/* ═══════════════════════════════════════════
   SeoWeb.top - UI Components
   Buttons, Cards, Forms, Alerts, Navigation
   ═══════════════════════════════════════════ */

/* ─── BUTTONS ─── */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2);
    padding: var(--space-3) var(--space-8); font-weight: 600; font-size: var(--text-sm);
    border-radius: var(--radius-full); transition: all var(--transition-slow);
    white-space: nowrap; position: relative; overflow: hidden;
    letter-spacing: 0.5px;
}
.btn svg { transition: transform var(--transition-base); }
.btn:hover svg { transform: translateX(3px) scale(1.1); }
.btn-icon svg { transition: none; }
.btn-icon:hover svg { transform: scale(1.2); }

.btn::after {
    content: ''; position: absolute; inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.3), transparent);
    opacity: 0; transition: opacity var(--transition-base);
}
.btn:hover { transform: translateY(-3px); }
.btn:hover::after { opacity: 1; }

.btn-primary {
    background: var(--gradient-primary); color: #fff;
    box-shadow: 0 10px 20px rgba(16,185,129,0.25);
}
.btn-primary:hover { box-shadow: 0 15px 30px rgba(16,185,129,0.35), var(--shadow-glow); }

.btn-outline {
    border: 2px solid var(--primary-500); color: var(--primary-600);
    background: transparent;
}
.btn-outline:hover { background: var(--primary-500); color: #fff; box-shadow: var(--shadow-glow); }

.btn-white { background: #fff; color: var(--primary-600); box-shadow: var(--shadow-lg); }
.btn-white:hover { box-shadow: var(--shadow-xl), 0 0 20px rgba(255,255,255,0.4); }

.btn-lg { padding: var(--space-4) var(--space-10); font-size: var(--text-base); }
.btn-sm { padding: var(--space-2) var(--space-5); font-size: var(--text-xs); }
.btn-icon { width: 52px; height: 52px; padding: 0; border-radius: var(--radius-full); display: inline-flex; align-items: center; justify-content: center; }

/* ─── GLASSMORPHISM ─── */
.glass {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--transition-base);
}
.glass:hover { background: rgba(255, 255, 255, 0.15); border-color: rgba(255, 255, 255, 0.2); }

.facebook-footer { color: #1877F2; }
.zalo-footer { color: #0068ff; }
.facebook-footer:hover, .zalo-footer:hover { transform: translateY(-5px) scale(1.1); box-shadow: 0 10px 20px rgba(0,0,0,0.3); }



/* ─── CARDS ─── */
.card {
    background: #fff; border-radius: var(--radius-2xl); padding: var(--space-8);
    box-shadow: var(--shadow-card); border: 1px solid rgba(0,0,0,0.03);
    transition: all var(--transition-slow); position: relative; overflow: hidden;
}
.card:hover { transform: translateY(-8px); box-shadow: var(--shadow-xl); border-color: var(--primary-100); }
.card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 4px;
    background: var(--gradient-primary); opacity: 0; transition: opacity var(--transition-base);
}
.card:hover::before { opacity: 1; }

.card-icon {
    width: 64px; height: 64px; border-radius: var(--radius-xl);
    background: var(--gradient-card); display: flex; align-items: center; justify-content: center;
    font-size: 30px; margin-bottom: var(--space-6); color: var(--primary-500);
    transition: transform var(--transition-spring);
}
.card:hover .card-icon { transform: scale(1.1) rotate(5deg); }
.card-title { font-size: var(--text-xl); margin-bottom: var(--space-3); color: var(--gray-900); }
.card-text { font-size: var(--text-sm); color: var(--gray-500); margin-bottom: var(--space-5); line-height: 1.7; }
.card-link {
    display: inline-flex; align-items: center; gap: var(--space-2);
    color: var(--primary-600); font-weight: 700; font-size: var(--text-sm);
    text-transform: uppercase; letter-spacing: 0.5px;
}
.card-link:hover { gap: var(--space-3); color: var(--primary-700); }


