/* ==========================================================================
   PORTFOLIO DƯƠNG TRUNG HIẾU - OFFICIAL CSS STYLESHEET
   Brand: DƯƠNG TRUNG HIẾU | trunghieuai.io.vn
   Theme: Light Theme | Navy - Deep Blue - Clean White
   ========================================================================== */

:root {
  --navy: #142b49;
  --navy-deep: #0c1b30;
  --navy-light: #1e3d65;
  --blue: #2d70b6;
  --blue-hover: #1f548e;
  --blue-light: #eaf2fa;
  --blue-soft: #f4f8fc;
  --ink: #182536;
  --ink-secondary: #3d4d60;
  --muted: #64748b;
  --line: #e2e8f0;
  --line-strong: #cbd5e1;
  --paper: #ffffff;
  --soft-bg: #f8fafc;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 30px;
  --shadow-sm: 0 2px 8px rgba(20, 43, 73, 0.04);
  --shadow-md: 0 10px 30px rgba(20, 43, 73, 0.07);
  --shadow-lg: 0 20px 50px rgba(20, 43, 73, 0.1);
  --warning-bg: #fef3c7;
  --warning-text: #92400e;
  --warning-border: #fcd34d;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --container-max: 1160px;
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--paper);
  color: var(--ink);
  line-height: 1.65;
  font-weight: 400;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  transition: var(--transition);
}

.wrap {
  width: min(var(--container-max), calc(100% - 48px));
  margin-inline: auto;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 999px;
  background-color: var(--navy);
  color: #ffffff;
  font-size: 13.5px;
  font-weight: 700;
  border: 1px solid var(--navy);
  letter-spacing: 0.01em;
  transition: var(--transition);
  box-shadow: 0 4px 14px rgba(20, 43, 73, 0.12);
}

.btn:hover {
  background-color: var(--blue);
  border-color: var(--blue);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(45, 112, 182, 0.25);
}

.btn.ghost {
  background-color: #ffffff;
  color: var(--navy);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-sm);
}

.btn.ghost:hover {
  background-color: var(--blue-soft);
  border-color: var(--blue);
  color: var(--blue);
  transform: translateY(-2px);
}

.btn.sm {
  padding: 8px 16px;
  font-size: 12px;
}

/* Navigation Header */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
  transition: var(--transition);
}

.navin {
  height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  flex-direction: column;
  font-weight: 850;
  letter-spacing: 0.05em;
  color: var(--navy);
  font-size: 18px;
  line-height: 1.15;
}

.brand-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-icon {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--navy), var(--blue));
  display: grid;
  place-items: center;
  color: white;
  font-size: 13px;
  font-weight: 900;
  box-shadow: 0 4px 10px rgba(20, 43, 73, 0.18);
}

.brand small {
  display: block;
  font-size: 9.5px;
  letter-spacing: 0.22em;
  color: var(--muted);
  font-weight: 700;
  margin-top: 3px;
}

.nav-links {
  display: flex;
  gap: 28px;
  align-items: center;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-secondary);
}

.nav-links a {
  position: relative;
  padding: 6px 0;
}

.nav-links a:hover {
  color: var(--blue);
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--blue);
  transition: width 0.25s ease;
}

.nav-links a:hover::after {
  width: 100%;
}

.menu-toggle {
  display: none;
  background: var(--blue-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  color: var(--navy);
  font-size: 18px;
  line-height: 1;
}

/* Hero Section */
.hero {
  padding: 80px 0 70px;
  background:
    radial-gradient(circle at 85% 15%, #ebf3fb 0, transparent 38%),
    radial-gradient(circle at 10% 90%, #f4f8fd 0, transparent 30%),
    linear-gradient(180deg, #ffffff 0%, #fbfcfe 100%);
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--blue);
  background: var(--blue-light);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 18px;
  border: 1px solid rgba(45, 112, 182, 0.15);
}

.eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--blue);
}

h1 {
  font-size: clamp(38px, 5.2vw, 68px);
  line-height: 1.08;
  letter-spacing: -0.045em;
  color: var(--navy);
  font-weight: 850;
  margin-bottom: 20px;
}

