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

:root {
  --dark: #121e2d;
  --white: #ffffff;
  --off-white: #f7f7f7;
  --text: #1a1a1a;
  --text-muted: #666;
  --accent: #2e7cf6;
  --font: 'Poppins', sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

img { display: block; width: 100%; height: auto; object-fit: cover; }

/* ── CONTAINER ── */
.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 60px;
}

/* ── SECTIONS ── */
.section { padding: 100px 0; }
.section--dark {
  background: var(--dark);
  color: var(--white);
  padding: 100px 0;
}

.label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0.6;
  margin-bottom: 16px;
}
.section--dark .label { opacity: 0.5; color: var(--white); }

.small-text { font-size: 0.8rem; color: var(--text-muted); margin-top: 8px; }
.section--dark .small-text { color: rgba(255,255,255,0.45); }

.btn {
  display: inline-block;
  padding: 13px 32px;
  border-radius: 6px;
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: opacity 0.2s;
}
.btn:hover { opacity: 0.85; }
.btn--primary { background: var(--accent); color: var(--white); border: none; }

/* ── NAV ── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 24px 60px;
}

.nav__inner {
  display: flex;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
}

.nav__logo {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--white);
  text-decoration: none;
  letter-spacing: -0.02em;
}

/* ── HERO ── */
.hero {
  position: relative;
  height: 100vh;
  min-height: 640px;
  background: url('images/hero.jpg') center center / cover no-repeat;
  display: flex;
  align-items: flex-end;
  padding-bottom: 100px;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(10, 18, 30, 0.3) 0%,
    rgba(10, 18, 30, 0.7) 100%
  );
}

.hero__content { padding-left: 6% !important; padding-right: 6% !important;
  position: relative;
  z-index: 1;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 60px;
  width: 100%;
}

.hero__heading {
  font-size: clamp(2.4rem, 4.5vw, 5rem);
  font-weight: 700;
  color: var(--white);
  line-height: 1.1;
  max-width: 900px;
}

/* ── INTRO ── */
.intro__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.intro__image img { border-radius: 6px; height: 520px; }

.intro__body { font-size: 1rem; line-height: 1.8; color: var(--text-muted); }
.intro__attribution { font-size: 0.8rem; color: var(--text-muted); margin-top: 8px; margin-bottom: 48px; }
.intro__heading {
  font-size: clamp(1.5rem, 2.2vw, 2.4rem);
  font-weight: 700;
  line-height: 1.25;
}

/* ── TUTORS ── */
.tutors__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.tutors__left h2 {
  font-size: clamp(1.6rem, 2.5vw, 2.6rem);
  font-weight: 700;
  line-height: 1.2;
  margin-top: 12px;
}

.tutors__right { display: flex; flex-direction: column; gap: 40px; }

.tutors__app {
  max-width: 280px;
  height: auto;
  border-radius: 24px;
  box-shadow: 0 24px 70px rgba(0,0,0,0.4);
}

.tutors__earn h3 {
  font-size: clamp(1.6rem, 2.5vw, 2.4rem);
  font-weight: 700;
  line-height: 1.2;
}

/* ── PARTIES ── */
.parties__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.parties__image img { border-radius: 6px; height: 500px; }
.parties__text p { font-size: clamp(1rem, 1.2vw, 1.15rem); line-height: 1.8; color: var(--text-muted); }

/* ── IMPROVE ── */
.improve { background: var(--off-white); }
.improve__intro {
  font-size: clamp(1rem, 1.3vw, 1.2rem);
  line-height: 1.8;
  color: var(--text-muted);
  max-width: 900px;
}

/* ── SUBJECTS ── */
.subjects__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: start;
}

.subjects__image img { border-radius: 6px; height: 380px; margin-bottom: 32px; }
.subjects__prompt { font-size: 0.95rem; line-height: 1.6; color: var(--text-muted); }

.subjects__list { list-style: none; display: flex; flex-direction: column; gap: 0; }
.subjects__list li {
  font-size: clamp(1.6rem, 2.4vw, 2.6rem);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

/* ── SIGNUP ── */
.signup { background: var(--off-white); border-top: 1px solid #eee; }

.signup__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.signup__handle { font-size: 0.9rem; color: var(--text-muted); }
.signup__handle span {
  display: inline-block;
  margin-left: 12px;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: var(--accent);
  color: #fff;
  padding: 2px 8px;
  border-radius: 3px;
}

.signup__label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.signup__form { display: flex; gap: 12px; flex-wrap: wrap; }
.signup__form input {
  flex: 1;
  min-width: 220px;
  padding: 13px 18px;
  border: 1.5px solid #ddd;
  border-radius: 6px;
  font-family: var(--font);
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.2s;
}
.signup__form input:focus { border-color: var(--accent); }

/* ── MESSAGES ── */
.messages__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.messages__app {
  max-width: 280px;
  border-radius: 24px;
  margin-top: 28px;
  box-shadow: 0 24px 70px rgba(0,0,0,0.45);
}

.messages__right h2 {
  font-size: clamp(2.4rem, 4vw, 4rem);
  font-weight: 700;
  line-height: 1.15;
}

