
  color: var(--accent-color);
}

/* Logo and Main Heading */
.tl_main_logo_wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0 auto;
}

.tl_main_logo {
  position: relative;
  width: 140px;
  height: 140px;
  border-radius: 36px;
  background: var(--card-bg);
  box-shadow: var(--shadow-badge);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.3s ease;
  cursor: pointer;
}

.tl_main_logo:hover {
  transform: translateY(-6px) scale(1.03);
  box-shadow: 0 16px 36px rgba(36, 129, 204, 0.3);
}

.tl_main_logo img {
  width: 104px;
  height: 104px;
  border-radius: 26px;
  object-fit: cover;
}

.tl_main_logo_title {
  font-size: 54px;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 6px;
  line-height: 1.1;
}

.tl_main_logo_title span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.tl_main_logo_lead {
  font-size: 21px;
  color: var(--text-secondary);
  font-weight: 400;
  letter-spacing: -0.01em;
}

/* ============================================================
   TELEGRAM DOWNLOAD MOBILE & DESKTOP SECTION
   ============================================================ */
.tl_main_download_section {
  padding: 30px 0 46px;
  text-align: center;
}

.tl_main_download_mobile {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

/* The signature blue pill download button */
.tl_main_download_link {
  height: 54px;
  padding: 0 28px;
  border-radius: 27px;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 16.5px;
  font-weight: 500;
  color: #ffffff;
  background: var(--accent-color);
  box-shadow: 0 4px 14px rgba(36, 129, 204, 0.35);
  transition: all 0.22s cubic-bezier(0.16, 1, 0.3, 1);
  text-decoration: none;
  border: 1px solid transparent;
}

.tl_main_download_link:hover {
  background: var(--accent-hover);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(36, 129, 204, 0.45);
}

.tl_main_download_link b {
  font-weight: 700;
}

.tl_main_download_link svg {
  width: 22px;
  height: 22px;
  fill: currentColor;
}

.tl_main_download_link .version_badge {
  font-size: 12px;
  font-weight: 700;
  padding: 3px 8px;
  background: rgba(255, 255, 255, 0.22);
  border-radius: 12px;
  margin-left: 2px;
}

/* Secondary outline button (Web Client) */
.tl_main_download_secondary {
  height: 54px;
  padding: 0 26px;
  border-radius: 27px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
  text-decoration: none;
}

.tl_main_download_secondary:hover {
  background: var(--bg-secondary);
  border-color: var(--text-secondary);
  color: var(--text-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.tl_main_download_secondary svg {
  width: 20px;
  height: 20px;
  fill: var(--accent-color);
}

/* Desktop link bar */
.tl_main_download_desktop_section {
  margin: 10px auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  color: var(--text-secondary);
  font-size: 15px;
}

.tl_desktop_link {
  color: var(--text-secondary);
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 8px;
  transition: all 0.18s ease;
}

.tl_desktop_link:hover {
  color: var(--accent-color);
  background: var(--accent-light);
}

.tl_desktop_link b {
  color: var(--text-primary);
}

/* Browse more apps link */
.tl_main_download_more_btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--accent-color);
  margin-top: 14px;
  transition: gap 0.2s ease;
}

.tl_main_download_more_btn:hover {
  gap: 10px;
}

.tl_main_download_more_btn svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

/* ============================================================
   INTERACTIVE PHONE DEMO (TELEGRAM STYLE DEMO PREVIEW)
   ============================================================ */
.tl_demo_container {
  margin: 36px auto 50px;
  max-width: 760px;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 30px;
  box-shadow: var(--shadow-md);
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 36px;
  align-items: center;
  text-align: left;
}

.phone_mockup {
  width: 290px;
  margin: 0 auto;
  border: 8px solid #2a2c30;
  border-radius: 36px;
  background: #111418;
  box-shadow: 0 18px 42px rgba(0,0,0,0.25);
  overflow: hidden;
}

.phone_screen {
  background: var(--bg-color);
  height: 380px;
  display: flex;
  flex-direction: column;
}

.phone_header {
  padding: 12px 14px;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 10px;
}

.phone_header_ava {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--accent-color);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 15px;
}

.phone_header_info b {
  display: block;
  font-size: 13.5px;
  color: var(--text-primary);
}

.phone_header_info span {
  font-size: 11.5px;
  color: #2ecc71;
}

.phone_chat_body {
  flex: 1;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  overflow-y: auto;
  background: var(--bg-secondary);
}

.chat_bubble {
  max-width: 82%;
  padding: 8px 12px;
  border-radius: 14px;
  font-size: 13px;
  line-height: 1.35;
  position: relative;
  animation: bubbleIn 0.4s ease forwards;
}

.chat_bubble.in {
  align-self: flex-start;
  background: var(--card-bg);
  color: var(--text-primary);
  border-bottom-left-radius: 3px;
  border: 1px solid var(--border-color);
}

.chat_bubble.out {
  align-self: flex-end;
  background: var(--accent-color);
  color: #ffffff;
  border-bottom-right-radius: 3px;
}

.chat_bubble_time {
  display: block;
  font-size: 10px;
  margin-top: 3px;
  text-align: right;
  opacity: 0.7;
}

.chat_voice_player {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 170px;
}

.chat_voice_btn {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: rgba(255,255,255,0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
}

