/* ===== Oral Course — Design System ===== */
/* Inspired by Hello AI: Swiss precision + Glassmorphism */

:root {
    --med-teal: #0d9488;
    --med-blue: #2563eb;
    --med-gradient: linear-gradient(135deg, #0d9488 0%, #2563eb 100%);
    --ink-900: #0f172a;
    --ink-200: #e2e8f0;
    --ink-100: #f1f5f9;
    --radius: 14px;
    --transition: 0.25s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* --- Glass Navigation --- */
.nav-glass {
    background: rgba(255, 255, 255, 0.82);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border-bottom: 1px solid rgba(226, 232, 240, 0.6);
    box-shadow: 0 1px 2px rgba(0,0,0,0.03), 0 4px 16px rgba(0,0,0,0.01);
}

/* --- Navigation Pills --- */
.nav-pill {
    padding: 7px 16px;
    font-size: 13px;
    font-weight: 500;
    color: #64748b;
    border-radius: 50px;
    transition: all 0.2s ease;
    letter-spacing: -0.005em;
}
.nav-pill:hover { color: #1e293b; background: rgba(0,0,0,0.04); }
.nav-pill.active {
    color: #fff;
    background: #1e293b;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(30,41,59,0.2);
}

/* --- Glass Cards --- */
.glass-card {
    background: rgba(255, 255, 255, 0.88);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(226, 232, 240, 0.7);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: all var(--transition);
    box-shadow: 0 1px 3px 0 rgba(0,0,0,0.02);
}
.glass-card:hover {
    border-color: rgba(13, 148, 136, 0.15);
    box-shadow: 0 10px 30px -5px rgba(0,0,0,0.06);
    transform: translateY(-2px);
}

/* --- Badges --- */
.badge {
    display: inline-flex; align-items: center; padding: 3px 10px;
    font-size: 11px; font-weight: 600; border-radius: 6px;
    letter-spacing: 0.02em; border: 1px solid transparent;
}
.badge-beginner { background: #ecfdf5; color: #059669; border-color: #d1fae5; }
.badge-intermediate { background: #eff6ff; color: #2563eb; border-color: #dbeafe; }
.badge-advanced { background: #fef3c7; color: #d97706; border-color: #fde68a; }

/* --- Buttons --- */
.btn-primary {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    padding: 10px 24px; background: var(--med-gradient); color: white;
    border-radius: 10px; font-size: 14px; font-weight: 600;
    transition: all 0.25s; border: none; cursor: pointer;
    box-shadow: 0 2px 8px rgba(13,148,136,0.2);
}
.btn-primary:hover {
    box-shadow: 0 8px 20px rgba(13,148,136,0.3);
    transform: translateY(-1px);
}

.btn-secondary {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    padding: 10px 24px; background: white; color: #334155;
    border-radius: 10px; font-size: 14px; font-weight: 600;
    transition: all 0.25s; border: 1px solid #e2e8f0; cursor: pointer;
}
.btn-secondary:hover { border-color: rgba(13,148,136,0.3); color: #0d9488; background: #f8fafc; }

/* --- Input --- */
.input-field {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    font-size: 14px;
    color: #1e293b;
    background: white;
    transition: all 0.2s;
    outline: none;
}
.input-field:focus {
    border-color: #0d9488;
    box-shadow: 0 0 0 3px rgba(13,148,136,0.1);
}
.input-field::placeholder { color: #94a3b8; }

/* --- Progress --- */
.progress-track { height: 4px; background: #e2e8f0; border-radius: 4px; overflow: hidden; }
.progress-fill {
    height: 100%; background: var(--med-gradient);
    border-radius: 4px; transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Stat Number --- */
.stat-num {
    font-variant-numeric: tabular-nums;
    font-weight: 600;
    letter-spacing: -0.02em;
}

/* --- Grid Dots --- */
.grid-dots {
    background-image: radial-gradient(circle, #cbd5e1 0.8px, transparent 0.8px);
    background-size: 24px 24px;
}

