/* ─── TOKENS ──────────────────────────────────────── */
:root {
  --bg:       #080a10;
  --bg2:      #0d1018;
  --surface:  #111520;
  --surface2: #171c2e;
  --border:   #1f2538;
  --border2:  #2a3050;
  --gold:     #f5c842;
  --gold2:    #e8a020;
  --blue:     #4f8ef7;
  --blue2:    #3a6fd8;
  --green:    #2dd4a0;
  --red:      #f06060;
  --text:     #dde2f0;
  --muted:    #5a6480;
  --muted2:   #8892aa;
  --r:        12px;
}

/* ─── RESET ───────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Lato', sans-serif;
  font-weight: 400;
  min-height: 100vh;
  overflow-x: hidden;
}

body::after {
  content: '';
  position: fixed; inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none; z-index: 9999; opacity: 0.4;
}

/* ─── NAV ─────────────────────────────────────────── */
nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 40px; height: 64px;
  background: rgba(8,10,16,0.88);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  font-family: 'Syne', sans-serif;
  font-weight: 800; font-size: 1.4rem;
  color: var(--gold); cursor: pointer; letter-spacing: -0.5px;
}
.nav-logo span { color: var(--muted2); font-weight: 400; }

.nav-links { display: flex; gap: 4px; align-items: center; }

.nav-btn {
  background: transparent; border: none;
  color: var(--muted2);
  font-family: 'Fira Code', monospace; font-size: 0.78rem;
  padding: 7px 16px; border-radius: 6px;
  cursor: pointer; transition: all 0.2s; letter-spacing: 0.03em;
}
.nav-btn:hover  { color: var(--text); background: var(--surface); }
.nav-btn.active { color: var(--gold); background: rgba(245,200,66,0.1); }

.nav-cta {
  background: var(--gold); color: #08090f;
  border: none; font-family: 'Syne', sans-serif;
  font-weight: 700; font-size: 0.82rem;
  padding: 8px 18px; border-radius: 7px;
  cursor: pointer; margin-left: 8px;
  transition: all 0.2s; letter-spacing: 0.02em;
}
.nav-cta:hover { background: var(--gold2); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(245,200,66,0.3); }

/* ─── PAGES ───────────────────────────────────────── */
.page { display: none; padding-top: 64px; min-height: 100vh; }
.page.active { display: block; }

/* ─── HERO ────────────────────────────────────────── */
.hero {
  position: relative;
  min-height: calc(100vh - 64px);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center; padding: 60px 24px; overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  width: 800px; height: 800px;
  background: radial-gradient(circle, rgba(79,142,247,0.07) 0%, transparent 65%);
  top: 50%; left: 50%; transform: translate(-50%, -55%);
  pointer-events: none;
}

.hero-grid {
  position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(79,142,247,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79,142,247,0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 30%, transparent 100%);
}

.hero-eyebrow {
  font-family: 'Fira Code', monospace;
  font-size: 0.72rem; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--blue);
  background: rgba(79,142,247,0.1); border: 1px solid rgba(79,142,247,0.2);
  padding: 5px 14px; border-radius: 20px; margin-bottom: 28px;
  display: inline-block; animation: fadeUp 0.8s ease both;
}

.hero-title {
  font-family: 'Syne', sans-serif; font-weight: 800;
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  line-height: 1.05; letter-spacing: -2px; margin-bottom: 24px;
  animation: fadeUp 0.8s 0.1s ease both;
}
.hero-title .line2 { color: var(--gold); display: block; }

.hero-sub {
  font-size: 1.05rem; color: var(--muted2);
  max-width: 520px; line-height: 1.75; margin-bottom: 44px;
  font-weight: 300; animation: fadeUp 0.8s 0.2s ease both;
}

.hero-btns {
  display: flex; gap: 12px; flex-wrap: wrap; justify-content: center;
  animation: fadeUp 0.8s 0.3s ease both;
}

.hero-stats {
  display: flex; gap: 40px; margin-top: 64px;
  animation: fadeUp 0.8s 0.4s ease both;
  flex-wrap: wrap; justify-content: center;
}
.stat { text-align: center; }
.stat-num {
  font-family: 'Syne', sans-serif; font-weight: 800;
  font-size: 2rem; color: var(--gold); display: block;
}
.stat-label {
  font-family: 'Fira Code', monospace; font-size: 0.7rem;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted);
}

