/* ── Studies page ────────────────────────────────────────────────── */

.studies-hero-actions {
  margin-top: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

.studies-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.platform-card {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding: 1.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: 0 20px 70px rgba(0,0,0,.18);
  position: relative;
  overflow: hidden;
  transition: border-color .25s ease;
}

.platform-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top right, rgba(59,130,246,.14), transparent 55%);
  opacity: 0;
  transition: opacity .25s ease;
}

.platform-card:hover {
  border-color: rgba(59,130,246,.35);
}

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

.platform-card > * {
  position: relative;
}

.platform-header {
  display: flex;
  align-items: center;
  gap: .75rem;
}

.platform-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--blue), var(--cyan));
  font-size: 1.1rem;
  flex-shrink: 0;
}

.platform-header h2 {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.platform-desc {
  margin: 0;
  font-size: .875rem;
  color: var(--muted);
  line-height: 1.65;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1rem;
}

.course-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: .55rem;
}

.course-group-label {
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--cyan);
  padding: .2rem 0 .1rem;
  margin-top: .2rem;
}

.course-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: start;
  gap: .6rem;
  font-size: .875rem;
  line-height: 1.5;
}

.course-check {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid var(--border);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: .05rem;
  font-size: .65rem;
  transition: background .2s ease, border-color .2s ease;
}

.course-item.done .course-check {
  background: #22c55e;
  border-color: #22c55e;
  color: white;
}

.course-item.done .course-check::after {
  content: "✓";
}

.course-item.active .course-check {
  background: linear-gradient(135deg, var(--blue), var(--cyan));
  border-color: var(--blue);
  color: white;
}

.course-item.active .course-check::after {
  content: ">";
  font-size: .55rem;
}

.course-item.pending .course-check {
  background: transparent;
  border-color: rgba(255,255,255,.2);
}

.course-name {
  color: var(--text);
}

.course-item.done .course-name {
  color: var(--muted);
  text-decoration: line-through;
  text-decoration-color: rgba(148,163,184,.4);
}

.course-badge {
  font-size: .7rem;
  font-weight: 600;
  padding: .15rem .55rem;
  border-radius: 999px;
  white-space: nowrap;
  letter-spacing: .03em;
  text-transform: uppercase;
}

.badge-done {
  background: rgba(34,197,94,.15);
  color: #4ade80;
  border: 1px solid rgba(34,197,94,.25);
}

.badge-active {
  background: rgba(59,130,246,.15);
  color: #60a5fa;
  border: 1px solid rgba(59,130,246,.3);
}

.badge-pending {
  background: rgba(255,255,255,.05);
  color: var(--muted);
  border: 1px solid var(--border);
}

.studies-legend {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: .4rem;
  font-size: .8rem;
  color: var(--muted);
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.legend-dot.done  { background: #22c55e; }
.legend-dot.active { background: var(--blue); }
.legend-dot.pending { background: rgba(255,255,255,.2); border: 1px solid rgba(255,255,255,.25); }

.course-link {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px dashed rgba(96,165,250,.45);
}

.course-link:hover {
  color: #93c5fd;
  border-bottom-color: rgba(147,197,253,.8);
}

.platform-actions {
  margin-top: .2rem;
  display: flex;
  flex-wrap: wrap;
  gap: .55rem;
}

.panel-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .5rem .95rem;
  border-radius: 999px;
  border: 1px solid rgba(59,130,246,.35);
  background: rgba(59,130,246,.12);
  color: #93c5fd;
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  text-decoration: none;
  transition: border-color .2s ease, background .2s ease, color .2s ease;
}

.panel-btn:hover {
  border-color: rgba(147,197,253,.65);
  background: rgba(59,130,246,.2);
  color: #dbeafe;
}

@media (max-width: 720px) {
  .studies-grid {
    grid-template-columns: 1fr;
  }
}

/* Single course card layout */
.studies-single-card {
  display: flex;
  justify-content: center;
}

.course-card {
  width: min(780px, 100%);
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: 0 20px 70px rgba(0, 0, 0, 0.18);
}

.course-card > span {
  display: inline-flex;
  margin-bottom: 0.75rem;
  font-size: 0.85rem;
  color: var(--muted);
}

.course-card h3 {
  margin: 0 0 1rem;
  font-size: 1.35rem;
}

.course-card p {
  margin: 0.55rem 0;
  line-height: 1.6;
}

.course-card a {
  color: #93c5fd;
  text-decoration: none;
  border-bottom: 1px dashed rgba(147, 197, 253, 0.65);
}

.course-card a:hover {
  color: #dbeafe;
  border-bottom-color: #dbeafe;
}

.progress-bar {
  margin: 0.45rem 0 0.85rem;
  height: 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--blue), var(--cyan));
}

.course-note {
  margin-top: 0.9rem;
  padding: 0.85rem 1rem;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.03);
}

.course-note p {
  margin: 0.5rem 0 0;
}

.course-tip {
  margin-top: 1rem;
}

.course-tip label {
  display: inline-block;
  margin-bottom: 0.45rem;
}

.course-tip textarea {
  width: 100%;
  min-height: 90px;
  padding: 0.7rem 0.8rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(12, 20, 33, 0.7);
  color: var(--text);
  font: inherit;
  resize: vertical;
}

.course-tip textarea:focus {
  outline: none;
  border-color: rgba(59, 130, 246, 0.6);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.18);
}

@media (max-width: 720px) {
  .course-card {
    padding: 1.1rem;
  }
}

/* Base course card visual style */
.course-card-base {
  position: relative;
  border: 1px solid rgba(56, 189, 248, 0.35);
  background:
    radial-gradient(circle at 92% 8%, rgba(56, 189, 248, 0.2), transparent 38%),
    radial-gradient(circle at 8% 92%, rgba(34, 197, 94, 0.12), transparent 44%),
    linear-gradient(165deg, rgba(14, 24, 40, 0.96), rgba(8, 14, 24, 0.98));
  box-shadow:
    0 28px 72px rgba(0, 0, 0, 0.36),
    inset 0 1px 0 rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(3px);
}

.course-card-base::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  background: linear-gradient(130deg, rgba(56, 189, 248, 0.16), transparent 46%);
}

.course-card-base > * {
  position: relative;
  z-index: 1;
}

.course-card-base > span {
  padding: 0.32rem 0.7rem;
  border-radius: 999px;
  background: rgba(251, 191, 36, 0.12);
  border: 1px solid rgba(251, 191, 36, 0.32);
  color: #fde68a;
  letter-spacing: 0.02em;
  font-weight: 600;
}

.course-card-base h3 {
  font-size: clamp(1.35rem, 1.9vw, 1.7rem);
  letter-spacing: -0.02em;
}

.course-card-base .progress-bar {
  height: 12px;
  background: rgba(148, 163, 184, 0.2);
}

.course-card-base .progress-fill {
  background: linear-gradient(90deg, #38bdf8, #22c55e);
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.45);
}

.course-card-base .course-note,
.course-card-base .course-tip {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(148, 163, 184, 0.25);
  border-radius: 14px;
  padding: 0.9rem 1rem;
}

.course-card-base .course-tip {
  margin-top: 1.1rem;
}

.course-card-base .course-tip textarea {
  background: rgba(5, 12, 22, 0.72);
}