/* ===== SKIP LINK ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--w);
  color: var(--bg);
  padding: 0.5rem 1.2rem;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  z-index: 200;
  transition: top 0.2s;
}
.skip-link:focus {
  top: 1rem;
  color: var(--bg);
}

/* ===== RESET & DESIGN TOKENS ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
:root {
  --bg: #0c0c0c;
  --bg2: #161616;
  --bg3: #1c1c1c;
  --w: #f5f5f0;
  --w2: #8a8a82;
  --w3: #555550;
  --bdr: rgba(255, 255, 255, 0.06);
  --sans: "Inter", "Noto Sans TC", "Helvetica Neue", sans-serif;
  --accent-blue: #3b5bdb;
}
html {
  scroll-behavior: smooth;
}
body {
  background: var(--bg);
  color: var(--w);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.95;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  word-break: keep-all;
  overflow-wrap: break-word;
}
::selection {
  background: rgba(255, 255, 255, 0.15);
}
a {
  color: var(--w2);
  text-decoration: none;
  transition: color 0.3s;
}
a:hover {
  color: var(--w);
}

/* ===== LAYOUT ===== */
.w {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 2.5rem;
}
section {
  padding: 9rem 0;
}
.bg-alt {
  background: var(--bg2);
}

/* ===== FADE ===== */
.fade {
  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity 0.7s ease-out,
    transform 0.7s ease-out;
}
.fade.on {
  opacity: 1;
  transform: translateY(0);
}

/* ===== NAV ===== */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1.1rem 0;
  transition:
    background 0.4s,
    padding 0.4s,
    border-color 0.4s;
  border-bottom: 1px solid transparent;
}
nav.scrolled {
  background: rgba(12, 12, 12, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 0.65rem 0;
  border-bottom-color: var(--bdr);
}
.nav-in {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 2.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--w);
  text-decoration: none;
  letter-spacing: 0.01em;
}
.nav-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}
.nav-links a {
  color: var(--w3);
  font-size: 0.82rem;
  transition: color 0.3s;
}
.nav-links a:hover {
  color: var(--w);
}
.toggle-group {
  display: flex;
  border: 1px solid var(--bdr);
  border-radius: 5px;
  overflow: hidden;
}
.toggle-btn {
  background: transparent;
  border: none;
  color: var(--w3);
  font-size: 0.72rem;
  padding: 0.3rem 0.55rem;
  cursor: pointer;
  transition: all 0.25s;
  font-family: var(--sans);
}
.toggle-btn.active {
  background: var(--w);
  color: var(--bg);
  font-weight: 600;
}
.nav-mob {
  display: none;
  background: 0;
  border: 0;
  cursor: pointer;
  padding: 4px;
}
.nav-mob span {
  display: block;
  width: 18px;
  height: 1.5px;
  background: var(--w);
  margin: 4px 0;
  transition: 0.3s;
}
.nav-mob.open span:nth-child(1) {
  transform: rotate(45deg) translate(4px, 4px);
}
.nav-mob.open span:nth-child(2) {
  opacity: 0;
}
.nav-mob.open span:nth-child(3) {
  transform: rotate(-45deg) translate(4px, -4px);
}
.mob-menu {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(12, 12, 12, 0.97);
  z-index: 99;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2rem;
}
.mob-menu.open {
  display: flex;
}
.mob-menu a {
  color: var(--w);
  font-size: 1.1rem;
  text-decoration: none;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-block;
  padding: 0.85rem 2.2rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 8px;
  text-decoration: none;
  transition: opacity 0.3s;
  cursor: pointer;
  border: none;
  font-family: var(--sans);
  background: var(--w);
  color: var(--bg);
}
.btn:hover {
  opacity: 0.85;
  color: var(--bg);
}
.btn-secondary {
  background: transparent;
  color: var(--w);
  border: 1px solid var(--bdr);
}
.btn-secondary:hover {
  color: var(--w);
  border-color: rgba(255, 255, 255, 0.2);
}