/* ─── BUTTONS ─────────────────────────────────────── */
.btn-primary {
  background: var(--gold); color: #08090f;
  border: none; font-family: 'Syne', sans-serif;
  font-weight: 700; font-size: 0.95rem;
  padding: 14px 32px; border-radius: 8px;
  cursor: pointer; transition: all 0.2s; letter-spacing: 0.01em;
}
.btn-primary:hover { background: var(--gold2); transform: translateY(-2px); box-shadow: 0 6px 24px rgba(245,200,66,0.35); }

.btn-ghost {
  background: transparent; color: var(--text);
  border: 1px solid var(--border2);
  font-family: 'Syne', sans-serif; font-weight: 600; font-size: 0.95rem;
  padding: 14px 32px; border-radius: 8px;
  cursor: pointer; transition: all 0.2s;
}
.btn-ghost:hover { border-color: var(--muted2); background: var(--surface); }

/* ─── FEATURES ────────────────────────────────────── */
.features {
  padding: 100px 40px; max-width: 1100px; margin: 0 auto;
}

.section-label {
  font-family: 'Fira Code', monospace; font-size: 0.72rem;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--green); margin-bottom: 14px;
}

.section-title {
  font-family: 'Syne', sans-serif; font-weight: 800;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  letter-spacing: -1px; margin-bottom: 16px;
}

.section-sub {
  color: var(--muted2); font-size: 0.98rem; font-weight: 300;
  max-width: 480px; line-height: 1.7; margin-bottom: 56px;
}

.feature-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px;
}

.feature-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 28px;
  transition: border-color 0.2s, transform 0.2s;
  position: relative; overflow: hidden;
}
.feature-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-color, var(--blue)), transparent);
  opacity: 0; transition: opacity 0.3s;
}
.feature-card:hover { border-color: var(--border2); transform: translateY(-3px); }
.feature-card:hover::before { opacity: 1; }

.feature-icon {
  width: 44px; height: 44px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem; margin-bottom: 18px;
  background: var(--surface2); border: 1px solid var(--border);
}

.feature-name {
  font-family: 'Syne', sans-serif; font-weight: 700;
  font-size: 1.02rem; margin-bottom: 8px;
}

.feature-desc { color: var(--muted2); font-size: 0.88rem; line-height: 1.65; font-weight: 300; }

/* ─── SUBJECTS ────────────────────────────────────── */
.subjects-section {
  padding: 80px 40px;
  background: var(--bg2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.subjects-inner { max-width: 1100px; margin: 0 auto; }

.subject-cards {
  display: grid; grid-template-columns: repeat(3,1fr);
  gap: 20px; margin-top: 48px;
}

.subject-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 32px;
  cursor: pointer; transition: all 0.2s;
  position: relative; overflow: hidden;
}
.subject-card:hover { border-color: var(--border2); transform: translateY(-4px); }
.subject-card:hover .subject-glow { opacity: 1; }

.subject-glow {
  position: absolute; inset: 0; opacity: 0;
  transition: opacity 0.3s; pointer-events: none;
}
.subject-card[data-s="algebra"]  .subject-glow { background: radial-gradient(circle at 50% 0%, rgba(79,142,247,0.08), transparent 60%); }
.subject-card[data-s="trig"]     .subject-glow { background: radial-gradient(circle at 50% 0%, rgba(245,200,66,0.08), transparent 60%); }
.subject-card[data-s="calculus"] .subject-glow { background: radial-gradient(circle at 50% 0%, rgba(45,212,160,0.08), transparent 60%); }

.subject-emoji { font-size: 2.2rem; margin-bottom: 14px; display: block; }
.subject-name  { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 1.3rem; margin-bottom: 8px; letter-spacing: -0.5px; }
.subject-count { font-family: 'Fira Code', monospace; font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); margin-bottom: 14px; }
.subject-topics { display: flex; flex-wrap: wrap; gap: 6px; }
.topic-chip { font-size: 0.72rem; color: var(--muted2); background: var(--surface2); border: 1px solid var(--border); padding: 3px 10px; border-radius: 4px; font-family: 'Fira Code', monospace; }

/* ─── CTA BANNER ──────────────────────────────────── */
.cta-banner {
  margin: 80px auto;
  max-width: 1100px; padding: 0 40px;
}
.cta-banner-inner {
  background: linear-gradient(135deg, var(--surface2) 0%, var(--surface) 100%);
  border: 1px solid var(--border2); border-radius: 20px;
  padding: 60px 48px;
  display: flex; align-items: center; justify-content: space-between;
  gap: 32px; flex-wrap: wrap;
}
.cta-text h2 { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 2rem; letter-spacing: -1px; margin-bottom: 10px; }
.cta-text p  { color: var(--muted2); font-weight: 300; font-size: 0.95rem; }

