:root {
  --bg-main: #0b0f1a;
  --bg-card: #111827;
  --text-main: #f9fafb;
  --text-muted: #cbd5f5;
  --accent: #6366f1;
  --accent-2: #22d3ee;
  --card-hover-glow: rgba(99, 102, 241, 0.15);
}

/* GLOBAL */
body {
  background:
    radial-gradient(1100px 600px at 15% -10%, #1e3a8a 0%, transparent 60%),
    radial-gradient(900px 600px at 90% 5%, #0891b2 0%, transparent 55%),
    var(--bg-main);
  color: var(--text-main);
  line-height: 1.75;
  font-size: 1.05rem;
}

/* NAV */
.tech-nav {
  background: rgba(11,15,26,0.9);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255,255,255,0.1);
  box-shadow: 0 4px 24px rgba(0,0,0,0.3);
}

.brand-accent {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

/* LINKS */
.tech-link {
  color: var(--text-muted) !important;
  font-weight: 500;
  transition: color 0.3s ease;
}

.tech-link:hover {
  color: #ffffff !important;
}

/* SPACING */
.py-6 {
  padding-top: 4rem !important;
  padding-bottom: 4rem !important;
}

.hero-section {
  padding-top: 5rem !important;
  padding-bottom: 5rem !important;
}

.content-section {
  padding-top: 3rem !important;
  padding-bottom: 3rem !important;
}

/* CARDS */
.tech-card {
  background: linear-gradient(135deg, rgba(17, 24, 39, 0.95), rgba(15, 23, 42, 0.9));
  border-radius: 24px;
  border: 1px solid rgba(255,255,255,0.1);
  box-shadow:
    0 30px 60px rgba(0,0,0,0.5),
    inset 0 1px 0 rgba(255,255,255,0.05);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.tech-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at top right, rgba(99, 102, 241, 0.08), transparent 50%);
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

.tech-card:hover {
  transform: translateY(-2px);
  box-shadow:
    0 40px 80px rgba(0,0,0,0.6),
    0 0 0 1px rgba(99, 102, 241, 0.2),
    inset 0 1px 0 rgba(255,255,255,0.08);
}

.tech-card:hover::before {
  opacity: 1;
}

.hero-card {
  background: linear-gradient(135deg, rgba(17, 24, 39, 0.98), rgba(15, 23, 42, 0.95));
}

.sidebar-card {
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.9), rgba(17, 24, 39, 0.85));
}

/* TYPOGRAPHY */
.hero-title {
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: #ffffff;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, #ffffff 0%, #e0e7ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-lead {
  font-size: 1.25rem;
  line-height: 1.7;
  color: var(--text-muted);
  font-weight: 400;
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #ffffff;
  line-height: 1.25;
}

.section-text {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--text-muted);
}

.sidebar-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

.sidebar-text {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text-muted);
  margin-bottom: 0;
}

.sidebar-divider {
  border-color: rgba(255,255,255,0.12);
  margin: 1.75rem 0;
  opacity: 1;
}

.card-body p,
.card-body li {
  color: var(--text-muted);
}

.card-body h1,
.card-body h2,
.card-body h5 {
  color: #ffffff;
}

/* BUTTONS */
.btn {
  font-weight: 600;
  padding: 0.75rem 2rem;
  border-radius: 12px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  letter-spacing: 0.01em;
}

.btn-lg {
  padding: 1rem 2.5rem;
  font-size: 1.05rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border: none;
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(99, 102, 241, 0.4);
}

.btn-outline-light {
  border: 2px solid rgba(255,255,255,0.3);
  color: #ffffff;
  background: transparent;
}

.btn-outline-light:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.5);
  transform: translateY(-2px);
}

/* BADGES */
.tech-badge {
  background: rgba(99,102,241,0.15);
  color: #e0e7ff;
  border: 1px solid rgba(99,102,241,0.35);
  padding: 0.5rem 1rem;
  margin-right: 0.5rem;
  margin-bottom: 0.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: 8px;
  transition: all 0.3s ease;
}

.tech-badge:hover {
  background: rgba(99,102,241,0.25);
  border-color: rgba(99,102,241,0.5);
  transform: translateY(-1px);
}

/* LISTS */
.mistakes-list li,
.criteria-list li {
  margin-bottom: 1rem;
  padding-left: 0.5rem;
  font-size: 1.05rem;
  line-height: 1.7;
}

