/* ===== Biến màu & font ===== */
:root {
    --color-primary: rgb(255, 22, 22);
    /* màu chủ đạo placeholder */
    --color-primary-dark: rgb(200, 0, 0);
    --color-dark: #1a1a1a;
    --color-text: #333;
    --color-muted: #777;
    --color-bg: #ffffff;
    --color-bg-alt: #f6f6f8;
    --color-border: #ddd;
    --color-success: #28a745;
    --color-success-bg: #d4edda;
    --color-error: #dc3545;
    --color-error-bg: #f8d7da;
    --radius: 10px;
    --font: "Segoe UI", Roboto, Arial, sans-serif;
    /* thay bằng font nhận diện */
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    color: var(--color-text);
    line-height: 1.6;
    background: var(--color-bg);
    margin: 0;
    padding: 0;
}

img {
    max-width: 100%;
    display: block;
    height: auto;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: background .2s, color .2s, transform .1s, box-shadow .2s;
}

.btn--primary {
    background: var(--color-primary);
    color: #fff;
}

.btn--primary:hover {
    background: var(--color-primary-dark);
    box-shadow: 0 4px 12px rgba(255, 22, 22, 0.3);
}

.btn--primary:active {
    transform: translateY(1px);
}

.btn--primary:disabled {
    background: #ccc;
    cursor: not-allowed;
    box-shadow: none;
}

.btn--ghost {
    background: transparent;
    color: #fff;
    border: 2px solid #fff;
}

.btn--ghost:hover {
    background: #fff;
    color: var(--color-primary);
}

.btn--full {
    width: 100%;
}

/* ===== Hero ===== */
.hero {
    position: relative;
    min-height: 85vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.hero__nav {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    z-index: 10;
    padding: 20px 6%;
}

.logo img {
    height: 40px;
    width: auto;
    filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.5));
}

.hero__inner {
    position: relative;
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 80px 6% 40px;
}

.hero__bg {
    position: absolute;
    inset: 0;
    z-index: 1;
}

.hero__bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top center;
    filter: blur(2px) brightness(0.45);
}

.hero__content {
    position: relative;
    z-index: 10;
    background: rgba(0, 0, 0, .55);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, .15);
    border-radius: 20px;
    padding: 48px 52px;
    max-width: 620px;
    width: 90%;
    text-align: center;
}

.hero__content h1 {
    font-size: 2.2rem;
    line-height: 1.25;
    margin-bottom: 14px;
    color: #fff;
}

.hero__content h1 span {
    color: #FF6B6B;
}

.hero__sub {
    font-size: 1rem;
    color: rgba(255, 255, 255, .8);
    margin-bottom: 24px;
}

/* ===== Form Styles ===== */
.signup {
    background: #fff;
    color: var(--color-text);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, .2);
}

.signup h2 {
    margin-bottom: 16px;
    color: var(--color-dark);
}

.form-group {
    margin-bottom: 16px;
}

.signup label {
    display: block;
    font-size: .9rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--color-dark);
}

.signup input {
    width: 100%;
    padding: 11px 12px;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color .2s, box-shadow .2s;
}

.signup input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(228, 0, 43, .15);
}

.signup input::placeholder {
    color: #aaa;
}

.req {
    color: var(--color-primary);
}

/* ===== Form Messages ===== */
.form-message {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px;
    border-radius: 8px;
    margin-top: 16px;
    font-size: .9rem;
}

.form-message svg {
    flex-shrink: 0;
    margin-top: 2px;
}

.form-message strong {
    display: block;
    margin-bottom: 4px;
}

.form-message p {
    margin: 0;
    opacity: .9;
}

.form-message--success {
    background: var(--color-success-bg);
    color: #155724;
    border: 1px solid #c3e6cb;
}

.form-message--success svg {
    stroke: var(--color-success);
}

.form-message--error {
    background: var(--color-error-bg);
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.form-message--error svg {
    stroke: var(--color-error);
}

/* ===== Spinner Animation ===== */
.spinner {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

/* ===== Sections chung ===== */
.section {
    padding: 64px 6%;
    max-width: 1200px;
    margin: 0 auto;
}

.section__title {
    text-align: center;
    font-size: 1.8rem;
    margin-bottom: 8px;
    color: var(--color-dark);
}

.section__subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--color-gray);
    margin-bottom: 40px;
}

/* ===== Selling points ===== */
.cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.card {
    background: var(--color-bg-alt);
    border-radius: var(--radius);
    padding: 32px 24px;
    text-align: center;
    transition: transform .2s, box-shadow .2s;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 24px rgba(0, 0, 0, .08);
}

.card__icon {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 64px;
    margin-bottom: 16px;
}

.card__icon img {
    width: auto;
    height: 100%;
    max-height: 64px;
    object-fit: contain;
}

.card h3 {
    margin-bottom: 8px;
    color: var(--color-dark);
}

.card p {
    color: var(--color-muted);
    font-size: .95rem;
}

/* ===== Gallery ===== */
.gallery {
    background: var(--color-bg-alt);
    max-width: none;
}

.gallery .section__title,
.gallery__grid {
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.gallery__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.gallery__item {
    overflow: hidden;
    border-radius: var(--radius);
    background: #e6e6ea;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    transition: transform .3s, box-shadow .3s;
}

