/* ============================================================
   GPA Vault — Global Stylesheet
   assets/css/style.css
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Sora:wght@400;600;700&display=swap');

:root {
  --indigo:       #4f46e5;
  --indigo-dark:  #3730a3;
  --indigo-light: #818cf8;
  --indigo-faint: #eef2ff;
  --slate:        #1e293b;
  --slate-mid:    #475569;
  --slate-light:  #94a3b8;
  --slate-faint:  #f8fafc;
  --border:       #e2e8f0;
  --white:        #ffffff;
  --gold:         #f59e0b;
  --gold-light:   #fef3c7;
  --green:        #10b981;
  --green-light:  #d1fae5;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', sans-serif;
  background: var(--white);
  color: var(--slate);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex; flex-direction: column;
}
footer { margin-top: auto; }

/* ── NAV ── */
nav {
  position: sticky; top: 0; z-index: 200;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  display: flex; align-items: center; justify-content: space-between;
  height: 60px;
  gap: 2rem;
  overflow: visible;
}

.logo {
  font-family: 'Sora', sans-serif;
  font-size: 1.15rem; font-weight: 700;
  color: var(--slate);
  text-decoration: none;
  flex-shrink: 0;
  letter-spacing: -0.02em;
}
.logo span { color: var(--indigo); }

/* ── NAV LINKS ── */
.nav-links {
  display: flex; align-items: center;
  list-style: none; gap: 0.25rem;
  height: 60px; flex: 1;
}
.nav-links > li {
  position: relative; height: 100%;
  display: flex; align-items: center;
}
.nav-links > li > a,
.nav-links > li > button {
  font-size: 0.85rem; font-weight: 500;
  color: var(--slate-mid);
  text-decoration: none;
  background: none; border: none; cursor: pointer;
  font-family: 'Inter', sans-serif;
  padding: 0 0.875rem; height: 100%;
  display: flex; align-items: center; gap: 0.25rem;
  transition: color 0.15s;
  white-space: nowrap;
  border-radius: 6px;
}
.nav-links > li > a:hover,
.nav-links > li > button:hover,
.nav-links > li > a.active { color: var(--indigo); }

.nav-links > li > button::after {
  content: '▾';
  font-size: 0.65rem;
  transition: transform 0.2s;
}
.nav-links > li.open > button::after { transform: rotate(180deg); }

/* ── DROPDOWN ── */
.nav-dropdown {
  display: none;
  position: absolute; top: calc(100% + 4px); left: 0;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
  min-width: 220px;
  padding: 0.5rem;
  z-index: 300;
}
.nav-links > li.open .nav-dropdown { display: block; }

.nav-dropdown a {
  display: block;
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  font-size: 0.83rem; font-weight: 400;
  color: var(--slate-mid);
  text-decoration: none;
  transition: background 0.1s, color 0.1s;
}
.nav-dropdown a:hover { background: var(--indigo-faint); color: var(--indigo); }

.nav-dropdown-label {
  font-size: 0.7rem; font-weight: 600;
  color: var(--slate-light);
  letter-spacing: 0.08em; text-transform: uppercase;
  padding: 0.5rem 0.75rem 0.25rem;
}
.nav-dropdown-section { padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); margin-bottom: 0.5rem; }
.nav-dropdown-section:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

/* NAV RIGHT */
.nav-right {
  display: flex; align-items: center; gap: 0.75rem; flex-shrink: 0;
}
.nav-back {
  font-size: 0.85rem; font-weight: 500;
  color: var(--slate-mid);
  text-decoration: none;
  display: flex; align-items: center; gap: 0.35rem;
  transition: color 0.15s;
}
.nav-back:hover { color: var(--indigo); }
@media (max-width: 768px) { .nav-back { display: none; } }

/* HAMBURGER */
.nav-hamburger {
  display: none;
  flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer;
  padding: 4px;
}
.nav-hamburger span {
  display: block; width: 22px; height: 2px;
  background: var(--slate);
  border-radius: 2px;
  transition: all 0.2s;
}

/* ── HERO ── */
.hero {
  background: linear-gradient(135deg, var(--slate) 0%, #1e1b4b 100%);
  padding: 5rem 2rem 4.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(79,70,229,0.3) 0%, transparent 70%);
}
.hero > * { position: relative; }