/* ===== HERO ===== */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 8rem 0 6rem;
}
.hero-h {
  font-weight: 700;
  font-size: clamp(2.8rem, 6vw, 4.5rem);
  line-height: 1.12;
  margin-bottom: 2rem;
  max-width: 600px;
  letter-spacing: -0.02em;
}
.hero-p {
  color: var(--w2);
  font-size: 1.05rem;
  line-height: 1.9;
  max-width: 480px;
  margin-bottom: 3rem;
}
.hero-cta {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ===== THE GAP ===== */
#gap {
  padding: 8rem 0;
}
.gap-label {
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--w3);
  margin-bottom: 2rem;
}
.gap-h {
  font-weight: 700;
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  margin-bottom: 4rem;
}
.gap-item {
  color: var(--w2);
  font-size: clamp(1.1rem, 2vw, 1.3rem);
  line-height: 1.8;
  max-width: 600px;
  margin-bottom: 3rem;
}
.gap-close {
  color: var(--w);
  font-weight: 700;
  font-size: 1.15rem;
  margin-top: 1rem;
  letter-spacing: 0.01em;
}

/* ===== SERVICES ===== */
#services {
  padding: 8rem 0;
}
.section-label {
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--w2);
  margin-bottom: 2rem;
}
.section-h {
  font-weight: 700;
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  margin-bottom: 3.5rem;
}
.section-note {
  color: var(--w2);
  font-size: 0.95rem;
  margin-top: 2rem;
  text-align: center;
}
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}
.three-col {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.service-block {
  padding: 2.5rem;
  background: var(--bg3);
  border: 1px solid var(--bdr);
  border-radius: 10px;
}
.service-block h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.8rem;
}
.service-block p {
  color: var(--w2);
  font-size: 0.95rem;
  line-height: 1.85;
}

/* ===== FEARS ===== */
.fears-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

/* ===== PRICING ===== */
#pricing {
  padding: 8rem 0;
}
.pricing-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}
.pricing-grid-bottom {
  grid-template-columns: 1fr;
  max-width: 50%;
}
.pricing-card-enterprise {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
}
.enterprise-desc {
  color: var(--w2);
  font-size: 1rem;
  line-height: 1.9;
  margin-bottom: 2rem;
}
.pricing-card {
  background: var(--bg3);
  border: 1px solid var(--bdr);
  border-radius: 10px;
  padding: 2.5rem;
}
.pricing-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
}
.pricing-table {
  width: 100%;
  border-collapse: collapse;
}
.pricing-table th,
.pricing-table td {
  padding: 0.7rem 0;
  text-align: left;
  border-bottom: 1px solid var(--bdr);
  font-size: 0.9rem;
}
.pricing-table th {
  color: var(--w3);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.pricing-table td {
  color: var(--w2);
}
.pricing-table .price-val {
  color: var(--w);
  font-weight: 700;
}
.badge {
  display: inline-block;
  background: var(--w);
  color: var(--bg);
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  margin-left: 0.5rem;
  vertical-align: middle;
  letter-spacing: 0.03em;
}
.tutoring-price {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 700;
  margin-bottom: 0.8rem;
}
.pricing-note {
  color: var(--w3);
  font-size: 0.85rem;
  line-height: 1.9;
  margin-top: 1.5rem;
}
.pricing-footer {
  color: var(--w3);
  font-size: 0.85rem;
  border-top: 1px solid var(--bdr);
  padding-top: 1.5rem;
}

/* ===== SECTION CTA ===== */
.section-cta {
  text-align: center;
  margin-top: 2.5rem;
}
#pricing .section-cta {
  margin-top: 1.5rem;
}

/* ===== TUTORING ===== */
.tutoring-unit {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--w2);
}
.tutoring-desc {
  color: var(--w2);
  font-size: 0.9rem;
  line-height: 1.8;
}

/* ===== TESTIMONIALS ===== */
#testimonials {
  padding: 8rem 0;
}
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2.5rem;
}
.testimonial-card {
  background: var(--bg3);
  border: 1px solid var(--bdr);
  border-radius: 12px;
  padding: 2rem;
}
.testimonial-text {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--w2);
  font-style: italic;
}
.testimonial-author {
  margin-top: 1.2rem;
  font-size: 0.85rem;
  color: var(--w3);
  font-weight: 600;
}

