/* css/main.css - PHIÊN BẢN PRO */
@import url('https://fonts.googleapis.com/css2?family=Quicksand:wght@400;600;700&display=swap');

:root {
    --primary: #10b981;
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(255, 255, 255, 0.9);
    --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Quicksand', sans-serif; 
}

body {
    background: linear-gradient(45deg, #dcfce7, #ccfbf1, #e0e7ff);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
    min-height: 100vh;
    color: #334155;
    display: flex;
    flex-direction: column;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.main-header {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px); 
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }
.header-content { display: flex; justify-content: space-between; align-items: center; }

.logo { 
    font-size: 1.6rem; font-weight: 800; color: var(--primary); 
    text-shadow: 0 2px 10px rgba(16, 185, 129, 0.2);
}

.navbar a {
    text-decoration: none; color: #64748b; margin-left: 30px; font-weight: 700;
    position: relative; transition: 0.3s;
}

.navbar a:hover, .navbar a.active { color: var(--primary); }

.navbar a::after {
    content: ''; position: absolute; width: 0; height: 3px;
    bottom: -5px; left: 0; background-color: var(--primary);
    transition: width 0.3s ease; border-radius: 2px;
}
.navbar a:hover::after, .navbar a.active::after { width: 100%; }

.welcome-card, .post-box, .post-card, .quote-card {
    background: var(--glass-bg);
    backdrop-filter: blur(8px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow);
    border-radius: 24px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.welcome-card:hover, .post-box:hover, .post-card:hover, .quote-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.2);
}

button {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white; border: none; border-radius: 50px;
    padding: 12px 30px; font-weight: 700; cursor: pointer;
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
    transition: 0.3s;
}
button:hover { transform: scale(1.05); box-shadow: 0 6px 20px rgba(16, 185, 129, 0.6); }

footer {
    text-align: center; padding: 20px; margin-top: auto;
    color: #94a3b8; font-size: 0.9rem;
}