/* ================== GLOBAL ================== */
body {
    font-family: 'Segoe UI', Arial, sans-serif;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    background: #f5f5f5;
    color: #2c2c2c;
}

/* ================== MENU ================== */
.menu-icon {
    display: none;
    font-size: 26px;
    cursor: pointer;
    background: #333333;
    color: #ffffff;
    border: none;
    padding: 12px;
    width: 100%;
    text-align: center;
    letter-spacing: 2px;
}

.navbar {
    display: flex;
    justify-content: center;
    background: #ffffff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    border-bottom: 1px solid #dddddd;
}

.navbar a {
    position: relative;
    color: #444444;
    padding: 15px 28px;
    text-decoration: none;
    font-weight: 600;
    letter-spacing: 1px;
    transition: all 0.3s;
    cursor: pointer;
}

.navbar a::after {
    content: "";
    position: absolute;
    left: 10%;
    bottom: 8px;
    width: 0;
    height: 2px;
    background: #222222;
    transition: width 0.3s;
}

.navbar a:hover {
    background: #f0f0f0;
    color: #000000;
}

.navbar a:hover::after {
    width: 80%;
}

/* ================== CONTAINER ================== */
.container {
    position: relative;
    overflow: hidden;
    padding: 30px;
    max-width: 520px;
    margin: 40px auto;
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #e0e0e0;
    box-shadow:
        0 4px 20px rgba(0,0,0,0.08),
        0 1px 3px rgba(0,0,0,0.05);
}

/* hoa văn */
.container::before {
    content: "";
    position: absolute;
    inset: 8px;
    border: 1px dashed #cccccc;
    pointer-events: none;
    border-radius: 8px;
}

.container::after {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: 12px;
    background:
        linear-gradient(45deg,
            transparent 30%,
            rgba(0,0,0,0.02),
            transparent 70%);
    pointer-events: none;
}

/* ================== TITLE ================== */
h1 {
    position: relative;
    text-align: center;
    margin-bottom: 25px;
    font-size: 1.9em;
    color: #1a1a1a;
    letter-spacing: 3px;
    font-weight: 700;
}

h1::after {
    content: "⚔";
    position: absolute;
    left: 50%;
    bottom: -15px;
    transform: translateX(-50%);
    color: #666666;
    font-size: 22px;
}

h3 {
    text-align: center;
    margin: 20px 0 10px;
    color: #555555;
    letter-spacing: 2px;
    font-weight: 500;
}

/* ================== TABLE ================== */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

td {
    padding: 12px 0;
}

td:first-child {
    font-weight: 600;
    color: #444444;
    width: 40%;
}

/* ================== INPUT ================== */
input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 12px;
    background-color: #fafafa;
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    box-sizing: border-box;
    font-size: 1em;
    color: #222222;
    transition: all 0.3s;
}

input::placeholder {
    color: #999999;
}

input:focus {
    outline: none;
    border-color: #555555;
    background-color: #ffffff;
    box-shadow: 0 0 8px rgba(0,0,0,0.1);
}

/* ================== CAPTCHA ================== */
.captcha {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 15px 0;
}

.captcha img {
    border: 1px solid #cccccc;
    border-radius: 8px;
    background: #ffffff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.refresh-btn {
    background: #444444;
    color: #ffffff;
    border: none;
    padding: 8px 14px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9em;
    transition: all 0.3s;
}

.refresh-btn:hover {
    background: #222222;
}

/* ================== SUBMIT ================== */
input[type="submit"] {
    position: relative;
    overflow: hidden;
    width: 100%;
    padding: 15px;
    background: #2c2c2c;
    color: #ffffff;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1.15em;
    font-weight: 700;
    letter-spacing: 2px;
    margin-top: 25px;
    transition: all 0.3s;
}

input[type="submit"]:hover {
    background: #000000;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transform: translateY(-1px);
}

input[type="submit"]:active {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

/* ================== FOOTER ================== */
footer {
    background: #ffffff;
    color: #666666;
    text-align: center;
    padding: 20px;
    margin-top: 50px;
    border-top: 1px solid #e0e0e0;
    font-size: 0.9em;
}

footer a {
    color: #333333;
    text-decoration: none;
    font-weight: 600;
}

footer a:hover {
    text-decoration: underline;
    color: #000000;
}

/* ================== MOBILE ================== */
@media (max-width: 768px) {
    .menu-icon { display: block; }
    .navbar { flex-direction: column; display: none; }
    .navbar.show { display: flex; }
    .container { margin: 20px; padding: 20px; }
    .captcha { flex-direction: column; }
}