/* ===== HOW IT WORKS ===== */
#how {
  padding: 8rem 0;
}
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}
.step {
  text-align: center;
}
.step-num {
  font-size: 0.8rem;
  color: var(--w3);
  display: inline-block;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--bdr);
  border-radius: 20px;
  margin-bottom: 1.2rem;
}
.step h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}
.step p {
  color: var(--w2);
  font-size: 0.88rem;
  line-height: 1.8;
}

/* ===== ABOUT ===== */
#about {
  padding: 8rem 0;
}
.about-layout {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 3rem;
  align-items: start;
}
.about-photo {
  width: 160px;
  border-radius: 12px;
}
.about-text {
  max-width: 600px;
}
.about-text p {
  color: var(--w2);
  font-size: 1rem;
  line-height: 1.9;
  margin-bottom: 1rem;
}
.about-text p:first-child {
  color: var(--w);
  font-weight: 600;
  font-size: 1.05rem;
}

/* ===== FAQ ===== */
#faq {
  padding: 8rem 0;
}
.faq-list {
  max-width: 640px;
}
.faq-item {
  border-bottom: 1px solid var(--bdr);
}
.faq-q {
  width: 100%;
  background: transparent;
  border: none;
  color: var(--w);
  font-family: var(--sans);
  font-size: 0.95rem;
  font-weight: 600;
  text-align: left;
  padding: 1.3rem 0;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color 0.3s;
}
.faq-q:hover {
  color: var(--w2);
}
.faq-q::after {
  content: "+";
  font-size: 1.1rem;
  color: var(--w3);
  transition: transform 0.3s;
}
.faq-item.open .faq-q::after {
  content: "\2212";
}
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease-out;
}
.faq-item.open .faq-a {
  max-height: 300px;
}
.faq-a p {
  color: var(--w2);
  font-size: 0.9rem;
  line-height: 1.85;
  padding: 0 0 1.3rem;
}

/* ===== BLOG LIST (homepage) ===== */
#blog {
  padding: 8rem 0;
}
.blog-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.blog-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.2rem 0;
  border-bottom: 1px solid var(--bdr);
  text-decoration: none;
  transition: color 0.3s;
}
.blog-item:first-child {
  border-top: 1px solid var(--bdr);
}
.blog-item-title {
  color: var(--w);
  font-size: 0.95rem;
  font-weight: 600;
}
.blog-item-date {
  color: var(--w3);
  font-size: 0.8rem;
  flex-shrink: 0;
  margin-left: 2rem;
}
.blog-item:hover .blog-item-title {
  color: var(--w2);
}

/* ===== BOTTOM CTA ===== */
#cta {
  padding: 8rem 0;
  text-align: center;
}
.cta-h {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  margin-bottom: 1rem;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}
.cta-urgency {
  color: var(--w2);
  font-size: 0.9rem;
  margin-bottom: 2rem;
}

/* ===== FOOTER ===== */
footer {
  border-top: 1px solid var(--bdr);
  padding: 2rem 0;
  text-align: center;
  font-size: 0.8rem;
  color: var(--w3);
}
footer a {
  color: var(--w3);
  margin: 0 0.6rem;
}
footer a:hover {
  color: var(--w);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  section {
    padding: 5rem 0;
  }
  .two-col {
    grid-template-columns: 1fr;
  }
  .three-col {
    grid-template-columns: 1fr;
  }
  .fears-grid {
    grid-template-columns: 1fr;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  .pricing-grid-bottom {
    max-width: 100%;
  }
  .steps {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  .testimonials-grid {
    grid-template-columns: 1fr;
  }
  .about-layout {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
  }
  .about-text {
    text-align: left;
  }
  .service-block {
    padding: 2rem;
  }
  .nav-links {
    display: none;
  }
  .nav-right > .toggle-group {
    display: none;
  }
  .nav-mob {
    display: block;
  }
  .mob-menu .toggle-group {
    display: flex;
    margin-top: 1rem;
  }
}
@media (max-width: 480px) {
  .w {
    padding: 0 1.5rem;
  }
  .hero-h {
    font-size: 2.2rem;
  }
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .fade {
    opacity: 1;
    transform: none;
    transition: none;
  }
  nav {
    transition: none;
  }
  .faq-a {
    transition: none;
  }
  .skip-link {
    transition: none;
  }
}