.chat_voice_waves {
  flex: 1;
  height: 14px;
  display: flex;
  align-items: center;
  gap: 2px;
}

.chat_wave_bar {
  width: 3px;
  background: currentColor;
  border-radius: 2px;
  animation: wavePulse 1.2s ease-in-out infinite alternate;
}

@keyframes wavePulse {
  0% { height: 4px; }
  100% { height: 14px; }
}

@keyframes bubbleIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.demo_text_content h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.demo_text_content p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.6;
  margin-bottom: 20px;
}

.demo_features_list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.demo_feature_item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--text-primary);
}

.demo_feature_item svg {
  width: 18px;
  height: 18px;
  fill: #2ecc71;
  flex-shrink: 0;
}

/* ============================================================
   RECENT NEWS (TELEGRAM BLOG CARDS SECTION)
   ============================================================ */
.tl_main_recent_news_wrap {
  padding: 40px 0;
}

.tl_main_recent_news_header {
  font-size: 26px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 28px;
  letter-spacing: -0.02em;
}

.tl_main_recent_news_header a {
  color: var(--text-primary);
}

.tl_main_recent_news_header a:hover {
  color: var(--accent-color);
}

.tl_main_recent_news_cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.dev_blog_card_wrap {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  height: 100%;
  transition: transform 0.22s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.22s ease, border-color 0.22s ease;
  text-decoration: none;
}

.dev_blog_card_wrap:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-border);
}

.dev_blog_card_image {
  width: 100%;
  height: 180px;
  object-fit: cover;
  background: var(--bg-secondary);
}

.dev_blog_card_alltext_wrap {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.dev_blog_card_title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
  margin-bottom: 10px;
  transition: color 0.15s;
}

.dev_blog_card_wrap:hover .dev_blog_card_title {
  color: var(--accent-color);
}

.dev_blog_card_lead {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
  flex: 1;
}

.dev_blog_card_date {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ============================================================
   "WHY TELEGRAM?" / "WHY U-CHAT?" SECTION
   ============================================================ */
.tl_main_body {
  padding: 50px 0 60px;
}

.tl_main_body_header {
  font-size: 32px;
  font-weight: 800;
  text-align: center;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  margin-bottom: 40px;
}

.tl_main_cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px 24px;
}

.tl_main_card_cell {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 18px;
  padding: 28px 24px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.22s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.22s ease, border-color 0.22s ease;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.tl_main_card_cell:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-border);
}

.tl_card_icon_wrap {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: var(--accent-light);
  color: var(--accent-color);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  transition: transform 0.2s ease, background 0.2s ease;
}

.tl_main_card_cell:hover .tl_card_icon_wrap {
  transform: scale(1.08);
  background: var(--accent-color);
  color: #ffffff;
}

.tl_card_icon_wrap svg {
  width: 26px;
  height: 26px;
  fill: currentColor;
}

.tl_main_card_header {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.tl_main_card_lead {
  font-size: 14.5px;
  line-height: 1.55;
  color: var(--text-secondary);
}

.tl_main_card_lead b {
  color: var(--text-primary);
  font-weight: 600;
}

/* ============================================================
   TELEGRAM MULTI-COLUMN FOOTER
   ============================================================ */
.footer_wrap {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 50px 0 40px;
  font-size: 14px;
  color: var(--text-secondary);
  transition: background-color 0.25s, border-color 0.25s;
}

.footer_columns_wrap {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 2fr 1.2fr 1.2fr 1.5fr;
  gap: 36px;
}

.footer_column h5 {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 14px;
}

.footer_column h5 a {
  color: var(--text-primary);
}

.footer_column h5 a:hover {
  color: var(--accent-color);
}

.footer_column p {
  line-height: 1.6;
  margin-bottom: 12px;
}

.footer_column ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer_column ul li a {
  color: var(--text-secondary);
  transition: color 0.15s;
}

.footer_column ul li a:hover {
  color: var(--accent-color);
}

.footer_bottom_note {
  max-width: 980px;
  margin: 36px auto 0;
  padding: 24px 20px 0;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--text-muted);
}

.footer_bottom_note a {
  color: var(--text-secondary);
}

.footer_bottom_note a:hover {
  color: var(--accent-color);
}

/* ============================================================
   RESPONSIVE QUERIES
   ============================================================ */
@media (max-width: 860px) {
  .tl_main_side_blog {
    position: static;
    width: 100%;
    margin-bottom: 28px;
  }

  .tl_demo_container {
    grid-template-columns: 1fr;
    text-align: center;
    padding: 24px;
  }

  .demo_features_list {
    align-items: center;
  }

  .footer_columns_wrap {
    grid-template-columns: 1fr 1fr;
    gap: 28px;
  }
}

@media (max-width: 580px) {
  .tl_header_wrap {
    padding: 0 14px;
  }

  .tl_nav_link {
    padding: 6px 10px;
    font-size: 13.5px;
  }

  .tl_main_logo_title {
    font-size: 40px;
  }

  .tl_main_logo_lead {
    font-size: 18px;
  }

  .tl_main_download_link {
    width: 100%;
    justify-content: center;
  }

  .tl_main_download_secondary {
    width: 100%;
    justify-content: center;
  }

  .footer_columns_wrap {
    grid-template-columns: 1fr;
  }

  .footer_bottom_note {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }
}