/* ========================================
   AI Course HK — Style Sheet
   Modern, clean design for HK market
   ======================================== */

/* ---------- Reset & Base ---------- */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}

:root{
    --primary: #4F46E5;
    --primary-light: #6366F1;
    --primary-dark: #3730A3;
    --primary-bg: #EEF2FF;
    --accent: #06B6D4;
    --accent-light: #22D3EE;
    --dark: #0F172A;
    --dark-700: #1E293B;
    --dark-600: #334155;
    --gray-500: #64748B;
    --gray-400: #94A3B8;
    --gray-300: #CBD5E1;
    --gray-200: #E2E8F0;
    --gray-100: #F1F5F9;
    --gray-50: #F8FAFC;
    --white: #FFFFFF;
    --success: #10B981;
    --warning: #F59E0B;
    --radius: 12px;
    --radius-lg: 20px;
    --radius-sm: 8px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,.05);
    --shadow: 0 4px 6px -1px rgba(0,0,0,.07), 0 2px 4px -2px rgba(0,0,0,.05);
    --shadow-md: 0 10px 15px -3px rgba(0,0,0,.08), 0 4px 6px -4px rgba(0,0,0,.05);
    --shadow-lg: 0 20px 25px -5px rgba(0,0,0,.1), 0 8px 10px -6px rgba(0,0,0,.05);
    --shadow-xl: 0 25px 50px -12px rgba(0,0,0,.15);
    --transition: .3s cubic-bezier(.4,0,.2,1);
    --font: 'Noto Sans TC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

html{scroll-behavior:smooth;font-size:16px}
body{font-family:var(--font);color:var(--dark);background:var(--white);line-height:1.7;overflow-x:hidden}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit;transition:var(--transition)}
ul{list-style:none}

/* ---------- Container ---------- */
.container{width:100%;max-width:1200px;margin:0 auto;padding:0 24px}

/* ---------- Buttons ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;padding:12px 28px;border-radius:var(--radius-sm);font-weight:600;font-size:.95rem;cursor:pointer;border:2px solid transparent;transition:var(--transition);font-family:var(--font);letter-spacing:.02em}
.btn-primary{background:var(--primary);color:var(--white);border-color:var(--primary)}
.btn-primary:hover{background:var(--primary-dark);border-color:var(--primary-dark);transform:translateY(-2px);box-shadow:0 8px 20px rgba(79,70,229,.3)}
.btn-outline{background:transparent;color:var(--white);border-color:rgba(255,255,255,.5)}
.btn-outline:hover{background:var(--white);color:var(--primary);border-color:var(--white)}
.btn-lg{padding:16px 36px;font-size:1.05rem}
.btn-full{width:100%}
.btn-nav{padding:10px 22px;font-size:.9rem}

/* ---------- Navbar ---------- */
.navbar{position:fixed;top:0;left:0;right:0;z-index:1000;padding:16px 0;transition:var(--transition)}
.navbar.scrolled{background:rgba(255,255,255,.95);backdrop-filter:blur(12px);box-shadow:var(--shadow);padding:10px 0}
.nav-container{display:flex;align-items:center;justify-content:space-between}

.logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:1.25rem}
.logo-icon{background:var(--primary);color:var(--white);padding:6px 10px;border-radius:var(--radius-sm);font-size:.85rem;font-weight:900;letter-spacing:.05em}
.logo-text{color:var(--white);transition:var(--transition)}
.navbar.scrolled .logo-text{color:var(--dark)}
.logo-hk{color:var(--accent)}

.nav-links{display:flex;align-items:center;gap:32px}
.nav-links a{color:rgba(255,255,255,.85);font-weight:500;font-size:.92rem;position:relative}
.nav-links a:hover{color:var(--white)}
.nav-links a::after{content:'';position:absolute;bottom:-4px;left:0;width:0;height:2px;background:var(--accent);transition:var(--transition)}
.nav-links a:hover::after{width:100%}
.navbar.scrolled .nav-links a{color:var(--dark-600)}
.navbar.scrolled .nav-links a:hover{color:var(--primary)}
.navbar.scrolled .nav-links a::after{background:var(--primary)}
.nav-links .btn-nav{color:var(--white)}
.navbar.scrolled .nav-links .btn-nav{color:var(--white)}

.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:4px}
.nav-toggle span{display:block;width:24px;height:2px;background:var(--white);transition:var(--transition)}
.navbar.scrolled .nav-toggle span{background:var(--dark)}

/* ---------- Hero ---------- */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--dark) 0%,var(--primary-dark) 50%,var(--dark-700) 100%);overflow:hidden;padding:120px 24px 80px}
.hero-particles{position:absolute;inset:0;pointer-events:none}
.hero-content{position:relative;text-align:center;z-index:2;max-width:900px}