.hero-tag {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  color: rgba(255,255,255,0.8);
  font-size: 0.75rem; font-weight: 500;
  letter-spacing: 0.05em;
  padding: 0.35rem 1rem; border-radius: 100px;
  margin-bottom: 1.75rem;
}

.hero h1 {
  font-family: 'Sora', sans-serif;
  font-size: clamp(2.2rem, 5.5vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--white);
  margin-bottom: 1.25rem;
  max-width: 800px; margin-left: auto; margin-right: auto;
}
.hero h1 span { color: var(--indigo-light); }

.hero-sub {
  font-size: 1.05rem; color: rgba(255,255,255,0.6);
  max-width: 520px; margin: 0 auto 2.5rem;
  font-weight: 300; line-height: 1.7;
}

.hero-cta {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: var(--indigo);
  color: white;
  padding: 0.875rem 2rem;
  border-radius: 8px;
  text-decoration: none;
  font-size: 0.9rem; font-weight: 600;
  transition: background 0.2s, transform 0.2s;
  box-shadow: 0 4px 16px rgba(79,70,229,0.4);
}
.hero-cta:hover { background: var(--indigo-dark); transform: translateY(-1px); }

/* ── STATS BAR ── */
.stats-bar {
  background: var(--slate-faint);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 1.5rem 2rem;
  display: flex; justify-content: center; gap: 5rem;
  flex-wrap: wrap;
}
.stat { text-align: center; }
.stat-num {
  font-family: 'Sora', sans-serif;
  font-size: 1.6rem; font-weight: 700;
  color: var(--indigo);
  letter-spacing: -0.02em;
}
.stat-label { font-size: 0.78rem; color: var(--slate-light); margin-top: 0.15rem; }

/* ── AD BANNER ── */
.ad-banner {
  background: var(--slate-faint);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  text-align: center;
  font-size: 0.75rem; color: var(--slate-light);
  padding: 0; min-height: 90px;
  display: flex; align-items: center; justify-content: center;
}

/* ── SECTION ── */
.section { padding: 5rem 2rem; max-width: 1100px; margin: 0 auto; }
.section-header { margin-bottom: 2.5rem; }
.section-label {
  font-size: 0.72rem; font-weight: 600;
  color: var(--indigo);
  letter-spacing: 0.1em; text-transform: uppercase;
  margin-bottom: 0.5rem;
}
.section-header h2 {
  font-family: 'Sora', sans-serif;
  font-size: 1.75rem; font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--slate);
}
.section-header p { color: var(--slate-mid); margin-top: 0.4rem; font-size: 0.95rem; }

/* ── CATEGORY TABS ── */
.category-tabs {
  display: flex; gap: 0.5rem; flex-wrap: wrap;
  margin-bottom: 2rem;
}
.cat-tab {
  padding: 0.45rem 1rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--white);
  font-size: 0.8rem; font-weight: 500;
  color: var(--slate-mid);
  cursor: pointer;
  transition: all 0.15s;
  font-family: 'Inter', sans-serif;
}
.cat-tab:hover, .cat-tab.active {
  background: var(--indigo-faint);
  border-color: var(--indigo-light);
  color: var(--indigo);
}

/* ── TOOLS GRID ── */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
}
.tool-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  text-decoration: none;
  color: inherit;
  transition: transform 0.15s, box-shadow 0.15s, border-color 0.15s;
  display: flex; flex-direction: column;
}
.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.07);
  border-color: var(--indigo-light);
}
.tool-card.featured {
  border-color: var(--indigo-light);
  background: var(--indigo-faint);
}

.tool-card-top {
  display: flex; align-items: flex-start;
  justify-content: space-between; gap: 1rem;
  margin-bottom: 0.75rem;
}
.tool-icon {
  width: 40px; height: 40px;
  background: var(--indigo-faint);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.25rem; flex-shrink: 0;
}
.tool-card.featured .tool-icon { background: rgba(79,70,229,0.15); }
.tool-badge {
  display: inline-block;
  background: var(--gold-light);
  color: #92400e;
  font-size: 0.68rem; font-weight: 600;
  letter-spacing: 0.04em; text-transform: uppercase;
  padding: 0.2rem 0.5rem; border-radius: 4px;
  white-space: nowrap;
}
.tool-card h3 {
  font-size: 0.95rem; font-weight: 600;
  margin-bottom: 0.35rem;
  color: var(--slate);
  line-height: 1.3;
}
.tool-card p {
  font-size: 0.83rem; color: var(--slate-mid);
  line-height: 1.55; flex: 1;
}
.tool-arrow {
  display: inline-flex; align-items: center; gap: 0.25rem;
  margin-top: 1rem;
  font-size: 0.78rem; font-weight: 600;
  color: var(--indigo);
}

