/*
Theme Name: TinHocKonTum
Theme URI: https://tinhockontum.com
Author: TinHocKonTum
Author URI: https://tinhockontum.com
Description: Website chia sẻ kiến thức IT, tài liệu học tập, quiz và khóa học làm web cơ bản - Kết nối đam mê
Version: 1.0.0
Requires at least: 6.0
Tested up to: 6.5
Requires PHP: 8.0
License: GNU General Public License v2 or later
License URI: LICENSE
Text Domain: tinhockontum
Tags: education, it, quiz, courses, blog
*/

/* ================================================
   CSS CUSTOM PROPERTIES
   ================================================ */
:root {
  --color-primary: #1a6ef5;
  --color-primary-dark: #0f55d4;
  --color-primary-light: #e8f0fe;
  --color-secondary: #10b981;
  --color-accent: #f59e0b;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-text-light: #94a3b8;
  --color-border: #e2e8f0;
  --color-bg: #ffffff;
  --color-bg-soft: #f8fafc;
  --color-bg-card: #ffffff;
  --color-dark: #0f172a;
  --color-dark-secondary: #1e293b;

  --font-heading: 'Be Vietnam Pro', 'Nunito', sans-serif;
  --font-body: 'Be Vietnam Pro', 'Nunito', sans-serif;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.1), 0 4px 16px rgba(0,0,0,0.05);
  --shadow-blue: 0 8px 30px rgba(26,110,245,0.25);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --transition: 0.25s cubic-bezier(0.4,0,0.2,1);
  --container-width: 1200px;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-dark); }
ul { list-style: none; }

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ================================================
   TYPOGRAPHY
   ================================================ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: clamp(2rem, 4vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: 1.25rem; }

.section-title {
  text-align: center;
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 40px;
  color: var(--color-text);
}

/* ================================================
   BUTTONS
   ================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
  box-shadow: var(--shadow-blue);
}
.btn-primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 12px 35px rgba(26,110,245,0.35);
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}
.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-light);
}

.btn-sm {
  padding: 7px 18px;
  font-size: 0.85rem;
}

/* ================================================
   HEADER & NAVIGATION
   ================================================ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 32px;
}

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}
.site-logo img { height: 38px; width: auto; }
.logo-text { display: flex; flex-direction: column; }
.logo-text .name {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.1;
}
.logo-text .tagline {
  font-size: 0.7rem;
  color: var(--color-text-muted);
  font-weight: 400;
}

/* Nav */
#primary-navigation { flex: 1; }
#primary-navigation ul {
  display: flex;
  align-items: center;
  gap: 4px;
}
#primary-navigation ul li a {
  display: block;
  padding: 8px 14px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
#primary-navigation ul li a:hover,
#primary-navigation ul li.current-menu-item > a {
  color: var(--color-primary);
  background: var(--color-primary-light);
}

/* Dropdown */
#primary-navigation ul li { position: relative; }
#primary-navigation ul li .sub-menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 200px;
  padding: 8px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
  gap: 2px;
  z-index: 100;
}
#primary-navigation ul li:hover > .sub-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
#primary-navigation ul li .sub-menu li a {
  font-size: 0.875rem;
  padding: 9px 14px;
}

/* Header actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.header-search-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text-muted);
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  display: flex;
  align-items: center;
}
.header-search-btn:hover { background: var(--color-bg-soft); color: var(--color-primary); }

/* Mobile toggle */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
}
.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ================================================
   HERO SECTION
   ================================================ */
.hero-section {
  background: linear-gradient(135deg, #f0f6ff 0%, #e8f0fe 40%, #f0fdf4 100%);
  padding: 80px 0 60px;
  overflow: hidden;
  position: relative;
}
.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(26,110,245,0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 18px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hero-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  color: var(--color-dark);
  margin-bottom: 18px;
}
.hero-title span { color: var(--color-primary); }

.hero-desc {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 440px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.btn-video {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--color-text);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 10px 0;
  transition: all var(--transition);
}
.btn-video .play-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: #fff;
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}
.btn-video:hover .play-icon {
  background: var(--color-primary);
  box-shadow: var(--shadow-blue);
}
.btn-video:hover .play-icon svg { fill: #fff; }
.btn-video:hover { color: var(--color-primary); }

.hero-stats {
  display: flex;
  gap: 32px;
}
.hero-stat { text-align: center; }
.hero-stat .num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-primary);
  display: block;
}
.hero-stat .label {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

