/* ========== CSS RESET & VARIABLES ========== */
        *, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

        :root {
            --orange: #E8750A;
            --orange-light: #FFF4EB;
            --orange-hover: #D06808;
            --white: #FFFFFF;
            --gray-50: #FAFAFA;
            --gray-100: #F5F5F5;
            --gray-200: #E5E5E5;
            --gray-300: #D4D4D4;
            --gray-500: #737373;
            --gray-600: #525252;
            --gray-700: #404040;
            --gray-800: #262626;
            --gray-900: #171717;
            --font-display: 'DM Serif Display', serif;
            --font-body: 'DM Sans', sans-serif;
        }

        html { scroll-behavior: smooth; }

        body {
            font-family: var(--font-body);
            color: var(--gray-800);
            background: var(--white);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
        }

        a { color: inherit; text-decoration: none; }
        img { max-width: 100%; display: block; }
        ul { list-style: none; }

        /* ========== UTILITY ========== */
        .container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }
        .section { padding: 96px 0; }
        .section--gray { background: var(--gray-50); }
        .text-orange { color: var(--orange); }
        .sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

        /* ========== NAVIGATION ========== */
        .nav {
            position: fixed; top: 0; left: 0; right: 0; z-index: 100;
            background: rgba(255,255,255,0.95);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--gray-200);
            transition: box-shadow 0.3s;
        }
        .nav.scrolled { box-shadow: 0 1px 12px rgba(0,0,0,0.06); }
        .nav__inner {
            display: flex; align-items: center; justify-content: space-between;
            height: 72px; max-width: 1120px; margin: 0 auto; padding: 0 24px;
        }
        .nav__logo {
            font-family: var(--font-display);
            font-size: 1.5rem; color: var(--gray-900);
            display: flex; align-items: center; gap: 10px;
        }
        .nav__logo img { height: 36px; width: 36px; border-radius: 8px; object-fit: cover; }
        .nav__logo span { color: var(--orange); }
        .nav__links { display: flex; align-items: center; gap: 36px; }
        .nav__link {
            font-size: 0.9rem; font-weight: 500; color: var(--gray-600);
            letter-spacing: 0.01em; position: relative; transition: color 0.2s;
        }
        .nav__link:hover, .nav__link.active { color: var(--gray-900); }
        .nav__link::after {
            content: ''; position: absolute; bottom: -4px; left: 0;
            width: 0; height: 2px; background: var(--orange);
            transition: width 0.25s ease;
        }
        .nav__link:hover::after, .nav__link.active::after { width: 100%; }
        .nav__cta {
            background: var(--orange); color: var(--white);
            padding: 10px 24px; border-radius: 8px; font-weight: 600;
            font-size: 0.88rem; letter-spacing: 0.01em;
            transition: background 0.2s, transform 0.15s;
        }
        .nav__cta:hover { background: var(--orange-hover); transform: translateY(-1px); }

        /* Mobile menu */
        .nav__toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
        .nav__toggle svg { width: 24px; height: 24px; stroke: var(--gray-700); }

        /* ========== HERO ========== */
        .hero {
            padding: 160px 0 96px;
            background: linear-gradient(165deg, var(--white) 60%, var(--orange-light) 100%);
            position: relative; overflow: hidden;
        }
        .hero::before {
            content: ''; position: absolute; top: -200px; right: -200px;
            width: 600px; height: 600px; border-radius: 50%;
            background: radial-gradient(circle, rgba(232,117,10,0.06) 0%, transparent 70%);
            pointer-events: none;
        }
        .hero__inner { max-width: 680px; text-align: center; margin: 0 auto; }
        .hero__badge {
            display: inline-flex; align-items: center; gap: 8px;
            background: var(--orange-light); color: var(--orange);
            padding: 6px 16px; border-radius: 100px; font-size: 0.82rem;
            font-weight: 600; letter-spacing: 0.02em; margin-bottom: 24px;
        }
        .hero__badge svg { width: 16px; height: 16px; }
        .hero__title {
            font-family: var(--font-display); font-size: 3.5rem;
            line-height: 1.12; color: var(--gray-900); margin-bottom: 20px;
        }
        .hero__subtitle {
            margin-left: auto; margin-right: auto;
            font-size: 1.15rem; color: var(--gray-600);
            line-height: 1.7; margin-bottom: 36px; max-width: 480px;
        }
        .hero__actions { display: flex; gap: 16px; flex-wrap: wrap; justify-content: center; }
        .btn {
            display: inline-flex; align-items: center; gap: 8px;
            padding: 14px 28px; border-radius: 10px; font-weight: 600;
            font-size: 0.95rem; transition: all 0.2s; cursor: pointer; border: none;
        }
        .btn--primary { background: var(--orange); color: var(--white); }
        .btn--primary:hover { background: var(--orange-hover); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(232,117,10,0.3); }
        .btn--secondary { background: var(--white); color: var(--gray-800); border: 1.5px solid var(--gray-300); }
        .btn--secondary:hover { border-color: var(--gray-500); background: var(--gray-50); }
        .btn svg { width: 18px; height: 18px; }

