/* Custom Styles for AI Instructor Profile Website */

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Body Base Styles */
body {
    font-family: 'Noto Sans KR', 'Inter', sans-serif;
    line-height: 1.6;
    color: #1f2937;
}

/* Fade-in Animation */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Navigation Scrolled State */
#navbar.scrolled {
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

/* Custom Gradient Text */
.gradient-text {
    background: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Hover Effects for Cards */
.card-hover {
    transition: all 0.3s ease;
}

.card-hover:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* Custom Button Styles */
.btn-primary {
    background: linear-gradient(135deg, #2563eb 0%, #4f46e5 100%);
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #1d4ed8 0%, #4338ca 100%);
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(37, 99, 235, 0.4);
}

/* Section Spacing */
section {
    position: relative;
}

/* Navigation Link Active State */
.nav-link {
    position: relative;
    padding-bottom: 4px;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #2563eb, #4f46e5);
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Stats Counter Animation */
@keyframes countUp {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.stat-number {
    animation: countUp 0.8s ease-out;
}

/* Back to Top Button */
#back-to-top {
    transition: all 0.3s ease;
}

#back-to-top.show {
    opacity: 1;
    pointer-events: auto;
}

#back-to-top:hover {
    transform: translateY(-4px);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, #2563eb 0%, #4f46e5 100%);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, #1d4ed8 0%, #4338ca 100%);
}

/* Loading Animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* Responsive Typography */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    h3 {
        font-size: 1.5rem;
    }
}

/* Mobile Menu Transition */
#mobile-menu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

#mobile-menu.open {
    max-height: 500px;
}

/* Icon Animations */
.icon-float {
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

/* Award Badge Glow */
.award-glow {
    box-shadow: 0 0 20px rgba(251, 191, 36, 0.3);
}

/* Link Underline Animation */
.link-underline {
    position: relative;
    text-decoration: none;
}

.link-underline::before {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, #2563eb, #4f46e5);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform 0.3s ease;
}

.link-underline:hover::before {
    transform: scaleX(1);
    transform-origin: left;
}

/* Section Divider */
.section-divider {
    height: 2px;
    background: linear-gradient(90deg, transparent, #2563eb, transparent);
    margin: 4rem auto;
    max-width: 200px;
}

/* Card Shine Effect */
.card-shine {
    position: relative;
    overflow: hidden;
}

.card-shine::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.card-shine:hover::before {
    left: 100%;
}

/* Print Styles */
@media print {
    nav, footer, #back-to-top {
        display: none;
    }
    
    section {
        page-break-inside: avoid;
    }
}

/* Focus Styles for Accessibility */
a:focus,
button:focus {
    outline: 3px solid #93c5fd;
    outline-offset: 2px;
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    .text-gray-600 {
        color: #000;
    }
    
    .bg-blue-50 {
        background-color: #fff;
        border: 2px solid #2563eb;
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Dark Mode Support (Future Enhancement) */
@media (prefers-color-scheme: dark) {
    /* Dark mode styles can be added here if needed */
}

/* Selection Color */
::selection {
    background: #93c5fd;
    color: #1e3a8a;
}

::-moz-selection {
    background: #93c5fd;
    color: #1e3a8a;
}

/* Loading State */
.loading {
    pointer-events: none;
    opacity: 0.6;
}

/* Success State */
.success-message {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
    padding: 1rem;
    border-radius: 0.5rem;
    margin: 1rem 0;
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        transform: translateY(-20px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Tooltip Styles */
.tooltip {
    position: relative;
}

.tooltip::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(-8px);
    padding: 0.5rem 1rem;
    background: #1f2937;
    color: white;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.tooltip:hover::after {
    opacity: 1;
}