.hero-image { position: relative; }
.hero-image img {
  width: 100%;
  border-radius: var(--radius-xl);
  animation: heroFloat 4s ease-in-out infinite;
}
@keyframes heroFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.hero-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 60px;
  padding-top: 48px;
  border-top: 1px solid rgba(0,0,0,0.06);
}
.hero-feature {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}
.hero-feature-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.1rem;
}
.hero-feature-icon.blue { background: var(--color-primary-light); }
.hero-feature-icon.green { background: #d1fae5; }
.hero-feature-icon.orange { background: #fef3c7; }
.hero-feature h4 { font-size: 0.9rem; font-weight: 700; margin-bottom: 2px; }
.hero-feature p { font-size: 0.8rem; color: var(--color-text-muted); line-height: 1.4; }

/* ================================================
   SECTIONS GENERAL
   ================================================ */
section { padding: 70px 0; }
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
}
.section-header h2 { font-size: 1.35rem; font-weight: 700; }
.view-all {
  font-size: 0.875rem;
  color: var(--color-primary);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap var(--transition);
}
.view-all:hover { gap: 8px; }

/* ================================================
   EXPLORE SECTION (Khám phá nội dung)
   ================================================ */
.explore-section { background: var(--color-bg-soft); }
.explore-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
}
.explore-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 28px 20px 24px;
  text-align: center;
  border: 1px solid var(--color-border);
  transition: all var(--transition);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  display: block;
}
.explore-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
  color: inherit;
}
.explore-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 1.5rem;
}
.explore-icon.green { background: #d1fae5; }
.explore-icon.blue { background: #dbeafe; }
.explore-icon.indigo { background: #e0e7ff; }
.explore-icon.cyan { background: #cffafe; }
.explore-icon.red { background: #fee2e2; }
.explore-card h3 { font-size: 0.95rem; font-weight: 700; margin-bottom: 8px; }
.explore-card p { font-size: 0.8rem; color: var(--color-text-muted); line-height: 1.5; margin-bottom: 16px; }
.explore-link {
  font-size: 0.8rem;
  color: var(--color-primary);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* ================================================
   QUIZ & COURSES COMBINED SECTION
   ================================================ */
.quiz-courses-section { background: #fff; }
.quiz-courses-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

/* Quiz list */
.quiz-list { display: flex; flex-direction: column; gap: 12px; }
.quiz-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
  text-decoration: none;
  color: inherit;
}
.quiz-item:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
  transform: translateX(4px);
  color: inherit;
}
.quiz-badge {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 800;
  color: #fff;
  flex-shrink: 0;
}
.quiz-badge.html { background: linear-gradient(135deg, #e34c26, #f16529); }
.quiz-badge.js { background: linear-gradient(135deg, #f0db4f, #d4ac0d); color: #333; }
.quiz-badge.tin6 { background: linear-gradient(135deg, #7c3aed, #9d5cd0); }
.quiz-badge.excel { background: linear-gradient(135deg, #217346, #2ecc71); }
.quiz-info { flex: 1; }
.quiz-info h4 { font-size: 0.9rem; font-weight: 600; margin-bottom: 4px; }
.quiz-meta { font-size: 0.77rem; color: var(--color-text-muted); }
.quiz-meta span {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  padding: 2px 8px;
  border-radius: 99px;
  background: var(--color-bg-soft);
  font-size: 0.72rem;
}
.quiz-btn {
  padding: 7px 18px;
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  white-space: nowrap;
  transition: all var(--transition);
  text-decoration: none;
  flex-shrink: 0;
}
.quiz-btn:hover { background: var(--color-primary-dark); color: #fff; }

/* Featured course card */
.featured-course {
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  background: #fff;
  border: 1px solid var(--color-border);
}
.featured-course-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
}
.featured-course-thumb img { width: 100%; height: 100%; object-fit: cover; }
.featured-course-body { padding: 24px; }
.featured-course-body h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 10px; line-height: 1.4; }
.featured-course-body p { font-size: 0.875rem; color: var(--color-text-muted); line-height: 1.6; margin-bottom: 16px; }
.course-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}
.course-meta-item {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* ================================================
   FOR STUDENTS SECTION
   ================================================ */
.students-section { background: var(--color-bg-soft); }
.students-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.student-card {
  background: #fff;
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  border: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: all var(--transition);
  text-decoration: none;
  color: inherit;
}
.student-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  color: inherit;
}
.student-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.student-level {
  font-size: 1rem;
  font-weight: 800;
  color: var(--color-primary);
}
.student-card p { font-size: 0.875rem; color: var(--color-text-muted); line-height: 1.6; }
.student-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-primary);
  transition: gap var(--transition);
  margin-top: auto;
}
.student-link:hover { gap: 10px; }

