:root {
  --primary: #c8102e;
  --accent: #ff6600;
  --gold: #f2c94c;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ===================== STICKY FOOTER ===================== */
body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    font-family: 'Segoe UI', system-ui, sans-serif;
    background: linear-gradient(135deg, #f8fbff 0%, #dceeff 40%, #b8dcff 100%);
    overflow-x: hidden;
}

.page-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* ===================== HEADER ===================== */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 999;
    background: rgba(255,255,255,0.97);
    backdrop-filter: blur(15px);
    border-bottom: 1px solid rgba(0,0,0,.06);
}

.nav {
    max-width: 1300px;
    height: 85px;
    margin: auto;
    padding: 0 40px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo img {
    width: 60px;
    height: 60px;
    object-fit: contain;
    border-radius: 50%;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    position: relative;
    color: #243b55;
    text-decoration: none;
    font-weight: 600;
    transition: .3s;
}

.nav-links a.active {
    color: var(--primary);
}

.nav-links a.active::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -10px;
    width: 100%;
    height: 3px;
    background: var(--primary);
}

.hamburger {
    display: none;
    font-size: 28px;
    cursor: pointer;
    color: var(--primary);
}

/* ===================== CONTACT SECTION ===================== */
.contact-section {
    padding: 120px 20px 80px;
    flex: 1;
}
.title-container {
    text-align: center;
    max-width: 780px;
    margin: 0 auto 60px;
}

.title-container h1 {
    font-size: clamp(2.6rem, 6vw, 3.8rem);
    color: var(--primary);
    font-weight: 700;
    margin-bottom: 16px;
}

.title-container p span {
    color: var(--primary);
    font-weight: 600;
}
.contact-card {
    max-width: 960px;
    margin: 0 auto;
    background: white;
    border-radius: 28px;
    overflow: hidden;
    box-shadow: 0 25px 70px rgba(200, 16, 46, 0.15);
    display: flex;
    flex-direction: column;
    height: calc(100vh - 180px);   /* Giảm chiều cao để vừa màn hình */
    min-height: 620px;
}

.card-header {
    background: linear-gradient(135deg, #c8102e, #e63939);
    padding: 40px 50px;
    color: white;
    flex-shrink: 0;
}

.header-content {
    display: flex;
    align-items: center;
    gap: 26px;
}

.icon-circle {
    width: 80px;
    height: 80px;
    background: rgba(255,255,255,0.25);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-circle i {
    font-size: 2.5rem;
}

/* Form Container */
.form-container {
    flex: 1;
    padding: 10px 15px 15px;
    background: #fff;
    overflow: hidden;           /* Quan trọng */
}

.iframe-wrapper {
    width: 100%;
    height: 100%;
    border-radius: 16px;
    overflow: hidden;           /* Loại bỏ thanh cuộn ngoài */
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

.iframe-wrapper iframe {
    width: 100%;
    height: 100%;
    border: none;
    min-height: 100%;           /* Để Google Form tự scroll */
}

/* Responsive */
@media (max-width: 767px) {
    .contact-card {
        height: calc(100vh - 140px);
    }
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    .form-container {
        padding: 8px;
    }
}

/* Footer */
footer {
   background:linear-gradient(135deg,#f8fbff,#dceeff,#b8dcff);
    color:#222;
    text-align:center;
    padding:60px 20px 30px;
    margin-top: auto;
}

/* Responsive */
@media (max-width: 767px) {
    .contact-card {
        height: calc(100vh - 140px);
    }
    .header-content {
        flex-direction: column;
        text-align: center;
    }
}

/* Mobile Menu */
@media (max-width: 767px) {
    .hamburger { display: block; }
    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        flex-direction: column;
        padding: 20px 0;
        display: none;
    }
    .nav-links.active { display: flex; }
}