.lead {
  font-size: 17.5px;
  color: var(--ink-secondary);
  max-width: 620px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.tag {
  font-size: 11.5px;
  font-weight: 600;
  color: var(--navy-light);
  background: var(--blue-soft);
  border: 1px solid var(--line);
  padding: 6px 13px;
  border-radius: 999px;
  transition: var(--transition);
}

.tag:hover {
  background: var(--blue-light);
  border-color: rgba(45, 112, 182, 0.3);
  color: var(--blue);
}

/* Portrait Visual Container */
.portrait-card {
  min-height: 440px;
  border-radius: var(--radius-xl);
  background: linear-gradient(145deg, #dbe8f5, #f5f8fb 60%, #d3e3f2);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(255, 255, 255, 0.8);
}

.portrait-card::before {
  content: "";
  position: absolute;
  width: 320px;
  height: 320px;
  border: 1px dashed rgba(45, 112, 182, 0.25);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.portrait-card::after {
  content: "";
  position: absolute;
  width: 240px;
  height: 240px;
  border: 1px solid rgba(45, 112, 182, 0.2);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.portrait-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: absolute;
  inset: 0;
  z-index: 1;
}

.portrait-inner {
  position: relative;
  z-index: 2;
  text-align: center;
  color: var(--navy);
  padding: 24px;
}

.monogram {
  width: 154px;
  height: 154px;
  border-radius: 50%;
  background: linear-gradient(145deg, #ffffff, #dce9f5);
  border: 6px solid rgba(255, 255, 255, 0.85);
  display: grid;
  place-items: center;
  margin: 0 auto 16px;
  font-size: 44px;
  font-weight: 850;
  letter-spacing: -0.06em;
  color: var(--navy);
  box-shadow: 0 16px 36px rgba(20, 43, 73, 0.12);
}

.portrait-inner strong {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--navy);
  margin-bottom: 4px;
}

.portrait-inner span {
  font-size: 11px;
  color: var(--muted);
  display: block;
  max-width: 240px;
  margin: 0 auto;
}

.float-note {
  position: absolute;
  z-index: 3;
  bottom: 20px;
  left: 20px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  padding: 10px 16px;
  border-radius: var(--radius-md);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--navy);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 8px;
}

.float-note-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
}

/* Sections Common */
section {
  padding: 82px 0;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 32px;
  align-items: flex-end;
  margin-bottom: 36px;
}

.kicker {
  font-size: 10.5px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--blue);
  font-weight: 800;
  display: inline-block;
}

.section-head h2 {
  font-size: clamp(28px, 3.8vw, 42px);
  line-height: 1.15;
  letter-spacing: -0.04em;
  color: var(--navy);
  margin-top: 8px;
  font-weight: 800;
}

.section-head p {
  max-width: 460px;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.6;
}

/* Expertise Grid */
.grid4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: #cbdcf0;
}

.icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-md);
  background: var(--blue-light);
  color: var(--blue);
  font-size: 22px;
  margin-bottom: 20px;
  font-weight: 800;
}

.card h3 {
  font-size: 17px;
  color: var(--navy);
  margin-bottom: 10px;
  font-weight: 750;
  line-height: 1.3;
}

.card p {
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.55;
}

/* About Section */
.about {
  background: var(--soft-bg);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.about-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 50px;
  align-items: start;
}

.about-panel {
  background: linear-gradient(155deg, var(--navy-deep), var(--navy));
  color: white;
  border-radius: var(--radius-xl);
  padding: 38px 34px;
  box-shadow: var(--shadow-lg);
}

.about-panel .big {
  font-size: clamp(30px, 3.6vw, 42px);
  line-height: 1.12;
  font-weight: 850;
  letter-spacing: -0.04em;
  margin: 16px 0 16px;
}

.about-panel p {
  font-size: 13.5px;
  color: #d1dfed;
  line-height: 1.6;
}

.edu-box {
  margin-top: 30px;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.edu-item {
  margin-bottom: 14px;
}