/* ================================================
   BLOG SECTION
   ================================================ */
.blog-section { background: #fff; }
.blog-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.post-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}
.post-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.post-thumb {
  aspect-ratio: 16/10;
  overflow: hidden;
}
.post-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.post-card:hover .post-thumb img { transform: scale(1.06); }
.post-body { padding: 20px; flex: 1; display: flex; flex-direction: column; }
.post-body h3 { font-size: 0.925rem; font-weight: 700; margin-bottom: 10px; line-height: 1.45; flex: 1; }
.post-body h3 a { color: var(--color-text); }
.post-body h3 a:hover { color: var(--color-primary); }
.post-date {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  gap: 5px;
}
.post-category {
  display: inline-block;
  padding: 3px 10px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  font-size: 0.72rem;
  font-weight: 600;
  margin-bottom: 10px;
}

/* ================================================
   FOOTER
   ================================================ */
#colophon {
  background: var(--color-dark);
  color: rgba(255,255,255,0.75);
}
.footer-main {
  padding: 64px 0 48px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 48px;
}
.footer-brand .logo-text .name { color: #fff; }
.footer-brand .logo-text .tagline { color: rgba(255,255,255,0.5); }
.footer-brand p {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.55);
  line-height: 1.7;
  margin: 16px 0 24px;
  max-width: 280px;
}
.footer-socials {
  display: flex;
  gap: 10px;
}
.footer-social-link {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,0.6);
  font-size: 0.875rem;
  transition: all var(--transition);
  text-decoration: none;
}
.footer-social-link:hover {
  background: var(--color-primary);
  color: #fff;
}
.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 18px;
}
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col ul li a {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.55);
  transition: color var(--transition);
}
.footer-col ul li a:hover { color: #fff; }

/* Newsletter */
.newsletter-form {
  display: flex;
  gap: 8px;
  margin-top: 8px;
}
.newsletter-form input {
  flex: 1;
  padding: 10px 16px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.07);
  color: #fff;
  font-size: 0.85rem;
  outline: none;
  transition: border-color var(--transition);
}
.newsletter-form input::placeholder { color: rgba(255,255,255,0.35); }
.newsletter-form input:focus { border-color: var(--color-primary); }
.newsletter-form button {
  padding: 10px 20px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition);
  white-space: nowrap;
}
.newsletter-form button:hover { background: var(--color-primary-dark); }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.07);
  padding: 20px 0;
}
.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.35);
}
.footer-bottom-inner span { display: flex; align-items: center; gap: 4px; }
.footer-heart { color: #ef4444; }

/* ================================================
   SEARCH OVERLAY
   ================================================ */
.search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15,23,42,0.85);
  backdrop-filter: blur(8px);
  z-index: 9999;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 120px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
}
.search-overlay.active { opacity: 1; visibility: visible; }
.search-box {
  background: #fff;
  border-radius: var(--radius-xl);
  padding: 8px;
  width: min(600px, 90vw);
  display: flex;
  gap: 8px;
  box-shadow: var(--shadow-lg);
}
.search-box input {
  flex: 1;
  border: none;
  outline: none;
  padding: 12px 16px;
  font-size: 1rem;
  font-family: var(--font-body);
  color: var(--color-text);
  background: transparent;
}
.search-box button {
  background: var(--color-primary);
  color: #fff;
  border: none;
  padding: 12px 24px;
  border-radius: var(--radius-lg);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition);
}
.search-close {
  position: fixed;
  top: 24px;
  right: 24px;
  background: rgba(255,255,255,0.15);
  border: none;
  color: #fff;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition);
}
.search-close:hover { background: rgba(255,255,255,0.25); }

/* ================================================
   BREADCRUMB
   ================================================ */
.breadcrumb {
  padding: 12px 0;
  font-size: 0.82rem;
  color: var(--color-text-muted);
}
.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb span.sep { margin: 0 6px; }
.breadcrumb span.current { color: var(--color-primary); font-weight: 500; }