/* ── FEATURES ── */
.features__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.features__image img { border-radius: 6px; height: 480px; }
.features__text p { font-size: clamp(1rem, 1.2vw, 1.15rem); line-height: 1.8; color: var(--text-muted); }

/* ── WHITEBOARD ── */
.whiteboard { background: var(--off-white); }

.whiteboard__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.whiteboard__text p:first-child { font-size: clamp(1rem, 1.2vw, 1.15rem); line-height: 1.8; color: var(--text-muted); }
.whiteboard__image img { border-radius: 6px; height: 420px; }

/* ── TESTIMONIALS ── */
.testimonials__label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 48px;
}

.testimonials__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
}

.testimonial p {
  font-size: clamp(1.2rem, 1.6vw, 1.6rem);
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 16px;
}

.testimonial cite {
  font-size: 0.85rem;
  font-style: normal;
  color: var(--text-muted);
  font-weight: 500;
}

/* ── DOWNLOAD ── */
.download__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  align-items: center;
}

.download__text h2 {
  font-size: clamp(1.2rem, 1.8vw, 1.8rem);
  font-weight: 600;
  line-height: 1.45;
  margin-bottom: 32px;
}

.download__image img {
  max-width: 320px;
  margin-left: auto;
  border-radius: 24px;
  box-shadow: 0 24px 70px rgba(0,0,0,0.45);
}

/* ── FOOTER ── */
.footer {
  background: #0a1220;
  color: rgba(255,255,255,0.6);
  padding: 36px 60px;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  max-width: 1400px;
  margin: 0 auto;
  flex-wrap: wrap;
  gap: 16px;
}

.footer__logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--white);
  text-decoration: none;
}

.footer__copy { font-size: 0.8rem; }

.footer__links { display: flex; gap: 28px; }
.footer__links span {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.5);
  text-decoration: none;
  transition: color 0.2s;
}

/* ── 27" / LARGE (1440px+) ── */
@media (min-width: 1440px) {
  .section, .section--dark { padding: 120px 0; }
  .hero__heading { font-size: 5.5rem; max-width: 1100px; }
  .intro__image img, .parties__image img, .features__image img { height: 580px; }
  .whiteboard__image img { height: 480px; }
  .subjects__image img { height: 420px; }
}

/* ── 13" LAPTOP (1024px–1280px) ── */
@media (max-width: 1280px) {
  .container { padding: 0 48px; }
  .nav { padding: 20px 48px; }
  .hero__content { padding-left: 6% !important; padding-right: 6% !important; padding: 0 48px; }

  .intro__grid,
  .tutors__grid,
  .parties__grid,
  .subjects__grid,
  .signup__grid,
  .messages__grid,
  .features__grid,
  .whiteboard__grid,
  .download__grid { gap: 72px; }

  .testimonials__grid { gap: 60px; }
}

/* ── 11" / TABLET (768px–1024px) ── */
@media (max-width: 1024px) {
  .container { padding: 0 36px; }
  .nav { padding: 18px 36px; }
  .hero__content { padding-left: 6% !important; padding-right: 6% !important; padding: 0 36px; }
  .section, .section--dark { padding: 80px 0; }

  .intro__grid,
  .tutors__grid,
  .parties__grid,
  .subjects__grid,
  .signup__grid,
  .messages__grid,
  .features__grid,
  .whiteboard__grid,
  .testimonials__grid,
  .download__grid { grid-template-columns: 1fr 1fr; gap: 48px; }

  .intro__image img,
  .parties__image img,
  .features__image img { height: 380px; }
  .whiteboard__image img { height: 340px; }
  .subjects__image img { height: 300px; }

  .tutors__app, .messages__app { max-width: 220px; }
  .subjects__list li { font-size: 1.6rem; }
}

/* ── MOBILE (<768px) ── */
@media (max-width: 768px) {
  .container { padding: 0 24px; }
  .nav { padding: 16px 24px; }
  .hero__content { padding-left: 6% !important; padding-right: 6% !important; padding: 0 24px; }
  .section, .section--dark { padding: 60px 0; }
  .footer { padding: 28px 24px; }

  .intro__grid,
  .tutors__grid,
  .parties__grid,
  .subjects__grid,
  .signup__grid,
  .messages__grid,
  .features__grid,
  .whiteboard__grid,
  .testimonials__grid,
  .download__grid { grid-template-columns: 1fr; gap: 36px; }

  .intro__image img,
  .parties__image img,
  .features__image img,
  .whiteboard__image img { height: 260px; }

  .subjects__image img { height: 240px; }
  .subjects__list li { font-size: 1.6rem; }
  .tutors__app, .messages__app { max-width: 200px; }

  .hero { min-height: 520px; padding-bottom: 60px; }
  .hero__heading { font-size: 2.2rem; }

  .signup__form { flex-direction: column; }
  .signup__form input, .signup__form .btn { width: 100%; }

  .footer__inner { flex-direction: column; text-align: center; }
  .footer__links { justify-content: center; }
  .download__image img { margin: 0 auto; }
}

.hero__content {
  max-width: none;
  padding: 0 6%;
}

.nav__logo { margin-left: auto; }