.criteria-list strong {
  color: var(--accent-2);
  font-weight: 700;
}

/* HR */
hr {
  border-color: rgba(255,255,255,0.15);
  margin: 2rem 0;
}

/* ACCORDION */
.accordion {
  background: transparent;
}

.accordion-item {
  background: linear-gradient(135deg, rgba(17, 24, 39, 0.6), rgba(15, 23, 42, 0.5));
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 16px;
  margin-bottom: 1rem;
  overflow: hidden;
  transition: all 0.3s ease;
}

.accordion-item:hover {
  border-color: rgba(99, 102, 241, 0.3);
}

.accordion-button {
  background: transparent;
  color: #ffffff;
  font-weight: 700;
  font-size: 1.1rem;
  padding: 1.25rem 1.5rem;
  box-shadow: none;
  transition: all 0.3s ease;
}

.accordion-button::after {
  filter: invert(1);
}

.accordion-button:hover {
  background: rgba(99,102,241,0.1);
}

.accordion-button:not(.collapsed) {
  background: rgba(99,102,241,0.2);
  color: #ffffff;
  box-shadow: inset 0 -1px 0 rgba(255,255,255,0.1);
}

.accordion-body {
  background: rgba(15,23,42,0.5);
  color: var(--text-muted);
  padding: 1.25rem 1.5rem;
  border-top: 1px solid rgba(255,255,255,0.08);
  font-size: 1.05rem;
  line-height: 1.7;
}

.accordion-button:focus {
  box-shadow: none;
  border-color: rgba(99, 102, 241, 0.3);
}

/* FOOTER */
.tech-footer {
  margin-top: 100px;
  padding: 40px 0;
  color: var(--text-muted);
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.95rem;
}

/* CONTACT FORM */
.contact-form {
  max-width: 700px;
  margin: 2rem auto 0;
  text-align: left;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent-2);
  margin-bottom: 0.5rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.form-input {
  width: 100%;
  padding: 1rem 1.25rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 12px;
  transition: all 0.3s ease;
  outline: none;
}

.form-input:focus {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.15);
}

.form-input::placeholder {
  color: rgba(203, 213, 245, 0.5);
}

.form-textarea {
  resize: vertical;
  min-height: 150px;
  line-height: 1.7;
}

.submit-btn {
  width: 100%;
  padding: 1.1rem 2rem;
  font-size: 1rem;
  font-weight: 700;
  font-family: inherit;
  color: #0b0f1a;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  margin-top: 0.5rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.submit-btn:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(99, 102, 241, 0.4);
}

.submit-btn:active:not(:disabled) {
  transform: translateY(0);
}

.submit-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.spinner {
  display: inline-block;
  width: 14px;
  height: 14px;
  border: 2px solid rgba(11, 15, 26, 0.3);
  border-top-color: #0b0f1a;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.form-status {
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  border-radius: 12px;
  font-size: 0.95rem;
  display: none;
  text-align: center;
  font-weight: 500;
}

.form-status.success {
  background: rgba(34, 197, 94, 0.15);
  color: #4ade80;
  border: 1px solid rgba(34, 197, 94, 0.3);
}

.form-status.error {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

/* RESPONSIVE */
@media (max-width: 768px) {
  .hero-section {
    padding-top: 3rem !important;
    padding-bottom: 3rem !important;
  }

  .content-section {
    padding-top: 2rem !important;
    padding-bottom: 2rem !important;
  }

  .tech-card {
    border-radius: 20px;
  }

  .card-body {
    padding: 2rem !important;
  }

  .btn-lg {
    padding: 0.85rem 2rem;
    font-size: 1rem;
  }

  .contact-form {
    max-width: 100%;
  }

  .form-input {
    font-size: 16px; /* Prevents iOS zoom */
  }

  .accordion-button {
    font-size: 1rem;
    padding: 1rem 1.25rem;
  }

  .accordion-body {
    padding: 1rem 1.25rem;
    font-size: 1rem;
  }
}

@media (max-width: 576px) {
  .btn {
    width: 100%;
    margin-bottom: 0.75rem;
  }

  .btn.me-3 {
    margin-right: 0 !important;
  }

  .tech-badge {
    font-size: 0.8rem;
    padding: 0.4rem 0.8rem;
  }
}