/* ================================================
   PAGINATION
   ================================================ */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  padding: 40px 0;
  flex-wrap: wrap;
}
.pagination a, .pagination span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  transition: all var(--transition);
}
.pagination a:hover { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
.pagination .current { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

/* ================================================
   SINGLE POST
   ================================================ */
.single-post-layout {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 40px;
  padding: 48px 0 64px;
}
.post-header { margin-bottom: 32px; }
.post-title { font-size: 2rem; font-weight: 800; line-height: 1.3; margin-bottom: 16px; }
.post-meta { display: flex; gap: 16px; flex-wrap: wrap; }
.post-meta-item { display: flex; align-items: center; gap: 6px; font-size: 0.82rem; color: var(--color-text-muted); }
.post-featured-image { border-radius: var(--radius-lg); overflow: hidden; margin-bottom: 32px; }
.post-featured-image img { width: 100%; height: auto; }
.post-content { line-height: 1.8; font-size: 1rem; }
.post-content h2, .post-content h3 { margin: 32px 0 12px; color: var(--color-text); }
.post-content p { margin-bottom: 18px; color: var(--color-text); }
.post-content ul, .post-content ol { padding-left: 24px; margin-bottom: 18px; }
.post-content li { margin-bottom: 6px; }
.post-content img { border-radius: var(--radius-md); margin: 24px 0; }
.post-content blockquote {
  border-left: 4px solid var(--color-primary);
  padding: 16px 20px;
  background: var(--color-primary-light);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 24px 0;
  font-style: italic;
  color: var(--color-primary-dark);
}
.post-content code {
  background: var(--color-bg-soft);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.875em;
  color: #e83e8c;
}
.post-content pre {
  background: var(--color-dark);
  padding: 20px;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: 20px 0;
}
.post-content pre code { color: #e2e8f0; background: none; padding: 0; }

/* Sidebar */
.sidebar { display: flex; flex-direction: column; gap: 28px; }
.widget {
  background: var(--color-bg-soft);
  border-radius: var(--radius-lg);
  padding: 24px;
  border: 1px solid var(--color-border);
}
.widget-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-primary);
  color: var(--color-text);
}

/* ================================================
   PAGE TEMPLATES
   ================================================ */
.page-hero {
  background: linear-gradient(135deg, var(--color-primary-light) 0%, #e0f2fe 100%);
  padding: 60px 0;
  text-align: center;
}
.page-hero h1 { font-size: 2.25rem; margin-bottom: 12px; }
.page-hero p { color: var(--color-text-muted); max-width: 520px; margin: 0 auto; }

/* ================================================
   CARDS ARCHIVE
   ================================================ */
.archive-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  padding: 48px 0;
}

/* ================================================
   RESPONSIVE
   ================================================ */
@media (max-width: 1024px) {
  .explore-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .blog-grid { grid-template-columns: repeat(2, 1fr); }
  .single-post-layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .archive-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .menu-toggle { display: flex; }
  #primary-navigation {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    padding: 16px 20px;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
  }
  #primary-navigation.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  #primary-navigation ul { flex-direction: column; }
  #primary-navigation ul li .sub-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    background: var(--color-bg-soft);
    padding-left: 16px;
    display: none;
  }
  #primary-navigation ul li.menu-open > .sub-menu { display: flex; }
  .hero-inner { grid-template-columns: 1fr; }
  .hero-image { display: none; }
  .hero-features { grid-template-columns: 1fr; }
  .explore-grid { grid-template-columns: repeat(2, 1fr); }
  .quiz-courses-grid { grid-template-columns: 1fr; }
  .students-grid { grid-template-columns: 1fr; }
  .blog-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom-inner { flex-direction: column; gap: 8px; text-align: center; }
  .archive-grid { grid-template-columns: 1fr; }
  .header-actions .btn { display: none; }
}

@media (max-width: 480px) {
  .explore-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 20px; }
}
/*
 * TinHocKonTum — LMS Style Additions
 * Bổ sung CSS cho nền tảng học sinh Cấp 1-2-3
 * Thêm vào cuối style.css hiện có
 */

