html { 
    scroll-behavior: smooth; 
    color-scheme: light dark; /* Support both light and dark modes */
}

body { 
    font-family: 'Be Vietnam Pro', sans-serif; 
    background-color: #f8fafc;
    color: #1e293b;
    transition: background-color 0.3s, color 0.3s;
}

body.dark-mode {
    background-color: #0f172a;
    color: #e2e8f0;
}

/* Dark mode specific styles */
body.dark-mode .bg-white,
body.dark-mode .bg-slate-50 {
    background-color: #1e293b !important;
    color: #e2e8f0;
}

body.dark-mode .text-slate-800 {
    color: #e2e8f0 !important;
}

body.dark-mode header {
    background-color: #1e293b !important;
}

body.dark-mode header .text-slate-800 {
    color: #ffffff !important;
}

body.dark-mode .hero-space {
    background-image: url('./anh.jpg');
    filter: brightness(0.7);
}

body.dark-mode .nav-link {
    color: #94a3b8 !important;
}

body.dark-mode .nav-link:hover {
    color: #e2e8f0 !important;
}

body.dark-mode .text-indigo-100 {
    color: #a5b4fc !important; /* Lighter indigo color for better readability */
}

#dark-mode-toggle {
    position: fixed;
    bottom: 5px;
    left: 5px;
    z-index: 50;
    background-color: #4f46e5;
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.2s, background-color 0.3s;
}

#dark-mode-toggle:hover {
    transform: scale(1.1);
    background-color: #6366f1;
}

#dark-mode-toggle i {
    font-size: 1.5rem;
}

.hidden { display: none !important; }

.interactive-element {
    transition: transform 0.2s ease-out, box-shadow 0.2s ease-out;
}

.interactive-element:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(79, 70, 229, 0.2);
}

.interactive-element:active {
    transform: translateY(0px) scale(0.98);
}

@keyframes card-fade-in {
    from { opacity: 0; transform: translateY(25px) scale(0.98); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.card-animate {
    animation: card-fade-in 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}

@keyframes fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
}

.animate-fade-in {
    animation: fade-in 0.3s ease-out forwards;
}

.hero-space {
    background-image: url('./anh.jpg');
    background-size: cover;  /* Phủ kín toàn bộ background */
    background-position: center; /* Căn giữa ảnh */
    background-repeat: no-repeat; /* Không lặp lại ảnh */
    position: relative;
    overflow: hidden;
}

.stars {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    overflow: hidden; pointer-events: none;
}

.star {
    position: absolute; background: white; border-radius: 50%;
    box-shadow: 0 0 10px 2px rgba(255, 255, 255, 0.8);
    animation: shooting-star 5s linear infinite;
}

@keyframes shooting-star {
    from { transform: translate(0, 0); opacity: 1; }
    to { transform: translate(100vw, 100vh); opacity: 0; }
}

@keyframes snowfall {
    0% {
        transform: translateY(-100%) rotate(0deg) translateX(0);
        opacity: 0.7;
    }
    50% {
        transform: translateY(50vh) rotate(180deg) translateX(20px);
        opacity: 0.9;
    }
    100% {
        transform: translateY(100vh) rotate(360deg) translateX(40px);
        opacity: 0.5;
    }
}

.snowflake {
    position: fixed;
    pointer-events: none;
    z-index: 9999;
    background: white;
    border-radius: 50%;
    box-shadow: 0 0 5px rgba(255,255,255,0.8);
    animation: snowfall linear forwards;
    will-change: transform, opacity;
}

.snowflake-text {
    position: absolute;
    color: white;
    text-shadow: 0 0 5px rgba(255,255,255,0.8);
    opacity: 0;
    animation: text-snow 20s linear forwards;
}

@keyframes text-snow {
    0%, 90% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: #f1f5f9; }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: #94a3b8; }

.nav-link.active {
    color: #4f46e5;
    font-weight: 700;
}

.nav-dropdown-link.active {
    background-color: #eef2ff;
    color: #4338ca;
    font-weight: 600;
}

#contact-sidebar {
    position: fixed;
    right: 15px;
    top: 65px;
    width: 200px;
    height: auto;
    transition: all 0.3s ease-in-out;
    opacity: 0; /* Completely transparent */
    visibility: hidden; /* Completely hidden */
    transform: translateX(100%) scale(0.9); /* Move off-screen and slightly scaled down */
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    padding: 10px;
    background-color: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    z-index: 50;
    border-radius: 8px;
}

#contact-sidebar.show {
    opacity: 1; /* Fully visible */
    visibility: visible; /* Make visible */
    transform: translateX(0) scale(1); /* Move to original position and full size */
}

#contact-toggle-btn {
    position: fixed;
    top: 15px;
    right: 15px;
    z-index: 60;
    cursor: pointer;
    background-color: rgba(255,255,255,0.8);
    border-radius: 6px;
    padding: 6px;
    transition: background-color 0.3s ease;
}

#contact-toggle-btn:hover {
    background-color: rgba(255,255,255,1);
}

#contact-toggle-btn .hamburger-icon {
    display: flex;
    flex-direction: column;
    width: 20px;
    height: 14px;
    justify-content: space-between;
}

#contact-toggle-btn .hamburger-icon span {
    width: 100%;
    height: 2px;
    background-color: #333;
    transition: all 0.3s ease;
}