.hero-badge{display:inline-block;background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);color:var(--accent-light);padding:8px 20px;border-radius:50px;font-size:.85rem;font-weight:500;margin-bottom:28px;backdrop-filter:blur(4px)}

.hero-title{font-size:clamp(2.2rem,5vw,3.8rem);font-weight:900;color:var(--white);line-height:1.2;margin-bottom:24px}
.hero-title-line{display:block;font-size:.75em;font-weight:600;color:var(--gray-300);margin-bottom:8px}
.hero-title-highlight{background:linear-gradient(135deg,var(--accent-light),var(--primary-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}

.hero-subtitle{font-size:clamp(1rem,2vw,1.2rem);color:var(--gray-300);max-width:680px;margin:0 auto 40px;line-height:1.8}
.hero-subtitle strong{color:var(--white)}

.hero-stats{display:flex;justify-content:center;gap:48px;margin-bottom:48px;flex-wrap:wrap}
.stat-item{text-align:center}
.stat-number{font-size:clamp(2rem,4vw,2.8rem);font-weight:900;color:var(--white);display:inline}
.stat-suffix{font-size:clamp(1.4rem,3vw,2rem);font-weight:700;color:var(--accent-light)}
.stat-label{display:block;font-size:.85rem;color:var(--gray-400);margin-top:4px}

.hero-cta{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}

.hero-scroll{position:absolute;bottom:32px;left:50%;transform:translateX(-50%);text-align:center;color:var(--gray-400);font-size:.8rem;z-index:2}
.scroll-arrow{width:20px;height:20px;border-right:2px solid var(--gray-400);border-bottom:2px solid var(--gray-400);transform:rotate(45deg);margin:8px auto 0;animation:scrollBounce 2s infinite}
@keyframes scrollBounce{0%,100%{transform:rotate(45deg) translate(0,0)}50%{transform:rotate(45deg) translate(5px,5px)}}

/* ---------- Sections ---------- */
.section{padding:100px 0}
.section-header{text-align:center;margin-bottom:60px}
.section-tag{display:inline-block;background:var(--primary-bg);color:var(--primary);padding:6px 16px;border-radius:50px;font-size:.85rem;font-weight:600;margin-bottom:16px}
.section-title{font-size:clamp(1.8rem,3.5vw,2.5rem);font-weight:800;color:var(--dark);margin-bottom:16px;line-height:1.3}
.section-desc{font-size:1.05rem;color:var(--gray-500);max-width:600px;margin:0 auto}

/* ---------- Course Filter ---------- */
.course-filter{display:flex;justify-content:center;gap:10px;margin-bottom:48px;flex-wrap:wrap}
.filter-btn{padding:10px 22px;border:2px solid var(--gray-200);border-radius:50px;background:var(--white);color:var(--gray-500);font-size:.9rem;font-weight:500;cursor:pointer;transition:var(--transition);font-family:var(--font)}
.filter-btn:hover{border-color:var(--primary);color:var(--primary)}
.filter-btn.active{background:var(--primary);color:var(--white);border-color:var(--primary)}

/* ---------- Course Grid ---------- */
.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:28px}

.course-card{position:relative;background:var(--white);border:1px solid var(--gray-200);border-radius:var(--radius-lg);padding:36px 32px 32px;transition:var(--transition);overflow:hidden}
.course-card:hover{border-color:var(--primary-light);box-shadow:var(--shadow-lg);transform:translateY(-4px)}
.course-card.hidden{display:none}

.course-card-featured{border-color:var(--primary-light);background:linear-gradient(135deg,var(--primary-bg) 0%,var(--white) 100%)}
.course-featured-badge{position:absolute;top:20px;right:-28px;background:var(--primary);color:var(--white);padding:4px 40px;font-size:.75rem;font-weight:600;transform:rotate(45deg)}

.course-icon{width:52px;height:52px;color:var(--primary);margin-bottom:20px}
.course-level{display:inline-block;background:var(--gray-100);color:var(--gray-500);padding:4px 12px;border-radius:50px;font-size:.78rem;font-weight:500;margin-bottom:14px}
.course-card h3{font-size:1.2rem;font-weight:700;color:var(--dark);margin-bottom:12px}
.course-card p{color:var(--gray-500);font-size:.92rem;margin-bottom:16px;line-height:1.7}

.course-topics{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:20px}
.course-topics li{background:var(--gray-50);color:var(--dark-600);padding:5px 12px;border-radius:6px;font-size:.8rem;border:1px solid var(--gray-200)}

