:root {
    --bg-black: #000000;
    --bg-card: #16181c; 
    --border-gray: #2f3336;
    --twitter-blue: #1d9bf0;
    --twitter-hover: #1a8cd8;
    --text-main: #e7e9ea;
    --text-dim: #71767b;
    --error-red: #f4212e;
}

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

body {
    background-color: var(--bg-black);
    color: var(--text-main);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    min-height: 100vh;
}

/* --- THE CENTERING MAGIC --- */
.auth-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    width: 100%;
}

.auth-box {
    width: 100%;
    max-width: 400px;
    padding: 20px;
    text-align: center;
}

.auth-box h1 {
    font-size: 3.5rem;
    font-weight: 900;
    line-height: 1;
    margin-bottom: 15px;
    letter-spacing: -2px;
}

/* --- FEED LAYOUT --- */
.app-container {
    display: flex;
    max-width: 1250px;
    margin: 0 auto;
    width: 100%;
}

.sidebar {
    width: 275px;
    padding: 10px 15px;
    height: 100vh;
    position: sticky;
    top: 0;
    border-right: 1px solid var(--border-gray);
}

.feed-content {
    flex: 1;
    max-width: 600px;
    border-right: 1px solid var(--border-gray);
    min-height: 100vh;
}

.widgets {
    width: 350px;
    padding: 15px 30px;
}

/* --- COMPONENTS --- */
.nav-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 12px 16px;
    font-size: 1.2rem;
    border-radius: 99px;
    cursor: pointer;
    width: fit-content;
    margin-bottom: 5px;
}

.nav-item:hover { background: rgba(255,255,255,0.1); }
.nav-item.active { font-weight: 800; }

input, textarea {
    width: 100%;
    padding: 16px;
    background: transparent;
    border: 1px solid var(--border-gray);
    color: white;
    border-radius: 4px;
    margin-bottom: 12px;
    font-size: 1rem;
}

input:focus { border-color: var(--twitter-blue); outline: none; }

.main-btn {
    width: 100%;
    padding: 15px;
    background: white;
    color: black;
    border: none;
    border-radius: 99px;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
}

.post-card {
    padding: 15px;
    border-bottom: 1px solid var(--border-gray);
}

.error-banner {
    background: var(--error-red);
    color: white;
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 20px;
}