.gallery__item:hover {
    transform: scale(1.02);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.gallery__item img {
    width: 100%;
    height: 100%;
    min-height: 180px;
    max-height: 220px;
    object-fit: cover;
}

/* ===== Form section ===== */
.form-section {
    text-align: center;
}

.signup--center {
    max-width: 440px;
    margin: 0 auto;
    text-align: left;
    box-shadow: 0 12px 30px rgba(0, 0, 0, .1);
}

.note {
    text-align: center;
    font-size: .85rem;
    color: var(--color-muted);
    margin-top: 12px;
}

/* ===== Footer ===== */
.footer {
    background: rgb(255, 22, 22);
    color: #fff;
    text-align: center;
    padding: 48px 6%;
}

.footer__logo img {
    height: 40px;
    width: auto;
    margin: 0 auto 16px;
    filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.25));
}

.footer__contact {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 16px;
    opacity: .9;
}

.footer__social {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: #fff;
    text-decoration: none;
    border: 1px solid rgba(255, 255, 255, .5);
    background: rgba(255, 255, 255, .15);
    padding: 8px 18px;
    border-radius: 20px;
    font-size: .9rem;
    transition: background .2s, color .2s, border-color .2s;
}

.social-link:hover {
    background: #fff;
    color: rgb(255, 22, 22);
    border-color: #fff;
}

.social-link--linkedin:hover {
    color: #0A66C2;
}

.social-link--facebook:hover {
    color: #1877F2;
}

.social-link--tiktok:hover {
    color: #000;
}

/* ===== About Section ===== */
.about-section {
    background: var(--color-light);
    text-align: center;
}

.about-section__inner {
    max-width: 680px;
    margin: 0 auto;
}

.about-section__title {
    font-size: 1.6rem;
    color: var(--color-dark);
    margin-bottom: 12px;
}

.about-section__text {
    font-size: 1rem;
    color: var(--color-muted);
    line-height: 1.7;
    margin-bottom: 28px;
}

.about-section__stats {
    display: flex;
    gap: 40px;
    justify-content: center;
    flex-wrap: wrap;
}

.about-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.about-stat__number {
    font-size: 2rem;
    font-weight: 800;
    color: rgb(255, 22, 22);
    line-height: 1;
}

.about-stat__label {
    font-size: .82rem;
    color: var(--color-muted);
    font-weight: 500;
}

/* ===== Zalo Group ===== */
.zalo-group {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.zalo-group__btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: #fff;
    text-decoration: none;
    border: 1px solid rgba(255, 255, 255, .5);
    background: rgba(255, 255, 255, .15);
    padding: 7px 14px;
    border-radius: 20px;
    font-size: .85rem;
    transition: background .2s, color .2s, border-color .2s;
}

.zalo-group__btn:hover {
    background: #fff;
    color: rgb(255, 22, 22);
    border-color: #fff;
}

.zalo-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
    background: rgba(0, 104, 173, .18);
    border: 1px solid rgba(0, 136, 204, .45);
    border-radius: 14px;
    padding: 16px 10px;
    text-decoration: none;
    transition: background .25s, border-color .25s, transform .25s, box-shadow .25s;
}

.zalo-btn:hover {
    background: rgba(0, 136, 204, .4);
    border-color: #00A0E9;
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 136, 204, .3);
}

.zalo-btn__icon {
    display: block;
    border-radius: 50%;
    overflow: hidden;
    flex-shrink: 0;
}

.zalo-btn__text {
    font-size: .85rem;
    font-weight: 700;
    color: #fff;
    letter-spacing: .3px;
    text-align: center;
}

.zalo-btn__sub {
    font-size: .7rem;
    color: rgba(255, 255, 255, .6);
    text-align: center;
    line-height: 1.3;
}

.footer__copy {
    opacity: .6;
    font-size: .85rem;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
    .hero__inner {
        flex-direction: column;
    }

    .hero__image {
        width: 100%;
        max-width: 500px;
    }

    .hero__image img {
        min-height: 250px;
    }

    .cards {
        grid-template-columns: 1fr;
    }

    .gallery__grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .hero__content h1 {
        font-size: 2rem;
    }

    .zalo-grid {
        grid-template-columns: repeat(2, 1fr);
        max-width: 320px;
    }
}

@media (max-width: 520px) {
    .gallery__grid {
        grid-template-columns: 1fr;
    }

    .hero__nav {
        display: flex;
        justify-content: center;
        padding: 16px 4%;
    }

    .hero__nav .logo {
        margin: 0 auto;
    }

    .hero__content {
        text-align: center;
    }

    .hero__content h1 {
        font-size: 1.7rem;
    }

    .section {
        padding: 48px 4%;
    }

    .logo img {
        height: 32px;
    }

    .card__icon {
        height: 56px;
    }

    .card__icon img {
        max-height: 56px;
    }
}

/* ===== Accessibility ===== */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    .btn,
    .card,
    .gallery__item,
    .spinner {
        transition: none;
    }

    .spinner {
        animation: none;
    }
}

/* Focus visible for keyboard navigation */
.btn:focus-visible,
.signup input:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}