        .hero__visual {
            position: relative; display: flex; justify-content: center; align-items: center;
        }

        /* Hero Slideshow */
        .hero__slides { position: relative; min-height: 220px; }
        .hero__slide {
            position: absolute; top: 0; left: 0; right: 0;
            opacity: 0; transition: opacity 0.7s ease;
            pointer-events: none;
        }
        .hero__slide.active { opacity: 1; position: relative; pointer-events: auto; }
        .hero__dots {
            display: flex; justify-content: center; gap: 8px;
            margin-top: 40px;
        }
        .hero__dot {
            width: 8px; height: 8px; border-radius: 50%;
            background: var(--gray-300); border: none;
            cursor: pointer; padding: 0;
            transition: all 0.25s ease;
        }
        .hero__dot.active {
            background: var(--orange);
            width: 24px; border-radius: 4px;
        }
        .hero__dot:hover:not(.active) { background: var(--gray-500); }
        .hero__visual-card {
            background: var(--white); border-radius: 20px;
            box-shadow: 0 20px 60px rgba(0,0,0,0.08), 0 1px 3px rgba(0,0,0,0.04);
            padding: 48px; width: 100%; max-width: 420px;
            display: flex; flex-direction: column; align-items: center; text-align: center;
        }
        .hero__visual-card .math-symbol {
            font-family: var(--font-display); font-size: 4rem; color: var(--orange);
            margin-bottom: 16px; line-height: 1;
        }
        .hero__visual-card p { color: var(--gray-500); font-size: 0.95rem; }
        .hero__visual-float {
            position: absolute; background: var(--white); border-radius: 12px;
            padding: 12px 20px; box-shadow: 0 8px 30px rgba(0,0,0,0.08);
            font-weight: 600; font-size: 0.85rem; color: var(--gray-700);
            display: flex; align-items: center; gap: 8px;
        }
        .hero__visual-float--1 { top: 20px; right: -20px; }
        .hero__visual-float--2 { bottom: 30px; left: -20px; }
        .hero__visual-float svg { width: 20px; height: 20px; color: var(--orange); }

        /* ========== SECTION HEADERS ========== */
        .section__header { text-align: center; margin-bottom: 64px; }
        .section__label {
            font-size: 0.8rem; font-weight: 700; letter-spacing: 0.1em;
            text-transform: uppercase; color: var(--orange); margin-bottom: 12px;
        }
        .section__title {
            font-family: var(--font-display); font-size: 2.5rem;
            color: var(--gray-900); margin-bottom: 16px;
        }
        .section__desc {
            font-size: 1.05rem; color: var(--gray-500); max-width: 560px; margin: 0 auto;
        }

        /* ========== ABOUT ========== */
        .about__grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 72px; align-items: center; }
        .about__image {
            background: var(--gray-100); border-radius: 20px;
            aspect-ratio: 4/5; display: flex; align-items: center;
            justify-content: center; color: var(--gray-400); font-size: 0.9rem;
            position: relative; overflow: hidden;
        }
        .about__image-placeholder {
            text-align: center; color: var(--gray-400);
        }
        .about__image-placeholder svg { width: 48px; height: 48px; margin-bottom: 8px; opacity: 0.5; }
        .about__text h3 {
            font-family: var(--font-display); font-size: 2rem;
            color: var(--gray-900); margin-bottom: 20px;
        }
        .about__text p { color: var(--gray-600); margin-bottom: 16px; font-size: 1rem; }
        .about__stats { display: flex; gap: 40px; margin-top: 32px; }
        .about__stat-num {
            font-family: var(--font-display); font-size: 2rem; color: var(--orange);
        }
        .about__stat-label { font-size: 0.82rem; color: var(--gray-500); margin-top: 2px; }