/* ─── FOOTER ──────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  padding: 32px 40px;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 16px;
}
.footer-logo { font-family: 'Syne', sans-serif; font-weight: 800; color: var(--gold); font-size: 1.1rem; }
.footer-text  { color: var(--muted); font-size: 0.8rem; font-family: 'Fira Code', monospace; }

/* ─── DASHBOARD ───────────────────────────────────── */
.dash-wrap {
  max-width: 1100px; margin: 0 auto;
  padding: 80px 40px 60px;
}

.dash-header { margin-bottom: 40px; }
.dash-title    { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 2rem; letter-spacing: -1px; margin-bottom: 6px; }
.dash-subtitle { color: var(--muted2); font-size: 0.9rem; font-weight: 300; }

.xp-bar-wrap {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 20px 24px;
  margin-bottom: 28px; display: flex; align-items: center; gap: 20px;
}
.xp-level       { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 2.2rem; color: var(--gold); min-width: 56px; text-align: center; line-height: 1; }
.xp-level-label { font-family: 'Fira Code', monospace; font-size: 0.6rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); display: block; margin-top: 2px; text-align: center; }
.xp-info        { flex: 1; }
.xp-label-row   { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.xp-name        { font-family: 'Syne', sans-serif; font-weight: 700; font-size: 0.95rem; }
.xp-pts         { font-family: 'Fira Code', monospace; font-size: 0.75rem; color: var(--muted2); }
.xp-track       { height: 8px; background: var(--surface2); border-radius: 4px; overflow: hidden; border: 1px solid var(--border); }
.xp-fill        { height: 100%; background: linear-gradient(90deg, var(--gold2), var(--gold)); border-radius: 4px; transition: width 1s ease; }

.stat-cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(180px,1fr));
  gap: 16px; margin-bottom: 32px;
}
.stat-card       { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r); padding: 20px 22px; }
.stat-card-label { font-family: 'Fira Code', monospace; font-size: 0.66rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin-bottom: 8px; }
.stat-card-val   { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 1.9rem; line-height: 1; letter-spacing: -1px; }
.stat-card-sub   { font-size: 0.78rem; color: var(--muted2); margin-top: 4px; }

.dash-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 20px; margin-bottom: 24px; }
.dash-panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r); padding: 24px; }
.panel-title { font-family: 'Syne', sans-serif; font-weight: 700; font-size: 0.92rem; margin-bottom: 20px; letter-spacing: -0.2px; }

.progress-row   { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.progress-row:last-of-type { margin-bottom: 0; }
.prog-label     { font-size: 0.85rem; min-width: 100px; }
.prog-track     { flex: 1; height: 6px; background: var(--surface2); border-radius: 3px; overflow: hidden; border: 1px solid var(--border); }
.prog-fill      { height: 100%; border-radius: 3px; transition: width 1.2s ease; }
.prog-pct       { font-family: 'Fira Code', monospace; font-size: 0.72rem; color: var(--muted2); min-width: 34px; text-align: right; }

.badges-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 10px; }
.badge-item  { background: var(--surface2); border: 1px solid var(--border); border-radius: 10px; padding: 12px 8px; text-align: center; transition: all 0.2s; }
.badge-item.earned { border-color: rgba(245,200,66,0.3); background: rgba(245,200,66,0.06); }
.badge-item.earned:hover { transform: scale(1.05); }
.badge-item.locked { opacity: 0.35; filter: grayscale(1); }
.badge-emoji { font-size: 1.5rem; display: block; margin-bottom: 5px; }
.badge-name  { font-family: 'Fira Code', monospace; font-size: 0.6rem; letter-spacing: 0.06em; color: var(--muted); text-transform: uppercase; }

.activity-list { display: flex; flex-direction: column; gap: 10px; }
.activity-item { display: flex; align-items: center; gap: 12px; padding: 10px 14px; background: var(--surface2); border: 1px solid var(--border); border-radius: 8px; font-size: 0.85rem; }
.activity-dot  { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }
.activity-text { flex: 1; }
.activity-time { font-family: 'Fira Code', monospace; font-size: 0.68rem; color: var(--muted); }
.activity-pts  { font-family: 'Fira Code', monospace; font-size: 0.75rem; color: var(--gold); font-weight: 500; }
.no-activity   { color: var(--muted); font-size: 0.83rem; font-family: 'Fira Code', monospace; text-align: center; padding: 20px 0; }