.edu-item:last-child {
  margin-bottom: 0;
}

.edu-item strong {
  display: block;
  font-size: 13px;
  color: #ffffff;
  font-weight: 700;
}

.edu-item span {
  font-size: 12px;
  color: #a4bed9;
}

.about-copy {
  padding-top: 6px;
}

.about-copy h3 {
  font-size: 28px;
  line-height: 1.25;
  color: var(--navy);
  margin: 6px 0 16px;
  font-weight: 800;
}

.about-copy > p {
  font-size: 14.5px;
  color: var(--ink-secondary);
  line-height: 1.65;
}

.timeline {
  border-left: 2px solid #e1e8f0;
  margin: 28px 0 0 6px;
  padding-left: 24px;
}

.tl {
  position: relative;
  margin-bottom: 22px;
}

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

.tl::before {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--blue);
  left: -30px;
  top: 7px;
  border: 2px solid white;
  box-shadow: 0 0 0 2px var(--blue-light);
}

.tl strong {
  font-size: 14px;
  color: var(--navy);
  font-weight: 700;
  display: block;
}

.tl span {
  display: block;
  font-size: 12.5px;
  color: var(--muted);
  margin-top: 3px;
}

.badge-verify {
  display: inline-block;
  font-size: 10.5px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 999px;
  background: var(--warning-bg);
  color: var(--warning-text);
  border: 1px solid var(--warning-border);
  margin-top: 4px;
}

/* Projects Section */
.projects {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.project {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--paper);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.project:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: #cbdcf0;
}

.project-art {
  height: 180px;
  background: linear-gradient(135deg, #e9f2fa, #f8fafc);
  display: grid;
  place-items: center;
  color: var(--blue);
  font-size: 46px;
  position: relative;
  border-bottom: 1px solid var(--line);
}

.project-art-icon {
  width: 72px;
  height: 72px;
  border-radius: var(--radius-md);
  background: #ffffff;
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-sm);
  font-size: 32px;
}

.project-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.project-body small {
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--blue);
  font-weight: 800;
  text-transform: uppercase;
}

.project-body h3 {
  font-size: 18px;
  color: var(--navy);
  margin: 8px 0 10px;
  font-weight: 750;
}

.project-body p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.55;
  margin-bottom: 16px;
  flex-grow: 1;
}

.project-footer {
  margin-top: auto;
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: 999px;
  background: var(--warning-bg);
  color: var(--warning-text);
  border: 1px solid var(--warning-border);
}

/* Training Section */
.training {
  background: var(--soft-bg);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.training-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
}

.training-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  gap: 22px;
  align-items: flex-start;
  transition: var(--transition);
}

.training-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #cbdcf0;
}

.date-badge {
  min-width: 68px;
  height: 72px;
  border-radius: var(--radius-md);
  background: var(--blue-light);
  color: var(--navy);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-weight: 850;
  border: 1px solid rgba(45, 112, 182, 0.15);
}

.date-badge .day {
  font-size: 20px;
  line-height: 1;
  color: var(--navy);
}

.date-badge .month {
  font-size: 10px;
  letter-spacing: 0.15em;
  color: var(--blue);
  margin-top: 4px;
}

.training-info h3 {
  font-size: 16.5px;
  color: var(--navy);
  margin-bottom: 6px;
  font-weight: 750;
}

.training-info p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.55;
  margin-bottom: 10px;
}

/* CTA & Contact Section */
.cta-box {
  background: linear-gradient(145deg, var(--navy-deep), var(--navy));
  color: white;
  border-radius: var(--radius-xl);
  padding: 50px 48px;
  box-shadow: var(--shadow-lg);
}

.cta-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
  margin-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  padding-bottom: 32px;
}

.cta-header h2 {
  font-size: clamp(28px, 3.6vw, 40px);
  line-height: 1.15;
  font-weight: 850;
  letter-spacing: -0.04em;
  margin-top: 8px;
}

.cta-header p {
  color: #c7d8e8;
  font-size: 14px;
  max-width: 540px;
  line-height: 1.6;
}

.cta-contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.contact-card {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  padding: 22px 20px;
  transition: var(--transition);
}

