/* ===============================
   HCM202 — Base Styles v2.1 (clean)
   =============================== */

/* -------- Theme tokens -------- */
:root {
  --bg: #91a400;
  --fg: #2c1810;
  --muted: #8b4513;

  --brand: #dc143c;
  --brand-light: #ff6b6b;
  --brand-lighter: #ffebeb;

  --bg-secondary: #f8f9fa;
  --text-muted: #6c757d;

  --gold: #ffd700;
  --red-flag: #da020e;
  --yellow-star: #ffff00;

  --card: #fff8dc;
  --card-hover: #ffefd5;

  --gradient-red: linear-gradient(135deg, #dc143c 0%, #8b0000 100%);
  --gradient-gold: linear-gradient(135deg, #ffd700 0%, #b8860b 100%);

  --radius: 12px;
  --shadow: 0 4px 15px rgba(220, 20, 60, 0.2);
  --text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);

  /* FAB layout (chat + back-to-top) */
  --fab-size: 64px; /* kích thước nút chat */
  --fab-gap: 20px; /* khoảng cách tới mép màn hình */
  --fab-stack-gap: 18px; /* khoảng giữa 2 nút */
}

/* -------- Reset / base -------- */
* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  color: var(--fg);
  font: 16px/1.6 system-ui;
  background: radial-gradient(
      circle at 25% 30%,
      rgba(255, 215, 0, 0.4) 4px,
      transparent 4px
    ),
    radial-gradient(
      circle at 75% 60%,
      rgba(220, 20, 60, 0.25) 3px,
      transparent 3px
    ),
    radial-gradient(
      circle at 50% 80%,
      rgba(255, 215, 0, 0.2) 2px,
      transparent 2px
    ),
    linear-gradient(
      135deg,
      #ffe4e4 0%,
      #ffebeb 20%,
      #fff0e6 40%,
      #ffebeb 60%,
      #ffe4e4 80%,
      #ffeaea 100%
    ) !important;
  background-size: 80px 80px, 120px 120px, 160px 160px, 100% 100%;
  background-attachment: fixed;
  min-height: 100vh;
}

a {
  color: var(--brand);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

h1,
h2,
h3 {
  line-height: 1.2;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px;
  position: relative;
}

/* viền trang trí */
.container::before {
  content: "";
  position: absolute;
  inset: -15px;
  background: radial-gradient(
      circle at 10% 10%,
      rgba(255, 215, 0, 0.12) 25px,
      transparent 25px
    ),
    radial-gradient(
      circle at 90% 90%,
      rgba(220, 20, 60, 0.08) 20px,
      transparent 20px
    ),
    radial-gradient(
      circle at 50% 50%,
      rgba(255, 215, 0, 0.06) 30px,
      transparent 30px
    );
  border-radius: 25px;
  z-index: -1;
  pointer-events: none;
}

/* -------- Cards / Buttons -------- */
.card {
  background: linear-gradient(145deg, #fff 0%, #fffbf7 100%);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15), 0 4px 16px rgba(220, 20, 60, 0.2),
    inset 0 1px 0 rgba(255, 255, 255, 0.9);
  border: 3px solid var(--gold);
  transition: all 0.3s ease;
  position: relative;
  backdrop-filter: blur(15px);
}
.card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  background: linear-gradient(
    45deg,
    transparent,
    rgba(255, 215, 0, 0.08),
    transparent,
    rgba(220, 20, 60, 0.05),
    transparent
  );
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: var(--radius);
  background: var(--gradient-red);
  color: #fff;
  border: none;
  cursor: pointer;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(220, 20, 60, 0.4);
  text-decoration: none;
}
.btn::before {
  content: "";
  position: absolute;
  inset: 0 0 0 -100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.2),
    transparent
  );
  transition: left 0.5s;
}
.btn:hover::before {
  left: 100%;
}

.nav a.active {
  background: var(--gold);
  color: var(--red-flag);
  font-weight: 700;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.muted {
  color: var(--muted);
}

.grid2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
@media (max-width: 900px) {
  .grid2 {
    grid-template-columns: 1fr;
  }
}

/* ===============================
   Coze Chat — Theming & Position
   =============================== */

/* Nút chat – style */
.coze-web-sdk-chat-button {
  background: var(--gradient-red) !important;
  border: 3px solid var(--gold) !important;
  box-shadow: var(--shadow) !important;
  border-radius: var(--radius) !important;
  transition: all 0.3s ease !important;
  animation: coze-pulse 2s infinite ease-in-out !important;
}
.coze-web-sdk-chat-button:hover {
  transform: translateY(-2px) scale(1.05) !important;
  box-shadow: 0 8px 25px rgba(220, 20, 60, 0.4) !important;
  border-color: var(--yellow-star) !important;
}
.coze-web-sdk-chat-button::before {
  content: "🇻🇳" !important;
  position: absolute;
  top: -8px;
  right: -8px;
  font-size: 16px;
  z-index: 10;
}