/* ─── PRACTICE ────────────────────────────────────── */
.practice-wrap { max-width: 860px; margin: 0 auto; padding: 80px 24px; }
.practice-header { margin-bottom: 40px; }
.practice-title  { font-family: 'Syne', sans-serif; font-weight: 800; font-size: 2rem; letter-spacing: -1px; margin-bottom: 6px; }
.practice-sub    { color: var(--muted2); font-size: 0.9rem; font-weight: 300; }

.controls { display: grid; grid-template-columns: auto 1fr 1fr auto; gap: 12px; margin-bottom: 20px; align-items: end; }
.field       { display: flex; flex-direction: column; gap: 6px; }
.field-label { font-family: 'Fira Code', monospace; font-size: 0.68rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }

select {
  background: var(--surface); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 11px 36px 11px 14px;
  font-family: 'Lato', sans-serif; font-size: 0.9rem;
  cursor: pointer; appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 10 10'%3E%3Cpath fill='%235a6480' d='M5 7L0 2h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 12px center;
  transition: border-color 0.2s; width: 100%;
}
select:focus    { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(79,142,247,0.12); }
select:disabled { opacity: 0.4; cursor: not-allowed; }

.diff-bar        { display: flex; gap: 8px; align-items: center; margin-bottom: 28px; }
.diff-label-text { font-family: 'Fira Code', monospace; font-size: 0.68rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); margin-right: 4px; }

.diff-pill { padding: 5px 14px; border-radius: 20px; font-size: 0.78rem; cursor: pointer; border: 1px solid var(--border); background: transparent; color: var(--muted); font-family: 'Lato', sans-serif; transition: all 0.15s; }
.diff-pill:hover:not(.active)   { border-color: var(--muted2); color: var(--text); }
.diff-pill.active[data-d="easy"]   { background: rgba(45,212,160,0.12); border-color: var(--green); color: var(--green); }
.diff-pill.active[data-d="medium"] { background: rgba(245,200,66,0.12); border-color: var(--gold);  color: var(--gold); }
.diff-pill.active[data-d="hard"]   { background: rgba(240,96,96,0.12);  border-color: var(--red);   color: var(--red); }

.btn-gen {
  background: var(--gold); color: #08090f;
  border: none; border-radius: 8px; padding: 11px 24px;
  font-family: 'Syne', sans-serif; font-weight: 700; font-size: 0.88rem;
  cursor: pointer; white-space: nowrap; transition: all 0.2s; letter-spacing: 0.02em;
}
.btn-gen:hover:not(:disabled) { background: var(--gold2); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(245,200,66,0.3); }
.btn-gen:disabled { opacity: 0.45; cursor: not-allowed; }

.loader       { display: none; padding: 56px; text-align: center; }
.loader.active { display: block; }
.loader-dots  { display: inline-flex; gap: 7px; margin-bottom: 16px; }
.loader-dots span { width: 9px; height: 9px; background: var(--gold); border-radius: 50%; animation: bounce 1.2s infinite ease-in-out; }
.loader-dots span:nth-child(2) { animation-delay: 0.15s; }
.loader-dots span:nth-child(3) { animation-delay: 0.3s; }
.loader-msg { font-family: 'Fira Code', monospace; font-size: 0.75rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); }

.problem-card   { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; overflow: hidden; opacity: 0; transform: translateY(12px); transition: opacity 0.35s ease, transform 0.35s ease; }
.problem-card.visible { opacity: 1; transform: translateY(0); }

.card-top     { background: var(--surface2); border-bottom: 1px solid var(--border); padding: 14px 22px; display: flex; align-items: center; justify-content: space-between; }
.card-tags    { display: flex; gap: 8px; flex-wrap: wrap; }
.card-actions { display: flex; gap: 6px; }

.tag       { font-family: 'Fira Code', monospace; font-size: 0.65rem; letter-spacing: 0.08em; text-transform: uppercase; padding: 3px 10px; border-radius: 4px; }
.tag-subj  { background: rgba(79,142,247,0.12); color: var(--blue); border: 1px solid rgba(79,142,247,0.2); }
.tag-topic { background: var(--surface); color: var(--muted2); border: 1px solid var(--border); }
.tag-easy   { background: rgba(45,212,160,0.1); color: var(--green); border: 1px solid rgba(45,212,160,0.2); }
.tag-medium { background: rgba(245,200,66,0.1); color: var(--gold);  border: 1px solid rgba(245,200,66,0.2); }
.tag-hard   { background: rgba(240,96,96,0.1);  color: var(--red);   border: 1px solid rgba(240,96,96,0.2); }