.contact-card:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.25);
}

.contact-card-icon {
  font-size: 20px;
  margin-bottom: 12px;
}

.contact-card h4 {
  font-size: 14px;
  color: #ffffff;
  margin-bottom: 6px;
  font-weight: 700;
}

.contact-card p {
  font-size: 12.5px;
  color: #9cb5ce;
  line-height: 1.5;
}

.contact-status-tag {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  color: #fde68a;
  background: rgba(245, 158, 11, 0.2);
  padding: 2px 8px;
  border-radius: 999px;
  margin-top: 8px;
}

.contact-status-tag.confirmed {
  color: #a7f3d0;
  background: rgba(16, 185, 129, 0.18);
  border: 1px solid rgba(52, 211, 153, 0.3);
}

.contact-link {
  color: #ffffff;
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 600;
}

.contact-link:hover {
  color: #93c5fd;
}

.zalo-qr-wrapper {
  margin-top: 14px;
  display: inline-block;
  position: relative;
}

.zalo-qr-box {
  display: inline-block;
  background: #ffffff;
  padding: 10px;
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
  position: relative;
  cursor: pointer;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s ease, border-color 0.3s ease;
  transform-origin: center center;
  border: 2px solid rgba(255, 255, 255, 0.9);
}

.zalo-qr-img {
  width: 130px;
  height: 130px;
  object-fit: contain;
  display: block;
  border-radius: 8px;
}

.zalo-qr-overlay-hint {
  position: absolute;
  bottom: 12px;
  right: 12px;
  background: rgba(14, 30, 51, 0.85);
  backdrop-filter: blur(6px);
  color: #ffffff;
  font-size: 10px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 999px;
  pointer-events: none;
  opacity: 0.9;
}

/* Phóng to mượt mà khi rê chuột */
.zalo-qr-box:hover,
.zalo-qr-box.zoomed {
  transform: scale(1.75);
  z-index: 200;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.65), 0 0 0 3px #38bdf8;
  border-color: #ffffff;
}

/* Modal Lightbox Toàn Màn Hình */
.zalo-modal-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(10, 22, 38, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 9999;
  align-items: center;
  justify-content: center;
  padding: 20px;
  animation: fadeInModal 0.2s ease;
}

.zalo-modal-backdrop.open {
  display: flex;
}

@keyframes fadeInModal {
  from { opacity: 0; }
  to { opacity: 1; }
}

.zalo-modal-card {
  background: #ffffff;
  border-radius: 26px;
  padding: 32px 28px 24px;
  max-width: 380px;
  width: 100%;
  text-align: center;
  position: relative;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.45);
  animation: zoomInModal 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes zoomInModal {
  from { transform: scale(0.88); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.zalo-modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: #f1f5f9;
  color: #0f172a;
  font-size: 16px;
  font-weight: 800;
  display: grid;
  place-items: center;
  border: none;
  cursor: pointer;
  transition: background 0.2s;
}

.zalo-modal-close:hover {
  background: #e2e8f0;
}

.zalo-modal-img-frame {
  background: #ffffff;
  padding: 12px;
  border-radius: 20px;
  display: inline-block;
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.08);
  margin: 18px 0;
  border: 1px solid #e2e8f0;
}

.zalo-modal-img {
  width: 260px;
  height: 260px;
  object-fit: contain;
  display: block;
  border-radius: 12px;
}

/* ==========================================================================
   VIDEO EVENT & PLAYLIST SHOWCASE
   ========================================================================== */
.media-section {
  background: #ffffff;
  border-top: 1px solid var(--line);
  padding: 80px 0;
}

.video-container-card {
  background: var(--navy-deep);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.video-responsive-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #000000;
}

.video-responsive-frame iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.playlist-meta-bar {
  padding: 28px 32px;
  background: linear-gradient(180deg, #112338 0%, #0c1827 100%);
  color: #ffffff;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.playlist-meta-info {
  max-width: 600px;
}

.playlist-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 10.5px;
  font-weight: 800;
  letter-spacing: 0.15em;
  color: #38bdf8;
  background: rgba(56, 189, 248, 0.12);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 10px;
  border: 1px solid rgba(56, 189, 248, 0.25);
}