.course-link{color:var(--primary);font-weight:600;font-size:.9rem;display:inline-flex;align-items:center;gap:4px}
.course-link:hover{color:var(--primary-dark);gap:8px}

/* ---------- Features ---------- */
.features{background:var(--gray-50)}
.features-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:28px}

.feature-card{background:var(--white);border-radius:var(--radius-lg);padding:40px 32px;border:1px solid var(--gray-200);transition:var(--transition)}
.feature-card:hover{border-color:var(--primary-light);box-shadow:var(--shadow-md);transform:translateY(-2px)}
.feature-number{font-size:2.5rem;font-weight:900;color:var(--primary-bg);margin-bottom:16px;line-height:1}
.feature-card:hover .feature-number{color:var(--primary-light)}
.feature-card h3{font-size:1.15rem;font-weight:700;margin-bottom:12px;color:var(--dark)}
.feature-card p{color:var(--gray-500);font-size:.92rem;line-height:1.7}

/* ---------- Trainer ---------- */
.trainer{background:var(--white)}
.trainer-content{display:grid;grid-template-columns:360px 1fr;gap:60px;align-items:center}

.trainer-image{text-align:center}
.trainer-image-wrapper{margin-bottom:24px}
.trainer-photo{width:200px;height:200px;border-radius:50%;object-fit:cover;margin:0 auto;box-shadow:0 20px 40px rgba(79,70,229,.2);border:4px solid var(--primary-bg)}

.trainer-badges{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}
.badge{background:var(--primary-bg);color:var(--primary);padding:6px 14px;border-radius:50px;font-size:.8rem;font-weight:500}

.trainer-info h3{font-size:2rem;font-weight:800;margin-bottom:8px;color:var(--dark)}
.trainer-role{color:var(--primary);font-weight:600;font-size:1rem;margin-bottom:20px}
.trainer-bio{color:var(--gray-500);font-size:.95rem;margin-bottom:16px;line-height:1.8}

.trainer-highlights{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:32px}
.highlight{text-align:center;padding:20px 12px;background:var(--gray-50);border-radius:var(--radius);border:1px solid var(--gray-200)}
.highlight-number{display:block;font-size:1.5rem;font-weight:800;color:var(--primary);margin-bottom:4px}
.highlight-text{font-size:.8rem;color:var(--gray-500)}

/* ---------- FAQ ---------- */
.faq{background:var(--gray-50)}
.faq-list{max-width:800px;margin:0 auto}
.faq-item{background:var(--white);border:1px solid var(--gray-200);border-radius:var(--radius);margin-bottom:12px;overflow:hidden;transition:var(--transition)}
.faq-item[open]{border-color:var(--primary-light);box-shadow:var(--shadow)}
.faq-question{padding:20px 24px;font-weight:600;font-size:1rem;cursor:pointer;display:flex;align-items:center;justify-content:space-between;color:var(--dark);list-style:none;user-select:none}
.faq-question::-webkit-details-marker{display:none}
.faq-question::after{content:'+';font-size:1.5rem;font-weight:300;color:var(--gray-400);transition:var(--transition);flex-shrink:0;margin-left:16px}
.faq-item[open] .faq-question::after{content:'-';color:var(--primary)}
.faq-item[open] .faq-question{color:var(--primary)}
.faq-answer{padding:0 24px 20px;color:var(--gray-500);font-size:.92rem;line-height:1.8}
.faq-answer a{color:var(--primary);text-decoration:underline}

/* ---------- Contact ---------- */
.contact{background:var(--white)}
.contact-cta-wrapper{max-width:700px;margin:0 auto}
.contact-cta-card{background:linear-gradient(135deg,var(--primary),var(--primary-dark));color:var(--white);padding:60px 48px;border-radius:var(--radius-lg);box-shadow:var(--shadow-xl);text-align:center}
.contact-cta-card h2{font-size:clamp(1.6rem,3vw,2.2rem);font-weight:800;margin:20px 0 12px}
.contact-cta-card>p{color:rgba(255,255,255,.8);font-size:1rem;margin-bottom:36px;line-height:1.7;max-width:500px;margin-left:auto;margin-right:auto}
.contact-email-cta{margin-bottom:28px}
.contact-email-icon{margin-bottom:12px}
.contact-email-icon svg{color:rgba(255,255,255,.6)}
.contact-email-link{font-size:clamp(1.3rem,3vw,1.8rem);font-weight:700;color:var(--white);letter-spacing:.02em;transition:var(--transition)}
.contact-email-link:hover{color:var(--accent-light)}
.contact-location{display:flex;align-items:center;justify-content:center;gap:8px;margin-top:24px;color:rgba(255,255,255,.6);font-size:.9rem}
.contact-location svg{color:rgba(255,255,255,.6)}