/* ── WHY SECTION ── */
.why-section {
  background: var(--slate);
  padding: 5rem 2rem;
}
.why-inner {
  max-width: 1100px; margin: 0 auto;
  display: grid; grid-template-columns: 1fr 1fr; gap: 4rem;
  align-items: center;
}
.why-text .section-label { color: var(--indigo-light); }
.why-text h2 {
  font-family: 'Sora', sans-serif;
  font-size: 2rem; font-weight: 700;
  line-height: 1.2; letter-spacing: -0.02em;
  color: var(--white);
  margin-bottom: 1.25rem;
}
.why-text h2 span { color: var(--indigo-light); }
.why-text p { color: rgba(255,255,255,0.55); margin-bottom: 1rem; font-size: 0.9rem; }

.why-list { list-style: none; display: flex; flex-direction: column; gap: 0.875rem; margin-top: 1.5rem; }
.why-list li {
  display: flex; gap: 0.75rem; align-items: flex-start;
  font-size: 0.88rem; color: rgba(255,255,255,0.7);
}
.why-list li .check {
  flex-shrink: 0;
  width: 20px; height: 20px;
  background: var(--indigo);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.65rem; color: white;
  margin-top: 1px;
}

.why-cards {
  display: grid; grid-template-columns: 1fr 1fr; gap: 1rem;
}
.why-card {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 12px;
  padding: 1.5rem; text-align: center;
}
.why-card.wide { grid-column: 1 / -1; background: var(--indigo); border-color: var(--indigo); }
.why-card-num {
  font-family: 'Sora', sans-serif;
  font-size: 2.25rem; font-weight: 700;
  color: var(--white);
  letter-spacing: -0.03em;
}
.why-card-label { font-size: 0.78rem; color: rgba(255,255,255,0.5); margin-top: 0.25rem; }
.why-card.wide .why-card-label { color: rgba(255,255,255,0.7); }

/* ── BLOG GRID ── */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}
.blog-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  text-decoration: none; color: inherit;
  transition: transform 0.15s, box-shadow 0.15s;
  display: flex; flex-direction: column;
}
.blog-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,0.07); }
.blog-tag {
  display: inline-block;
  background: var(--green-light);
  color: #065f46;
  font-size: 0.68rem; font-weight: 600;
  letter-spacing: 0.04em; text-transform: uppercase;
  padding: 0.2rem 0.5rem; border-radius: 4px;
  margin-bottom: 0.75rem;
}
.blog-card h3 {
  font-size: 0.95rem; font-weight: 600;
  color: var(--slate); line-height: 1.4;
  margin-bottom: 0.4rem; flex: 1;
}
.blog-card p { font-size: 0.82rem; color: var(--slate-mid); line-height: 1.55; }
.blog-meta { font-size: 0.75rem; color: var(--slate-light); margin-top: 1rem; }

/* ── FOOTER ── */
footer {
  background: var(--slate);
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: 2.5rem 2rem;
}
.footer-inner {
  max-width: 1100px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 1rem;
}
.footer-logo {
  font-family: 'Sora', sans-serif;
  font-size: 1rem; font-weight: 700;
  color: var(--white); text-decoration: none;
  letter-spacing: -0.02em;
}
.footer-logo span { color: var(--indigo-light); }
.footer-links { display: flex; gap: 1.5rem; flex-wrap: wrap; }
.footer-links a {
  font-size: 0.83rem; color: rgba(255,255,255,0.45);
  text-decoration: none; transition: color 0.15s;
}
.footer-links a:hover { color: rgba(255,255,255,0.8); }
.footer-copy { font-size: 0.75rem; color: rgba(255,255,255,0.3); }