/* ================================================
   1. DESIGN SYSTEM — MỞ RỘNG
   ================================================ */
:root {
  /* Per-cap colors */
  --color-cap-tieuhoc:     #7C3AED;
  --color-cap-tieuhoc-bg:  #F5F3FF;
  --color-cap-thcs:        #2563EB;
  --color-cap-thcs-bg:     #EFF6FF;
  --color-cap-thpt:        #DC2626;
  --color-cap-thpt-bg:     #FEF2F2;

  /* Fun / gamification colors */
  --color-fun:             #EC4899;
  --color-fun-bg:          #FDF2F8;
  --color-success:         #059669;
  --color-success-bg:      #ECFDF5;
  --color-warning:         #D97706;
  --color-warning-bg:      #FFFBEB;
  --color-danger:          #DC2626;
  --color-danger-bg:       #FEF2F2;

  /* Quiz colors */
  --color-quiz-correct:    #059669;
  --color-quiz-wrong:      #DC2626;
  --color-quiz-option-hover: #EFF6FF;
  --color-quiz-selected:   #DBEAFE;
}

/* ================================================
   2. CẤP HỌC BADGES
   ================================================ */
.cap-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.cap-badge.tieuhoc {
  background: var(--color-cap-tieuhoc);
  color: #fff;
}
.cap-badge.thcs {
  background: var(--color-cap-thcs);
  color: #fff;
}
.cap-badge.thpt {
  background: var(--color-cap-thpt);
  color: #fff;
}
.cap-badge.outline-tieuhoc {
  background: var(--color-cap-tieuhoc-bg);
  color: var(--color-cap-tieuhoc);
  border: 1.5px solid var(--color-cap-tieuhoc);
}
.cap-badge.outline-thcs {
  background: var(--color-cap-thcs-bg);
  color: var(--color-cap-thcs);
  border: 1.5px solid var(--color-cap-thcs);
}
.cap-badge.outline-thpt {
  background: var(--color-cap-thpt-bg);
  color: var(--color-cap-thpt);
  border: 1.5px solid var(--color-cap-thpt);
}

/* Độ khó badges */
.do-kho-badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: 0.72rem;
  font-weight: 600;
}
.do-kho-badge.de       { background: #D1FAE5; color: #065F46; }
.do-kho-badge.tb       { background: #FEF3C7; color: #92400E; }
.do-kho-badge.kho      { background: #FEE2E2; color: #991B1B; }

/* ================================================
   3. CAP HOC NAVIGATION TABS (Filter)
   ================================================ */
.cap-hoc-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.cap-hoc-tab {
  padding: 9px 20px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.875rem;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
  text-decoration: none;
}

.cap-hoc-tab[data-cap="all"] {
  background: var(--color-bg-soft);
  color: var(--color-text);
  border-color: var(--color-border);
}
.cap-hoc-tab[data-cap="tieuhoc"] {
  background: var(--color-cap-tieuhoc-bg);
  color: var(--color-cap-tieuhoc);
  border-color: var(--color-cap-tieuhoc);
}
.cap-hoc-tab[data-cap="thcs"] {
  background: var(--color-cap-thcs-bg);
  color: var(--color-cap-thcs);
  border-color: var(--color-cap-thcs);
}
.cap-hoc-tab[data-cap="thpt"] {
  background: var(--color-cap-thpt-bg);
  color: var(--color-cap-thpt);
  border-color: var(--color-cap-thpt);
}

.cap-hoc-tab.active,
.cap-hoc-tab:hover {
  opacity: 1;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}
.cap-hoc-tab[data-cap="all"].active {
  background: var(--color-text);
  color: #fff;
  border-color: var(--color-text);
}

/* ================================================
   4. QUIZ ENGINE
   ================================================ */
.quiz-engine {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  margin-bottom: 32px;
  box-shadow: var(--shadow-md);
}

.quiz-engine-header {
  background: var(--color-primary);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #fff;
}

.quiz-engine-header h3 {
  color: #fff;
  font-size: 0.95rem;
  margin: 0;
}

.quiz-progress-bar-wrap {
  height: 6px;
  background: rgba(255,255,255,0.25);
  border-radius: 3px;
  flex: 1;
  margin: 0 16px;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  background: #fff;
  border-radius: 3px;
  transition: width 0.4s ease;
}

.quiz-timer {
  background: rgba(255,255,255,0.2);
  padding: 4px 12px;
  border-radius: 20px;
  font-weight: 700;
  font-size: 0.875rem;
  white-space: nowrap;
}