.playlist-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #ef4444;
  animation: pulse 1.8s infinite;
}

.playlist-meta-info h3 {
  font-size: 19px;
  color: #ffffff;
  margin-bottom: 6px;
  font-weight: 800;
}

.playlist-meta-info p {
  font-size: 13px;
  color: #94a3b8;
  line-height: 1.55;
  margin: 0;
}

.playlist-input-box {
  display: flex;
  gap: 10px;
  background: rgba(255, 255, 255, 0.06);
  padding: 8px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.15);
  min-width: 380px;
}

.playlist-input-box input {
  flex-grow: 1;
  background: transparent;
  border: none;
  color: #ffffff;
  font-size: 12.5px;
  font-family: inherit;
  padding: 8px 12px;
  outline: none;
}

.playlist-input-box input::placeholder {
  color: #64748b;
}

.playlist-input-box .btn {
  white-space: nowrap;
  padding: 8px 16px;
  font-size: 12px;
}

/* ==========================================================================
   ALBUM ẢNH SLIDESHOW DẠNG ẢNH LẬT 3D (3D FLIPPING ALBUM)
   ========================================================================== */
.album-section {
  background: var(--soft-bg);
  border-top: 1px solid var(--line);
  padding: 80px 0;
}

.flip-album-wrapper {
  max-width: 860px;
  margin: 0 auto;
}

.flip-card-viewport {
  perspective: 1400px;
  width: 100%;
  min-height: 480px;
}

.flip-card {
  width: 100%;
  min-height: 480px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.75s cubic-bezier(0.2, 0.85, 0.4, 1.15);
  cursor: pointer;
}

.flip-card.is-flipped {
  transform: rotateY(180deg);
}

.flip-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--line);
}

/* Mặt trước (Ảnh sự kiện) */
.flip-face-front {
  background: #ffffff;
  display: flex;
  flex-direction: column;
}

.flip-photo-box {
  width: 100%;
  height: 340px;
  position: relative;
  overflow: hidden;
  background: #0f172a;
}

.flip-photo-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.flip-card:hover .flip-photo-box img {
  transform: scale(1.03);
}

.flip-badge-top {
  position: absolute;
  top: 18px;
  left: 18px;
  background: rgba(14, 30, 51, 0.85);
  backdrop-filter: blur(10px);
  color: #38bdf8;
  font-size: 11px;
  font-weight: 800;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid rgba(56, 189, 248, 0.3);
}

.flip-hint-badge {
  position: absolute;
  bottom: 18px;
  right: 18px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  color: var(--navy);
  font-size: 11px;
  font-weight: 750;
  padding: 8px 14px;
  border-radius: 999px;
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 6px;
}

.flip-front-caption {
  padding: 22px 28px;
  background: #ffffff;
  flex-grow: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.flip-front-caption h3 {
  font-size: 18px;
  color: var(--navy);
  font-weight: 800;
  margin-bottom: 4px;
}

.flip-front-caption p {
  font-size: 13px;
  color: var(--muted);
  margin: 0;
}

/* Mặt sau (Thông tin chi tiết) */
.flip-face-back {
  background: linear-gradient(150deg, #0d1e33 0%, #153154 50%, #1a4270 100%);
  color: #ffffff;
  transform: rotateY(180deg);
  padding: 42px 40px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.flip-back-header {
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  padding-bottom: 18px;
}

.flip-back-header small {
  font-size: 10.5px;
  letter-spacing: 0.18em;
  color: #38bdf8;
  font-weight: 800;
  text-transform: uppercase;
}

.flip-back-header h3 {
  font-size: 24px;
  color: #ffffff;
  font-weight: 850;
  margin-top: 6px;
}

.flip-back-body {
  margin: 20px 0;
}

.flip-back-body p {
  font-size: 14px;
  color: #cbd5e1;
  line-height: 1.65;
  margin-bottom: 18px;
}

.flip-bullets {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.flip-bullets li {
  font-size: 12.5px;
  color: #e2e8f0;
  background: rgba(255, 255, 255, 0.07);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.12);
  display: flex;
  align-items: center;
  gap: 8px;
}