        /* ========== MEDIA ========== */
        .media__grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
        .media__card {
            background: var(--white); border: 1px solid var(--gray-200);
            border-radius: 16px; overflow: hidden;
            transition: transform 0.25s, box-shadow 0.25s;
            cursor: pointer;
        }
        .media__card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,0.08); }
        .media__card-thumb {
            aspect-ratio: 16/9; background: var(--gray-100);
            display: flex; align-items: center; justify-content: center;
            position: relative;
        }
        .media__card-play {
            width: 56px; height: 56px; border-radius: 50%;
            background: var(--orange); color: var(--white);
            display: flex; align-items: center; justify-content: center;
            box-shadow: 0 4px 20px rgba(232,117,10,0.4);
            transition: transform 0.2s;
        }
        .media__card:hover .media__card-play { transform: scale(1.1); }
        .media__card-play svg { width: 22px; height: 22px; margin-left: 2px; }
        .media__card-body { padding: 20px; }
        .media__card-title { font-weight: 600; color: var(--gray-900); margin-bottom: 6px; }
        .media__card-desc { font-size: 0.88rem; color: var(--gray-500); }

        /* Video Lightbox */
        .lightbox {
            display: none; position: fixed; inset: 0; z-index: 200;
            background: rgba(0,0,0,0.85); backdrop-filter: blur(4px);
            align-items: center; justify-content: center;
            padding: 24px;
        }
        .lightbox.open { display: flex; }
        .lightbox__close {
            position: absolute; top: 20px; right: 24px;
            background: none; border: none; color: var(--white);
            cursor: pointer; padding: 8px; border-radius: 8px;
            transition: background 0.2s;
        }
        .lightbox__close:hover { background: rgba(255,255,255,0.1); }
        .lightbox__close svg { width: 32px; height: 32px; }
        .lightbox__video {
            max-height: 85vh; max-width: 480px; width: 100%;
            border-radius: 12px; background: #000;
        }

        .media__socials { display: flex; justify-content: center; gap: 16px; margin-top: 48px; }
        .media__social {
            width: 48px; height: 48px; border-radius: 12px;
            border: 1.5px solid var(--gray-200); display: flex;
            align-items: center; justify-content: center;
            transition: all 0.2s; color: var(--gray-600);
        }
        .media__social:hover {
            border-color: var(--orange); color: var(--orange);
            background: var(--orange-light);
        }
        .media__social svg { width: 22px; height: 22px; }

        /* ========== TUTORING ========== */
        .tutoring__grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
        .tutoring__card {
            background: var(--white); border: 1px solid var(--gray-200);
            border-radius: 16px; padding: 36px; transition: border-color 0.25s;
        }
        .tutoring__card:hover { border-color: var(--orange); }
        .tutoring__card-icon {
            width: 48px; height: 48px; border-radius: 12px;
            background: var(--orange-light); color: var(--orange);
            display: flex; align-items: center; justify-content: center;
            margin-bottom: 20px;
        }
        .tutoring__card-icon svg { width: 24px; height: 24px; }
        .tutoring__card h3 {
            font-family: var(--font-display); font-size: 1.35rem;
            color: var(--gray-900); margin-bottom: 10px;
        }
        .tutoring__card p { color: var(--gray-500); font-size: 0.95rem; margin-bottom: 20px; }
        .tutoring__card ul { display: flex; flex-direction: column; gap: 8px; }
        .tutoring__card li {
            display: flex; align-items: center; gap: 8px;
            font-size: 0.9rem; color: var(--gray-600);
        }
        .tutoring__card li svg { width: 16px; height: 16px; color: var(--orange); flex-shrink: 0; }

        .tutoring__cta {
            text-align: center; margin-top: 56px; padding: 48px;
            background: var(--gray-900); border-radius: 20px; color: var(--white);
        }
        .tutoring__cta h3 {
            font-family: var(--font-display); font-size: 1.8rem; margin-bottom: 12px;
        }
        .tutoring__cta p { color: var(--gray-300); margin-bottom: 28px; max-width: 480px; margin-left: auto; margin-right: auto; }
        .tutoring__cta .btn--primary { font-size: 1rem; padding: 16px 32px; }