/* ── TOOL PAGE ── */
.tool-page {
  max-width: 780px; margin: 0 auto;
  padding: 3rem 2rem 5rem;
}
.tool-page-header { margin-bottom: 2rem; }
.tool-page-header h1 {
  font-family: 'Sora', sans-serif;
  font-size: 1.75rem; font-weight: 700;
  letter-spacing: -0.02em; color: var(--slate);
  margin-bottom: 0.4rem;
}
.tool-page-header p { color: var(--slate-mid); font-size: 0.9rem; }

.calc-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  margin-bottom: 2rem;
}

.form-group { margin-bottom: 1.25rem; }
.form-group label {
  display: block;
  font-size: 0.83rem; font-weight: 500;
  color: var(--slate); margin-bottom: 0.4rem;
}
.form-group input,
.form-group select {
  width: 100%;
  padding: 0.625rem 0.875rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.9rem; font-family: 'Inter', sans-serif;
  color: var(--slate);
  background: var(--white);
  transition: border-color 0.15s, box-shadow 0.15s;
  outline: none;
}
.form-group input:focus,
.form-group select:focus {
  border-color: var(--indigo-light);
  box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
}

.calc-btn {
  width: 100%;
  padding: 0.875rem;
  background: var(--indigo);
  color: white;
  border: none; border-radius: 8px;
  font-size: 0.95rem; font-weight: 600;
  font-family: 'Inter', sans-serif;
  cursor: pointer;
  transition: background 0.15s, transform 0.15s;
  margin-top: 0.5rem;
}
.calc-btn:hover { background: var(--indigo-dark); transform: translateY(-1px); }

.result-box {
  display: none;
  background: var(--indigo-faint);
  border: 1px solid var(--indigo-light);
  border-radius: 12px;
  padding: 1.5rem;
  margin-top: 1.5rem;
  text-align: center;
}
.result-box.show { display: block; }
.result-num {
  font-family: 'Sora', sans-serif;
  font-size: 2.5rem; font-weight: 700;
  color: var(--indigo);
  letter-spacing: -0.03em;
}
.result-label { font-size: 0.85rem; color: var(--slate-mid); margin-top: 0.25rem; }
.result-detail { font-size: 0.83rem; color: var(--slate-mid); margin-top: 1rem; line-height: 1.6; }

.explainer h2 {
  font-family: 'Sora', sans-serif;
  font-size: 1.25rem; font-weight: 700;
  color: var(--slate); margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}
.explainer p { font-size: 0.88rem; color: var(--slate-mid); line-height: 1.7; margin-bottom: 1rem; }

/* ── RESPONSIVE ── */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }

  .nav-links.open {
    display: flex; flex-direction: column;
    position: absolute;
    top: 60px; left: 0; right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 0 1rem;
    gap: 0; z-index: 199;
    max-height: calc(100vh - 60px);
    overflow-y: auto;
    height: auto; align-items: stretch;
  }
  .nav-links > li {
    height: auto; flex-direction: column;
    align-items: stretch;
    border-bottom: 1px solid var(--border);
  }
  .nav-links > li:last-child { border-bottom: none; }
  .nav-links > li > a,
  .nav-links > li > button {
    padding: 0.875rem 1.5rem;
    font-size: 1rem; height: auto;
    justify-content: space-between; width: 100%;
  }
  .nav-dropdown {
    position: static; box-shadow: none;
    border: none; border-radius: 0;
    border-top: 1px solid var(--border);
    padding: 0; background: var(--slate-faint);
    white-space: normal; min-width: unset; width: 100%;
  }
  .nav-has-dropdown:nth-child(1) .nav-dropdown,
  .nav-has-dropdown:nth-child(2) .nav-dropdown { left: auto; right: auto; }
  .nav-links > li.open .nav-dropdown { display: block; }
  .nav-dropdown-label { padding: 0.625rem 1.5rem 0.25rem; }
  .nav-dropdown a { padding: 0.6rem 2rem; font-size: 0.9rem; white-space: normal; }
  .nav-dropdown-section + .nav-dropdown-section { border-top: 1px solid var(--border); }

  .why-inner { grid-template-columns: 1fr; }
  .why-cards { grid-template-columns: 1fr 1fr; }
  .stats-bar { gap: 2rem; }
  .footer-inner { flex-direction: column; gap: 1.25rem; }
}