.flip-back-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.flip-back-footer span {
  font-size: 12px;
  color: #94a3b8;
}

/* Album Controls */
.album-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 24px;
  padding: 0 6px;
}

.album-btn-group {
  display: flex;
  gap: 10px;
  align-items: center;
}

.album-nav-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #ffffff;
  border: 1px solid var(--line);
  color: var(--navy);
  display: grid;
  place-items: center;
  font-size: 16px;
  font-weight: 700;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.album-nav-btn:hover {
  background: var(--blue-light);
  border-color: var(--blue);
  color: var(--blue);
  transform: translateY(-2px);
}

.album-autoplay-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 18px;
  border-radius: 999px;
  background: #ffffff;
  border: 1px solid var(--line);
  font-size: 12px;
  font-weight: 700;
  color: var(--navy);
  box-shadow: var(--shadow-sm);
}

.album-autoplay-btn:hover {
  background: var(--blue-soft);
  color: var(--blue);
}

.album-indicator {
  font-size: 13px;
  font-weight: 800;
  color: var(--navy);
  letter-spacing: 0.05em;
}

/* ==========================================================================
   KHU VỰC LOGO ĐỐI TÁC (PARTNERS LOGOS)
   ========================================================================== */
.partners-section {
  padding: 70px 0;
  background: #ffffff;
  border-top: 1px solid var(--line);
}

.partners-marquee-container {
  overflow: hidden;
  position: relative;
  margin-top: 36px;
  mask-image: linear-gradient(to right, transparent, black 10%, black 90%, transparent);
  -webkit-mask-image: linear-gradient(to right, transparent, black 10%, black 90%, transparent);
}

.partners-track {
  display: flex;
  gap: 22px;
  width: max-content;
  animation: partnersMarquee 30s linear infinite;
}

.partners-track:hover {
  animation-play-state: paused;
}

@keyframes partnersMarquee {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

.partner-logo-item {
  width: 260px;
  height: 90px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  cursor: pointer;
}

.partner-logo-item img {
  max-width: 100%;
  max-height: 58px;
  object-fit: contain;
  filter: grayscale(10%);
  transition: var(--transition);
}

.partner-logo-item:hover {
  transform: translateY(-4px);
  border-color: var(--blue);
  box-shadow: var(--shadow-md);
}

.partner-logo-item:hover img {
  filter: grayscale(0%);
}

@media (max-width: 900px) {
  .playlist-meta-bar {
    flex-direction: column;
    align-items: flex-start;
  }
  .playlist-input-box {
    width: 100%;
    min-width: auto;
  }
  .flip-card, .flip-card-viewport {
    min-height: 520px;
  }
  .flip-bullets {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .flip-card, .flip-card-viewport {
    min-height: 540px;
  }
  .flip-photo-box {
    height: 260px;
  }
  .flip-face-back {
    padding: 26px 22px;
  }
  .flip-front-caption {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
}

/* Footer */
footer {
  padding: 38px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12.5px;
  background: #ffffff;
}

.foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
}

.foot strong {
  color: var(--navy);
  font-size: 14px;
  font-weight: 800;
}

.foot-center {
  letter-spacing: 0.15em;
  font-weight: 600;
  font-size: 11px;
  color: var(--muted);
}

.foot-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.back-to-top {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 11.5px;
  font-weight: 700;
  color: var(--navy);
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--blue-soft);
  border: 1px solid var(--line);
}

.back-to-top:hover {
  background: var(--blue-light);
  color: var(--blue);
}

/* AI Assistant Widget (Demo UI) */
.chat-launch {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 90;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--navy), var(--blue));
  color: #ffffff;
  padding: 13px 22px;
  box-shadow: 0 12px 32px rgba(20, 43, 73, 0.28);
  font-size: 13px;
  font-weight: 750;
  display: flex;
  align-items: center;
  gap: 9px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  transition: var(--transition);
}

.chat-launch:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 16px 40px rgba(45, 112, 182, 0.38);
}