.quiz-timer.warning { background: rgba(245,158,11,0.8); }
.quiz-timer.danger  { background: rgba(220,38,38,0.8); animation: pulse 1s infinite; }

@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:0.7} }

.quiz-engine-body {
  padding: 28px 28px 20px;
}

.quiz-question-number {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  font-weight: 600;
  margin-bottom: 8px;
}

.quiz-question-text {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.5;
  margin-bottom: 20px;
}

.quiz-options-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 16px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 0.95rem;
  background: var(--color-bg);
  user-select: none;
}

.quiz-option:hover:not(.revealed) {
  border-color: var(--color-primary);
  background: var(--color-quiz-option-hover);
}

.quiz-option.selected:not(.revealed) {
  border-color: var(--color-primary);
  background: var(--color-quiz-selected);
}

.quiz-option.correct {
  border-color: var(--color-quiz-correct);
  background: #D1FAE5;
  color: #065F46;
  font-weight: 600;
}

.quiz-option.wrong {
  border-color: var(--color-quiz-wrong);
  background: #FEE2E2;
  color: #991B1B;
}

.quiz-option-key {
  width: 30px;
  height: 30px;
  min-width: 30px;
  border-radius: 50%;
  border: 2px solid currentColor;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.8rem;
}

.quiz-option-icon {
  margin-left: auto;
  font-size: 1.1rem;
}

.quiz-explanation {
  margin-top: 14px;
  padding: 12px 16px;
  background: #F0FDF4;
  border-left: 3px solid var(--color-success);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 0.875rem;
  color: #065F46;
  line-height: 1.6;
  display: none;
}

.quiz-explanation.show { display: block; }

.quiz-engine-footer {
  padding: 16px 28px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--color-border);
  margin-top: 16px;
}

.quiz-score-inline {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.quiz-score-inline strong {
  color: var(--color-primary);
  font-size: 1rem;
}

/* Quiz Result Card */
.quiz-result-card {
  text-align: center;
  padding: 40px 28px;
}

.quiz-result-emoji {
  font-size: 4rem;
  margin-bottom: 12px;
  display: block;
  animation: bounce 0.6s ease;
}

@keyframes bounce {
  0%,100%{transform:translateY(0)} 40%{transform:translateY(-16px)} 60%{transform:translateY(-8px)}
}

.quiz-result-title {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.quiz-result-score-circle {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  border: 6px solid var(--color-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 20px auto;
}

.quiz-result-score-circle .big { font-size: 1.6rem; font-weight: 900; color: var(--color-primary); }
.quiz-result-score-circle .small { font-size: 0.7rem; color: var(--color-text-muted); }

.quiz-result-stats {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin: 20px 0;
  flex-wrap: wrap;
}

.quiz-result-stat {
  text-align: center;
}

.quiz-result-stat .num {
  display: block;
  font-size: 1.3rem;
  font-weight: 800;
}

.quiz-result-stat .lbl {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.result-correct  .num { color: var(--color-success); }
.result-wrong    .num { color: var(--color-danger); }
.result-time     .num { color: var(--color-primary); }

/* ================================================
   5. KIẾN THỨC VUI CARDS
   ================================================ */
.fun-fact-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition);
  position: relative;
}

.fun-fact-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.fun-fact-card .fun-tag {
  position: absolute;
  top: 12px;
  left: 12px;
  background: var(--color-fun);
  color: #fff;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.7rem;
  font-weight: 700;
}

.fun-fact-card .card-thumb {
  aspect-ratio: 16/9;
  overflow: hidden;
}

.fun-fact-card .card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.fun-fact-card:hover .card-thumb img {
  transform: scale(1.05);
}

.fun-fact-card .card-body {
  padding: 16px 18px 18px;
}

.fun-fact-card .card-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}

.fun-fact-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 8px;
}

.fun-fact-card p {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* ================================================
   6. BÀI ÔN TẬP — Lesson Cards
   ================================================ */
.lesson-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  transition: all var(--transition);
  text-decoration: none;
  color: var(--color-text);
}

.lesson-card:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
  transform: translateX(4px);
  color: var(--color-text);
}

.lesson-number {
  width: 44px;
  height: 44px;
  min-width: 44px;
  border-radius: 50%;
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.875rem;
}

.lesson-card.completed .lesson-number {
  background: var(--color-success-bg);
  color: var(--color-success);
}