.act-btn { background: transparent; border: 1px solid var(--border); color: var(--muted2); border-radius: 6px; padding: 5px 12px; font-size: 0.76rem; cursor: pointer; font-family: 'Lato', sans-serif; transition: all 0.15s; }
.act-btn:hover { border-color: var(--muted2); color: var(--text); }

.card-body    { padding: 30px 26px; }
.problem-text { font-family: 'Syne', sans-serif; font-weight: 600; font-size: 1.2rem; line-height: 1.65; margin-bottom: 22px; }

.hint-box, .solution-box { border-radius: 8px; padding: 18px 20px; margin-top: 14px; display: none; font-size: 0.9rem; line-height: 1.75; animation: fadeUp 0.3s ease both; }

/* ─── MARKDOWN / KATEX INSIDE BOXES ──────────────── */
.problem-text p, .hint-box p, .solution-box p { margin: 0 0 10px; }
.problem-text p:last-child, .hint-box p:last-child, .solution-box p:last-child { margin-bottom: 0; }
.hint-box ul, .solution-box ul { padding-left: 20px; margin: 8px 0; }
.hint-box li, .solution-box ul li { margin-bottom: 6px; }
.hint-box strong, .solution-box strong { color: var(--text); font-weight: 700; }
.hint-box code, .solution-box code { font-family: 'Fira Code', monospace; font-size: 0.85em; background: var(--surface2); border: 1px solid var(--border); padding: 1px 5px; border-radius: 4px; }
.hint-box .katex, .solution-box .katex, .problem-text .katex { font-size: 1em; }
.hint-box .katex-display, .solution-box .katex-display, .problem-text .katex-display { margin: 14px 0; overflow-x: auto; padding: 4px 0; }

/* ─── SOLUTION STEP STYLING ───────────────────────── */
.solution-box ol {
  list-style: none;
  padding-left: 0;
  margin: 4px 0;
  counter-reset: step;
}
.solution-box ol li {
  counter-increment: step;
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 12px 0;
  border-bottom: 1px solid rgba(45,212,160,0.08);
  margin-bottom: 0;
}
.solution-box ol li:last-child { border-bottom: none; }
.solution-box ol li::before {
  content: counter(step);
  min-width: 26px; height: 26px;
  border-radius: 50%;
  background: rgba(45,212,160,0.12);
  border: 1px solid rgba(45,212,160,0.28);
  color: var(--green);
  font-family: 'Fira Code', monospace;
  font-size: 0.72rem; font-weight: 500;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0; margin-top: 2px;
}
.hint-box.show, .solution-box.show { display: block; }
.hint-box     { background: rgba(245,200,66,0.05); border: 1px dashed rgba(245,200,66,0.25); }
.solution-box { background: rgba(45,212,160,0.05); border: 1px solid rgba(45,212,160,0.2); border-left: 3px solid var(--green); }

.box-label { font-family: 'Fira Code', monospace; font-size: 0.66rem; letter-spacing: 0.12em; text-transform: uppercase; display: block; margin-bottom: 10px; }
.hint-box .box-label     { color: var(--gold); }
.solution-box .box-label { color: var(--green); }

.err-box { background: rgba(240,96,96,0.08); border: 1px solid rgba(240,96,96,0.25); border-radius: 8px; padding: 14px 18px; color: #fca5a5; font-size: 0.85rem; margin-bottom: 20px; display: none; }
.err-box.show { display: block; }

.empty-state  { text-align: center; padding: 64px 24px; border: 1px dashed var(--border); border-radius: 16px; }
.empty-symbol { font-family: 'Syne', sans-serif; font-size: 4rem; font-weight: 800; color: var(--border); margin-bottom: 16px; display: block; line-height: 1; }
.empty-state p { color: var(--muted2); font-size: 0.88rem; line-height: 1.65; }

.history-section   { margin-top: 36px; }
.history-label-text { font-family: 'Fira Code', monospace; font-size: 0.68rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin-bottom: 10px; }
.history-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.history-chip  { background: var(--surface); border: 1px solid var(--border); border-radius: 6px; padding: 5px 12px; font-size: 0.76rem; color: var(--muted2); cursor: pointer; transition: all 0.15s; max-width: 280px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-family: 'Fira Code', monospace; }
.history-chip:hover { border-color: var(--blue); color: var(--text); }