.chat-pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.7);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.7); }
  70% { box-shadow: 0 0 0 8px rgba(52, 211, 153, 0); }
  100% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}

.chatbox {
  display: none;
  position: fixed;
  right: 26px;
  bottom: 90px;
  width: min(390px, calc(100vw - 32px));
  background: #ffffff;
  border: 1px solid var(--line-strong);
  border-radius: 22px;
  box-shadow: 0 24px 70px rgba(20, 43, 73, 0.22);
  z-index: 91;
  overflow: hidden;
  animation: chatFadeIn 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.chatbox.open {
  display: flex;
  flex-direction: column;
}

@keyframes chatFadeIn {
  from { opacity: 0; transform: translateY(12px) scale(0.97); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.chathead {
  background: linear-gradient(135deg, var(--navy-deep), var(--navy));
  color: white;
  padding: 16px 20px;
  font-size: 13.5px;
  font-weight: 750;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.chathead-title {
  display: flex;
  align-items: center;
  gap: 8px;
}

.chatclose {
  color: #ffffff;
  font-size: 20px;
  line-height: 1;
  padding: 4px 8px;
  border-radius: 6px;
  opacity: 0.8;
}

.chatclose:hover {
  opacity: 1;
  background: rgba(255, 255, 255, 0.15);
}

.chatbody {
  padding: 18px 20px;
  font-size: 12.5px;
  color: var(--ink-secondary);
  max-height: 380px;
  overflow-y: auto;
}

.demo-banner {
  background: #fffbeb;
  border: 1px solid #fef3c7;
  color: #92400e;
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 11px;
  font-weight: 600;
  display: flex;
  align-items: flex-start;
  gap: 6px;
  margin-bottom: 14px;
}

.chatbubble {
  background: var(--blue-light);
  border-radius: 16px 16px 16px 4px;
  padding: 14px 16px;
  color: var(--ink);
  line-height: 1.55;
  margin-bottom: 14px;
  border: 1px solid rgba(45, 112, 182, 0.15);
}

.chat-suggestions {
  margin-top: 12px;
}

.chat-suggestions-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.chip-btn {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--blue-soft);
  border: 1px solid var(--line);
  padding: 8px 12px;
  border-radius: 10px;
  font-size: 11.5px;
  color: var(--navy);
  font-weight: 600;
  margin-bottom: 6px;
}

.chip-btn:hover {
  background: var(--blue-light);
  border-color: var(--blue);
  color: var(--blue);
}

.chat-response-area {
  margin-top: 14px;
  padding: 12px;
  background: #f8fafc;
  border-radius: 12px;
  border: 1px dashed var(--line);
  font-size: 12px;
  color: var(--ink-secondary);
  display: none;
}

.chat-response-area.active {
  display: block;
}

/* Responsive Breakpoints */
@media (max-width: 992px) {
  .hero-grid, .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .grid4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .projects {
    grid-template-columns: repeat(2, 1fr);
  }
  .cta-contact-grid {
    grid-template-columns: 1fr;
  }
  .cta-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 18px;
  }
}

@media (max-width: 820px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 78px;
    left: 0;
    right: 0;
    background: #ffffff;
    padding: 22px 28px;
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    box-shadow: var(--shadow-lg);
  }
  .nav-links.show {
    display: flex;
  }
  .menu-toggle {
    display: block;
  }
  .nav-cta {
    display: none;
  }
  .section-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
}

@media (max-width: 640px) {
  .wrap {
    width: calc(100% - 32px);
  }
  section {
    padding: 58px 0;
  }
  .hero {
    padding: 50px 0 40px;
  }
  h1 {
    font-size: 34px;
  }
  .lead {
    font-size: 15px;
  }
  .grid4, .projects, .training-grid {
    grid-template-columns: 1fr;
  }
  .portrait-card {
    min-height: 320px;
  }
  .cta-box {
    padding: 32px 24px;
  }
  .chat-launch {
    right: 16px;
    bottom: 16px;
    padding: 11px 18px;
  }
  .chatbox {
    right: 16px;
    bottom: 76px;
    width: calc(100vw - 32px);
  }
  .foot {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }
}