/* --- Gradient Shimmer --- */
@keyframes gradientShimmer {
    0%   { background-position: 0% 50%; }
    50%  { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}
.gradient-shimmer {
    background: linear-gradient(270deg, #0d9488, #2563eb, #6366f1, #0d9488);
    background-size: 300% 300%;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: gradientShimmer 6s ease infinite;
}

/* --- Floating Orb --- */
@keyframes floatOrb {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25%      { transform: translate(30px, -20px) scale(1.05); }
    50%      { transform: translate(-15px, 15px) scale(0.95); }
    75%      { transform: translate(20px, 10px) scale(1.02); }
}
.float-orb { animation: floatOrb 20s ease-in-out infinite; }
.float-orb-slow { animation: floatOrb 28s ease-in-out infinite reverse; }

/* --- Card Enter Animation --- */
@keyframes cardEnter {
    0%   { opacity: 0; transform: translateY(24px) scale(0.97); }
    100% { opacity: 1; transform: translateY(0) scale(1); }
}
.card-stagger { animation: cardEnter 0.5s cubic-bezier(0.25, 0.8, 0.25, 1) both; }

/* --- Path Row --- */
.path-row {
    position: relative; background: white; border-radius: 14px;
    transition: all 0.35s cubic-bezier(0.25, 0.8, 0.25, 1);
    text-decoration: none;
}
.path-row::before {
    content: ''; position: absolute; inset: 0; border-radius: 14px; padding: 1.5px;
    background: linear-gradient(135deg, transparent, transparent);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor; mask-composite: exclude;
    opacity: 0; transition: all 0.35s ease;
}
.path-row:hover::before { opacity: 1; }
.path-row.path-blue:hover::before {
    background: linear-gradient(135deg, #93c5fd, #2563eb, #3b82f6, #93c5fd);
    background-size: 300% 300%; animation: gradientShimmer 3s ease infinite;
}
.path-row.path-purple:hover::before {
    background: linear-gradient(135deg, #c4b5fd, #7c3aed, #8b5cf6, #c4b5fd);
    background-size: 300% 300%; animation: gradientShimmer 3s ease infinite;
}
.path-row.path-emerald:hover::before {
    background: linear-gradient(135deg, #6ee7b7, #10b981, #34d399, #6ee7b7);
    background-size: 300% 300%; animation: gradientShimmer 3s ease infinite;
}
.path-row:hover {
    box-shadow: 0 4px 24px -6px rgba(0,0,0,0.08);
    transform: translateY(-1px);
}

/* --- Flashcard --- */
.perspective-container { /* container */ }
.flashcard {
    position: relative;
}
.flashcard-face {
    transition: opacity 0.35s ease;
}
.flashcard-front {
    display: block;
    opacity: 1;
}
.flashcard-back {
    position: absolute; inset: 0;
    opacity: 0;
    pointer-events: none;
    background: white;
    border-radius: var(--radius);
    overflow-y: auto;
}
.flashcard.flipped .flashcard-front {
    opacity: 0;
    pointer-events: none;
}
.flashcard.flipped .flashcard-back {
    opacity: 1;
    pointer-events: auto;
}

/* --- Keyboard Hint --- */
.kbd {
    display: inline-block;
    padding: 2px 6px;
    font-size: 11px;
    font-family: inherit;
    background: #f1f5f9;
    border: 1px solid #e2e8f0;
    border-radius: 4px;
    box-shadow: 0 1px 0 #e2e8f0;
}

/* --- Selection --- */
::selection { background: rgba(13,148,136,0.15); color: #0f172a; }
:focus-visible { outline: 2px solid #0d9488; outline-offset: 2px; border-radius: 4px; }

/* --- Mobile --- */
@media (max-width: 767px) {
    .glass-card { max-width: 100%; }
}

html, body { overflow-x: hidden; }