/* ─── FORMS ─── */
.form-group { margin-bottom: var(--space-5); }
.form-label { display: block; font-weight: 600; font-size: var(--text-sm); color: var(--gray-700); margin-bottom: var(--space-2); }
.form-input, .form-textarea, .form-select {
    width: 100%; padding: var(--space-3) var(--space-4);
    border: 2px solid var(--gray-200); border-radius: var(--radius-lg);
    font-size: var(--text-base); color: var(--gray-800);
    background: var(--gray-50); transition: all var(--transition-fast);
}
.form-input:focus, .form-textarea:focus, .form-select:focus {
    border-color: var(--primary-400); background: #fff;
    box-shadow: 0 0 0 3px rgba(99,102,241,0.1);
}
.form-textarea { min-height: 120px; resize: vertical; }
.form-input::placeholder { color: var(--gray-400); }

/* ─── ALERTS ─── */
.alert {
    padding: var(--space-4) var(--space-5); border-radius: var(--radius-lg);
    font-size: var(--text-sm); font-weight: 500; margin-bottom: var(--space-4);
    display: flex; align-items: center; gap: var(--space-3);
    animation: fadeInUp 0.3s ease;
}
.alert-success { background: #f0fdf4; color: #166534; border-left: 4px solid var(--success); }
.alert-error { background: #fef2f2; color: #991b1b; border-left: 4px solid var(--error); }
.alert-warning { background: #fffbeb; color: #92400e; border-left: 4px solid var(--warning); }
.alert-info { background: #eff6ff; color: #1e40af; border-left: 4px solid var(--info); }

/* ─── NAVIGATION / HEADER ─── */
.header {
    position: fixed; top: 0; left: 0; right: 0; z-index: var(--z-fixed);
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(25px) saturate(180%);
    -webkit-backdrop-filter: blur(25px) saturate(180%);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    transition: all var(--transition-slow);
}
.header.scrolled { 
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    height: 64px;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 80px; transition: height var(--transition-base); }
.header.scrolled .header-inner { height: 64px; }

.logo { 
    font-family: var(--font-heading); 
    font-weight: 900; 
    font-size: var(--text-2xl); 
    letter-spacing: -0.5px;
}
.logo span { background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

.nav-list { display: flex; align-items: center; gap: var(--space-8); }
.nav-link {
    font-weight: 600; font-size: var(--text-sm); color: var(--gray-700);
    position: relative; padding: var(--space-1) 0;
    text-transform: uppercase; letter-spacing: 1px;
    display: flex; align-items: center; gap: 8px;
}
.icon-nav { opacity: 0.6; transition: all var(--transition-base); }
.nav-link:hover .icon-nav, .nav-link.active .icon-nav { opacity: 1; transform: translateY(-1px); color: var(--primary-500); }
.nav-link::after {

    content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 3px;
    background: var(--gradient-primary); border-radius: var(--radius-full);
    transition: width var(--transition-spring);
}
.nav-link:hover, .nav-link.active { color: var(--primary-600); }
.nav-link:hover::after, .nav-link.active::after { width: 100%; }


.nav-toggle { display: none; flex-direction: column; gap: 5px; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--gray-700); transition: all var(--transition-fast); }

/* ─── FOOTER ─── */
.footer { 
    background: var(--gray-900); 
    color: var(--gray-300); 
    padding: var(--space-16) 0 var(--space-8); 
    position: relative; 
    overflow: hidden; 
}
.footer h4 { color: #fff; margin-bottom: var(--space-4); font-size: var(--text-lg); }
.footer a { color: var(--gray-400); transition: color var(--transition-fast); }
.footer a:hover { color: var(--primary-400); }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr 1.5fr; gap: var(--space-8); position: relative; z-index: 2; }
.footer-bottom {
    border-top: 1px solid var(--gray-800); margin-top: var(--space-8);
    padding-top: var(--space-6); text-align: center; font-size: var(--text-sm); color: var(--gray-500);
    position: relative; z-index: 2;
}