/* ─── XP TOAST ────────────────────────────────────── */
.xp-toast {
  position: fixed; bottom: 30px; right: 30px;
  background: var(--surface); border: 1px solid rgba(245,200,66,0.4);
  border-radius: 12px; padding: 14px 20px;
  display: flex; align-items: center; gap: 12px;
  font-family: 'Syne', sans-serif; font-weight: 700;
  transform: translateY(80px); opacity: 0;
  transition: all 0.4s ease; z-index: 200; pointer-events: none;
}
.xp-toast.show     { transform: translateY(0); opacity: 1; }
.xp-toast-icon     { font-size: 1.4rem; }
.xp-toast-text     { font-size: 0.9rem; }
.xp-toast-pts      { color: var(--gold); font-size: 1.1rem; }

/* ─── ANSWER SECTION ─────────────────────────────── */
.answer-section {
  margin-top: 20px;
  display: flex; flex-direction: column; gap: 10px;
}

.answer-input {
  width: 100%;
  background: var(--surface2); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 12px 14px;
  font-family: 'Lato', sans-serif; font-size: 0.9rem;
  resize: vertical; min-height: 70px;
  transition: border-color 0.2s;
}
.answer-input:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(79,142,247,0.12); }
.answer-input::placeholder { color: var(--muted); }

.answer-actions { display: flex; align-items: center; gap: 10px; }

.btn-check {
  background: var(--gold); color: #08090f;
  border: none; border-radius: 7px; padding: 8px 18px;
  font-family: 'Syne', sans-serif; font-weight: 700; font-size: 0.82rem;
  cursor: pointer; transition: all 0.2s; letter-spacing: 0.02em;
}
.btn-check:hover:not(:disabled) { background: var(--gold2); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(245,200,66,0.3); }
.btn-check:disabled { opacity: 0.45; cursor: not-allowed; }

.answer-loader { display: none; width: 16px; height: 16px; border: 2px solid var(--border); border-top-color: var(--gold); border-radius: 50%; }
.answer-loader.active { display: block; animation: spin 0.7s linear infinite; }

.answer-result { border-radius: 8px; padding: 14px 18px; font-size: 0.88rem; line-height: 1.65; display: none; }
.answer-result.show { display: block; animation: fadeUp 0.3s ease both; }
.answer-result.correct   { background: rgba(45,212,160,0.07); border: 1px solid rgba(45,212,160,0.25); border-left: 3px solid var(--green); }
.answer-result.incorrect { background: rgba(240,96,96,0.07);  border: 1px solid rgba(240,96,96,0.25);  border-left: 3px solid var(--red); }
.answer-result p { margin: 0 0 8px; }
.answer-result p:last-child { margin-bottom: 0; }

/* ─── HAMBURGER ──────────────────────────────────── */
.hamburger {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 8px;
}
.hamburger span {
  width: 22px; height: 2px;
  background: var(--text); border-radius: 1px;
  transition: all 0.25s; display: block;
}
.hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ─── ANIMATIONS ──────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes bounce {
  0%, 80%, 100% { transform: scale(0.65); opacity: 0.4; }
  40%            { transform: scale(1);    opacity: 1; }
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ─── RESPONSIVE ──────────────────────────────────── */
@media (max-width: 768px) {
  nav { padding: 0 20px; position: relative; }
  .hamburger { display: flex; }
  .nav-links {
    display: none; flex-direction: column; gap: 6px;
    position: absolute; top: 64px; left: 0; right: 0;
    background: rgba(8,10,16,0.97); border-bottom: 1px solid var(--border);
    padding: 16px 20px; backdrop-filter: blur(16px); z-index: 99;
  }
  .nav-links.open { display: flex; }
  .nav-btn { width: 100%; text-align: left; padding: 10px 14px; font-size: 0.82rem; }
  .nav-cta { width: 100%; text-align: center; margin-left: 0; }
  .features, .subjects-section { padding: 60px 20px; }
  .subject-cards { grid-template-columns: 1fr; }
  .dash-grid { grid-template-columns: 1fr; }
  .controls { grid-template-columns: 1fr; }
  .btn-gen { width: 100%; }
  .dash-wrap { padding: 80px 20px 60px; }
  .cta-banner { padding: 0 20px; }
  .cta-banner-inner { padding: 36px 24px; }
}