@media(max-width:480px){.contact-cta-card{padding:40px 24px}}

/* ---------- SEO Content ---------- */
.seo-content{background:var(--gray-50);padding:80px 0}
.seo-content-wrapper{max-width:900px;margin:0 auto}
.seo-content h2{font-size:1.8rem;font-weight:800;color:var(--dark);margin-bottom:28px;text-align:center}
.seo-text h3{font-size:1.2rem;font-weight:700;color:var(--dark);margin:32px 0 16px;padding-left:12px;border-left:3px solid var(--primary)}
.seo-text p{color:var(--gray-500);font-size:.95rem;margin-bottom:20px;line-height:2;text-align:justify}
.seo-text strong{color:var(--dark-600)}
.seo-table{width:100%;border-collapse:collapse;margin:16px 0 28px;font-size:.9rem;background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow-sm)}
.seo-table thead{background:var(--primary);color:var(--white)}
.seo-table th{padding:12px 16px;text-align:left;font-weight:600;font-size:.85rem}
.seo-table td{padding:10px 16px;border-bottom:1px solid var(--gray-200);color:var(--dark-600);font-size:.88rem}
.seo-table tbody tr:hover{background:var(--primary-bg)}
.seo-table tbody tr:last-child td{border-bottom:none}
@media(max-width:768px){.seo-table{display:block;overflow-x:auto;white-space:nowrap}}

/* ---------- Footer ---------- */
.footer{background:var(--dark);color:var(--gray-400);padding:60px 0 0}
.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:40px;padding-bottom:40px;border-bottom:1px solid var(--dark-600)}
.footer-brand p{font-size:.9rem;margin-top:16px;line-height:1.7}
.footer-links h4{color:var(--white);font-size:.95rem;font-weight:600;margin-bottom:16px}
.footer-links li{margin-bottom:10px}
.footer-links a{color:var(--gray-400);font-size:.88rem;transition:var(--transition)}
.footer-links a:hover{color:var(--accent-light)}
.footer-bottom{text-align:center;padding:24px 0;font-size:.82rem;color:var(--gray-500)}

/* ---------- Animations ---------- */
[data-aos]{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
[data-aos].aos-animate{opacity:1;transform:translateY(0)}
[data-aos="fade-right"]{transform:translateX(-30px)}
[data-aos="fade-right"].aos-animate{transform:translateX(0)}
[data-aos="fade-left"]{transform:translateX(30px)}
[data-aos="fade-left"].aos-animate{transform:translateX(0)}

/* ---------- Success Message ---------- */
.form-success{display:none;text-align:center;padding:40px 20px}
.form-success.show{display:block}
.form-success h3{font-size:1.3rem;color:var(--success);margin-bottom:12px}
.form-success p{color:var(--gray-500);font-size:.95rem}

/* ---------- Responsive ---------- */
@media(max-width:1024px){
    .trainer-content{grid-template-columns:1fr;text-align:center}
    .trainer-info{text-align:left}
    .trainer-highlights{grid-template-columns:repeat(2,1fr)}
    .contact-content{grid-template-columns:1fr}
    .footer-grid{grid-template-columns:1fr 1fr}
}

@media(max-width:768px){
    .nav-toggle{display:flex}
    .nav-links{position:fixed;top:0;right:-100%;width:80%;max-width:360px;height:100vh;background:var(--white);flex-direction:column;padding:80px 32px 32px;gap:0;box-shadow:var(--shadow-xl);transition:var(--transition);z-index:999}
    .nav-links.active{right:0}
    .nav-links li{width:100%}
    .nav-links a{color:var(--dark-600)!important;padding:16px 0;display:block;border-bottom:1px solid var(--gray-100);font-size:1rem}
    .nav-links a::after{display:none}
    .nav-links .btn-nav{margin-top:16px;text-align:center;color:var(--white)!important}

    .hero{padding:100px 24px 60px}
    .hero-stats{gap:24px}
    .stat-item{min-width:80px}

    .section{padding:70px 0}
    .section-header{margin-bottom:40px}

    .course-grid,.features-grid{grid-template-columns:1fr}

    .form-row{grid-template-columns:1fr}

    .footer-grid{grid-template-columns:1fr;gap:32px}
    .footer-links{margin-bottom:0}
}

@media(max-width:480px){
    html{font-size:15px}
    .container{padding:0 16px}
    .hero-title{font-size:2rem}
    .hero-subtitle{font-size:.95rem}
    .course-card{padding:28px 24px 24px}
    .contact-form{padding:28px 20px}
    .trainer-highlights{grid-template-columns:1fr 1fr}
}

/* Overlay for mobile nav */
.nav-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:998}
.nav-overlay.active{display:block}