/* Cửa sổ chat */
.coze-web-sdk-chat-window {
  border: 3px solid var(--gold) !important;
  border-radius: var(--radius) !important;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3), 0 8px 20px rgba(220, 20, 60, 0.2) !important;
  overflow: hidden !important;
}
.coze-web-sdk-chat-header {
  background: var(--gradient-red) !important;
  color: #fff !important;
  padding: 16px !important;
  border-bottom: 2px solid var(--gold) !important;
  font-weight: 600 !important;
}
.coze-web-sdk-chat-header::before {
  content: "🤖 " !important;
}
.coze-web-sdk-chat-messages {
  background: radial-gradient(
      circle at 25% 30%,
      rgba(255, 215, 0, 0.05) 4px,
      transparent 4px
    ),
    radial-gradient(
      circle at 75% 60%,
      rgba(220, 20, 60, 0.03) 3px,
      transparent 3px
    ),
    linear-gradient(145deg, #fff 0%, #fffbf7 100%) !important;
  background-size: 80px 80px, 120px 120px, 100% 100% !important;
}
.coze-web-sdk-user-message {
  background: var(--gradient-red) !important;
  color: #fff !important;
  border-radius: 18px 18px 6px 18px !important;
  padding: 12px 16px !important;
  margin: 8px !important;
  box-shadow: 0 2px 8px rgba(220, 20, 60, 0.3) !important;
  font-weight: 500 !important;
}
.coze-web-sdk-bot-message {
  background: linear-gradient(145deg, #fff 0%, #f8f9fa 100%) !important;
  color: var(--fg) !important;
  border: 2px solid var(--gold) !important;
  border-radius: 18px 18px 18px 6px !important;
  padding: 12px 16px !important;
  margin: 8px !important;
  box-shadow: 0 2px 8px rgba(255, 215, 0, 0.2) !important;
  line-height: 1.6 !important;
}
.coze-web-sdk-input-area {
  background: var(--bg-secondary) !important;
  border-top: 2px solid var(--gold) !important;
  padding: 12px !important;
}
.coze-web-sdk-input {
  border: 2px solid var(--gold) !important;
  border-radius: var(--radius) !important;
  padding: 12px 16px !important;
  font: inherit !important;
  transition: all 0.3s ease !important;
}
.coze-web-sdk-input:focus {
  border-color: var(--brand) !important;
  box-shadow: 0 0 0 3px rgba(220, 20, 60, 0.1) !important;
  outline: none !important;
}
.coze-web-sdk-send-button {
  background: var(--gradient-red) !important;
  color: #fff !important;
  border: 2px solid var(--gold) !important;
  border-radius: var(--radius) !important;
  padding: 10px 20px !important;
  font-weight: 600 !important;
  text-transform: uppercase !important;
  letter-spacing: 1px !important;
  transition: all 0.3s ease !important;
}
.coze-web-sdk-send-button:hover {
  transform: translateY(-1px) !important;
  box-shadow: 0 4px 15px rgba(220, 20, 60, 0.4) !important;
  border-color: var(--yellow-star) !important;
}

/* Nhịp mạch cho nút chat */
@keyframes coze-pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

/* ===============================
   FABs: Back-to-top (TRÊN) & Chat (DƯỚI) – cùng kích thước
   =============================== */

/* Kích thước & khoảng cách chuẩn */
:root {
  --fab-size: 63px; /* kích thước CHUNG cho cả 2 nút */
  --fab-gap: 20px; /* khoảng cách tới mép màn hình */
  --fab-stack-gap: 18px; /* khoảng cách giữa 2 nút */
}

/* ---------- Nút Chat (Coze) – DƯỚI ---------- */
.coze-web-sdk-chat-button,
.coze-web-sdk-chat-button[style] {
  width: var(--fab-size) !important;
  height: var(--fab-size) !important;
  right: calc(var(--fab-gap) + env(safe-area-inset-right, 0px)) !important;
  bottom: calc(var(--fab-gap) + env(safe-area-inset-bottom, 0px)) !important;
  z-index: 999 !important; /* cao hơn back-to-top 1 lớp */
}

/* ---------- Nút Lên đầu trang – TRÊN chat ---------- */
.back-to-top {
  position: fixed !important;
  right: 33px;
  bottom: calc(
    var(--fab-gap) + var(--fab-size) + var(--fab-stack-gap) +
      env(safe-area-inset-bottom, 0px)
  ) !important;

  width: 50px;
  height: 50px;
  border: 0 !important;
  border-radius: 9999px !important;

  background: var(--brand) !important;
  color: #fff !important;
  cursor: pointer !important;

  display: grid !important;
  place-items: center !important;

  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.18) !important;
  opacity: 0 !important;
  visibility: hidden !important;
  transform: translateY(12px) scale(0.96) !important;
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease !important;

  z-index: 998 !important; /* dưới chat */
}

.back-to-top:hover {
  filter: brightness(1.05);
}
.back-to-top:active {
  transform: translateY(12px) scale(0.94);
}
.back-to-top:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 2px;
}
.back-to-top.show {
  opacity: 1 !important;
  visibility: visible !important;
  transform: translateY(0) scale(1) !important;
}

/* (Tùy chọn) Icon bên trong back-to-top cho cân đối */
.back-to-top svg {
  width: 30px;
  height: 30px;
}

/* ---------- Mobile: co giãn đồng bộ & giữ đúng trật tự ---------- */
@media (max-width: 768px) {
  :root {
    --fab-size: 56px;
    --fab-gap: 16px;
    --fab-stack-gap: 14px;
  }

  .coze-web-sdk-chat-button,
  .coze-web-sdk-chat-button[style] {
    bottom: calc(var(--fab-gap) + env(safe-area-inset-bottom, 0px)) !important;
  }

  .back-to-top {
    bottom: calc(
      var(--fab-gap) + var(--fab-size) + var(--fab-stack-gap) +
        env(safe-area-inset-bottom, 0px)
    ) !important;
  }
}

/* ---------- Màn hình thấp: nhích cả cụm lên chút ---------- */
@media (max-height: 620px) {
  .coze-web-sdk-chat-button,
  .coze-web-sdk-chat-button[style] {
    bottom: calc(
      var(--fab-gap) + 8px + env(safe-area-inset-bottom, 0px)
    ) !important;
  }
  .back-to-top {
    bottom: calc(
      var(--fab-gap) + var(--fab-size) + var(--fab-stack-gap) + 8px +
        env(safe-area-inset-bottom, 0px)
    ) !important;
  }
}