/* ─── GLOBAL HONEYCOMB MESH ─── */
.honeycomb-mesh::before, .honeycomb-mesh::after {
    content: ''; position: absolute; inset: 0; pointer-events: none;
}
.honeycomb-mesh::before {
    opacity: 0.08;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='48' height='28' viewBox='0 0 48 28'%3E%3Cpath d='M12 0L36 0L48 14L36 28L12 28L0 14Z' fill='none' stroke='%23ffffff' stroke-width='0.5'/%3E%3C/svg%3E");
    background-size: 48px 28px; z-index: 0;
    -webkit-mask-image: radial-gradient(circle at center, black 0%, transparent 90%);
    mask-image: radial-gradient(circle at center, black 0%, transparent 90%);
}
.honeycomb-mesh::after {
    z-index: 1;
    background-image: 
        url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='48' height='28' viewBox='0 0 48 28'%3E%3Cpath d='M12 0L36 0L48 14L36 28L12 28L0 14Z' fill='none' stroke='%2322d3ee' stroke-width='1'/%3E%3C/svg%3E"),
        url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='48' height='28' viewBox='0 0 48 28'%3E%3Cpath d='M12 0L36 0L48 14L36 28L12 28L0 14Z' fill='none' stroke='%2310b981' stroke-width='1'/%3E%3C/svg%3E"),
        url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='48' height='28' viewBox='0 0 48 28'%3E%3Cpath d='M12 0L36 0L48 14L36 28L12 28L0 14Z' fill='none' stroke='%23ffffff' stroke-width='1'/%3E%3C/svg%3E");
    background-size: 48px 28px;
    -webkit-mask-image: linear-gradient(135deg, white 0%, transparent 20%), linear-gradient(225deg, white 0%, transparent 20%), linear-gradient(90deg, white 0%, transparent 20%);
    mask-image: linear-gradient(135deg, white 0%, transparent 20%), linear-gradient(225deg, white 0%, transparent 20%), linear-gradient(90deg, white 0%, transparent 20%);
    -webkit-mask-size: 30% 20%; mask-size: 30% 20%;
    -webkit-mask-repeat: no-repeat; mask-repeat: no-repeat;
    animation: mCyan 12s infinite linear, mGreen 16s infinite linear 4s, mWhite 20s infinite linear 8s;
}

@keyframes mCyan { 0% { mask-position: -20% 20%; opacity:0; } 10% { opacity: 1; } 100% { mask-position: 120% 20%; opacity:0; } }
@keyframes mGreen { 0% { mask-position: 120% 80%; opacity:0; } 10% { opacity: 1; } 100% { mask-position: -20% 80%; opacity:0; } }
@keyframes mWhite { 0% { mask-position: 50% -20%; opacity:0; } 10% { opacity: 1; } 100% { mask-position: 50% 120%; opacity:0; } }

/* ─── BACK TO TOP ─── */
.back-to-top {
    position: fixed; bottom: 24px; right: 24px; width: 52px; height: 52px;
    background: var(--gradient-primary); color: #fff; border-radius: var(--radius-full);
    display: flex; align-items: center; justify-content: center; font-size: 20px;
    box-shadow: var(--shadow-lg); opacity: 0; visibility: hidden;
    transform: translateY(20px); transition: all var(--transition-slow);
    z-index: var(--z-sticky); border: 1px solid rgba(255,255,255,0.2);
}
.back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { transform: translateY(-5px); box-shadow: var(--shadow-glow), 0 10px 25px rgba(16,185,129,0.3); }


/* ─── MOBILE RESPONSIVE ─── */
@media (max-width: 768px) {
    .nav-toggle { display: flex; }
    .nav-list {
        position: fixed; top: 72px; left: 0; right: 0; bottom: 0;
        flex-direction: column; background: #fff; padding: var(--space-8);
        gap: var(--space-6); transform: translateX(100%); transition: transform var(--transition-slow);
    }
    .nav-list.open { transform: translateX(0); }
    .footer-grid { grid-template-columns: 1fr; }
    .card { padding: var(--space-6); }
}