        /* ========== CONTACT ========== */
        .contact__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; }
        .contact__info h3 {
            font-family: var(--font-display); font-size: 2rem;
            color: var(--gray-900); margin-bottom: 16px;
        }
        .contact__info > p { color: var(--gray-500); margin-bottom: 36px; }
        .contact__detail {
            display: flex; align-items: flex-start; gap: 16px; margin-bottom: 24px;
        }
        .contact__detail-icon {
            width: 44px; height: 44px; border-radius: 12px;
            background: var(--orange-light); color: var(--orange);
            display: flex; align-items: center; justify-content: center; flex-shrink: 0;
        }
        .contact__detail-icon svg { width: 20px; height: 20px; }
        .contact__detail-label { font-size: 0.82rem; color: var(--gray-500); margin-bottom: 2px; }
        .contact__detail-value { font-weight: 600; color: var(--gray-800); }

        .contact__form { display: flex; flex-direction: column; gap: 20px; }
        .form__group { display: flex; flex-direction: column; gap: 6px; }
        .form__label { font-size: 0.85rem; font-weight: 600; color: var(--gray-700); }
        .form__input, .form__textarea {
            padding: 12px 16px; border-radius: 10px; border: 1.5px solid var(--gray-200);
            font-family: var(--font-body); font-size: 0.95rem; color: var(--gray-800);
            transition: border-color 0.2s; background: var(--white); outline: none;
        }
        .form__input:focus, .form__textarea:focus { border-color: var(--orange); }
        .form__textarea { resize: vertical; min-height: 120px; }
        .form__row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

        /* ========== FOOTER ========== */
        .footer {
            background: var(--gray-900); color: var(--gray-300);
            padding: 64px 0 32px;
        }
        .footer__inner { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 48px; }
        .footer__brand { }
        .footer__logo {
            font-family: var(--font-display); font-size: 1.4rem;
            color: var(--white); margin-bottom: 12px;
        }
        .footer__logo span { color: var(--orange); }
        .footer__brand p { font-size: 0.88rem; color: var(--gray-500); line-height: 1.6; }
        .footer__col h4 {
            font-size: 0.8rem; font-weight: 700; letter-spacing: 0.08em;
            text-transform: uppercase; color: var(--gray-400); margin-bottom: 16px;
        }
        .footer__col a {
            display: block; font-size: 0.9rem; color: var(--gray-400);
            margin-bottom: 10px; transition: color 0.2s;
        }
        .footer__col a:hover { color: var(--white); }
        .footer__bottom {
            border-top: 1px solid rgba(255,255,255,0.08);
            margin-top: 48px; padding-top: 24px; text-align: center;
            font-size: 0.82rem; color: var(--gray-500);
        }

        /* ========== ANIMATIONS ========== */
        .js-loaded .fade-in {
            opacity: 0; transform: translateY(24px);
            transition: opacity 0.6s ease, transform 0.6s ease;
        }
        .js-loaded .fade-in.visible { opacity: 1; transform: translateY(0); }

        /* ========== RESPONSIVE ========== */
        @media (max-width: 900px) {
            .hero__inner { grid-template-columns: 1fr; text-align: center; }
            .hero__subtitle { margin-left: auto; margin-right: auto; }
            .hero__actions { justify-content: center; }
            .hero__visual { display: none; }
            .hero__title { font-size: 2.6rem; }
            .about__grid { grid-template-columns: 1fr; }
            .about__image { max-width: 360px; margin: 0 auto; }
            .media__grid { grid-template-columns: 1fr; max-width: 480px; margin: 0 auto; }
            .tutoring__grid { grid-template-columns: 1fr; }
            .contact__grid { grid-template-columns: 1fr; }
            .footer__inner { grid-template-columns: 1fr 1fr; }
            .section__title { font-size: 2rem; }
        }
        @media (max-width: 600px) {
            .nav__links { display: none; }
            .nav__toggle { display: block; }
            .nav__links.open {
                display: flex; flex-direction: column;
                position: absolute; top: 72px; left: 0; right: 0;
                background: var(--white); border-bottom: 1px solid var(--gray-200);
                padding: 24px; gap: 20px; box-shadow: 0 8px 30px rgba(0,0,0,0.08);
            }
            .hero { padding: 120px 0 64px; }
            .hero__title { font-size: 2rem; }
            .section { padding: 64px 0; }
            .form__row { grid-template-columns: 1fr; }
            .footer__inner { grid-template-columns: 1fr; }
            .about__stats { flex-direction: column; gap: 20px; }
        }