.lesson-card .lesson-info { flex: 1; min-width: 0; }
.lesson-card .lesson-title {
  font-weight: 700;
  font-size: 0.95rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-bottom: 3px;
}

.lesson-card .lesson-meta {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  display: flex;
  gap: 12px;
}

.lesson-check {
  color: var(--color-success);
  font-size: 1.1rem;
}

/* Progress Bar */
.course-progress-wrap {
  margin-bottom: 20px;
}

.course-progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  margin-bottom: 6px;
  color: var(--color-text-muted);
}

.course-progress-bar {
  height: 8px;
  background: var(--color-border);
  border-radius: 4px;
  overflow: hidden;
}

.course-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  border-radius: 4px;
  transition: width 0.8s ease;
}

/* ================================================
   7. ĐỀ THI THỬ
   ================================================ */
.exam-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  transition: all var(--transition);
}

.exam-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.exam-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 12px;
  gap: 12px;
}

.exam-card h3 {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0;
}

.exam-card .exam-stats {
  display: flex;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.exam-stat-item {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ================================================
   8. GAMIFICATION — Điểm & Huy hiệu
   ================================================ */
.achievement-badge {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 14px 12px;
  border-radius: var(--radius-md);
  background: var(--color-bg-soft);
  border: 2px solid var(--color-border);
  min-width: 72px;
  text-align: center;
}

.achievement-badge.earned {
  background: linear-gradient(135deg, #FEF3C7, #FDE68A);
  border-color: var(--color-accent);
}

.achievement-badge .badge-icon { font-size: 1.8rem; }
.achievement-badge .badge-name { font-size: 0.68rem; font-weight: 700; color: var(--color-text-muted); }

.score-display {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, var(--color-accent), #F97316);
  color: #fff;
  padding: 6px 16px;
  border-radius: 20px;
  font-weight: 800;
  font-size: 0.9rem;
}

/* ================================================
   9. FRONT PAGE — SECTION CHỌN CẤP HỌC
   ================================================ */
.grade-selector-section {
  background: linear-gradient(135deg, #1e3a8a 0%, #1d4ed8 50%, #2563eb 100%);
  padding: 56px 0;
  position: relative;
  overflow: hidden;
}

.grade-selector-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Ccircle cx='30' cy='30' r='20'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.grade-selector-section .container { position: relative; }

.grade-selector-title {
  text-align: center;
  color: #fff;
  font-size: clamp(1.3rem, 3vw, 1.75rem);
  font-weight: 800;
  margin-bottom: 8px;
}

.grade-selector-subtitle {
  text-align: center;
  color: rgba(255,255,255,0.75);
  font-size: 0.9rem;
  margin-bottom: 36px;
}

.grade-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  max-width: 860px;
  margin: 0 auto;
}

.grade-card {
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: var(--radius-xl);
  padding: 28px 20px;
  text-align: center;
  text-decoration: none;
  color: #fff;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.grade-card:hover {
  background: rgba(255,255,255,0.2);
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.2);
  color: #fff;
}

.grade-card-icon {
  font-size: 3rem;
  line-height: 1;
}

.grade-card-name {
  font-weight: 800;
  font-size: 1.1rem;
}

.grade-card-desc {
  font-size: 0.8rem;
  opacity: 0.8;
  line-height: 1.5;
}

.grade-card-classes {
  display: flex;
  gap: 5px;
  flex-wrap: wrap;
  justify-content: center;
}

.grade-class-tag {
  background: rgba(255,255,255,0.2);
  padding: 2px 8px;
  border-radius: 10px;
  font-size: 0.72rem;
  font-weight: 600;
}

/* ================================================
   10. RESPONSIVE ADJUSTMENTS
   ================================================ */
@media (max-width: 768px) {
  .grade-cards {
    grid-template-columns: 1fr;
    max-width: 320px;
  }

  .quiz-engine-body { padding: 20px 16px 14px; }
  .quiz-engine-footer { padding: 12px 16px 16px; flex-direction: column; gap: 12px; }

  .cap-hoc-tabs { gap: 6px; }
  .cap-hoc-tab { padding: 7px 14px; font-size: 0.8rem; }

  .quiz-result-stats { gap: 16px; }
}

@media (max-width: 480px) {
  .grade-cards { max-width: 100%; }
  .quiz-question-text { font-size: 1rem; }
  .quiz-option { padding: 11px 12px; font-size: 0.875rem; }
}